Tuesday, April 30, 2013

People are Bananas--Part 3

Part one of the coverage of this infographic covered here.
Part two of coverage of this infographic is covered here.

17) Help body deliver oxygen to the brain.  Bananas do not do anything special to carry oxygen to the brain, but you do have to have unblocked arteries so that you can get blood, and therefore red blood cells, to carry oxygen to the brain.  What we have here is a repeat of #14 again in that a higher potassium intake might reduce your risk of stroke.

18) Fights depression and anxiety.  Bananas do contain serotonin, and some people who have depression have a shortage of this, but the serotonin found in the banana does not cross the blood-brain barrier.  If someone has been eating poorly, eating a banana or another carbohydrate rich food might give them a temporary sense of well being, but it won't last.  Bananas could be worked in to an otherwise healthy meal plan to help overall depression but they are not a cure unto themselves.

19) Reduce menstrual pain.  Bananas do actually contain B6, which has been used to treat dysmennorhea or "painful periods."  But keep in mind that the supplement given contained 200 mg of vitamin B6, and bananas only contain 0.4 mg.  So, unless you want to try to down 500 bananas a day during your period you might want to just try a supplement (and let your doctor know what you are doing). (Link).  I have actually seen some people mention that the potassium in the bananas helps; I think what happened is that they heard about a medication called diclofenac potassium, which is an anti-inflammatory drug used to treat dysmennorhea, and made the leap that some how the potassium would help.

20) Reduces itches and pain of bug bites (peel).  Lots of anecdotal information on this one, but no studies that I could find.  I wouldn't recommend trying this if you have already scratched and have an open wound though.

21) Anti-inflammatory.  If the inflammation is in the digestive tract, as in a condition like Crohn's disease, bananas may be one of the foods that doesn't aggravate the problem at least (Link).  If your problem is a condition like rhuematoid arthritis, or you are worried about arterial inflammation increasing your risk for a cardio vascular event, there isn't any evidence.  I was also amused to find on certain complimentary medicine boards that people were actually calling bananas pro-inflammatory!

22) May prevent kidney cancer.  Some observational studies, and if you have been reading my blog for a while you will know that observational studies are only useful for finding correlations for further study, showed a lower risk of renal (kidney) cancer with a higher fruit and vegetable consumption period.  I have had some patients who will only eat bananas, so I guess whatever works for you to help increase your fruit and vegetable intake.

23) Help curb sugar cravings.  If you reach for a small banana instead of the bag of cookies, you might be able to satisfy your desire for something sweet with less calories/carbohydrates.  But if you are like me you better clear the sweets out of the house in the first place.  You will also need to think about what is causing the craving in the first place--like waiting too long to eat, not eating an adequate amount of protein and good fats, etc.  I wish there was a special substance in the banana that helped me eat better, but there isn't.

24) Prevent age related macular degneration.  Eating a variety of fruits and vegetables will help, but bananas aren't necessarily the best sources of the vitamins and minerals focused on by eye specialists.

Whew.  If you are still with me you are waiting for today's take home message--Bananas are good sources of potassium which might help reduce risk of stroke and related problems, but there are other lower calorie/carbohydrate ways to do so.

Monday, April 29, 2013

People are still bananas--Part 2

Are we ready for Part 2 of the misleading infographics like this one?  Covered the first section in this post.
9) Anti-diabetic.  A substance that is anti-diabetic is something, usually a drug, that actively lowers the blood glucose.  Since a banana, like any other fruit, contains carbohydrate it will actually raise the blood glucose levels.  A seven inch banana will contribute roughly 15 grams of carbohydrate so it will need to be counted as part of your meal time allotment if you are controlling your levels with diet; once again each person will have to test his/her own blood sugar to determine if this is a safe food.

10) Enhance nutrient absorption.  I wonder which ones they are talking about?  Possibly they are talking about the vitamin C in bananas helping with iron absorption?  If so, there are plenty of other fruits and vegetables like oranges, apples, red peppers, etc that can do just as well.

11) Fight obesity.  How exactly do they do that I wonder?  I have seen some websites talk about how the fiber in the banana is satiating, but then in the next paragraph they will turn around and state that they are easily digested and good for weight gain.  Small bananas could be part of your fiber allotment, but the contribution to satiety is variable and of course bananas don't cause you to burn more fat.  Since bananas do come in a variety of sizes I have seen people have more trouble working this in to their calorie/carbohydrate allotment.  

12) Heartburn remedy.  There was a small study done in India back in 1990 hat used a banana powder to treat GERD, but that is not the same as eating a whole banana.  Anecdotally, some people complain of worse GERD symptoms after eating bananas.  If you are unable to handle too much fructose, like yours truly, it could be that the resulting intestinal gas puts pressure on the lower esophageal sphincter.   There does not seem to be any harm in trying the banana powder for GERD as long as you are working to find out what is causing the problem.

13) Help maintain regular heartbeat. If your body is depleted of potassium (hypokalemia) you could develop an irregular heart beat, but potassium depletion is usually caused by illness (think of a bad bout of diarrhea), or by a medication (think of someone with advanced heart failure who takes high doses of diuretics to keep from retaining fluid); potassium depletion is rarely caused by lack of it in the diet.  Quite often people who take certain diuretics need to take potassium supplements because they cannot eat enough bananas or other potassium foods to keep up with the losses.  One should never take a potassium supplement (other than the little bit found in a multivitamin) unless you are under the direction of a physicican as a dangerous condition called hyperkalemia (too much potassium in the blood) could result (and that will definitely cause irregular heart beat).

14) Reduce the risk of stroke. Looks like this is referring to an observational study published about 11 years ago noting a correlation between higher potassium intake and lower risk of stroke.  Of course we have to remember that correlation does not equal causation, as even the authors of the study said, and remember that you can also get potassium from all meats, fish like salmon, avocados, apricots, legumes, leafy greens, etc.  I suppose bananas might be a convenient source for some, but not the only one. (Link)

15)  Reduce symptoms of nicotine withdraw.  I was unable to find any good evidence here for the various nutrients found in bananas actually helping.  Some people do experience nausea, vomiting, and/or diarrhea as part of the withdraw, however, and the potassium found in the bananas could help replete the losses of potassium.

16) Lower blood pressure.   This is related to #14 in that your potassium intake helps, but there are other foods besides bananas that you can eat.

Take home message for today--bananas can be a convenient source of potassium, of which an adequate intake is needed to possibly lower your risk of stroke and help control blood pressure.  Banana powder might help people with GERD.

Friday, April 26, 2013

People are still bananas--Part 1

Have you ever longed for that one perfect food that would cure everything?  I have, even though I know it's not rational, and I don't seem to be alone, particularly when I see graphics like this:
Looks like I have another two or three parter here.  Ready?

