Thursday, December 20, 2012

Gumming up the works

Today as I was scrolling through my news feed I came across a news article referencing this particular study on the use of gum arabic to help people lose weight. (Link)  I know this has been used before in weight loss products like Slim Fast and has been used as a food stabilizer for a long time, but apparently there isn't a lot of research done in humans as far as weight loss is concerned.  What kind of evidence do we have for using this in weight loss?

First of all, gum arabic (also called acacia gum) is a, well, gummy substance made from the sap of two different kinds of the acacia tree.  If you've ever eaten candy like gum drops, or marshmallows, or M & M's, or things like that, you have probably eaten acacia gum.  It's chemical structure is actually similar to other dietary fiber; edible but not digested by humans.  One of the reasons that it was thought to be useful in losing weight is that it has the potential to increase satiety; in other words, you feel fuller sooner and longer and you wind up eating less.    Gum arabic also doesn't seem to have any negative side effects when consumed by humans. (Link)

Some of the things that I like about this study is that they made an effort to find a large sample size and it was double blinded, which are major advantages.  They also noted that there were some side effects of mild nausea in the morning and mild diarrhea and/or bloating, so they were clear that this didn't come without its problems.

I do, however, see some limitations, meaning that we may not be able to generalize the results to other populations.  Note that the study was only done in women, all the participants were volunteers and may not represent a general population, they most likely ate a diet fairly unique to that part of Sudan, and the were listed as "healthy."  You might not have the same impact in men or someone who eats a culturally different diet.

Since there is potential here, though, and many people fight hunger pangs when trying to lose weight, I know some people are going to try it.  Keep in mind, though, that the problems w/nausea and bloating, etc were probably from the gum arabic slowing down the emptying of the stomach (which is why they felt fuller sooner and longer).  Some people are wanting/needing to lose weight bad enough that they are willing to put up with mild nausea and bloating.  But I think there are some people with certain health conditions that should stay away from this.  If you have any kind of condition that already slows down your digestion (such as diabetic gastroparesis or irritable bowel syndrome (IBS) with constipation predominant), or a history of a narrowing of your esophagus, or if you have had gastric bypass surgery or lap band surgery, or you take a drug like Victoza (a diabetes/weight loss drug made famous by Paula Deen), you want to AVOID using arabic gum because there is the potential to get an esophageal or intestinal blockage.  And if nausea/bloating/diarrhea just aren't on your top ten list of things to do period, then you probably don't want to use this.

So, if you are skeptical about using this and want other ways to increase your satiety, there are a few other things you can do:
1) Make sure you eat enough good fat and protein at each meal.
2) Load up on vegetables--you can consume a lot without worrying about carbs or calories and the fiber can be filling also.
3) Limit excess carbohydrate so that the resulting surge in insulin from eating these doesn't promote hunger.
4) When you do eat carbs choose higher soluble fiber/unprocessed ones like fruit and sweet potatoes.

Take home message--Gum arabic might help people lose weight by promoting fullness, but avoid if you already have digestive issues.

Tuesday, December 18, 2012

Boost Your Metabolism?

Today as I was scrolling through my feed I came across this lovely little headline: 16 Ways to Boost Your Metabolism Without Even Trying.  Now, anytime anyone tries to tell you that you can somehow change your body without work should be a big red flag, but I am sure that like me you were interested to see what they had to say.  So, please go ahead and read the article, and then let us examine each point to see if there is any substance there.


1) Eat Pineapple.  Yes, pineapple does contain bromelain, which might have some use in reducing inflammation associated with arthritis and asthma, but the evidence for it helping digestion is very weak. (Link)  I found it interesting that even the people at Dole did not tout pineapple for its digestive properties, and you think they would being trying to use every selling point they could get. (Link)  Also, you will notice that there is nothing in this little paragraph that implies that you will burn more calories by eating pineapple anyway.  If you decide you want to eat pineapple for the vitamin C and other healthy attributes, just try to stick with fresh and avoid the dried and canned versions as they often have sugar added.  And keep in mind the 83 calories and 19 grams of net carbs per cup of chunks.

