Tuesday, July 31, 2012

The Biting Arthropods: Natural isn't always better

Here in Skepticville we have been hearing daily reports about people being struck down by West Nile Virus (Link) and so at dusk people are avoiding their porches and avoiding having pool parties and grilling outside in order to avoid the pesky mosquitoes.  (It's also extremely hot here, even at dusk, so many people are avoiding the porch to seek air conditioning inside).    Now of course with reports of the outbreak come a host of "natural" alternatives.

Some of the "natural" alternatives involve fixing screens in the house, getting rid of standing water, and not being outside if possible at dawn and dusk.  Chances are even the most skeptical among us would see the value of fixing screens that need to be fixed anyway, avoiding the time when mosquitos are most active, and trying to keep them from breeding.  Our entomology friends will tell us that lactic acid (strong evidence) and carbon dioxide (weaker evidence), which we humans naturally produce, more so when we exercise, also serve to attract mosquitoes.  (Read more about how the entomologists have been examining human attractants here.  Certain kinds of mosquitoes are attracted to dark clothing and foliage (Link.)  Once again, science has come to our rescue in helping us evaluate simple things we can do to prevent mosquito borne illnesses.
Why is SkepticRD writing about this on a nutrition blog?  Because many of the people who are seeking out "natural" remedies are trying to avoid the other recommendation given by the Centers for Disease Control (CDC):  wear insect repellant that contains N, N-diethyl-3-methylbenzamide, otherwise known as DEET.  Some of those remedies, include, you guessed it, certain foods that are supposed to help you repel the biting arthropods.
First of all, our northern friends in the Michigan Skeptics Association have already done quite a bit of work discussing the safety profile of DEET.    They have also collected some of the available data regarding one of the essential oils usually touted as a "natural" mosquito repellant, catnip oil.  Here at chemistry/about.com you can find a very well written letter toting why "natural" is not always better, especially when we don't have enough data regarding how much of that oil is safe to use (Link).
As far as the foods and vitamins are concerned, usually the foods/supplements people are told to consume to repel mosquitoes are onions, garlic, and vitamin B1.  Unfortunately, none of these claims have any scientific evidence to support it (Link).  Now, we know that science is often not enough to convince our non-skeptical friends to avoid doing crazy things, so is there any danger in eating or taking any of these alternatives?
Onions—other than the halitosis, eating onions at every meal will likely not hurt you.  Some people will experience bloating and gas from the sulfur that's found in onions, and some other people might experience a burning in the stomach.  This is more of a danger for people who take sulfur as a supplement than people who are eating the onions (you would think the bad breath might cause people to stop overeating, but you never can tell).  And please, if you are also trying to protect your cats and dogs from insect bites, DO NOT give them onions as onions contain thiosulphate which can cause their red blood cells to burst (hemolytic anemia).
Garlic—once again, except for the bad breath and possible flatulence, eating 2-4 garlic cloves per day will likely not hurt you.  Once again, the problem comes when people take garlic supplements.  Some people do get an upset stomach, bloating, bad breath, body odor, and there are rare but other possible side effects of garlic supplements like headache, fatigue, loss of appetite, muscle aches, dizziness described as vertigo, and allergies such as an asthmatic reaction or skin rash.  There are also several medications that can be affected by garlic supplements like birth control pills, blood thinners, and medications for HIV/AIDS.  If someone is taking aspirin or ibuprofen regularly w/garlic the risk of bleeding might also increase.  And if you are trying to protect your children from mosquitos, remember the safety profile for garlic tablets has not been evaluated in children! (Link)  Also, garlic has been touted as a “natural” insect repellant for your pets, but this could also be toxic to them as well.

Vitamin B1 (thiamine)—taking enough to achieve a toxic level in your blood is fortunately very rare with this vitamin.  Unfortunately, too much B1 can interfere with your body's ability to produce insulin and thyroid hormones, but this seems to happen at long term supplementation of 500 or more grams per day.  SkepticRD has usually seen tablets of the thiamine in 100 mg doses, but there are some tablets that contain 500 mg. Hopefully the signs of toxicity of shortness of breath, flushing, and fluid retention, etc would clue the person in that something is wrong, but I have learned not to underestimate the “more is better” philosophy of so many.  Keep in mind that you might also be "peeing away" the money you spent on supplements as excess B1 is excreted in the urine.
Bottom line—staying indoors and using DEET if you have to be outside, particularly in active mosquito time, is your best and still safest bet for avoiding the biting arthropods.