1) Anti-diarrheal (green banana).  One small study done in Bangladesh indicated that rice and cooked green banana seemed to reducethe amount of diarrhea and need for oral and intravenous rehydration fluids. (Link).  Would this work in adults as well?  And does it work for people with chronic diarrhea from conditions Irritable Bowel Syndrome (IBS) as well as diarrhea from a virus and/or bacteria? Doesn't seem to be any evidence against trying this as long as the green banana is cooked and mashed, you are still watching out for signs of dehydration in the child or yourself, and you are actively working on eliminating the cause of the diarrhea.

2) Provide energy.   This is one of those vague statements used by makers of infographics that doesn't seem to mean anything.  Do they mean provides glucose which many people (except for those on ketogenic diets) use for fuel?  Well, yes, bananas provide that, as do any other fruits or grains, so there is nothing special there.  Do they mean provide a special burst of energy?  Well, yes, many people will eat carbohydrates (or overeat on carbohydrates) to provide a "burst" of energy, but see above on other fruits.   So, nothing to see hear people, let's move on.

3) Help circulation.  I have a feeling what they are getting at here is that people with poor circulation do want to make sure that they are getting enough B-vitamins in their diet.  Once again, bananas do have b-vitamins, but they don't own the rights to it.  Here is a chart that gives a brief overview of food sources for vitamins/minerals including the "B" ones. 

4) Fight infections.   This seems to be another intentionally vague phrases that makers of infographics love to use.  As I said in this post, "I think in this context, the definition they are trying to employ is "The invasion of the body of a human or an animal by a pathogen such as a bacterium, fungus, or virus. "  and " Infections can either be localized, as in the case of sinusitis, or they can be a nasty systemic infection (often called "blood poisoning)."  So what kind of infections are they suppossed to fight?  Possibly they were thinking of a substance that is derived from bananas that is looking promising in the treatment of HIV, but that is a pretty big leap to say bananas fight infections.  I have seen anecdotal stories of people using banana peels to treat wounds, but considering that bananas can carry bacteria like pseudomonas and most of my patients with wounds are immune compromised I would not recommend this.  I did find a small study that showed good results using banana leaves--but after the preparation was made the banana leaves were put through an autoclave to kill bacteria.

5) Protect skin from damage from U-V light.  This one seems to be patently false.  There was a small study done using strawberry extract on skin cell cultures in Spain (Link), but no bananas seemed to be harmed in that study.  There was speculation that the anthocyanins in the berries might be what protected the cells, but bananas do not contain the same abundance of these.  And remember, we are dealing with 1) an extract as oppossed to the whole fruit, 2) it was applied topically as oppossed to consuming/taking internally, 3) it was a strawberry, not a banana, 4) bananas do not have as high an anthocyanin content, 5) the study was done on cell cultures, not actual humans. 

6) Anti-ulcer. If someone has peptic ulcer diseaes (PUD) or gastro-esophageal reflux disease (GERD), foods with greater acidity often cause more pain when eaten, so a lower acid banana would be much better tolerated than an orange.  Unfortunately, there are no good studies to indicate that bananas actually help knock out the bacteria (H. pylori) that cause ulcers.  I did see one claim that bananas contained anti-viral agents, which means they wouldn't work on bacteria.  The other claim I saw was that bananas contain serotonin to help regulate gastric acid production; yes, you do actually have sertonin in your GI tract cells, but there is no serotonin in food.  Your body MAKES serotonin when you eat carbohydrates and also from tryptophan when enough carb isn't present.

7) Suppress prostate gland enlargement.  Maybe, except according to this small study you have to 1) take a banana peel extract, 2) be a castrated mouse taking large doses of testosterone.  Might want to study that one a little bit more.

8) Suppress oxalate kidney stone formation (banana extract).  At least this time they pointed out that there was an extract used (every time I see that, I wonder how many bananas you would have to eat to get the same properties, and it's probably an unrealistic amount).  Once again, this might work if you are a rat, but we don't know what this will do for humans. (Link)

Will cover the other points over the next couple days.  So far, however, the anti-diarrheal properties of cooked green banana are all that's holding up.

Tuesday, April 16, 2013

Grizzly diet?

I'll have to admit, my Skeptic senses were tingling when I saw the title of this paticular post: Grizzly Bears May Have Diet Lessons that are Helpful for Humans.   I was a little worried that someone was going to suggest that needed to meditate to find my guardian animal, or that I strap on Wolverine-like claws and start hunting for my own food and eating it raw.  Instead, I actually saw some evidence-based reminders about how I as a bipedal mammal have my behavior impacted by my environment, and what kind of things I could do help make changes that would help me better control my weight and weight related illnesses.   Let's summarize those lessons.

1) Removing processed food is a good thing.   By removing the loaves of bread, dog food, etc from the bears diet they got rid of a lot of empty calories--thing that might fill you up but provided little to no nutritional value.  The substitutes actually contained much for fiber and other vitamins/minerals the bears apparently needed.  We homo sapiens could stand to cut out our meats with fillers and white bread and substitute more fruits and vegetables as well.

2) Having to work harder for your food can also be good thing.  If you have a tennis ball sized orange and a 1/2 cup of orange juice, your calorie and carbohydrate intake will be the same.  But you have to peel the orange, remove the pith, chew on the sections, spit the seeds out, etc.  You will probably be satisfied with that orange when you are done with it.  If you have a 1/2 cup of OJ you will probably knock it back in a couple of swallows and then go looking for more (and you won't get the fiber to add satiety either).  So, eating food that takes longer to eat may help you be satisfied with less.

3) Working harder for your food can be a good thing.  Once the bears had to forage they expended more energy, and we humans could stand to do more of that.  The closest most of us get to foraging however is wandering through the supermarket and moving around our kitchen to cook, so we should probably do that more often instead of going through the drive through.  And if you are like me (a lazy person with good intentions), you might do something like I did last night, "Well, I could cut up some potatoes and make oven fries to go with the grilled burgers, but I don't feel like it.  I'll just have some pickles as a side and then I can save time and feel good about the carbohydrate I've saved."  (You all may not be as lazy as me, but you hopefully get the "work harder/eat less" thing I was going for.)

4) Creating scarcity can be a good thing.  If it's not there and you don't have ready access to it, you are going to be less likely to eat it (particularly if you are a captive bear).  If you are someone who typically lies awake thinking about the cookies in the cabinet, you probably need to not have the temptation available.

5) Being active can distract you from overeating.  Looks like humans aren't the only creatures who eat when they are bored.  You might have to be creative, but try to find something to keep you from oversnacking.  One of my patients who was limited w/transportation and funds made a point of taking the bus to the nearby library on a regular basis.  She loved to read, it didn't cost her anything at the library, and she couldn't eat in the library, so that worked out well for her.

