Short-Term Diet Gains Hurt Long-Term Health

CHICAGOEvolution has trained our bodies to sacrifice long-term health to meet short-term needs for survival when diets are only modestly deficient in one or more vitamins and minerals (micronutrients), according to Bruce N. Ames, Senior Scientist at Childrens Hospital Oakland Research Institute, and Professor at the University of California, Berkeley. In a presentation at the Natural Health Research Institutes (NHRI) symposium on the cost effectiveness and safety of dietary supplements on Nov. 18, 2010, he said science has taught us that we need about 30 essential vitamins and minerals to survive, but most Americans are not getting enough for long-term health.

He referenced the Centers for Disease Control and Prevention (CDC) National Health and Nutrition Examination Survey (NHANES), which found that a significant percent of Americans are moderately deficient in iron, magnesium, folate, zinc, calcium, omega-3s and vitamins B6, C, D, K and E.

Such moderate lack of micronutrients may be contributing to an increase in age-related disease, he said, citing studies that show moderate deficiency of folic acid causes the same chromosome breaks in DNA as radiation from X-rays, zinc deficiency increases oxidative stress, and magnesium deficiency induces DNA-protein cross-links. Additionally, research has shown that not getting enough of any one of various micronutrients (e.g., calcium, vitamin D, potassium, vitamin B12, selenium, omega-3s, niacin, choline) is associated with either chromosome breaks, cancer or other diseases of aging.

Ames micronutrient triage theory, grounded in an evolutionary theory of aging called the disposable soma theory, posits that recurrent shortages of micronutrients during evolution caused natural selection to develop rebalancing mechanisms to protect micronutrient-dependent critical functions on shortage. Rebalancing favors micronutrient-dependent proteins needed for short-term survival while those only required for long-term health are starved. This impairment, he said, results in damage that, over time, leads to the acceleration of age-associated diseases. However, in the short term, we are able to survive and fulfill lifes demands. Nature wants us to be strong to reproduce; then nature doesnt care what happens," he said.

To test his theory, Joyce McCann and Ames evaluated published evidence on the relative lethality of 11 known mouse knockout mutants to categorize the essentiality of 16 known vitamin Kdependent (VKD) proteins (Am J Clin Nutr. 2009 Oct;90(4):889-9070). Results indicated that eliminating any one of six VKD proteins was not immediately lethal, but resulted in age-associated conditions. For instance, mice without the matrix Gla protein (Mgp) suffered increased arterial calcification linked to cardiovascular disease, mice lacking osteocalcin exhibited bone fragility after estrogen loss, and transforming growth factor beta-inducible protein (Tgfbi or beta-ig-h3) elimination increased spontaneous cancer and caused mitotic spindle abnormalities. Because these proteins need more vitK for optimal function than VKD-proteins required for coagulation (an essential function required for short-term survival), McCann and Ames concluded that impairment due to moderate vitK deficiency may be responsible for the associations observed between modest vitK deficiency and arterial calcification and bone mineral density loss. McCann and Ames have just completed a similar analysis of published evidence on selenium deficiency (October 2010, to be submitted for publication), and also find supportive evidence for the triage theory.

Thus, Ames said that such modest deficiency in critical vitamins and minerals needed for long-term health could be behind much of age-related disease we face today. He said convenient supplements can be a step to reducing this problem, and current recommended daily allowances should be reviewed on the basis of triage theory.  He noted Diet is really the big thing," and said that adopting a healthier eating pattern would greatly increase the health of the population.