Monday, July 30, 2012

You're not an Olympic athlete, stop eating like one

The other day as I was reading through my myriad of newsletters I came across this article looking at the activity level of hunter gatherers.  Of course there was also plenty of new coverage on the Olympics that had exercise on my mind as well. It reminded me of another set of questions (and complaints!) that I get from people are trying to lose weight and/or improve some other type of health condition they have.  The question/complaint usually goes something along the lines of "Well, if I eat more can't I just exercise more later?" or "I can't lose weight because I can't exercise" or "I've been working out like crazy with the elliptical/treadmill/Zumba class and I still haven't lost much weight."
In the article listed above (you read it right, you're not just taking SkepticRD's word for it?) there is a study done on people who appear to be a lot more active than those of us in the "west."  You would think that with all that daily activity that they would be burning tons more calories, especially since they have a much lower body fat percentage than their western counterparts.  But the physiologic studies indicate that that's simply not true.  Now naturally, because the authors of this study are trying to be good scientists, the conclusions that were drawn had to do with inherited physical traits in relation to totally energy expenditure.  They were opening up the door for more scientific research on how our lifestyles impact our energy expenditure and therefore our body weight as well.    SkepticRD, however, does think this article poses some interesting information that we may be able to include in our own quests for better health. 
One thing that can be gleaned from this is that most of us are not burning as many calories as we think we are.  For example, if SkepticRD walked a 20 minute mile, keeping up the same pace for an hour, which is a pretty fast walk, she would burn---a whopping 200 calories!  All I would have to do is eat two pieces of bread, or an ounce of nuts, or an "energy bar" and I've just taken in what I've "burned" off if not more.  In other words, many people suddenly feel they are fat burning machines just because they have gotten on the treadmill.  And related to this, many people are not really paying attention to how much or what they're taking in.  For example, in just about every diet plan I've evaluated nuts will be listed as a healthy snack, but every ounce (roughly a cupped palmful) contains about 180-200 calories.  So, if you eat the whole bag of nuts (you know who you are!) and still do that hour on the treadmill; well, you're probably not dropping any clothing sizes soon.  In other words, your magical thinking about the exercise you  did and the not paying attention to how much you ate does not add up to helping you lose any weight.
Another reason that your exercise might keep you from losing weight is that you might not have really stopped to think about what you are taking in.  Hunter gatherers eat what's available to survive.  Most of us in the west have a lot more choices, but for a variety of reasons people don't pay attention to where those extras might be creeping in.  One of the times where I see people having the most trouble is with foods that are labeled "healthy."  Let's take fruit for example as I have seen plenty of people who have their blood glucose and weight loss goals thwarted by not paying attention to fruit.  One cup of watermelon pieces has about 12 grams of carbohydrate and about 50 calories.  Given that I have patients who can down at least half of a watermelon in one sitting, it really adds up.  I've also had a lot of patients who have had trouble with commercially prepared snacks that carry a healthy label.  One time SkepticRD actually subscribed to a company that would send me a sample of dairy/gluten/soy free snacks once per month.  I thought it was a great idea to try new snacks without buying in bulk, but pretty much every box contained things that were way over the carbohydrate limit that this insulin resistant gal could eat.  I stopped it so I wouldn't even have the temptation in the house.  Think about, we as skeptics are very critical about what goes into our minds, but a lot of us stop scrutinizing when it comes to our food.
On a related note, some people when they start exercising also start using products that are not made for the average "I exercise to try to get healthy" person.  One of these is sports drinks such as Gatorade, etc.  There is no evidence that people who exercise for under 45 minutes need to replenish the sodium beyond what they might get in your diet, and you've just undone whatever work you did in that past 45 minutes. (Link)  Another product is protein powders.  Once again, people who are exercising to be healthy do not have protein requirements that are really higher than anyone else.  Remember, even excess protein can eventually cause trouble with blood sugar control as can the fact that you are consuming a food like substance that will be absorbed quickly and likely leave you feeling hungry later.
A third problem that people have, even when they do try to change their diet, is that intense exercise actually just serves to make you hungrier.  I think this tends to be more true of people who were used to eating a lot of sweets and starches—many people do not feel good when they cut these out because their bodies are used to have readily available blood glucose for energy and their body has not adjusted to using to breaking down fat for energy. (Some people call this detoxing—if you use that word SkepticRD will take your Skeptic card from you!)  If you do intense exercise that you are not used to doing, that will also cause you to quickly use up any available glucose causing you to feel hungry (or "hangry") and all you can think about during and after your workout is EATING A GIGANTIC PLATE OF PASTA DAMMIT!  (Not that SkepticRD knows what this is like, no, not at all).  So, you will be much better off allowing your body to get used to a change of diet first and starting off with light walking, etc.
Keep in mind too, that the high level competitive athletes whom you are watching at the Olympics didn't get there by eating a poor diet.  Sure, those athletes might get to eat a bigger piece of chicken than you, or eat a bigger sweet potato, but they usually eschew sodas, deep fried foods, snack foods, etc, especially when they have an important competition coming up.  Now, if someone has a job that requires that much athletic training and he or she STILL has to be careful with what he or she eats to avoid gaining extra fat, then think about how much more careful those of us who are doing moderate exercise have to be!
Speaking of professional athletes, one of the other exercise fallacies that is touted by gyms is that by building muscle you will actually increase your resting metabolism.  Unfortunately, in order for you to actually achieve this benefit, you will need to bulk up like Lou Ferrigno or Ms. Olympia 2012 Iris Kyle.  In other words, unless you are a highly competitive athlete you won't get enough of an increase in resting metabolism to justify the extra cookies. (Link)
So, does this mean that exercise does not confer any benefit?  No, moderate exercise, especially exercises that help you build muscle, can improve your sensitivity to insulin, which very important for controlling the blood glucose levels in the pre-diabetic and Type 2 diabetic, lowering your risk of heart disease, and might even ultimately regulate your appetite (Link).  If you are an older adult or hope to someday become an active older adult exercise can help you build strength, maintain bone density, improve your balance, improve your coordination, keep or improve your mobility, reduce your risk of falling, and help you be more independent throughout your life cycle.  (Link).  And for some people, well, they just want to look better naked.
Bottom line—the evidence points to diet as the greatest impact on body fat loss.  Keep exercising to improve your strength and maintain quality of life, but those hours on the elliptical won't help.

Thursday, July 26, 2012

Will it blend?