2) Eat Organic.  Once again, if you are looking for any good evidence from human studies, you are out of luck here.  There are apparently some researchers that are looking at a possible role of industrial pollutants in obesity but there just aren't any good human studies out there.  And think about it, if you go into a store like Whole Foods and buy the organic potato chips or the organic sugar you are going to get the same calories.  There are other benefits to choosing local organic foods as far as a better taste (in my opinion), putting money back into the local economy, maybe even getting animal protein that has a healthier fat profile, etc, but when it comes to reducing your caloric intake or helping you burn more calories the evidence isn't there.

3) Get It On.  You probably thought you were going to learn that you burned a lot of calories during sex weren't you?  Well, you are out of luck here too, as what you got was some vague notion about elevating your sex hormones and your metabolism.  First of all, for women, if you could actually significantly elevate your estrogen levels through sex that could actually be a bad thing as you are putting yourself at more risk for breast and ovarian cancers, but fortunately sexual frequency does not seem to be linked to cancer of the breast or ovaries. (Whew!).  For men, if your testosterone is low you will likely have a harder time losing fat and gaining muscle, but you're not going to feel like having sex anyway.  What you want to do is talk to a good endocrinologist about testosterone replacement therapy and start improving your diet to lose body fat; then you might actually want to get it on.  And as far as calories burned--the pace of sexual activity is so varied among individuals that it is hard to pin down a number.  You might burn 86-100 calories in an hour of foreplay, but then you eat one piece of bread and you've just cancelled that out.  There are plenty of other reasons to enjoy sex, it being a basic human need as one of them; but you might want to use a healthy sex life as a reason to improve your diet, your exercise, quit smoking, etc.  A healthier daily lifestyle can result in better sex.

