Studies assessing the effects of whole grain consumption within a good diet
I'm curious if there are any studies done with human subjects assessing the effects of whole grains on otherwise healthy people.
I would be very interested to see two groups of people who exercise, eat lots of natural foods with plenty of good meats and vegetables, the only difference being one eats whole grains and one doesn't at all.
The reason I'm skeptical about the "all grains are garbage" idea is that the principal of us "not being evolved" to eat grains is rather specious seeming.
You see, the pace of human evolution has sped up tremendously since the various Agricultural Revolutions we've had.
[quote]Explosive population growth is driving human evolution to speed up around the world, according to a new study.
The pace of change accelerated about 40,000 years ago and then picked up even more with the advent of agriculture about 10,000 years ago, the study says.
And while humans are evolving quickly around the world, local cultural and environmental factors are shaping evolution differently on different continents.
"We're evolving away from each other. We're getting more and more different," said Henry Harpending, an anthropologist at the University of Utah in Salt Lake City who co-authored the study.[/quote]
[url=http://www.pnas.org/content/104/52/20753.abstract]Recent acceleration of human adaptive evolution[/url]
[url=http://news.nationalgeographic.com/news/2007/12/071211-human-evolution.html]Human Evolution Speeding Up, Study Says[/url]
[url=http://johnhawks.net/weblog/topics/evolution/selection/acceleration/accel_story_2007.html#gsc.tab=0]Why human evolution accelerated | john hawks weblog[/url]
So anyway, I would really like to see a direct study on the situation of people who, within a healthy lifestyle, eat whole grains, verses people who follow the primal model. Because the argument that our ancestors didn't do it has little persuasive power when we've evolved so far away from what they were.
For instance, this study comes close to the mark:
"Although the very low-carbohydrate diet produced the greatest improvements in most metabolic syndrome components examined herein, we identified 2 potentially deleterious effects of this diet. Twenty-four hour urinary cortisol excretion, a hormonal measure of stress, was highest with the very low-carbohydrate diet. Consistent with this finding, Stimson et al31 reported increased whole-body regeneration of cortisol by 11β-HSD1 and reduced inactivation of cortisol by 5α- and 5β-reductases over 4 weeks on a very low- vs moderate-carbohydrate diet. Higher cortisol levels may promote adiposity, insulin resistance, and cardiovascular disease, as observed in epidemiological studies.32- 34 In a 6-year prospective, population-based study of older adults in Italy,35 individuals in the highest vs lowest tertile of 24-hour cortisol excretion, with or without preexisting cardiovascular disease, had a 5-fold increased risk of cardiovascular mortality. C-reactive protein also tended to be higher with the very low-carbohydrate diet in our study, consistent with the findings of Rankin and Turpyn.36 Other studies also have found reductions in measures of chronic inflammation, including CRP with a low–glycemic index diet."