Over the years one of the other questions I have received is about juicing.  Quite often these questions came from people who watched a lot of late night TV and saw infomercials featuring people like Jack LaLanne, but I have received  a few reports of people getting encouragement to "juice" from their health care providers as well.  Does juicing do what it says it should and is it ok as a regular healthy practice?  Let's see what the evidence says.
One claim made by juicing proponents is that juicing can reduce your risk of getting cancer, keep cancer from reoccurring, or cure the cancer that you already have.  There is plenty of scientific evidence to indicate that people who have a higher fruit and vegetable consumption consume more anti-oxidants and other nutrients that can help reduce your risk for cancer.  Does consuming the fruit and vegetable in a juice form up the risk reduction even more?  Here the evidence is very shaky.  For people who haven't been eating a lot of vegetables drinking the juice might be a way to easily consume more, but that just speaks to the consumption, not the form.  As far as a high fruit and vegetable intake preventing cancer or curing what you already have?  Well, maybe, but not b/c there is anything magical surrounding fruits and vegetables in their regular or juiced form.  For some people cancer is a very rude awakening to the state of their health, and they start improving their health in a lot of different ways, such as quitting smoking, eating less processed foods, exercising more, building social relationships by attending support groups, getting more sleep, etc.  Chances are they also ate more fruits and vegetables; and they might have juiced to include more.  Was it the juice that helped their cancer go into remission or a combination of surgery, chemotherapy, better overall diet, better overall exercise, not smoking, etc?  Hard to pin it down on just the juice.  Bottom line—eating more fruits and vegetables, along with other lifestyle changes, may help reduce your risk of cancer and help improve your quality of life as part of your treatment for cancer but there is no evidence that juicing adds to the benefits.
A second claim is that juicing boosts the immune system.  I have a sneaking suspicion that this claim may have stemmed from the belief that vitamin C "cures" colds and many people associate vitamin C with fruit juices.  Unfortunately, there is no evidence that vitamin C prevents or cures colds (Link), so you could almost dismiss the immune boosting claims on this.  However, fruits and vegetables are good sources of vitamin A, C, and E which do help support our white blood cells (which do fight bacteria, viruses, etc that enter our body), but we also get some of these same vitamins from organ meats (vitamin A) and nuts/oils (vitamin E).  So, if you are not getting enough fruits and vegetables, you might be more vulnerable to succumbing to the common cold, but your immune system is also influenced by your sleep, how much protein you're eating, how you are handling stress, and of course, how often you wash your hands.  But does putting the fruit through a juicer somehow boost your immunity?  Once again we are faced with a lack of evidence.  Bottom line—eating more fruits and vegetables, along with other lifestyle changes, may cause you to be less vulnerable to illness but there is no evidence that juicing adds benefits.
A third claim is that juicing helps remove toxins from the body.   "Toxins" are basically the modern day equivalent of "imbalanced humors" or "miasmas"  or even evil spirits that people used to think caused disease before we understood that viruses and germs did so.  So if a toxin doesn't exist, anymore than miasmas do, then how can they be removed from the body?  Of course there are poisonous substances out there, but they are not a secret and often the results of ingesting such poisons are known.  Many of these "poisons" are derived from the "natural" world and many people ingest them willingly in the forms of alcohol, tobacco, and opiates (i.e. pain killers).  If you are a smoker, the best way to get rid of the nicotine in your system is to stop smoking.  I have seen people embark on a "juice fast" as part of their "detox" from nicotine or whatever they were "detoxing" from.  Chances are they came through it feeling better because they were able to get through the initial nicotine withdraw but substituting a lot of sugary juices and they got the nicotine out of their systems.   Bottom line—juicing does not help remove something that doesn't exist in the first place, and the best way to avoid "poisoning" yourself is to not take the poison in the first place or stop taking it.
The fourth claim is that juicing can aid digestion.   There might actually be a grain of truth here.  Most species on this planet have evolved with survival in mind.  Plants cannot "run away" from creatures that want to consume it or climates that want to destroy it, so plants have had to develop ways to ensure their survival.  Many plants contain substances collectively called "anti-nutrients" that prevent the absorption of many vitamins and minerals.  Fruits and vegetables are no exception, although a lot of the modern day fruit and vegetables have been bred for increased palatability and ease of chewing.   For the average person with a healthy digestive system, just chewing the raw fruits and vegetables well, or eating them lightly steamed or roasted, or even cooking them in a little fat, should give you access to enough vitamins and minerals.  For someone who has an inflammatory bowel disease, or has damage to the digestive tract from chemo therapy, or who has lost the ability to chew because of a stroke, etc.  The blender can help "pre-digest" the fruits and vegetables and help that person absorb vitamins better.  Bottom line—if your digestion is already fine, blending won't help you, but if you have known damage to the GI tract you might benefit.
That last paragraph actually brings up another problem with juicing, and that is that sometimes the ability to consume and digest something quickly can be detrimental.  Once again let me point you to yesterday's post where I gave a brief description about how overeating on carbohydrate (and ultimately protein) can lead to elevated insulin levels which can increase your hunger and cause poor glucose control (Here).  So let's say that you are keeping your carbohydrate grams to no more than 15-30 per meal (or less if your blood glucose levels are wildly out of control), but you decide to do a juice recipe.  I have seen fruit juice recipes that contain 30-60 grams of carbohydrate for one glass—so if you are not careful you could go way over limit.  Now, if you are mostly doing vegetables you will likely do much better on the carbohydrate intake, but depending on the vegetables you consume you might get more carbohydrate and calories than you think.  I can still remember the guy with uncontrolled diabetes who came to my office unable to comprehend why his blood sugars were going up when he was eating more vegetables with his juicer.  Turns out one of his favorite recipes required 1.5-2 POUNDS of raw carrots, it would produce one large glass of juice, and he would drink the whole thing.   If he would have eaten one carrot, he would have consumed about 5 grams of carbohydrate.  With the juice, he was consuming 45-60 grams at one time, on top of all the other carb foods he was eating.  Another problem with juicing is that we have evolved to "work" for our calories –which means our body is used to getting nutrients in smaller quantities (i.e. eat one orange instead of drinking a glass of juice that's the equivalent of 2-3 oranges).  Our body is also used to receiving nutrients after we have chewed on the food and probably eaten in a fibrous form (and with some fat) to keep the food digesting at a normal pace.  Bottom line—when food is in liquid form we absorb it quicker than our bodies are supposed to and this could lead to increased hunger, overeating, poor blood sugar control, and other problems w/elevated insulin levels.
Disclaimer: SkepticRD loves to have a quick breakfast, and when it's hot like it is here is Skepticville right now, cold fruits taste really good.  When I need a  quick and cold breakfast I have been known to do a smoothie.  My damage control—measure out the amount of fruit I'm using, add protein powder to make it more of a meal, add some time of fat like coconut or avocadoes, and I add a green leafy vegetable like spinach.  It's still liquid, but I've still got the fiber from the fruit and vegetables,  the good fats to help me digest the meal at a regular pace,  and I've kept my carb under control (and had protein too). 
Take away message—unless you have trouble chewing or a damaged GI tract you can save your money on juicing.  Keep eating fruit and vegetables raw or lightly cooked and you will still get the known benefits, just none of the magic.

Tuesday, July 24, 2012

Is it time to eat yet?

