It's bad enough when you hear lousy information and poor science being perpetuated by the general public. It's even worse when someone who is supposed to have education and experience in a science related field does the same thing. On today's edition of "Clinicians Behaving Badly" I want to discuss this little article that I came across last week: Dietitian Names Five Foods That Help Fight Fat.
Now, I will be the first to admit that it is entirely possible that she was misquoted or that her words were taken out of context. I have had a conversation with patients before where what I said and what they heard/remembered later were very different things. Since there is no by line--it is also possible that she talked to someone who works for a large news service and that she talked to someone in another state over the phone who in turn gave the info to someone else to be typed, resulting in a poorly written article. But if these words were pretty close to what she said, then the bad science award is definitely going to her today.
Problem number one: "Berries stimulate a hormone that burns fat." First of all, I would never word a statement that way, because I know that when I am dealing with the public I am often dealing with people who don't always have the best idea of how their body really works. A statement like that can conjure up images of a person dropping weight in a short period of time, or "all I changed was I added berries and the weight just started dropping off!" Typically our bodies are much more complex than that; the addition of one food does not change our metabolism. Since she is not available for interview at the writing of this blog, I assume she is talking about the hormone adiponectin which does help us break down fat. Unfortunately, so far this is only seems to be true if you are a rat fed raspberry ketones, and remember, humans are not rats (in case you had forgotten!), and there haven't been any human studies on these, yet. There was one small study done in Europe that indicated people fed berries did have smaller waist circumference measures, but levels of adiponectin were not measured that I could see (Link).
Problem number two: "Berries stablize blood sugar." This is another statement I hear all the time and I wish I could find a way to make it go away. It still has the connotation, in my mind, that if your blood glucose is high or low the addition of berries will "magically" bring your glucose levels to an appropriate level. Once again, it's more complicated than that. Now, are there advantages to eating berries if a person has Type 2 diabetes or some other insulin-resistant related condition? From a practical standpoint, yes, but it has to do with the volume that you eat. Let's say you had a choice between eating a cup of berries or 12-15 small grapes (both of these have roughly the same amount of carbohydrate and calories FOR THAT PORTION SIZE). Chances are if you eat the cup of berries, you will eat more by volume, and you will feel fuller, and be less likely to oversnack or overeat in general. And by keeping your carbohydrate intake under control, your blood sugar will hopefully not elevate if you have and your body will not have to produce excess insulin to keep your blood sugar under control (or cause your blood sugar to drop later because you produced excess insulin). See the difference in what I said there? Oh, and by the way, if you eat half a flat of strawberries in about a day, like some of my patient's have done, it's probably not going to help you.
Problem number three: "Researchers found eating in-shell pistachios helps trick the brain into thinking you have eaten more than you have." I assume she is talking about this particular study. Now, there is some evidence that setting up your meals and/or snacks in such a way so that they take longer to eat may help you feel satisfied with less, which is a tenant of a program called mindful eating. One of the red flags for me, however, is that once again a specific food was held up as having "magical properties" when there are plenty of other "nuts in the shell" that could be substituted and she neglected to talk about how it was likely the process of having to shell nuts that caused people to slow down and let the satiety hormones kick in. The other red flag for me is that I had a hard time finding the original study that wasn't part of a "Nut health" website and other studies that I found were also funded by organizations like the "Western Pistachio Association." Confirmation bias anyone?
Problem number four: "Schwabenbauer suggests including an egg in your breakfast to avoid cravings later in the day." She's right in that people who make a point of including protein (and healthy fats) at their meals do feel less hungry later on, but I really have a problem with the wording here. If you are just adding an egg to your large bagel, or you eat a boiled egg with a gigantic bowl of cereal, then you are probably going way over your calorie/carb limit. I would have (hopefully) said something like "Have a breakfast that includes a source of protein, like eggs, and leave the bagels and the cereal alone" if I was trying to fit that into a soundbite.
Problem number five: "The caffeine combined with a unique type of antioxidant help rev up your metabolism and boost fat burning." She is probably referring to this study done in 2008: Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Before we jump to the conclusion, let's look at the study. First of all it was done using a very small sample size, only ten people. Second of all, all the participants were adult men, we don't know if this would apply to women or not. Third, the increase in metabolism would mean that these men would have burned an extra 50-100 calories a day; would could easily be made up for by eating 1 piece of fruit, 1 cookie, 1 slice of bread, etc. I would hardly think that constitutes a huge increase.
Take home message--while there may be aother dvantages to consuming a variety of protein foods, berries, vegetables, and nuts, there is no one particular food that is going to help you lose weight. And if you are a clinician who is being interviewed, if you have enough warning try writing out your answers ahead of time or even ask if you can see the article before it goes to print to make sure you come across correctly. And remember, look for a health care person with a good grounding in science before taking their advice.