6) A "trapped" animal eats what it can to survive.  These bears were obese because they ate whatever was available to survive, and the caretakers did not "punish" them but instead helped make changes in the environment so they could be healthier.  This is more of a lesson for health care providers I suppose; in other words, you need to consider the persons circumstances, motivation, funds to buy foods, etc. before coming up with some creative ways to change the environment together. 

Take home message--Making changes in your eating environment can influence your choices and help you meet your health goals.

Monday, April 15, 2013

Portion Distortion

Back when I used to teach classes for diabetes and weight loss, one of the questions I would get went something like, "So, should I concentrate on what I'm eating or how much I'm eating?"  The answer would be "Yes!" if I could tell that they liked my snarky sense of humor, and "I'm sorry, but you need to watch both" if they were a more staid group of people.   I would always encourage them to measure out what they were eating at least once and read the label so they would really have an idea of how much they were eating.  If they didn't read the labels and take a serious look at how much they were actually eating they were essentially letting someone else do the thinking for them, and as a result they would probably wind up eating things that would probably not be to their benefit for losing weight and/or controlling their blood glucose levels.  (And then they would be whining in my office about how they were "eating everything you told me and I still can't control my blood sugar.").

Let's face it, there are very few of us who say "Yay!  I love to read labels and measure out my food at least once!"  Quite often that's what will sell people on a particular diet plan or diet product is that you don't have to count calories or carbohydrates, and of course I've seen some authors of diet books or "nutrition bloggers" actually go so far as to mock people who still count calories or think about their carbohydrate intake.  I will agree that being worried about eating one more gram of carbohydrate is not my idea of good quality of life.  I will also happily concede that for people who do follow a simple plan of eating a high satiety plan of adequate protein, good fats, and vegetables that they probably can do more of an amorphous "just eat until you are full and listen to your body" plan and still meet their health goals.   But does the latter approach really fit and evidence-based way of eating?

Not initially, no.  If you are a newly diagnosed diabetic/pre-diabetic, or you are attempting to follow a carbohydrate controlled plan to lose weight, you may not even know how much carbohydrate is in certain foods, let alone where they are "hiding" in foods you thought might be "safe" (like in the beef jerky I almost bought yesterday!).  So you will have to carefully read the labels for everything, at least once, to figure out what is safe for you and what is not.  And then when it comes to the carbohydrate foods that do have nutrition that you would like to include, like fruit and sweet potatoes, etc, those still contain calories and carbohydrates so eating too much can still interfere with your goals.  So you will need to measure out the berries or whatever you are eating at least one time (and test your blood sugar before and after if applicable), to see if the amount you are eating is safe for you.  

And once you've gotten a handle on what's working, are you suddenly exempt from monitoring your portion sizes?  Probably not, particularly if you a) like to try new foods and new combination of foods, b) have not perfected the "I'm going to stop eating even though this is tasty" routine, and/or c) like to eat in restaurants sometime.  As an example of "a," one time I had signed up to receive a monthly sample of snacks that were suppossed to be safe for people like me who are dairy/gluten/soy free.  One of the snacks included was a brownie made with nut flour, and when I read the label I noticed that that roughly 2 inch brownie contained about 250 calories.  I could have eaten a handful of nuts and consumed roughly half that amount of calories.  I paid for it, ate it, and enjoyed it, but I certainly wouldn't have made a habit out of it.  And that relates to "b."  Boyfriend of SkepticRD is very good at stopping when full, I am not, so I have to be careful with portioning out my plate ahead of time to make sure I don't eat too much.  This in turn, is related to "c," in which I have to ask for certain things to be left off my plate or ask for a takeout box right away so I can portion appropriately (and then I also have to remember to take my box with me!).

All this talk about portions, and how so many of us don't pay attention, was actually inspired by this article that popped up in my news feed today.    Because after I would get done reminding people about the necessity of reading and measuring (at least once!  And when you try a new food!  Or if you are having trouble losing weight!) we would talk about some of the ways people could judge their portion sizes in a restaurant, etc, and a lot of times we would use the odd hand signals that were demonstrated in a video.  But what they don't explain, and this is what I would try to explain in the classes, is that these portions are not just arbitrary, they were established to help people have some sort of standard for measurement.  I'm sure some of you who have had diabetes for a long time or who have done Weight Watchers remember the Exchange Lists and how you could have "x" number of servings from each food group, and each portion said 1/2 cup of this, and 1/3 of a cup of that?  The reason for these portion sizes is that someone had the job of taking all the different foods and making each one into a portion size that had roughly the SAME amount of calories and the SAME amount of carbohydrate.  That's it.  It's just a unit of measurement--meaning that we needed some sort of standardization so we could quickly tell how much carbohydrate we are getting.  Same thing with some of the goofy hand signals, it's just a unit of measurement.

Now, I know that some of you who dealt the exchange system are clutching your pearls and fainting, because you were probably given a plan that contained way more carbohydrate than what was safe for you, and of course the plan you were given said nothing about the quality of food you were eating.  I wish people didn't have to go through that, but I hope you can see that the real intention of all of this is to just to try to give people a way to keep track of what they were eating.  It was never meant to be a tool to chastise people.  Have we all stopped hyperventilating for a bit?  Good.

Back to the unit of measurement, this is also useful for determining how accurate someone is when they are saying "food X has more of this or less of this than food Y."  For example, I remember watching one Facebook thread where someone wondered if quinoa was actually better for people with diabetes because they thought it "didn't have as much carbohydrate."  Another person who had been diabetic for a long time said "no" and I thought (I wasn't feeling brave enough to jump in at the time), "She's asking the wrong questions!"  What would have been a better, albeit more involved series of questions, would be to ask "How much carbohydrate can I safely tolerate at a meal?" and "How much net carbohydrate is in 1 cup [1 fist sized portion]"  and "Can I handle eating that much or does the portion look too small?"  I would say "I can handle roughly about 30 grams at a meal" and "One cup will give me about 34 net grams of carb, so I'll probably do more like 1/2-3/4 of a cup" and "As long as I have my protein and vegetables mixed in with that it will be a satisfying meal."  Yes, it does take more work to go through that, and I can see why some people just leave it alone, but after you've been thinking this way for a while the right questions pop in your head easier and you answer them faster too.

Take home message--Just watching what you eat is not enough, you still have to watch how much.  You need to get an idea of how much of something you can safely eat, and use whatever technique works for you to keep track.

Friday, April 12, 2013

Can eating breakfast really help me lose weight?

My last post was, essentially, about using the right kind of language to convey information and what can happen if we as health care people do not choose our words carefully.  I saw another example today that could be titled "why I am afraid to talk to the media if asked."  It happened in this article about eating breakfast, particularly this paragraph right here:
"This first meal of the day is what can influence your appetite the rest of the day. When you skip the morning meal, it can have a huge effect on your metabolism,” she said. “By skipping breakfast, you’re kind of sabotaging yourself the whole day. You’ll have no control over your appetite and you’ll tend to overeat at lunch and at your evening meals and snacks. This can lead to weight gain. It’s best to distribute all your calories throughout the day — over four to five meals or snacks a day. To lose weight, you must really eat." (emphasis mine).