One piece of “advice” that I frequently get questions about is how often a person needs to eat, usually framed something along the lines of “I’ve heard several smaller meals per day is better, is that right?” 
Now, if that question had “from reading on the internet that” or “my mother’s cousin’s veteranarian’s brother said” after the “I’ve heard” part, then many of you out in readerland would raise an eyebrow and probably dismiss it.  However, in my fifteen years of experience I have heard that from plenty of well meaning health care providers (particularly physicians and nurse educators) as well.  In today’s post I will not only try to answer your question but also show you how vulnerable educated health care practioner’s can be to accepting “wisdom” that has no scientific backing.
One of the main reasons that people who are trying to lose weight are told to eat more often is to “rev up their metabolism,” by which I assume they mean increase your Resting Energy Expenditure (REE), the amount of energy your body uses by you just existing.  I can see why some individuals may have gone down that path, as whenever we consume food our body does go through a process called “the thermic effect of food” (TEF) which is used to describe the energy expended by
our bodies in order to consume and process food.
  In other words, you do have an increase in your metabolism whenever you eat.  Unfortunately, it’s not as big an increase as most of us wish it was (sorry!) and when the evidence is examined, meal pattern and TEF really doesn’t seem to have an impact on whether or not a person loses weight and/or maintains that weight loss (Link).   Bottom line—eating more often will not speed up your fat burning abilities by any appreciable amount.
One of the other reasons I think this idea is still around surrounds the treatment of diabetes.  First of all, let me remind you that there are actually two main types of diabetes out there, Type 1 and Type 2.  People with Type 1 make up only about 5%-10% of the diabetes population and need to take shots of the hormone insulin to live.  (Brief refresher, you need insulin to remove blood glucose or “blood sugar” out of the blood and into your cells to be used for energy or stored as fat).  For many years (and SkepticRD is old enough to remember these) the only forms of insulin available did not really match what a non-diabetic body would produce and the insulin would be “most” active (what we can “peaking”) at odd times.  People HAD to eat multiple times per day at the same time every day or they risked dropping their blood sugar dangerously low.  Also, children with Type 1 tend to be very thin and so they would have to eat more often to get enough calories.  Fortunately we now have insulin injection regimens and even insulin pumps that allow people to have much greater meal time flexibility—but the “old way” of doing things still persists.  Boyfriend of SkepticRD has Type 1 and is the type of person that would go without food if he had something better to do; so when he first let on that he didn’t eat breakfast he braced himself for a lecture and was rather surprised (and maybe pleased) when I shrugged it off.  I think this “old way of eating for Type 1” translated to a similar meal pattern for Type 2’s, only this created some more problems.
People with Type 2 diabetes, on the other hand usually start their diabetes “career” by making TOO MUCH insulin.  Yes, you read that correctly.  In brief, people eat food—particularly carbohydrates (aka sugars/starches), it converts to glucose, and the body is supposed to make just enough insulin to handle it.  But a person with pre-diabetes or early Type 2 diabetes has insulin that doesn’t work as fast as it should (either because of genetics, excess body fat, poor activity, all of the above), so the body actually has to make MORE insulin to control the blood glucose.  Now when the body, specifically the pancreas, has to do all that overtime and doesn’t get comp time or paid extra?  Just like any employee, it will keep working but it will not work as well and eventually quit.  Now, picture an overweight type two person with diabetes eating five or 6 times per day.  His or her pancreas is going to be working overtime to keep up with all the food they are eating, which could eventually lead to less insulin production, which leads to poor glucose control, which means they have to take more medication, they one shot of insulin, then two, and then four shots of insulin, etc just to keep everything under control.  So does using one eating pattern for essentially a different type of disease process (that was less than ideal anyway) have any good evidence to support it?  Doesn’t look like it.
I also think the 6 smaller meals a day idea came from a way of thinking that states “if you let yourself go too long without eating, you will just be ravenous and eat more.”  Here is where we turn the study of evolutionary biology to see if this ultimately makes sense.  For the most of the 250,000 years that homo sapiens have been around, we haven’t had a consistent supply of food.  We evolved to build up fat and muscle stores when food is available and use it for energy when food was scare.  During the scarce times our body even evolved to function off of ketones (a byproduct of fasting) as opposed to blood glucose.  Now, as far as having food in general readily available, particular in the form of starches and sugars which give us a lot of glucose, that only accounts for a short time in human history, and our bodies haven’t caught up.  So what happens when a typical modern human tries to eat six times per day (especially if that modern human is trying to lose weight)?  They eat food, it changes to glucose, the body makes insulin to control it, and depending on their genetic history the body probably makes extra insulin than needed.  Oh, did I mention insulin also plays a role in appetite regulation?  As in more insulin, you’re more likely to be hungrier sooner?  Yes, so you eat, and then you eat again two-three hours later, and then by the end of the day you should be sick of eating, but no, you still want to have an evening meal, and then another snack before bed, pretty soon your calorie intake has maybe crept up a little higher than it needs…..So does reason for eating six times per day make sense or seem evidence based?  Doesn’t look like it to me either.
I’m also going to venture into the anecdotal here and mention that I have seen this “6 smaller meals per day” work for very few people over the years.  Some of the reasons why include 1) Some people hear this and just add extra snacks on top of what they were eating and 20 or more pounds later I am counseling them on weight loss.  2) Eating 6 times per day can be hard to schedule so people rely on convenient items like “energy” or trail mixes, or they are eating while working and not paying attention, and they wind up once again taking in too many calories. 3) As stated above, sometimes this type of pattern actually messes with your appetite regulation and you wind up not being able to make good decisions about your food intake.  Remember my post about being "hangry?"
So, for many of us, eating two to three times per day is the way to go.  I will usually lean more towards the three times per day for several reasons.  1) Most of my patients are elderly and some are very sick, so I need to make sure they are consuming enough protein and absorbing it.  Apparently the older a person gets, the better their body absorbs protein if they spread it out over three meals per day, so I need to make sure they are not trying to “make up” their nutrient intake later. 2) Since I have worked with adults, usually “middle aged” and older for most of my career, I have encountered a lot of people whose appetite regulatory system (involving other hormones like leptin, etc) is messed up for one reason or another and their body can no longer send the signals that say they have consumed enough.  People in that state often wind up relying on external cues to eat, and so they need to be on a regular schedule to learn what it’s really like to feel hungry.  3) Some of us, including SkepticRD and her patients, have to take medicine with food or we will have nasty GI side effects, so we do have to at least eat that boiled egg so we can have a good day the rest of the day. 4) Many of us are used to readily available sources of glucose and eating less than three times per day will just promote “hangryness” and make it hard to stick with a new way of eating if we are trying to lose weight.  Once you are more comfortable with your new eating plan, you might be able to skip a meal here or there without crying but I wouldn’t try it at the beginning.
Bottom line, there is no evidence to support eating 6 times per day for blood glucose regulation or weight loss.  You can put the trail mix down now.
**Note 1:  If you have had weight loss surgery or have otherwise had surgery resulting in a large part of your digestive system being removed, you might not be able to eat all of your protein requirements at three meals and 6 smaller meals might be better for you.
**Note 2: People who already eat very low carbohydrate—you are not off the hook.  If you wind up eating six times per day and consume way more protein than what your body requires, that is going to convert to glucose too.   This means that you can still over produce insulin even if you are carefully watching your carb intake.  Sticking with three meals per day will more likely help you keep your protein intake at adequate levels.
**Note 3:  I have had to give very, very brief descriptions of the wonderfully complex way our body regulates appetite and blood glucose control.  For additional reading, look here and here .  The book “Good Calories: Bad Calories” by Gary Taubes gives more details as well.

Monday, July 23, 2012

This Post is Full of Crap

There really are days when SkepticRD wishes she didn't have as many scruples as she does.  Especially when I see how much money can be made selling products to lose weight.  Today I want to talk about another piece of quackery that keeps coming back to haunt me, and that is the concept of detoxification through colon cleansing.
Colon cleansing actually has a pretty fascinating history, at least if you are a history of medicine nerd like yours truly.  Apparently the first records of this practice were found in both the Hindu Vedas and also in Ancient Egyptian writings (link), and contain fascinating stories about the "god of medicine and healing" landing on the banks of the Nile in the form of an ibis, picking up water in his beak, and shoving its beak up the physicians'…..(let's just say that SkepticRD spat her water all over the computer screen while reading that).  Recently I've heard that Rachel Ray and Dr. Oz were also touting said products, but a very quick internet search indicates that the colon cleanse people love to use the big name celebrities to give false endorsements (link)
One of my other SkepticHeros, Dr. David Gorski, has already done an extensive article on this over at the Science Based Medicine Blog.  He goes point by point over many of the different claims made by "colon therapists" including how you can't lose weight because of the accumulation of feces (or "toxic sludge" or "gunk" or whatever inflammatory term colon cleansers want to use).  Ask any GI surgeon who has performed a colonoscopy or any surgeon who has operated on the GI tract and you will find this simply does not happen.   And if your system was "clogged," wouldn't you think you would lose weight because no nutrition was actuality getting through.  And yet I still get questions, especially people who are wanting to try yet another diet, about "colon cleansing."  Why is the idea of colon cleansing so appealing to people?  Here are a few reasons why I think this doesn't go away:
1) The idea behind "I can't lose weight because of all the toxins in my body" is a nice way of lifting some of the responsibility off of one's self.  And honestly, what person who has struggled with their weight hasn't wished for a potion to "magically" clear out at least five or more pounds?  I also think that if people do have some guilt related to smoking, or drinking too much alcohol, or eating too much processed food they are hoping that taking this cleanser will somehow relieve them of the guilt.
2) Poor understanding of anatomy and our digestive system.  Very little absorption happens in the colon, about 90% of our nutrients are absorbed in the small intestine.  Anything that is considered toxic would have already been absorbed before it got to the large intestine.
3) Poor appreciation for how efficient our digestive system in clearing out the bi-products of normal metabolism and any other "extras" we take in.  Isn't it odd that the people who promote colon cleansing are usually touting it as a "natural" solution are usually the same ones that can't appreciate how much our body already does. 
4) Some people do have diets that lack fruit and vegetable fiber or they wind up taking medications that cause constipation.  They feel better after taking laxatives so they think—"wow, I don't have to change my diet I can just do this herbal product!"  Unfortunately the "quick fix" can be something they become dependent on.
5) Western obsession with cleanliness.  We are afraid of things that smell bad or that might have "germs" on it.  We take showers, why shouldn't we clean out the colon?  Because more often than not, the bacteria that is supposed to be in our digestive system is there for a reason.    Doing something as not-natural as a colonic (even if you use medical looking tubes and not an ibis) could disrupt the gut flora balance that's supposed to be there.
6) I also agree with Dr. Gorski's assessment that there are a lot of parallels to religious doctrine here—most world religions will speak of and have rituals involving "cleansing" and "purging."  Typically our bodies are seen as inherently bad and nothing that goes on inside the body is "purifying" enough; we need to have something come from the outside to make us clean.  Once again, this shows a poor understanding of how wonderful the body is and how the organs of elimination have evolved to keep the body in balance.
Take away message—there are no scientific reasons for any to do a colon cleanse, particularly for weight loss reasons.  If your diet has been less than healthy or you have put some un-healthy substances in your body,  there are no herbs or washes that will make up for that.  You have to start by putting the right foods in your body and let your wonderful digestive system do what it has evolved  to do.   (And if an ibis lands near you, you might want to keep an eye on it).

