This was a large, long-term study. (74,341 women from the Nurses’ Health Study, 43,990 men from the Health Professionals Follow-Up Study, 25 years follow-up). Those who ate the most vs. the least whole grains lived longer.
Study: Association Between Dietary Whole Grain Intake And Risk Of Mortality, Two Large Prospective Studies In US Men And Women, JAMA Internal Medicine, 5 January, 2015
Press Release: More Whole Grains Linked With Lower Mortality, Harvard School of Public Health, 5 January 2015
Whole grains included “brown rice, dark breads, whole-grain ready-to-eat cereals, cooked cereal, popcorn, bran, and other grains.” I left out “wheat germ” from this quote because they did not find a benefit for it.
Eating bran had an especially strong effect, as did replacing meat with grains:
Eating more whole grains is associated with up to 15% lower mortality – particularly cardiovascular disease (CVD)-related mortality. … Bran intake was linked with a 20% lower CVD-related mortality. … Swapping just one serving of red meat with one serving of whole grains was linked with a 20% lower CVD-related mortality.
They didn’t have to eat much:
“For each serving of whole grains (28g/day), overall mortality dropped by 5%, and by 9% for CVD-related mortality.”
28 grams is just one ounce, about 1/3 cup of dry oatmeal.
Dr. Qi Sun from Harvard, an author of this study, said whole grain eaters “did have much healthier habits than non-whole grain eaters, but our model controls for that.”
Related study: Dietary Fiber Intake And Total Mortality: A Meta-Analysis of Prospective Cohort Studies, American Journal of Epidemiology, September 2014, “In conclusion, high dietary fiber intake may reduce the risk of total mortality.” They found a 23% lower mortality risk for eating high fiber, especially cereal fiber.
If it’s true that eating whole grains makes us sick, as several diet book authors claim, why do people who eat the most live the longest?