So let's talk some science to see what's wrong with this phrasing.

I think when most people hear "metabolism" in this context they are really thinking "how much fat a person is burning/how many calories am I burning off," but metabolism encompasses a lot more than that.  Metabolism is something that includes all the physical and chemical processes that your body goes through to keep you alive, including keeping your heart pumping, etc.  What is really being referred to here is a related concept called the metabolic rate, which basically relates to "How much food do I need and where should I get it from?"  Or as I like to put it, "how much can I eat of different things and still meet my health goals?" and most of my patients put as "How much of different types of food can I get away with eating and still lose weight/control my blood sugar, etc").  Now the other problem is that we really do not have any good human studies that indicate that eating breakfast actually boosts your body's metabolic rate (Link).  Sure, part of our metabolic rate does come from what is called the Thermic Effect of Food, but's it's only roughly about 10% of our metabolic rate, and that's really only going to make a difference if we just stop eating period.

So, why the emphasis on eating breakfast?  One possible reason is that many of us are used to eating a diet that contains way more carbohydrate (particularly the refined, low nutrition things), that what is really good for us, and remember carbohydrate converts to glucose faster than fat or protein.  Of course, we need to produce the hormone insulin to actually allow our bodies to use that glucose for energy, and more glucose means more insulin.  Your glucose supply starts to fall (while you've still got plenty of insulin left in your blood) and you will hungry.  As a result of this whole process (which I just gave a super-simple version of), your body gets used to having a ready source of glucose available for energy, and it's become less adapt at tapping into any fat reserves you might have.  When you wake up in the morning after not eating for several hours, you will probably feel a little sluggish until you get some more carbohydrate (aka glucose) in your system.  And some people try to skip that morning meal because they are trying to lose weight, or they are in a hurry, and they don't take anything to eat with them, and they don't realize how bad they feel until someone at work brings in donuts, and then their lack of energy overwhelms their judgement, and then they've eaten 3 or 4 donuts.  A couple hours later your supply of glucose is depleted again, and you haven't packed a lunch, and by now potato chips sound good, etc.  Now, what some of you are thinking is "Alright SkepticRD, I'm going to cut all the refined carbs out of my diet, start bringing my own snacks and my own lunch, and stop my dependence on so much glucose!  And that way if I'm in a hurry or don't feel like eating breakfast, my body will just tap into those fat reserves!"  And I'll say "Good for you for wanting to do better!" and then I'll remind you that the reality is that you have been dependent on that glucose for a long time, and that it may take days (sometimes weeks, sometimes years!) for your body to become so efficient that you can skip meals without feeling super hungry and wanting a quick source of glucose.  (So, yeah, you better plan on having that vegetable omelette with a little fruit in the morning or grabbing that handful of nuts or eating that Greek yogurt in the morning in the mean time).

Another reason for the emphasis on eating breakfast is that depending on where you are at in life you might need to spread your intake out through the day.  If you are a growing infant/child/adolescent, and trying to be an active one at that, you probably need to eat at least three times per day to provide enough protein/good fat/calories to meet your needs.  If you are part of that "older adult" group, and maybe you haven't eaten so healthy throughout your life, your body might not absorb nutrition as efficiently as it once did, and it's better to spread out the food a little.   If you have any kind of GI condition, you might only be able to handle so much food at one sitting without feeling cramps or nausea, so it's better that you spread it out through the day.  And then there are those of us who do have to take some kind of medication for one reason or another, and you'll need to eat something to keep the medicine from upsetting your stomach.

Does the type of breakfast you have in the morning make a difference?  It seems to, and the reasons are related to that whole glucose dependence thing I mentioned above.  Let's say you have a large bowl of bran cereal in the morning or you have a smoothie that is just a bunch of fruit (in other words, all you had was carbohydrate).   First of all, you didn't have hardly any good fat or protein to speak of at that meal, so you are probably going to be hungrier sooner (and those donuts will be tempting).  If you have a history of Type 2 diabetes or prediabetes (or in my case, a strong family history of insulin resistance), you will probably get a surge of insulin to shuttle all that glucose out of the blood, and then 2-3 hours later those donuts are going to start looking really good again.  If you make a point of having the above mentioned veggie omelette and fruit, etc), you will get less of a glucose/insulin surge and you will have that protein and fat to provide a longer lasting feeling of fullness.

Take home message--if eating a protein rich breakfast seems to help keep you from overeating the rest of the day, eat breakfast.   But don't expect it to change your metabolic rate.

Wednesday, April 10, 2013

Chemistry is Complex

One of the main tasks of my job is to understand our wonderfully complex body processes and explain them in such a way that someone without a biology degree can understand them.  (Or as one of my elderly patients said, “I think like a truck driver, not a doctor.  You explain things in ways that I can relate to.”).  It’s fun, and not without its challenges, as sometimes I have greatly overestimated the person’s desire to learn (I’ve had to deal with a lot of “mandatory” patients over the years) or because the analogy simply was not part of that person’s world (getting older and more experienced helps with that).  Since I am constantly working to better convey these concepts of how our bodies work, I have developed a list of pet peeves regarding the use of certain phrases that are used by health care types that I think convey the wrong idea to our not so science literate public.  One of those phrases is that of “complex carbohydrates” usually coupled with “needed for energy.”  I have dealt with this subject before, but as I keep seeing this phrase pop up and it still makes me mad I wanted to complain again in more detail.
A “complex carbohydrate” is merely a chain of three or more single sugar molecules linked together, colloquially known as “starch.”  It’s a description of how molecules are put together, period, end of story.  It says NOTHING about the impact on our blood glucose levels (i.e. how slowly they are digested), the nutritional value of those foods, or the fiber content.  A “simple carbohydrate” on the other hand, is a chemical structure with only two sugar molecules linked.  Once again, it is a description of how the molecules are put together, period, end of story.  Let's think about it this way--the sugar molecules are a bunch of beads, and a complex carbohydrate is a bunch of those beads woven together, like these:
That's a fairly complex pattern( (to me anyway), but what you have is a bunch of beads held together with string.  And now let's think of the simple carbohydrates as a bunch of beads strung together in a very simple bangle, like this one:
 That's a much more simple pattern, but it's still a bunch of beads on a string.  Now, if I dipped the woven bracelet in some type of acid--it would dissolve the string and the beads would scatter.  If I dipped the bangle in the same acid--it would also dissolve the string and the beads would scatter, maybe somewhat faster, but not really.  You're still going to have a bunch of beads (aka sugar molecules) flying around. 