For the not faint of heart, you may also want to watch the Penn and Teller Bullsh*t episode on detoxing here.

Saturday, July 21, 2012

Know Your Blood Type to Donate, Not For Your Diet

SkepticRD has over 15 years experience in the field of nutrition; long enough to not only see a lot of quackery but also to see the same quackery come around again and again.  One of the books that keeps coming back to haunt me and other Fighters of Food Woo is the book "Eat Right For Your Type" by Peter D'Adamo, ND, first published in 1996.  And no, I am not even going to dignify this book with a link.

As far as why this book is wrong on so many levels, this has already been covered by many authors who are devoted to skepticism and anti-quackery.  Probably the best summary that SkepticRD has encountered is this article done done for The Skeptic's Dictionary: Link.
In summary of that summary:
1) If those of us who had been eating the "wrong" foods really are suffering from the multi-organ failure from lectins and agglutinations it would show up on the same type of imagining used to diagnose atherosclerosis and also on autopsies.  It doesn't.
2) D'Adamo claims that "O" is the oldest blood type, however, studies in humans and other primates indicate that alleles coding for type "A" are the most ancient.  Given that hunter-gatherer cultures are much older than agrarian types, and the hunter-gatherer diet is not suitable for type A's in D'Adamo's head, then this is not a scientific fact is it.
3) Pathologist Karl Landsteiner identified the different blood types in the earlier part of the twentieth century by classifying blood on the presence or lack thereof of different antigens.  Since then, over 276 red blood cell antigens have been identified.  Notice there are only 4 different types of diets in this book, not 276 different plans.
4) The author goes beyond diet into a type of "blood type astrology" attributing different personality characteristics to various blood types.  This includes the use of the terms "master race" and stating that Type A's tend to become paranoid like Hitler; that should be enough to raise red flags in the mind of any one with a drop of skeptical blood in their body (pun intended).

SkepticRD is even more interested in why people keep falling for this kind of quackery.  Some of my thoughts include:
1) People who struggle with their weight want to find something to do that will cease their struggles.  The idea of finally finding something that doesn't involve counting carbohydrate grams, etc sounds very appealing.  **Sidebar** There is a predominant myth that obese/overweight people are lazy.  If you would see some of the things people go through to lose weight, you would likely not believe that.  When a person says "I've tried everything" I often find them to be right.
2) One person may do better with one diet plan than another person, and we as humans want to know why that is.  Throwing around the terms "antigen" and "evolution" can sound like quite a scientific solution to those who do not know much about human physiology or evolutionary biology.
3)  People don't question authority or tiles that sound like they should have authority. Typically when I see ND ("Doctor" of Naturopathy) my Baloney Detector siren starts ringing as I know pseudoscience abounds; see Quackwatcher Stephen Barrett's article here.  Also, when I asked a co-worker why she was reading that book (and this was a health care professional) she stated "A doctor at my church recommended it."
4) There are just enough healthy recommendations in it that it sounds like it could actually be healthy--none of the groups are supposed to consume added sugars, white flour, fast food, etc.  Most of could stand to do that, but it doesn't mean that if a type O eats dairy that his/her organs will suddenly fail.
5) People falling victim to the fallacy of "it's natural so it must be better."  Time for a cliche: "You know what else is natural?  Arsenic!"
6) People falling victim to the "ancient wisdom" fallacy.  There was once a time when people sacrificed children to stop natural disasters, but we wouldn't think of doing something similar today.   People also used to live without refrigeration (many cultures still do!) but we in western society find that a necessity for keeping our food supply healthy.  Ancient does not necessarily mean better.

What can we do to stop the revolving door of quackery?  Try to understand people's motivations, and try to research the wonderful world of science behind it.  And if you're wanting to find out your blood type, go do something useful and life giving in the mean time, like donate blood!

Friday, July 20, 2012

Soda on Facebook or Why SkepticRD is not allowed to work in Marketing

To be honest, one of the reasons I started this blog was to expound upon my Facebook rants.  Today I got my blog idea before I even finished my coffee.  And yes, it all started with the above stated photo.

Here we have just enough big scientific words and just enough correct information to make this sound like wise, shareable, information.  But let's look again and examine the claims one by one shall we?

1) Phosphoric Acid - Weakens Bones and rots teeth. Phosphoric acid is not only found in sodas, it's also found in meat, milk, nuts, egg yolks, poultry, and fish.  In other words, things that we as humans would normally consume to get protein would cause us to intake phosphoric acid.  We certainly don't need to stop eating protein.   Can taking in an EXCESSIVE amount of phosphorus cause dental erosion and weakened bones?  Since the normal way to get rid of excessive phosphorus is to bind with calcium, most likely.  I do have a friend (Warning, anecdote alert!) who is on a low carb diet and eats animal protein at every meal, and when he started drinking 3 or four diet sodas a day (they were tasty!) he notice cramping and joint pain.  Since the diet sodas were the only change in his diet, he read more about them and concluded that it was excessive phosphorus that caused the problem.  So, here was a person who was probably already getting his daily dose of phosphorus, and his excessive consumption of diet soda may have pushed him over the edge.  A lot of people also point out that phosphoric acid is used as an industrial cleaners.  Sure it is, just like hydrochloric acid is also used, but we also need hydrochloric acid in our stomachs to digest our food! 
Take away message--Phosphoric acid by itself is not a bad thing.  Is one diet soda a day excessive?  Probably not.  Is drinking more than one or two a day excessive?  Most likely, especially if you eat animal protein.
SkepticRD rant--Too much of anything can throw your body out of balance.  Making blanket statements about chemicals that naturally occur in foods that humans need to consume is bad science.