4) Meditate.  There have been a very few studies conducted on Buddhist monks who appeared to have been able to increase or decrease their metabolism via meditation (Link).  I happen to think that’s interesting, but what does that say about the rest of us?  First of all, I wouldn’t want to compare my own attempts at mediation to someone who essentially does that for a living, and second of all you can’t take three people and extrapolate the results to an entire population.  If you a person that goes after high caloric food when you are under stress and you need an alternative to eating your weight in doughnuts, and meditation helps, then by all means use it to decrease the impact of stress on your life.  But once again, I recognize that the meditation is a tool to help you decrease your caloric intake and not depend on it to burn more calories.
5) Sip Green Tea.  There are a very limited amount of studies that indicate that there is something to the claim about green tea increasing the metabolism (Link).  The downside, however, is that you are going to have to do more than sip the green tea; you will have to drink about three to five cups per day.  And even after you consume that amount you will maybe burn off an extra 80 calories per day.  Every little bit helps when  you are trying to lose weight, but keep in mind that about one smaller sized chocolate chip cookie will undo those 3-5 cups of green tea.
6) Take a Cold Shower.  Sounds like a good idea since your muscles are actually doing work by contracting to make you shiver.  There is an estimate that you might burn up to 400 more calories per hour if you are EXERCISING in the cold, but that’s cross country skiing, not standing under the shower head.  You probably don’t want to stand under the shower for an hour as you will have wasted a lot of water besides being miserable.  Keep in mind also that if you have a substantial fat layer that you are trying to lose; it is going to take you longer to start shivering when you are exercising because you are insulated against the cold.  As always, if you do choose to exercise in the cold, take precautions not to get hypothermia.
7) Limit Cocktails.  Since one cocktail may cause you to intake 150-250 calories depending on the type and size of the glass, this is good advice for keeping your caloric intake under control.  Alcohol can act like an appetite stimulant, and if your judgment is impaired on top of that, you can wind up taking in way more calories at the meal than you intended.  But does it actually slow your metabolism?   Not in the way you think it does.  Let’s say that you’re trying to lose body fat and you have reduced your caloric intake and also limited your carbohydrate intake so your body does not have blood glucose readily available to be used as fuel.  Your body will be more likely to use the fat for fuel.  If you take in alcohol, your body will use that for fuel and you may not use your fat for fuel in the next several hours.  So if you are a chronic user of alcohol you might have trouble losing fat and building muscle over time, but the problem is not because your overall ability to burn calories is slower.
8) Sniff peppermint or citrus.  There is a very small amount of evidence that peppermint oil may help reduce cramping and diarrhea in people with irritable bowel syndrome, but no evidence that drinking peppermint tea or sniff the essential oils will actually help you burn more calories.  Perhaps flavoring your water with peppermint or citrus will keep you away from high caloric sodas and fake fruit drinks though.
9) Drink Cold Water.  According to a small study done in Germany a couple years ago, if you drink at least six cups of cold water per day you will burn more calories—a whole whopping 50 calories per day.  (Link)  Once again, every little bit helps, but when you think about how about eating half a slice of bread can undo that, it really doesn’t make much of a difference in my book.  If you prefer your water cold and it helps you drink more, by all means go ahead, but you still better be careful with how much you are taking in.
10) Spice it Up. There was a very small study done by Purdue University that showed that you may have a slight increase in metabolism after eating a spicy meal (Link).  But, as I’ve mentioned several times before, the effect is so little that it can easily be undone by eating what seems to be a small amount of food.  The other problem is that the increase in metabolism only seemed to happen in people who weren’t used to eating spicy food, so it appears that if you made a habit of eating spicy food you wouldn’t get that effect after a while.  This shouldn’t stop you from spicing thing up though—if you are already restricting your caloric intake you want to make sure that what  you are eating actually tastes good and you will stay on your plan better if you have more variety.  So add those different spices to help you stay on the plan.
11) Take a stand at work.  If you are more active, you will burn more calories, so there is actually something good that is finally coming out of this list.  But as I have said before, you are very likely not going to burn enough calories to compensate for any high caloric snacks you might be eating at work.  Be more active at work or wherever you can, but watch what you are taking in too.
12) Have a Cup of Joe.  See what I said about drinking green tea as I know I am sounding like a broken record.  Sure, you may burn a few more calories, but not much to make a difference.  And if your caffeine source is a high calorie drink from Starbuck’s, or is a sugary soda, or comes from an energy drink, chances are the benefits of the caffeine was cancelled out by all the other calories you just had.  Some people may have trouble with their blood pressure or with their mood after too much caffeine, so you have to weigh that risk too.  If you still want to enjoy the coffee, minimize the caloric add-ons from milk/milk substitutes and sugar.
13) Breathe.  Let me preface this explanation by stating that I read a lot of detective and science fiction/fantasy novels.  If you were kidnapped and trapped in an underground bunker with no supplemental oxygen, your respiratory rate would naturally slow and you would start burning fewer calories so that you would be more likely to survive long enough for your favorite hero or heroine to rescue you.  Once you were rescued and able to “breathe the air” again your metabolism would return to normal as you took in more air.  For the rest us who do not have such exciting lives, however, breathing deeper will not increase your metabolism.  If you do deep breathing exercises like you might do meditation, to relieve/handle stress, you might be able to cope without eating high calorie foods, however.
14) Laugh.  Yes, you will burn calories by laughing, a whole 1 calorie per minute per a study done at Vanderbilt University (Link).  So if you were sitting listening to a comedian that actually kept you laughing for a straight 60 minutes, you could burn off about a half a slice of bread again.  See my above advice regarding stress relief.
15) Drizzle extra virgin olive oil.  First of all, there is no evidence to support that somehow eating something that contains 100 calories per tablespoon will actually help you burn more calories, period.  I did try to follow the convoluted path that someone’s brain must have taken to come up with this, and all I can figure out is that someone thought that since olive oil was metabolized (i.e. processed) differently than animal fats in the body it must somehow cause you to burn more calories.  But my mind fortunately does not take the same convoluted path.  Olive oil does not raise bad cholesterol, and having enough fat at a meal can satisfy your hunger sooner so you consume fewer calories, but you don’t actually burn more calories.
16) Get more sunshine.  Sunshine does help us make vitamin D which is essential for bone health, and low levels have also been associated with insulin resistance and depression.  There also seems to be a link between obesity and low vitamin D levels, but there isn’t any evidence that supplementing with vitamin D or getting more sunshine actually raises the body’s ability to burn calories.    Some people report less hunger when their vitamin D levels improve, but once again, their weight loss is likely from a caloric deficit, not from an increased metabolism.
Take home message—You have probably already figured it out, the only proven way to increase your body’s ability to burn calories is to exercise.  And fat loss only comes with making major changes in your caloric intake, especially if you are overeating on carbohydrate.