Now, whenever I would teach the diabetes classes and use this metaphor, I would still get a lot of protests (mostly from people who had been taught all the wrong things about carbs before) that went something like "But don't complex carbs digest more slowly?"  So then I would point them to the glycemic index--(non-diabetic) people were fed 50 grams of carbohydrate of various kinds of carbohydrate containing foods, blood sugars were checked at various intervals, and then the foods were assigned a rating from 0-100 (100 being a very sharp increase in blood glucose).   What happened was some of those foods that are labeled as "complex" (like whole wheat bread) actually had a glycemic index above 50!   (Link) The "complex" structure had nothing to do with how it affected the blood glucose.  The next question I would get would usually come from people who had had diabetes for a while (and/or used insulin to control their blood glucose readings) would sound like "But why was I told to use a simple carbohydrate when my blood glucose was low [hypoglycemia]?" or "Why do crackers raise my blood sugar just as well as drinking regular soda?"  I would (and still do) basically make the excuse that "What they really meant was 'eat 15 grams of carbohydrate in a form that you can chew/swallow very quickly.'" And then I would launch into how once their blood glucose was normalized and they were thinking straight, they would actually need to figure out what happened to keep that from happening again. 

Oh yeah, I would also point out that the GI was figured out using non-diabetic subjects.  If you have diabetes, you will probably still have a different reaction to what's "on the list."  You need to test your blood glucose levels when you try new foods or eat different levels of carbohydrate.  There isn't an easy way around it if you want to figure out what's right for you.  It can also give you a little more flexibility in what you eat.  Boyfriend of SkepticRD, for example, normally does very well with limiting his carbohydrate intake, but on a very rare occaision someone will bring in Krispy Kreme donuts, and they call his name, and he is able to compensate with his short acting insulin.  Now, I am NOT advocating this as a daily thing (nor is he, but it's his body), as that can result in some serious weight gain, which means more insulin will have to be taken overall.  And people with Type 2 diabetes who are not treated with insulin would have to have a spike in blood glucose, and have to deal with the weight gain, and have to deal with the complications of chronically spiking blood glucose.  So, if you have diabetes, when it comes to carbohydrate of any type--test, test, test, and control, control, control the amount you eat!

I know some of you are already wondering "well don't complex carbohydrates have more nutritional value?"  Not necessarily.  Remember, white bread, crackers, and pasta are considered "complex" carbohydrates, but the only nutrition they have is some fortified B vitamins and extra calories.  True whole grains and legumes fare much better on the fiber, b-vitamins, and potassium--but they aren't always better for blood glucose control.  Fruits are technically "simple" carbohydrates (as the predominant form of carbohydrate is fructose), but they also have more fiber and higher nutrition density than complex carbohydrates like pasta.   

Next question that I'm sure is popping in your head is "Don't I need "complex" carbohydrates for energy?"  Technically, no, unless you are a hard core athlete who is depleting your reserves.  If you get enough protein, good fat, and vegetables, your body can make glucose (fuel) from those nutrients (and you can also get fuel from ketones if you are not a poorly controlled Type 1 diabetic and have some fat reserves to use up, so to speak).   If you have difficult to control blood glucose and/or need to lose a lot of weight (or have severe GI problems), you might do a lot better if you stick with minimal carbohydrate from vegetables.  Now, we also live in a carbohydrate centric culture, and some of us (me) like to have the variety that whole grains and legumes provide.  As long as you are not having GI issues, as long as you are staying w/in your blood glucose range, and as long as you are meeting your weight goals (or other health goals), there isn't any reason why you can't include these.  If eating a bowl of "whole wheat" pasta just leaves you feeling hungry an hour later or you find yourself wanting to eat the whole pot of organic heirloom rice on a regular basis (not that I know what that is like), then you are probably shooting yourseslf in the foot and need to make some changes.

Take home message--complex and simple are mere descriptions of how molecules are linked together, it doesn't send a message on health.

Tuesday, April 9, 2013

Can Fat Slim Down the Appetite?

A crucial part of of maintaining a new eating plan is eating in such a way that you can feel fuller longer and still take in less, a concept that we health care people called "satiety."  One of the ways that people can achieve satiety is to make sure that they are actually getting adequate fat in their diet, as fat is one of the things that slows down the emptying of our stomachs.  If the emptying of our stomach is slowed, it will take longer to get to our bloodstream, and there will be a smaller increase in the production of hormones like insulin which can stimulate the appetite (that was, once again, a really simple explanation of a very complicated process).   It has also been proposed that one of the reasons people report increased satiety when they switch to a carbohydrate controlled plan, such as Atkins or Paleo, is because people have added fat bck in to their diet and therefore the above stated happens.  They are, of course, probably eating a lot less carbohydrate per day (I had one friend who figured out he was eating the equivalent of 13 cups of pasta per day before he went on Atkins), so they are not getting the same elevations in insulin, etc.  Historically people on these type of plans have tried to avoid trans-fats and overloading on omega-6, but otherwise the diet contains more saturated fat (and monounsaturated) then they probably were eating before.

I have to admit that I have been guilty of thinking "fat slows down the emptying of the stomach so all good fats must increase satiety" and stopping right there.  I had a few other studies/reminders, however, remind me that satiety seems to be more than just the action of slowing down the emptying of the stomach.   Last week I attended a lecture given by Dr. Deborah Clegg from UT Southwestern, and she discussed a study she had authored in which palmitic acid, a type of saturated fat, did not seem to promote satiety as well as unsaturated fats.  In the lecture she talked about how this actually makes sense from an evolutionary (aka human as an opportunistic omnivore) standpoint; if you eat whatever you can when you can get it, and what you can get is animal fat (which contains saturated fat), then it wouldn't make sense for you to fill up after a few bites.  Now, a few caveats about the study; first of all we can all see that it was done in rats and not in humans, so there is something here to speculate about for human studies later.  Second of all, the authors of study acknowledged that people in the United States tend to eat a lot of carbohydrate with their fat, so the rats were given a controlled amount of carbohydrate as well as different infusions of fat.  (Oddly enough I was able to figure that one out by reading this dialogue between one of the study authors and a blogger who had said some very caustic things about the study before it was pointed out that the media reports and the studies are not the same thing).  Third, I will admit that my reading of the study was tempered by reading a more recently released human study in which olive oil had a higher satiety value over butterfat (and it was mixed in yogurt, which also contains a certain amount of carbohydrate as well).

So let's summarize--when people eat a high fat and high carbohydrate diet all of that carbohydrate seems to stimulate you to eat more and all that fat makes it taste so good that it makes that tasty food harder to resist.  When the amount of carbohydrate is controlled (and the amount in the yogurt could have been anywhere from 7 grams to 12 grams--about 1/2 a small appple to a whole small apple--still less than a donut or a hamburger bun), the olive oil seems to provide more satiety than the butterfat.