2)  Excessive artificial sweeteners cause you to crave more.  More what?  Sodas?  Broccoli?  Sex?  Ok, maybe the photo person was just trying to use up limited space, but I couldn't resist poking a little fun.  He might be on to something here, especially in rats.  Also, keep in mind that our brains have evolve to recognize a sweet taste as a signal that a quick source of energy (i.e. glucose) is on it's way, so it is possible that the sweet taste may confuse the complex interplay between our brain, stomach, hormones, etc.  There is also a placebo effect at work here; you might feel less hungry after giving up diet sodas because you believed you would.
Take away message--Is one or two diet sodas per day excessive?  Probably not.  If the placebo effect is working for you, go for it.
Skeptic RD rant--But seriously, why are you paying all that money for something that provides no nutritional value?  Coffee and tea can provide anti-oxidants.  Water is much cheaper.  If you must have bubbly, do mineral water with a squeeze of lemon or lime.

3) Caramel color, made from the chemical caramel, is purely cosmetic, it doesn't add flavor yet is tainted with carcinogens.  Ok, I'm going to be the Grammar Police again.  There is no chemical named caramel.  What they probably meant was that caramel coloring is manufactured by heating carbohydrates, either alone or in the presence of acids, alkalies, and/or salts.  Is it tainted with "known carcinogens?" Probably in the same way that an apple has "known poisons" in it's apple seeds--yes there is something there but the dose determines a poison.  Apparently you have to consume 1000 cans of soda per day to get a carcinogenic amount, particularly if you are a lab rat.
Also, the fights over caramel coloring are happening between two groups with know bias--The American Beverage Association and the Center for Science in the Public Interest.  Remember my post on confirmation bias?
Take away message--Obviously one or two sodas per day is pretty far away from 1000 per day.
SkepticRD rant--Too much of anything can throw your body out of balance.  Those of us in the USA love to consume to excess, but 1000 cans or more of soda a day is excessive even for us. (Link)

4) Formaldehyde--carcinogen, it is not added in soda but when you digest aspartame, it will break down into two amino acids and methanol = formic acid + formaldehyde (diet sodas).  One of SkepticRD's hero's, Dr. Harriet Hall has already answered that "Some of the things we ingest are directly absorbed and utilized unchanged, like water. But most of what we ingest is metabolized.  Aspartame is metabolized. It does indeed break down into aspartic acid, phenylalanine, and methanol.  Aspartic acid and phenylalanine are amino acids that we need to survive. Methanol is produced in small amounts by the metabolism of many foods; it is harmless in small amounts. A cup of tomato juice produces six times as much methanol as a cup of diet soda. Methanol is completely metabolized via formaldehyde to formic acid; no formaldehyde remains. Lastly, the formic acid is broken down into water and carbon dioxide. Human studies show that formic acid is eliminated faster than it is formed after ingestion of aspartic acid.  So yes, those compounds appear, but so what?  We get much larger amounts of the same compounds from our food, and they don’t hurt us."
Take away message--The last two sentences in that quote say it all.
SkepticRD rant--Why do people have to take a normal body process and make it into something scary?  Why can't we educate people on how fascinating our body is--that it can take a tomato and break it down into things we need and things we don't?

5) High Fructose Corn Syrup is a concentrated form of sugar derived from corn.  It increases body fat, cholesterol, and triglycerides and it also makes you hungry.  Here is where we are finally on to something, although the main problem here is that HFCS has made sodas a cheap and easy source of extra sugar in our diets.  There is a tendency to store excess calories from sugar (or any form of carbohydrate) in the abdominal area which might lead to your body becoming more resistant to the hormone insulin (which regulates blood glucose levels, among other things).  If you are resistant to insulin, then your body will produce higher levels whenever you ingest a nice load of carbohydrate from soda, fruit juice, eating half a flat of strawberries, beer, eating a doughnut, etc.  The elevated levels of insulin do kick off another fascinating body process that causes our liver to kick out excess cholesterol and triglycerides.  Also, insulin does play a large role in appetite regulation so people with elevated levels do tend to have trouble with appetite control.
Take away message--Excess sugar in any form can cause the above stated problems.  Sodas make it very convenient to get sugar we don't need, as do fruit juices (do not get me started on fruit juices!)
SkepticRD rant--I will actually ask forgiveness here for having to condense a complicated body process into a paragraph.  Looks like I have material for another blog post.

6) Potassium Benzoate = preservative that can be broken down to benzene in the body.  Keep your soda in the sun and benzene = carcinogen.  Once again we may be on to something, but the breaking down usually happens in the soda itself, not the body.  This preservative works well in an acidic environment so it is usually combined with ascorbic acid (commonly known by the less scary sounding name vitamin C), but the combination of the two can produce benzene.  Once again, we are back to a "dose produces the poison" type thing, but information on doses is hard to come by. 
Take away message--The "I don't know" part might be enough to scare people off here. 
SkepticRD rant--Sketchy science is not always a good reason to avoid things.

7) Food Dyes = impaired brain function, hyperactive behavior, difficulty focusing, lack of impulse control. I am assuming that the creator of this photo is talking about the studies that were done on children with Attention Deficit Hyperactivity Disorder (ADHD).  Possibly about the diet developed by pediatrician Benjamin Feingold back in the 1970's.  First of all, the studies were done on children with a known diagnosis of ADHD, and the results of eliminating food dyes have been mixed and not enough to give conclusive evidence.  There is also no evidence that the food dyes can cause these problems in children who don't have a known diagnosis of ADHD, and would the results yield the same in adults?  We don't know.
Take away message--Don't make a choice where there isn't evidence to support your choice, and beware of studies done on specific populations.
SkepticRD rant--Parents who have kids who have learning difficulties are easy prey for "food woo" and we need to be extra supportive of promoting evidence based treatment. (Link)

As you can see above there is strong evidence to avoid regular sodas altogether listed IN ONE POINT out of the seven.  For avoiding diet sodas, there is evidence for avoiding drinking more than one or two a day, but I would say the financial reason is a stronger reason there.   Unfortunately my one reason (s) don't sound as good as the seven, but as a Skeptic I choose to make my choices based on good science, not a group of inflammatory statements.