Monday, December 10, 2012

Where's the salt?

If you've ever been diagnosed with high blood pressure or you have a family history or condition that puts you more at risk for high blood pressure, you have probably been told to cut back on your sodium intake.  And I'm sure one of the first things that you were told was to put the salt shaker away.  But back in June you might have seen this article pop up in the New York Times questioning that "wisdom" and in my news feed I also saw another article reviewing that there doesn't seem to be a lot of hard evidence stating that merely focusing on the sodium intake does not prevent or help high blood pressure.  So does this mean those who cannot imagine having a meal without the salt shaker are vindicated?  Well, let's look at the evidence.

First of all, in my experience, a lot of people think of these different minerals as existing all by themselves.  When they hear "cut back on sodium" all they can think about is what it's the salt shaker (what I call "table salt" or a combination of sodium and chloride) but they don't necessarily think about what other foods they might also be eating that 1) contain a lot of sodium and 2) affect other systems in our body that regulate our blood pressure.  So a person may be avoiding the salt shaker, but if they are consuming a lot of breads, cured meats, fast food, canned soups, etc you probably haven't really reduced your sodium intake all that much.  So when it comes to good hard evidence that reducing sodium actually influences blood pressure, if we are looking at population studies that use those notoriously unreliable food frequency questionnaires, we maybe don't have a really good idea of how much sodium people really were taking in or how much they  might have actually reduced.  So that is problem number one is that without more double blind studies it's hard to make recommendations.

Now, we are also have to keep in mind that even if we did a double blind study, or if even one person really looks at labels to truly reduce their sodium intake, the people consuming this low sodium diet are going to wind up having to consume a lot less bread/bread products, pizza, fast food sandwiches, sandwiches with lunch meat, fried chicken, canned soups etc as listed in the linked article above.  Since they won't be eating as much processed food, they will probably have to eat meats without any added sodium (fresh meats), real cheeses (not processed), and more fruits and vegetables because they have to fill up their plate with something if they are not eating a ton of pasta at everymeal (or they get a chicken salad as opposed to a sandwich). So, they go from a diet that is sodium/carbohydrate but likely low in fiber/potassium/magnesium/calcium to a diet that is lower in sodium/carbohydrate and likely higher in fiber/postassium/magnesium/calcium.  If people make these radical changes in their diet and their blood pressure goes down--obviously the diet did change something, but it looks like more than the sodium might be at play here.

Keep in mind too that the pressure of blood flowing through your circulatory system is also regulated by a very complex interplay of body systems, and I think does a nice job of making it a little more understandable.  But what you need to know is that these complex systems are also affected by your fluid intake, your mineral intake (sodium and potassium, for example), and yes, your intake of carbohydrate foods.  For people that are already insulin resistant for whatever reason, if they eat too much carbohydrate they are going to have elevated insulin levels which can in turn impact your blood pressure. (Link)  So, if you are someone who has been consuming a lot of processed foods, maybe we do have to worry about your sodium intake, but it looks like your overconsumption of carbohydrate and your lack of vegetables is going to be a bigger problem.

So if you have high blood pressure or are at risk for such because of a family history, etc, before you remove the salt shaker take a long hard look at the rest of your intake.  If you know you're getting more than 30-45 grams of carbohydrate at a meal (that's just a ballpark number now) from bread, etc or you've been eating a lot of other processed foods, that's where you need to start cutting back or cutting out.  And if you know you're not getting a couple servings of fruit per day and non-starchy vegetables at every meal, you probably need to add those back in.  If you are still not noticing a difference in  your blood pressure (or you haven't noticed a reduction in ankle/wrist/abdominal swelling if that is a problem) then you should start using less of the salt shaker and more herbs and spices.  Give yourself a couple weeks to get used to the different tastes of things, and read more about the fascinating history of salt to get yourself in the mood for treating it as a precious commodity.