So what do we do with this information?  First of all we realize that something has to give.  If there was a choice between the newer version of the Atkins diet (meaning you eat animal protein, fat from a variety of sources, and vegetables) and the so-called Standard American Diet (animal protein coupled with excessive carbohydrate and trans fats), it looks the Atkins diet would be a better choice for satiety.  (Keep in mind that in the first phase you are eating in such a way to promote ketosis, which also suppresses the appetite).  If you throw a more Meditteranean diet in there--animal protein, lots of olive oil, vegetables and frt, only whole grains if you eat them, this might actually work out to be a good compromise (of course you won't get the appetite suppressing ketosis, and you don't get free reign to eat all the brown rice you want either).  I think it's also important to keep in mind that someone who is eating animal fat from feedlot sources is going to be getting fat that has a different fatty acid composition that grass fed beed and foraging pigs; so if you aren't paying the extra money for the grass-fed stuff you can use the lean cuts and use olive oil to cook with, etc.   Third, we should keep in mind that what worked for a group of people that had limited access to food might not work the same for people who have easier access to food, and maybe we just need to have a nice variety of good fats to help promote satiety and not just eat animal fat.  Fourth, we also have to keep in mind that scents/smells/tastes may also impact our satiety (as is speculated with the olive oil).  Fifth, we have to acknowledge that some of us eat past the point of satiety and we still need to work on behavior change and controlling our environment.

Take home message--less carbohydrate and adequate fat might promote physical satiety, but it looks like it couldn't hurt to include olive oil as a regular fat source if you are trying to lose weight.

Monday, April 8, 2013

Surgery Diet without Surgery?

When a person who has been defined as morbidly obese has been unable to lose weight via conventional methods he or she might turn to weight loss surgery.  If the person has Type 2 diabetes he/she might elect to have Gastric Bypass Surgery as the rapid weight loss after this surgery often results in a rapid normalization of blood glucose levels (and some people are able to remove oral diabetic agents and insulin from their regimen).  The diet one has to follow when one is post Gastric Bypass, however, is very strict as one hopefully wants to avoid vomiting and/or diarrhea from eating too much period or too much of the "wrong" thing, and wants to avoid the expanding of the pouch so you wind up gaining the weight back.  Since the diet is so strict, some scientists have been doing studies to attempt to determine whether it's just the diet or other factors associated with the surgery that help blood glucose levels (Of particular interest to me is the research being done on alteration of absorption as it pertains to gut microbes.

Such was the reasoning behind this small study that was done at UT Southwestern, and it indicated that the diet itself has quite a bit to do with the reduction in blood glucose levels.  One of the obvious limitations of this study is it's small sample size, but I'm not going to spend this post critiquing the study; instead I am going to complain about the inaccurate reporting of the diet in this particular news post.  The only description of this "strict" diet was this:
"During each of these observations, which lasted for 10 days, the volunteers consumed less than 2,000 calories total each day - the customary diet for gastric bypass surgery patients."

Well, yes they did consume fewer calories.  But let me tell you what else you have to do, particularly in that first six months post surgery.  You have to make sure that you get your daily requirement of protein in so your body can heal, so your protein source is eaten first.  Your portions are measured out carefully before you even sit down to eat.  If you have no room for your starch, you don't eat it, unless you want to have nausea and vomiting.  You make sure that you chew each bite 25-30 times and make your meal last 20-30 or longer so you can let the salivary enzymes and chewing action aid in digestion so you don't have nausea and vomiting.  You don't eat anything that is deep fried because you will have (guess what) nausea and vomiting.  You don't have anything with added sugar, because that will give you nausea, heart palpitations, and diarrhea.  You don't have any caffeine or alcohol because that will irritate the stomach pouch and you will either be having heart palpitations (caffeine) or be intoxicated (alcohol) because of the rapid absorption.  So, if you are one of those people who don't find nausea/vomiting/diarrhea as part of your list of top ten fun things to do, you have some pretty good incentive to eat less period and severely limit your carbohydrate, hence the falling blood glucose levels.  On the slightly less scary side, when someone's carbohydrate intake (and intake period) is that restricted after surgery the person might go into ketosis which supresses the appetite (that's why breath strips on the pre-surgery shopping list I give to patients).

So the point that I hopefully made in the above paragraph was that saying that they merely just ate less than 2000 calories per day is a gross misrepresentation of what a person has to go through post surgery and the "added incentives" they have for actually sticking with the diet.  The potential complications/risks are also why gastric bypass surgery is still seen as a "last resort" for a lot of obese individuals (and why people need to go into it as informed as possible, and have a variety of evaluations by a variety of health care professionals); on the flip side, it is also why some individuals have the surgery because they feel like they need that extra incentive to stay on the plan (it certainly isn't the "easy way out" that some people think it is.  And why Dr. Lingvay made this comment:
"Unfortunately, such a restrictive diet is nearly impossible to adhere to long-term in the absence of bariatric surgery. We found that the success of bariatric surgery is mediated through its ability to control food intake, which in turn has a beneficial effect on diabetes."

I'm sure of you are wondering if there isn't a "half-way" point for your self or a love one who has both type 2 diabetes and has had difficulty losing weight.  I would say if  you could find a to engage in the eating habits listed above MOST of the time (e.g. measuring your portions, eating protein first, only eating a little starch at the end of the meal if you are still actually hungry, etc), then you might be able to accomplish your goals without surgery.  In other words, if you would put as much work into your diet as a post surgery person does, a lot could be accomplished even without the negative feedback.  There are some people who elect to have the surgery as they still are not able to lose to their goal weight, or because they want the "negative feedback," but that is a decision between that person and their physician.   (Keep in mind too that I am talking about people whose weight is causing a health crisis, not someone who just needs to lose a few pounds.  Someone who needs to lose a lot less weight [and maybe isn't diabetic] might be able to get away with making much more gradual changes and still lose weight).

Take home message--Losing weight and controlling your blood glucose levels takes hard work and is a major lifestyle change if you want to keep that weight off; said changes go way beyond the reduction of calories.

Thursday, April 4, 2013

Probiotics for Everything!