Wednesday, July 18, 2012

Grocery Shopping with RadioLab

One of the major complaints I get when I talk to people about changing their diet (and I get many), is that it takes longer to do food shopping because you are actually having (gasp!) read labels to determine whether or not the food fits the bill.  Not only is the extra time spent sometimes frustrating, but the amount of choices that are available to us can seem overwhelming.  Hearing these complaints reminding me of an episode of one of SkepticRD's favorite podcasts: RadioLab, particularly the Season 5 episode on "Choice."  The full episode is available here.:
The podcast does contain a lot of interesting information on how our choices can be influenced by, how much information we are presented with, what kind of pressure we are under to remember information, the connection between our "rational" and "emotional" parts of our brain, what kind of reinforcement we have about our choices, perceptions from our childhood, and even unconscious messages that our society sends us.  It is an hour long podcast, and definitely worth listening to the whole thing, but I am going to focus on the first part of the podcast, how having so many choices can make our decisions harder.
**Soapbox**Now, the fear that SkepticRD has now is that I am going to trigger a discussion on free-will vs. not, or that I am claiming that people make decisions about food based solely on whether or not they had a bad childhood.  I am using the evidence presented in the podcast to talk about how the complexity of our brains can influence how we make choices when it comes to our food, and how to decrease the stress associated with it.**Step off soapbox**
One of the things that can influence us to make not so good choices when it comes to food is simply that we have so many choices to make when we go into the grocery stores.  I personally am very glad that I do have a variety of grocery stores to choose from that contain a variety of different items, but at the same time this privilege can turn into a nightmare when trying to best take care of ourselves.  Here are some things you can do to narrow down the choices, avoid information overload, and save some time while shopping.
1) Do your research on what food items you need ahead of time vs. trying to make it up as you go along in the store.
2) Use your research to make up a list, whether you use pencil and paper or your SmartPhone.
3) Make the list as specific as possible.  This way you only have to visit specific areas of the store and you don't have to wander aimlessly.  You will also not be faced with as many choices on one item.  For example, if you put down "unsweetened coconut milk" instead of "dairy substitute" you will have narrowed it down where you just have to compare prices between a much smaller amount of items.
4) Shop "the perimeter" of the store as much as you can.  Here is where you are going to find most of the basics of a healthy meal plan—produce and protein.
5) Check out farmer's markets whenever you can, you will usually have less, but good quality, choices to make.
6) Be very careful of the specialty stores—here is where you really want to have a list or you will spend a lot of time looking at everything (if you enjoy recreational shopping, which SkepticRD does not, you can ignore this).  Boyfriend of SkepticRD can attest to what happens if I go in the spice shop without a list.
7) Keep in mind that you will get faster at picking out things on the label and ingredient list with practice.  You can amaze your friends with how quickly you can pick out food allergens with a glance!
8) Pick a day of the week to do your shopping and keep to it as much as you can.  That way you have put it on your calendar, made a date, cleared the time, etc.
9) Try to just shop for food items instead of trying to buy all the household items at once.  (I'm saying this to help you limit the information overload, but I also just happen to think that having food, cat litter, and a decorative Buddha statue in your cart all at the same time is just weird.)
10)  Shop with only a certain amount of cash on hand.  You will be less likely to spend time looking at things when you know you don't have the money to spend on it anyway.
Another point that was made in the podcast is that if people are under duress of some sort they are less likely to make choices with the rational part of their brain.  Once again, it's not that you CAN'T make rational choices it's just that it's more difficult.  Some ways that you can keep "stress" from influencing your decisions are:
1) Do not shop when you are hungry, particularly if you are experiencing that combination of hungry and cranky/angry (you know who you are!) called "hangry."  At this point, it's tempting to just shout out your favorite curse words and just throw whatever into your cart just so that you can get out of there.  (Not that SkepticRD knows what this is like.  Not at all.)
2) Do not be afraid to stick with simple to prepare recipes with simple to prepare ingredients, especially when you are first making changes.  If you want to eat the same thing for lunch for the rest of this week because it causes you less anxiety, do it.  Heck, I have had people that would eat the same thing for tw or three meals a day until they started to feel more comfortable with their new plan. Once you are ready to experiment you can branch out.  Otherwise, driving yourself crazy trying to find that one particular spice might decrease your ability to stick with your plan.
3) If you hate crowds like SkepticRD does, try to shop during hours when the stores are less crowded if you can.
Once again, we have some pretty fascinating brains that process a lot of information.  Hopefully you can use some of the above suggestions to help make the best decisions for you!

Tuesday, July 17, 2012

Baloney Detection: Part II

Yesterday's post included applying questions 1-5 of the "Baloney Detection Kit" to evaluating nutrition claims.  Today I will discuss questions one through six.  I have also found a link that contains the "written" version of the Baloney Detection kit here::
6) Where does the preponderance of evidence point?
You are going to find a lot of articles about how this one particular food or one particular nutrient is going to help you lose weight, have better skin, ease your aches and pains, etc.   There are people out there who are deficient in certain nutrients, but they can usually improve their health by eating more of a certain general category versus eating one specific  food.  Sometimes it can actually be detrimental to your health in other ways.  For example, I had one patient who had to take a medication that caused him to lose a lot of potassium through his urine.  "Someone" told him that bananas had a lot of potassium so eat started eating about 3-4 per day.  When I looked at his blood glucose records I noticed his blood sugars were elevated in the past few weeks.  He told me what happened and I reminded him that he was now going way over his carbohydrate intake and that's likely why his blood sugars were high.  We talked about some other ways for him to increase his potassium intake (e.g. Greek yogurt) without eating as many of that one food and his blood glucose levels came down.
7) Is the claimant employing the accepted rules of reason and tools of research, or have these been abandoned in favor of others that lead to the desired conclusion? (In other words, is the claimant playing by the rules of science?)
There are some people out there that start with the premise that this particular food, or nutrient, or food additive is always good or always bad.  Typically they will only "evidence" that supports whatever they were trying to say.  A lot of times the "evidence" is also anecdotal and any studies they cite are obscure, unpublished, and not in peer- reviewed journals. Often you will find them trying to market a particular alternative that may or may not have any evidence to support it.   If the claim about a food seems anecdotal, be skeptical.
8)  Is the claimant providing positive evidence?
I have seen a lot of websites and books where the author spends a lot of time criticizing the other side but he/she doesn't actually provide evidence on why their diet plan, etc is actually better.  Typically if the author mentions that they are being criticized and/or "persecuted" by another group this should raise a red flag on the validity of the information they are providing.  If the author uses phrases like "what your doctor doesn't want you to know about" and "everyone is being ruled by Big Pharma" more red flags should go up.
I have actually seen websites where the author was able to provide positive evidence and express the frustration that they have had dealing with other health care professionals, etc.  You can do both, but merely making fun of something is not scientific evidence.
9) Does the new theory account for as many phenomena as the old theory?
Most of us who work in nutrition related fields are fascinated by how some diet plans work better for some people than others.  I have seen all sorts of "reasons" presented from differences in blood type to the type of pesticides used on foods  to how well you chew and so on.  There might be something to some of the issues that are raised, but not all of these theories will take into account, for example, the many different ways of classifying blood besides the A/B/O, etc or the amount of certain foods that people take in.  If the new explanation is raising more questions or outright ignoring other factors you should start seeing more red flags.
10) Are personal beliefs driving the claim?
When I first starting hanging around with other people of a skeptical mindset I was fascinated how people could be very logical about many things, but when it comes to their diet they are willing to believe some pretty crazy things.  In other words, most of us have been guilty of allowing personal beliefs to get in the way.  I'm not sure I have an easy answer to avoiding this, but usually I will try to go to someone who has more expertise in that area than I do to try to find verification.  For example, one time I was skulking around on a blog that normally contained some pretty sound info, but then author linked a story about a woman who "cured" her child's cavity by giving him supplemental fermented butter oil capsules because they were anti-fluoride and a lot of anti-other things too.  Something smelled quite fermented to me, but I went to a friend who I will call "SkepticDentist" to get his opinion.  I not only had my suspicions confirmed, but got some other good info as well.  Also, another way of detecting whether or not someone is letting their personal beliefs get in the way is to look at how much time they spend ranting against "the other guy."  SkepticRD acknowledges that there are plenty of people out there who have had unfortunate run ins with doctors and other people in the medical profession, and this is one reason why people turn to the internet and other sources, but please, find ways to keep looking at everything with a critical eye.

