Misleading Diabetes News Reports
It seems as if almost every day there's a news story about diabetes, and most of these stories include misinformation and hyperbole.
The hyperbole occurs when some study shows a small difference in blood glucose control or a small difference in the risk of diabetes when some factor or other is given to a group of people, or just a group of mice.
A good historical example is oat bran. Studies, many of which were sponsored by companies producing oat bran, showed that fiber reduced cholesterol levels. Suddenly, every product on the supermarket shelves, except perhaps toilet paper, trumpeted "Contains oat bran!" as if eating small amounts of oat bran while continuing to shovel in tons of unhealthy pizzas and cheesecakes would make you immune from heart disease.
A current example is a study showing that coffee increases BG levels in people with diabetes. Some people are considering depriving themselves of the pleasure of a cup of coffee or two in the morning. But if you look at the research paper cited by the journalists (which unfortunately, isn't available online unless you pay for it), you'll find that the study subjects had a "standard breakfast" containing 90 g of carbohydrate. This is equivalent to 6 carbohydrate exchanges, a lot even by ADA standards.
After this breakfast, participants who also ingested caffeine went up to about 175 mg/dL; those without caffeine peaked at 171. Big deal! The caffeine drinkers also went up more quickly and came down more slowly, so the total area under the curve was significantly different, after an "ad lib" lunch and dinner as well as the huge breakfast. But they also seemed to be going lower at bedtime (not low; just lower: 117 instead of 126) with the caffeine, and the researchers didn't measure overnight levels.
Cutting back on their carbohydrate intake would have resulted in much larger changes in blood glucose levels than cutting back on their caffeine intake. But this was never suggested. Instead, they concluded, "The presence of hyperglycemic effects in these free-living individuals raises concerns about the potential hazards of caffeinated beverages for patients with type 2 diabetes. Repeated episodes of elevated glucose readings from daily consumption of caffeinated beverages could impair clinical efforts aimed at glucose control and increase the risk of diabetes complications."
Of course the conclusions are what the journalists and popular medical journals will read and trumpet to the world. I can imagine headlines saying things like "Caffeine causes diabetes complications." So some patients reading these stories will stop drinking coffee with their doughnuts, but they'll keep on eating the doughnuts. It's sort of like the people who order a triple cheeseburger and double fries and a diet soda.
Another example of bad information comes from the surprising announcement recently that the ADA now supports low-carb diets for short-term use in weight control.
"Prior to the release of the 2008 recommendations, the ADA did not support low-carbohydrate diets for diabetes management due to a lack of evidence supporting their safety and effectiveness," said one story.
It's true that no one has ever done a randomized double-blinded study of low-carb diets over 20 or 30 years. No one has ever done such studies of low-fat diets either, or of any diets at all. Such studies are almost impossible because you'd know what you were eating, and no one would want to eat anything but some liquid formula for 30 years. But the press release implied that it's known that low-fat diets are safe.
Then they went on to say, "According to the U.S. Centers for Disease Control and Prevention, people who have pre-diabetes can avoid diabetes if they lose 7 percent of their body weight and get more than 150 minutes of activity a week."
This is not true. The Diabetes Prevention Prevention program showed that people who lost weight had a 58% lower risk of progressing to type 2 diabetes (4.8 cases per 100 instead of 11). They didn't all lose 7 percent of their body weight; that was the average loss at about 6 months and they then tended to regain weight until the total loss was smaller.
Some of those who lost weight progressed to type 2 diabetes anyway, and most of those who didn't lose weight didn't progress to type 2 diabetes. You can't always prevent or avoid type 2 diabetes. You can just reduce your risk. The original article in the New England Journal of Medicine uses the more accurate term "delaying or preventing" type 2 diabetes, to indicate that the outcomes aren't guaranteed. The press picks up on the "preventing" and that message is what remains in the minds of the public.
Another problem with these news stories trumpeted by newspapers and TV newscasts is that in many cases, these studies are done in mice, which have a different metabolism from ours. In the wild, they tend to eat cereal grains and insects and don't get a lot of fat. "Sand rats" (actually a type of gerbil) eat primarily a particular plant (the salt bush plant), and when brought into the lab and fed a high-fat diet, they develop diabetes. When returned to their native diet, the diabetes goes away. This is often cited as proof that diabetes is caused by a high-fat diet.
But we're not mice.
Alaskan Eskimos eating a native diet eat a high-fat diet and don't get diabetes. If they ate nothing but salt bush plants, they'd most likely get sick. Does this mean that eating a lot of plants causes disease? I don't think so.
One particular strain of sand rat has been used to investigate the genetics of obesity and diabetes: "This discovery has proved that obesity is largely genetic. Research has shown that it is possible for the rodent to have a litter of 3 to 4 individuals all with different genetic composition; one pup would overeat and develop obesity, another pup would overeat and develop obesity and diabetes, others would just develop diabetes or neither. So by environmental manipulation it provides excellent study of the genes involved because the differences in the animals have to be genetic differences."
But to return to the headlines, because we're not mice, we have to take these daily headlines that shout something like "Eating fried grasshopper tongues prevents diabetes" with a grain of salt.
A recent headline, on Science Daily, was "Natural Purple Pigments In Fruits, Vegetables And Berries, Such As Blueberries, May Help Prevent Obesity." I wonder how many obese people will now have to face friends and strangers who will tell them that if only they'd eaten more blueberries instead of Big Macs, they'd be thin now.
Yeah, right. When you read the story in full, you find that actually the fruits aren't as effective as extracts of the fruits. In fact, according to the original article abstract, the mice given a high-fat diet plus blueberries ended up fatter than the control mice given a high-fat diet without fruit. It was berry extracts that made the mice thinner. They don't say in the abstract how much thinner the mice with the berry extracts were, and I think this type of study is silly enough that I'm not about to pay to read the full text.
Last week everyone was babbling about an equally silly -- in my opinion -- study saying that drinking diet sodas made rats fat. There could be a lot of explanations for this effect in rats, and like mice, rats have physiologies that are different from ours.
Furthermore, for people with diabetes, the effect that drinking regular sodas would have on blood glucose levels would undoubtedly outweigh the effect on appetite and weight gain.
A lot of studies showing that ingredient X reduces the risk of diabetes or helps control blood sugar or reduces the risks of obesity are sponsored by a food manufacturer that sells X and is looking for any possible evidence that will help it sell more of its product. Even when the results are in rats and mice and the effect was miniscule, the headlines will blare that "Eating Gretchen BrandTM Apple Pies Reduces Risk of Diabetes." This is what they want.
So what should you do? I'd suggest reading all these stories, packing the information away somewhere in the deep recesses of your brain, and then pretty much ignoring it until we get some confirmation that there's a significant effect in humans. Use your meter and see how various foods affect you.
Remember that the news media is always looking for news. They're going to take small results and turn them into sensational headlines. You're smarter than that. Read with caution.
More posts by Gretchen:
The Golden Age of diets? What dinner looked like in the '50s
Cholesterol and Diabetes: Could HDL be bad for you?
Opium-den prescriptions? Diabetes treatments way back when