Since I have been trolling a particular website for bad info-graphics this week, I have been witnessing the most amazing leaps in logical fallacies.  Since some of these graphics actually contain a grain of truth, I have been having fun playing "How much truth distortion can we fit in?"  Want to play too?  Good, let's start with this info-graphic on one of my favorite topics:
Since this is a favorite topic/pet peeve with me, yes, I have written a similar post before.Not feeling like following links today?  Ok, let me summarize.  Pro-biotics that we take over the counter or in yogurt, etc are usually seen as foreign bodies and eliminated as waste.  The only strong evidence we have for the use of pro-biotics is when they are given to someone who is on antibiotics--they can form a temporary "shield" against unfavorable bacteria until the person ceases the course of antibiotics and gets a chance to start repleneshing by eating pre-biotic foods.    Now to the game:

1) Treats infections.  I think in this context, the definition they are trying to employ is "The invasion of the body of a human or an animal by a pathogen such as a bacterium, fungus, or virus. "  It seems as thought the creators of this graphic have started with the assumption, however, that all "infections" are caused by bacterium, and they are skipping over the whole "virus" part.  Anti-biotics can only be used to treat BACTERIAL infections and not viral infections, otherwise you wind up with antibiotic resistance.  Second, infections can either be localized, as in the case of sinusitis, or they can be a nasty systemic infection (often called "blood poisoning).  So what kind of "infection" are we talking about here, and would I really want to mainline yogurt for sepsis (no).  There is a limited amount of evidence that pro-biotic suppositories can be used to treat vaginal yeast infections, but that evidence is mixed (Link).  And I have noted that some sites that recommend the vaginal suppositories usually have to spell out that the pro-biotics need to be placed directly in the vagina.
Your point? Not all infections are bacterial, and the thought of pouring pro-biotics into my sinuses is really grossing me out.  Oh sorry, there's only limited evidence for treating vaginal yeast infections.

2) Prevents eczema.  We actually have a repeat of point one, in that eczema is another all encompassing term for a variety of different skin conditions with a variety of different causes.  Anytime you see that substance "A" is suppossed to treat a wide spectrum of things you should be suspicious.  I am also trying to figure out how taking pro-biotics could actually prevent, let's say, someone from reacting to a shampoo additive, and they probably just need to not use that shampoo anymore.  And then there was this rather frightening little notation about how people with eczema and certain autoimmune conditions actually developed life threatening conditions while taking pro-biotics.
Your point? You are going to be much safer figuring out the cause of the eczema and removing the offending agent.

3) Decreases the Severity of Colds and Flu.  Well, they might actually be on to something here.  We have one little study done on college students that did assign a placebo or a pro-biotic supplement during a cold outbreak, and those on pro-biotics did report a reduction in symptoms.  Apparently the study was randomized and double-blind which is positive.  Of course, one of the things that was pointed out in the press release was that a particular strain of pro-biotics was used for this study as oppossed to someone just buying whatever came off the shelf (or whatever was cheapest). (Link)
Your point?  If you don't have any other conditions that would preclude the use of probiotics, then taking this particular strain if you have a cold might provide you with some symptom relief (but not a cure).

4) Treats Irritable Bowel Syndrome.  Once again, we have another positive leaning "maybe" here.  There have been some small studies, including randomized ones, that indicate a relief of symptoms with both diarrhea and constipation dominant IBS.   I will throw in an anecdote/caveat, however, that in a real world situation, someone who has IBS might be changing his/her diet (i.e. eliminate the foods that are aggravating the IBS) along with taking probiotics, and then it becomes harder to determine whether it was really the probiotics or the diet that treated it.  Let me throw in one more anecdote if you don't mind--as a person who likes to minimize what I have to "take," I found that my symptoms are controlled with diet and that probiotics are not necessary (and actually cause more gas/bloating when I take them).  But for those that are still having problems after changing their diet (or who have trouble changing their diet for whatever reason) I could see how the potential for treatment would be welcome.
Your point?  If diet changes do not improve your IBS symptoms, probiotics might be worth a try if you continue with your diet changes.

5) Prevents diarrhea.  And now we have a repeat of point one and two!  Diarrhea from what?  From a viral illness?  From a food borne illness?  From a medication reaction?  From eating something that you know normally gives you diarrhea?  Here, let me repeat myself again--The only strong evidence we have for the use of pro-biotics is when they are given to someone who is on antibiotics--they can form a temporary "shield" against unfavorable bacteria until the person ceases the course of antibiotics and gets a chance to start repleneshing by eating pre-biotic foods.
Your point? It can prevent diarrhea from a specific cause only.

6) Treats painful inflammation. I think whomever created this graphic was trying to see how many vague conditions they could fit into one space.  Since the term was "painful" inflammation it appears as though the reference is to arthritis pain, possibly a type of rheumatoid arthritis which is often characterized by painful, swollen joints.  I could only find one study, non-peer reviewed and not done in humans that pertained to this, so I can't draw any conclusions here. (Link)
Your point? Might help with inflammatory bowel disease, but not with arthritis.

7) Helps maintain a healthy immune system. Covered that here, second to last paragraph. 
Your point? If you want to sell something, claim something about the immune system.

Tuesday, April 2, 2013

Liver Function

Mis-info graphics are usually present on social networking sites, but some weeks seem to be worse than others.  Here is the latest one that I came across:

I think it's time we talk a little bit about basic liver anatomy and physiology.

Here's your basic diagram of the liver pulled  from the internet:
Image index.thumb.f7118aa51bb8322295b3a21b1824d955v1_abs_446x360_b3535db83dc50e27c1bb1392364c95a2.jpg
Your liver is located in the right upper abdominal area, and on the diagram you can see a larger right lobe and a smaller left lobe separated by a band of connective tissue that binds the liver to the abdominal wall.  Within the lobes are lots of smaller liver cells called lobules, and between the lobules are canals that carry blood and bile, which are in turn connected to the portal vein.

Blood from the digestive organs flows through that portal vein and carries nutrients, by-products of medications/vitamins/herbal supplements, and by-products of metabolism that would be toxic if allowed to remain in the bloodstream.  Once these substances reach the liver cells they are altered/detoxified and then either stored or passed back into the blood or released to the bowel to be eliminated. For example, whenever we eat a protein-rich food like an egg, the protein is broken down into amino acids in the stomach and intestine, then those amino acids flow down the portal vein to the liver, then in the liver the amino acids are further broken down and either stored in the liver as glycogen or sent out to the bloodstream.  That whole process then forms ammonia (toxic) which the
liver converts to urea (less toxic) to be eliminated by the kidneys.

And that is a really, really basic overview.  For a more extensive review on the liver's role in blood clotting, breaking down damaged blood cells, bile production for fat breakdown/absorption, blood glucose regulation, vitamin storage, cholesterol synthesis, hormonal modification, etc you can go here: National Liver Foundation.

So, your liver is performing it's many, many important functions, including detoxification, 24/7.  It will do this without you eating brocolli or drinking green tea.   To say that these foods/beverages cleanse the liver implies that there are substances just hanging around in between the liver cells just waiting for a person to eat cauliflower or drink green tea so that the liver can actually do its job.  Fortunately your liver will keep working just fine whether or not you drink green tea, etc.  Of course, these foods provide other vitamins, minerals, that are important for our body to function, but they are not "liver sweepers."

