October 21, 2010
Another Study Against Refined Grains
Don't eat that white bread or pasta.
BOSTON (October 20, 2010) - People who consume several servings of whole grains per day while limiting daily intake of refined grains appear to have less of a type of fat tissue thought to play a key role in triggering cardiovascular disease and type 2 diabetes, a new study suggests. Researchers at the Jean Mayer USDA Human Nutrition Researcher Center on Aging (USDA HNRCA) at Tufts University observed lower volumes of Visceral Adipose Tissue (VAT) in people who chose to eat mostly whole grains instead of refined grains.
“VAT volume was approximately 10 % lower in adults who reported eating three or more daily servings of whole grains and who limited their intake of refined grains to less than one serving per day,” says first author Nicola McKeown, PhD, a scientist with the Nutritional Epidemiology Program at the USDA HNRCA. “For example, a slice of 100% whole wheat bread or a half cup of oatmeal constituted one serving of whole grains and a slice of white bread or a half cup of white rice represented a serving of refined grains.”
The whole wheat wasn't protective for those study participants who also ate a lot of refined grains. So the whole grains aren't so much beneficial as just not harmful or perhaps less harmful than refined grains.
Paelo Diet advocate Loren Cordain says avoid grains. Stephan Guyenet says grain preparation techniques make a difference in determining whether grains are good or bad for us. Whole grains might even be harmful, but less harmful than white bread.
I have been off bread and pasta since February. I've been off all honey and non-natural sugars since Feb 2008. I quickly lost 10 pounds when going off just the refined sugars and then gained them all back within 10 months. Frustrating.
In Feb 2010 I additionally went off all carbs for three weeks and then very gradually added minimal non-refined carbs. I lost 27 pounds and have not gained any back. Key difference in the outcome is that now I don't "antici-taste" (gustatorial anticipation-sensing) food items with my eyes anymore. It's not a reduction in apatite...it's a cessation of food imaginings.
At first, the difference in glycemic index looks like the culprit, but the following study -
"Dietary glycemic index and load, measures of glucose metabolism, and body fat distribution in older adults"
- may indicate that something else is responsible for body fat deposition/distribution.
Could maintaining a tourniquet around the hips for 30 years influence fat deposition and retention. In other words, does wearing a belt to hold up one's pants cause a medical affect that causes or exacerbates the deposition of male pattern midriff fat? One could do a retrospective study of cultures that have similar demographics/ecographics but just don't wear belts to see if there is a difference in fat deposition patterns. FYI, I have stopped wearing belts. I never liked them anyway.
Correlation/causation. Is this study even adjusted for class? If not, it's probably no good. Even if it is, those who eat this way are probably more solicitous of their health in general. I don't have time to look at the paper but I'll give an 80%-confident guess that it's virtually worthless. There are so many potential confounds here that this work probably isn't worth doing except as a prelude to interventional study.
Somepuns gonna getcha.
I eat white bread and pasta regularly and am completely healthy. I think people pay too much attention to these fad studies. There's only one rule one must apply to their eating habits: everything in moderation.
It's a pity they didn't compare the effect on visceral fat of avoiding grains entirely. It would have been an interesting result.
@David Gobel: I subscribed to the belt theory myself for a while. Now I wear a much smaller belt, and it gives me no problems at all. ;)
@TheLastBrainLeft: That's what I thought prior to the surgery. In fact, consumption of high amounts of wheat and grains in the fad, if you compare it to the historical norm, as Dr. Cordain and others have done.
@FuturePundit: Keep up the good work. The answer's not always in the future. ;)
After my father's first heart attack (big history of arterial disease in the fam) in 1965 at the age of 32, he was on 30 years of no fat (read no protein), high carb (pastas, etc) diets of one form or another. Cholesterol and body weight always up. Then, after his third heart attack and subsequent bypass, a young doctor put him on the Atkins diet. He not only lost 40 pounds, but his cholesterol went down over 100 points without meds. Kept it off for 10 years. Now, the researchers are even poo-poo-ing the effects of cholesterol......
I stopped listening to any declarative statement that begins with "Studies show...." a long time ago and am much happier for it.
I never trust these studies. They all seem so self serving. What if they found the opposite results. Their raison detre would be destroyed -- and funding. In 10 years they'll find they made a mistake and it will be some other fad of the day.