The Myth of Super Foods
After your diabetes diagnosis, you'll be much more likely to notice the never-ending stream of reports in the media about how this or that food has healing properties.
Can you really use dark chocolate to control your blood pressure and yogurt to keep your blood sugar in line?
Alas, the answer in every case is "No. Not if you actually want to make significant improvements."
In fact, quite a lot of the foods touted by their manufacturers as being "healthy" is based on research that, as we'll demonstrate below, is criminally flawed, so that eating these foods may even worsen your diabetes.
A Perfect Example of a Perfectly Flawed Study - "Soy Yogurt Could Help Control Diabetes"
This news item was distributed by the AP in November of 2006. Here's the entry I wrote about it in my Diabetes Update Blog
Soy Yogurt Could Help Control Diabetes
A more perfect example of flawed research would be tough to find.
1. The study concludes that blueberry soy yogurt "controls" diabetes because it contains more of a phytochemical which inhibits the alpha glucosidase enzyme that break down sugars than did the other fruit yogurts it was compared to.
In this study one fruit yogurt (full of sugar, of course!) is compared to other fruit yogurts containing even more sugar only in terms of how much phytochemical it contains.
Note also that there is a pharmaceutical drug that completely inhibits the same alpha glucosidase enzyme discussed here. That drug has a very weak affect on blood sugar and works only in people with very mild blood sugar abnormalities. That drug is Precose. The tiny amounts of phytochemicals found in this yogurt, of course, would have a far weaker effect than does the much stronger pharmaceutical drug.
2. The researchers drew their conclusion that this substance "controls diabetes" from the fact that the phytochemical was present in the food. They did not observe the effect that eating the sugary fruit-filled yogurt had on blood sugar.
Fruit yogurt is loaded with sugar or corn syrup. It usually contains 23 grams per serving, often more. That is enough to raise the blood sugar of most people who are controlling diabetes with diet alone into dangerous territory.
3. The researchers also claimed that soy fruit yogurt lowered ACE, a hormone involved with the regulation blood pressure, more than other yogurts. I imagine it also lowered it more than Milky Ways and chocolate cake. This does NOT make it a drug in food form. Then they used this finding about the effect of yogurt on ACE to make the claim that their sugary fruit yogurt lowers blood pressure. Again, they did not examine what happened to the blood pressure of people who ate their yogurt compared to that of people who didn't. In fact, the powerful pharmaceutical drugs that suppress ACE only work for people with diabetes when taken in doses hundreds of times higher than the amount of the phytochemicals found in the sugary yogurt.
4. One major company that makes soy yogurt, LightLife, coincidentally happens to have headquarters located near the UMASS lab doing the research. Lightlife was recently purchased by Conagra, a huge conglomerate that grows soy. The article does not disclose whether LightLife/Conagra funded this study or others being done at this nutrition lab. Want to guess if they were?
Finally, The study did not mention that soy is poisonous to thyroid glands and that people with type 2 diabetes have a high incidence of thyroid disease and should therefore avoid soy foods.
This study gives you a good idea of the techniques used to promote foods that harm people with diabetes and the skepticism you need to employ when reading this kind of report.
Does Dark Chocolate Control Blood Pressure?
Here's another example of how bad research is used to sell you damaging products. If you have diabetes, controlling your blood pressure is the next most important thing you can do to keep yourself healthy after controlling your blood sugar.
So you probably were thrilled on July 4, 2007, when you saw some version of this headline in your newspaper: "Dark Chocolate lowers blood pressure!" But before you hit the Hershey's, it's worth taking a look at the pesky details.
Here are two different online versions of the story you can refer to, each includes only part of the data released to the press:
Dark chocolate in a medicinal light
Dark Chocolate Lowers Blood Pressure, New Study
In the words of the first article: The study took "44 adults ages 56 to 73 who had untreated pre-hypertension or mild, stage 1 hypertension. Test participants were divided into two groups. One consumed a daily dose of dark chocolate; the other the same amount of white chocolate."
The second version includes an important fact omitted in the first: "Every day for 18 weeks, the volunteers were instructed to eat one-square portions of a 16-square Ritter Sport bar, or a similar portion of white chocolate. White chocolate doesn't contain cocoa."
So, after consuming their square of Ritter Sport dark chocolate every day "Systolic blood pressure, the top number, fell an average of nearly three points and diastolic dropped almost two points in the group that ate dark chocolate, compared with no change in blood pressure readings in the group eating white chocolate."
Sounds pretty good doesn't it?
But here's the kicker. In over half the versions of the story which I read online the following piece of information was omitted: Average blood pressure at the start of the 18-week test was 147 over 86. This level is high enough to be flagged as "high blood pressure requiring medication" by any ethical doctor.
These people were not given medication to lower their blood pressure. Instead, they were given chocolate. Eighteen weeks later, their average blood pressure had been lowered to 144 over 82, which I'm sure your doctor will confirm is still over the level where they should have been treated.
So here's what the journalists should have been asking, but didn't ask.
1. Why were people with damagingly high blood pressures allowed to maintain those damagingly high blood pressures for 18 weeks without being put on one of the many effective drugs that could have lowered them rather than being subjected to what turned out to be a feeble and mostly ineffective treatment?
2. Why didn't anyone ask whether German candy manufacturer, Ritter Sport, whose candy was used exclusively in this study funded this German study? If they did, why didn't someone point out the ethical issues involved in delaying treatment for high blood pressure for 18 weeks in order to promote the dubious health benefits of their candy?
I like chocolate as much as the next woman, possibly more. So, trust me, if dark chocolate had healing properties, I'd be healed!
But contrary to the headline, what this study really showed was that eating chocolate, whatever its benefits, does not provide enough improvement in blood pressure to make chocolate an alternative to one of the more effective methods available for getting blood pressure control. And when the chocolate companies are rolling out $3 chocolate bars plastered with health claims, this is worth keeping in mind.
Most "Health" Claims for Food Are Questionable
You will read about how lycopene in tomatoes cures everything from diabetes to cancer, how miracle antioxidants in blueberries, black raspberries that can cure cancer. The American Diabetes Association has gone so far as to team of with its big money sponsor, Campbell’s Soup, to convince you that their salt and chemical laden high carbohydrate juices should be part of your diabetes diet.
In the face of such claims? So what are you to do?
The answer is simple: Ignore them. There are no magical "healing foods." There are a lot of foods you can fit into your diet without raising your blood sugar to damaging heights. There are healthful micronutrients in fresh, unprocessed vegetables, low carb fruits, meats, and cheeses. Eat a wide variety of them, make sure to get lots of greens, and you've pretty much done what you can do. If you can grow your own vegetables in a garden, do it. Those fresh picked and home-frozen vegetables are among the very best foods you can eat. If not, don't stress, but eat a wide variety of foods from different places.
And when you see this kind of self-serving "research" promoted in the media write to the people who published it asking why they did not reveal who funded research and why they did not make it clear that this flawed research was conducted as part of an advertising campaign.