Stanford biostatistician talks about saving your aging brain

http://scopeblog.stanford.edu/2011/06/qa-with-stanford-biostatistician-on-how-to-save-your-aging-brain/

Previous studies have shown that eating berries can boost brain health. How can certain foods slow the brain’s natural aging process?

Three major food choices affect our brain function. The first is total caloric intake, which dramatically affects both lifespan and cognitive decline. In animal studies, for every 2 percent reduction in total calories, we see about a 1 percent to 2 percent extension of lifespan. So reducing calories by 20 percent gives about a 10 percent to 20 percent extension in lifespan. There is a limit: 100 percent reduction doesn’t work. Up to 50 percent calorie reduction appears to extend lifespan.  In the island of Okinawa in Japan, more people live to over 100 years of age than anywhere else in the world. Their rates of stroke, cancer, dementia and other age-associated diseases are among the lowest in the world. Why? While many factors may contribute, caloric restriction appears to be one of the most important. In the course, we’ll look at effective ways to reduce caloric intake.

The second is the type of fat we eat. The type and amount of fat you eat determines:

• The number of dendrites and synapses in your neurons
• The type and amount of neurotransmitters your neurons produce
• Your ability to learn
• Your mood
• Your risk of stroke, Alzheimer’s disease and Parkinson’s disease

Good fats (polyunsaturated fats such as omega-3 fatty acids) are major components of our neural synapses and the mitochondria that produce the energy our neurons need. Insufficient omega-3 can contribute to loss of cognitive abilities as well as to early death from heart disease. Saturated fats and hydrogenated fats are bad for your brain.

Carol Greenwood, PhD, at the University of Toronto has studied the effects of fat on the brain.  In one set of experiments, Dr. Greenwood fed rats diets containing up to 10 percent saturated fat and tested their learning ability. The result: The rats’ ability to learn fell directly with the amount of saturated fat in the diet. For rats on a diet of 10 percent saturated fat, their learning ability was near zero. The average saturated fat in Americans diets? About 11 percent.

The third food choices with major effects on our brain function are the antioxidants. This is where berries come in. Many studies in animals show that high levels of anti-oxidants can greatly extend lifespan and maintain cognitive function. However, for humans, achieving these benefits probably requires more antioxidants that we get from food sources. In the course, we’ll talk about which supplementary sources are effective.