Michael Shermer concluded his article by stating ”Clearly, there are no foolproof methods of detecting baloney or drawing the boundary between science and pseudoscience" and I would remind people that this applies to all the above stated.  You will probably also find plenty of books, articles, websites, etc that contain a range of info that is both useful and totally erroneous.    So I will tell you what I told my co-worker who asked "Is there any grocery store where I can just walk in and everything is good for me?"
"No, you still have to think."

Monday, July 16, 2012

Baloney Detection: Part 1

"Many patterns are real, and it's good to know what those patterns are, it's called learning…"
~Michael Shermer
Sometimes I think one of the worst things a person can say to SkepticRD when I am doing nutrition education is "I've been reading this book…." Now, why would I, as a good skeptic, groan inwardly whenever I hear that statement?  Shouldn't I be encouraging free inquiry and people learning?  Of course I should, but I also know that there are a lot of people out there who haven't had a good grounding in learning and learning science, and there is so much information out there about what constitutes good nutrition that even those of us who feel we are relatively intelligent people can feel a little hopeless.
There are some basic questions you can ask yourself when you do read something or hear something to help you try to sort out what is worthwhile information or not.  These questions are taken from Michael Shermer's Video: The Baloney Detection Kit, the full video can be viewed here.  Michael Shermer's questions are also based on the Baloney Detection Kit offered up by Carl Sagan in his book  "The Demon Haunted World."  I plan to cover the first of the five questions today and the remaining five questions tomorrow.
1)  How reliable is the source of the claim?
Whenever someone is making a claim about a particular food or nutrient, there are always errors that are going to "creep in."  But if everything appears to be slanted in one direction, you should start to be suspicious.  The way I relate this to nutritional claims is that if you see a claim about a diet, or nutrient, or a particular food that seems to "cure" or "improve" a lot of different ailments (or actually cause a lot of different ailments!) I would be very suspicious.  One example of this is the use of a gluten free diet being used to "treat" autism.  There are plenty of studies that show for people who have celiac disease or related GI illness's that indicate that a gluten free diet will improve (and in celiac disease, this is the only treatment), but very little actual evidence that removal of gluten itself actually improved the symptoms of children with autism.  (Do some children with autism have terrible diets and see improvement because they are eating more nutritious food?  Quite possibly.  Does the removal of one particular item do so?  Show me the evidence.)
2)  Does the source make similar claims?
One of the banes of SkepticRDs existence is that whenever I get pre-printed "education materials" on how vital a certain nutrient is, I find out that said materials come from a particular organization lobbying for an industry that markets/sells a food product that contains that particular vitamin, mineral, food substitute, etc.  If I go to a conference, most likely I will get education materials sponsored by the Beef Council, the Dairy Council, Novo-Nordisk, etc.  At these same conferences I will see booths sponsored by products like Sweet and Low, Splenda, Egg-lands best, etc.  Now, knowing how much money these conferences cost, I am not surprised that money changed hands between these organizations and whatever seminar I was at.  It also costs a lot of money to do research, so I am not surprised to find research articles in my packet or e-mailed to me that say "sponsored by the National Dairy council." But what's really disappointing is that I don't see more people like me asking pointed questions about these materials at conferences.  So whenever you read about a certain food helping you lose weight, etc, do some digging to find out who sponsored the study.  They might be on to something, but be skeptical.
3) Have the claims been verified by someone else?
If I see information in one news article or on one particular website, I search around to see if I can find any other non-related sources to verify it.  For example, if I see that a study has been done that states chocolate consumption is good for you, and I see that the Hershey corp has sponsored it, I'm going to start digging around for any other universities, etc not sponsored by Hershey that may have done other studies to verify this.
You also want to make sure the different sources are using the same terminology.  For example, there was recently a study published in Europe that stated that an "Atkins type diet" was bad for the heart.  An Atkin's type diet, however, only contains about 10-30% of the calories from carbohydrates, and the diet used in the study contained 50% of the calories from carbohydrates.  You can't verify a claim if you are not using a similar study plan.
On a related note, I would also ask "Am I getting all the information here?"  It is so easy to read the headlines and not read the fine print.  How many of us rejoiced when we heard "chocolate is good for you?"  But when you dig deeper, you find out that it was the so call "dark chocolate" (70% or higher) that was actually used in the study, not the Snicker's bar you were eating.  And then you find out that the amount recommend was 1 oz of chocolate—a quarter of a bar or less.  Yeah, you still haven't found your justification for your thrice daily Snickers.
4) Does this really fit with the way the world works?
You are going to find a lot of nutrition related studies that that use animal models, sometimes rats, sometimes primates.  If a certain substance puts lab rats at risk, there's definitely something there for future study but human physiology may not react the same.  Also, think about the amount of a particular substance that is often given in these particular studies.    Would humans realistically consume the equivalent of hundreds of cans of diet soda every day for the rest of their lives as in the controversial research done on saccharine in the 1970's? (That wasn't a challenge!)  In other words, we may not be able to consume enough of a substance for it to do us any harm or good, at least at the present time.
I think here is where I would also state that one should be very, very careful of research that is done where people get to self report what they were eating over a period of time.  There are a lot of us that simply report what we think the researchers want to hear, or you're filling out your food log at the end of the week and your memory becomes faulty and selective, or you don't really know what "half a cup" of something looks like, so you under-report because you just "guessed."  You can't base dietary recommendations on someone's faulty memory.
5)  Has anyone tried to dispute the claims?
One of the things scientists love to do is disprove claims.  A good scientist will enjoy looking at his/her own claims just to see if they can be disproven and they will name any faults or limitations to their own studies.  They welcome a challenge.  So, if you see advertisements for nutritional supplements or even articles that talk about how "they" don't want you know about this special secret nutritional ingredient, somebody is probably afraid of being challenged and that should raise suspicions.
Make sure that you are looking for refutation that has a scientific backing to it.  It can be easy for even the most rational among us to say "Well, my grandfather ate [insert food here] every day of his life and he lived to be 100!" We don't know if your grandfather was eating the same quality of food (he probably wasn't), we don't know what kind other factors came into play (air quality, stress level, sleep, family support), and he may have had some interesting genetics that may or may not have been passed on to you.
Stay tuned, part 2 should be coming.