Take home message--it's your overall diet that will help control your blood pressure if you are at risk.  Concentrate on reducing the amount of processed meats and carbohydrate foods and increase fresh meats and fruits and vegetables.

P.S. Yes, there are certain medical conditions and medications that can cause low blood sodium (aka hyponatremia) but you need to check with your physician first and possibly get lab work done to make sure this actually applies to you.  Competitive athletes might also need to supplement with sodium but I've written before about how that's probably not you.

Sunday, December 2, 2012

What to do with soy?

Not too long ago I was having lunch with a new acquaintance and he asked me what I did for a living.  When I told him he wondered out loud if a lot of people start asking me questions when they find out about my chosen profession.  When I replied in the affirmative, he sighed and stated that he didnt have that problem, as he was a mathematician, and apparently not as many people found prime numbers fascinating.  Of course I get a lot of internet articles too, and someone asked me to chime in on this particular one: Dangers of Soy.

Of course, one of the things we all need to think about when reading something on the internet is the quality of the source.  Skeptoid and a few other skeptical bloggers have compiled this particular website which is a good place to start (Top Ten Worst Anti-Science Websites), but you might need to do a little bit more digging.  Another physician friend of mine beat me to it and started digging around on this particular website only to find a lot of other anti-science misinformation regarding vaccines, etc.  That is usually enough to make me want to ignore the information right there, as I would rather not give too much traffic to websites that are anti-science.

The other thing you need to do is examine how the information is presented.  One red flag that immediately jumped out at me was the phrase independent research.  Often this means that the reasearch was not accepted for peer review, meaning that there was no outside verification.  I did follow the links in this article and found that there was a lot of information on animal studies, but you cannot directly apply this information to humans.  We have peer review for a reason--not to stop people from coming up with ideas but to keep certain ideas from being taken too far.   And the physiology of humans is different than that of rats, chickens, felines, etc., so we really cannot make health decisions based on animal studies.

And just like human physiology differs from other animals, we are also different than, well, plants as well.  That might seem kind of obvious to many of us, but when people start tossing around phrases like estrogen like compounds it seems that people start thinking that isoflavones and estradiol concentrations as the same thing.  So we they talk about the isoflavone level of the plasma concentrations of formula fed infants vs. others---they are comparing isoflavone levels only, not actual levels of human estradiol.  That is like comparing the levels of iron to the levels of B12 in the blood stream--you are looking at components of cells in the blood but they are not the same thing.  We also have to keep in mind that when isoflavones do bond to estrogens in the human body it is a pretty weak bond.

The rest of the article contains a lot of other statements that are made to sound scary but we do not have the evidence to support them.  I could find some studies where they talked about soy being of concern in thyroid function because of animal studies, but it was just that, of concern.  We do not have enough information to start making doomsday proclamations.

All that said, we do have to consider what I like to call the culture of eating in the United States where we have trouble with overconsumption.  The author was right in that in cultures where soy is consumed it is usually done in MUCH smaller amounts and in different forms.  So, if a person consumes soy sausage for breakfast, soy milk in the coffee (a lot of coffee), then has soy yogurt for a snack, then has a soy burger at lunch, then has edamame for a snack (like the whole bag), then soybean oil on their vegetables in the  evening, followed up by some soy ice cream for dessert they MIGHT be getting a lot more isoflavones, phystic acid, and trypsin inhibitors than the human body has historically been able to handle. (And probably a few more pro-inflammatory omega-6 fats)  For those that do sometimes throw in a little miso soup/natto sometimes, or eat a handful of edamame (and they maybe do not even do that everyday), there really is not enough evidence to make you give that up. For those of us who are not able to consume dairy and have been using soy cheese/milk/yogurt, etc whenever you need to have some kind of dairy-like goodness, you can rejoice because there are soy free options available for those things too.

And always keep in mind this phrase from our friend Paraclesus:
"All things are poison, and nothing is without poison; only the dose permits something not to be poisonous."

Take home message--overconsumption of soy is probably not a good idea, but then neither is overconsumption of anything.   If you are not sure of where the soy might have crept into your diet, or you know that you have been consuming soy at every meal, it is time to start doing more label reading and time to get way more variety in your diet.