Unfortunately, the liver, like any other organ, can become diseased, in my practice I usually see alcoholic liver disease and hepatitis C, but those are only two of the many different diseases out there. When someone has a diseased liver, the only things that can be done to preserve liver function is to remove the offending agent (e.g. stopping all alcohol), possibly starting anti-inflammatories like prednisone or other agents, and in some cases a liver transplant a la Larry Hagman.  I would love to tell you that drinking green tea, etc would help the remaining part of the liver "work harder," but that simply isn't true.

Take home message--Eat your fruits and vegetables to get your vitamins without loading up on calories.  Don't expect cleansing from an organ doing just fine though (or get redemption from your years of drinking too much).

Monday, April 1, 2013

More soda not-so-infographics

Some of you might remember this post that I did about soda (or soft drinks, or pop, depending on where you are from) several months ago.  The major conclusion, for those of you feeling too lazy to follow the link, is that regular soda is an easy way to overload on sugar--therefore, avoiding soda can help reduce the chance of sugar-overload problems like excessive body fat, poor blood glucose regulation, and tooth decay.    1-2 diet sodas per day might be ok but it's hard on the wallet.  For me--show me good scientific evidence that an excess of one thing causes problems (e.g. soda is a calorie bomb influencing weight gain) and I will consider that good enough.  Apparently I am in the minority, however, as I am still seeing articles like this one: This is what happens when you drink soda.  Some of the claims I have written about before, but there was enough new material that I thought I had to make a comment or two (or eight).  Ready?

1) Brain.  I love how these articles never seem to provide a link to the actual study, or at least a summary.  Probably because if one does actually link to it, you will not always find things to support your premise.  The "study" reference 1) utilizes a high saturated fat/high sugar diet, not just a high sugar diet; 2) doesn't say (in the blurb anyway) where the sugar and fat was coming from; and 3) was a study conducted in rats and not humans.  So, 1) we don't know if the reduction of BDNF comes from saturated fat, sugar, or the combining of the two; 2) there are different kinds of saturated fat out there--was it from meat/coconut/chocolate, etc, and what form did the sugar take; and 3) humans aren't rats.  I definitely see some potential for more research, and a few alarm bells going off,  but I can't make any recommendations based on a non-human more-than-just-excessive-sugar study.

2) Teeth.  I already talked about the problems with regular soda and problems with EXCESSIVE phosphoric acid consumption here.  Unfortunately they are making statements in this article that are patently false, particularly the one about diet soda having a lower pH that regular--it doesn't take more than a quick Google search to find out that on average regular sodas have a lower pH than diet sodas.  Oh, and while we are on the subject, battery acid has a pH of 1.0, so regular and diet sodas with a pH of 2-4 are obviously not as acidic if you have a basic knowledge of chemistry.  Also, for your entertainment pleasure, I found this little study in which slices of freshly cut tooth enamel were soaked in sodas for 48 hours straight, and then a spokesperson from the American Beverage Association (obviously with their own bias) had to point out that this doesn't mimic "real life" conditions  (no saliva to buffer, etc), and I had to say the beverage dude has a point--it's hard to take recommendations seriously when you haven't noted your own flaws.  Oh, and while we are on the subject of acidity, let's talk about dosage here.  If you followed the link that has the pH values--I noticed that two of my favorite add-ons, lemon juice and vinegar, have a lower pH than any of the sodas listed (and think of all the people who claim that apple cider vinegar cures everything!).  Now, granted, if I would actually drink a soda I'd probably get more of an infusion of acid that when I put the vinegar all over my salad; but I'm not drawing a false equivalency of saying "all things that are acidic are bad."  (Yeah, I've had people who do drink enough regular soda that they probably do have it in their mouth for most of a 24 hour period, but can you apply these same statements to 1-2 diet cokes per day?  Likely not).

3) Heart.  Have I pointed out the problem with observational studies lately?  Like, how they usually rely on unreliable instruments like food frequency questionaires in which people have to try to remember how much soda, etc they've consumed (when they probably have trouble remembering where they put there car keys at)?  Have I also mentioned that correlation does not equal causation?  Observational studies have a purpose--to establish a link so we can do a controlled study later on.  Period.  Amazing how people forget this when they have an agenda to push--but remember it very quickly once someone attacks their favorite food.  Moral of the story here--I'm not making recommendations based on someone's memory--and neither should anyone else.

4) Lung.  Already covered the whole sodium benzoate thing previously as well, and with the development of COPD we are right back to the "observational study" and "correlation does not equal causation" statement again.  Just as an FYI, however, if someone already has COPD, particularly if you are already requiring oxygen, if you consume excessive amounts of carbohydrate from any source you are going to increase your carbon dioxide load--in other words your breathing is going to become even more difficult.   If you have COPD, and you happen to be getting excessive sugar from soda--you probably want to cut back on that or cut it out.

5)  Bones.  I know, you've already read the link before where I talked about this.  So, maybe it is the phosphoric acid, or maybe it is just because you have a crummy diet overall and don't do any muscle building exercise.  Or maybe all of the above.  It's worth thinking about, but I would hate to concentrate on someone's soda intake, particulary if it's limited anyway, and not think about what else they might be missing.

6) Kidneys.  Observational study, covered the acid thing before, etc.  Now, another FYI for you, if you have end stage renal (kidney) disease and are on dialysis, you have to limit your phosphorus consumption period (so no colas, but no dairy or nuts either).

7) Digestive system.  They are on to something here, but we are talking about one section of the population (which unfortunately includes me)--people with irritable bowel syndrome.  So, yes, if you already have trouble with bloating and flatulence (and the pain that comes with it), and you don't want to make it worse, you probably want to avoid carbonated drinks.  Some of us with IBS do not tolerate fructose very well (meaning that you might get diarrhea or constipation bloating) from excessive fructose, so avoiding high fructose corn syrup sweetened things is also a good idea (unfortunately I also have to avoid too much fruit as well).   The sweeteners in the sodas, however, are not usually known for having a laxative effective.  The confusion probably stems from the fact that many "sugar-free" candies, etc, contain sorbitol or other sugar alcohols which can have a powerful laxative effect (that's also why prunes and prune juice can help laxation, because of the sorbitol content). 

8) Weight.   Take is excess calories and carbohydrate from anything, particularly in liquid form so that you really don't feel full, and you will gain weight.  Death "caused" by soda on the other hand?  Maybe if a pallet of soda crushes you, you could say that.  And interacting with genes that regulate weight?  Perhaps they were confusing that with interacting with hormones such as insulin which play a prominent role in appetite?  Some of us are genetically predisposed toward insulin resistance, but that's thanks to our parents, not because of soda.

Take home message--Regular consumption of "regular" soda will make weight control, blood glucose control, and dental health extremely difficult because it is a readily available source of excess carbohydrate.  Consuming more than 1-2 diet sodas per day might be problematic, but the evidence is much weaker.  And "evidence" that is false or misleading is not evidence.