Many of the physical changes that we know as aging can be traced to accumulated damage caused by compounds called free radicals. There's growing evidence that aging changes are produced by free-radical reactions and that the addition of one of a number of different antioxidants in the diet can increase the average life span.

Researchers now believe that the average life expectancy could be extended by five years through dietary modifications. Researchers now believe that the average life expectancy could be extended by five years through dietary modifications and the addition of antioxidants to the diet. The primary antioxidants in this regard are vitamin C, vitamin E, the carotenoids, selenium, and zinc. Choose foods rich in these nutrients (fruits and vegetables) and take antioxidant supplements as a back-up plan. Limit consumption of foods that generate free radicals (such as fried, processed, and high-fat foods) as well as meat and processed vegetable oils, a source of trans-fatty acids. Instead, focus on longevity power foods such as cruciferous vegetables, soybeans, green tea, and garlic.

Will low calorie diet dramatically extend your life span? It does not look like it. Severely restricting calories over decades may add a few years to a human life span, but will not enable humans to live to 125 and beyond, as many have speculated, evolutionary biologists have found in recent studies. Scientists have known for six decades that cutting the caloric intake of rodents by 40 percent or 50 percent results in dramatically longer lives for them. However, scientists have found the results are not quite as dramatic in humans. While the relationship between how much you eat and your life span is not so dramatic, there are very real costs of being overweight -- including greater risk for heart disease and other life threatening illnesses.

The aging process begins in our 20s, but the signs don't start showing up until our 40s. The sooner you grab onto your health and vitality, the longer you can stretch those healthy middle years and the slower you will glide into old age. It's never too late to slow the ticking of the aging clock.

"Eat less and exercise" is traditional advice dispensed to those wanting to lose weight, improve health, and reduce susceptibility to certain diseases. With the national obesity epidemic growing by the day, this is sound advice. But recent studies show the first part alone of that classic line may be sufficient to lengthen one's lifespan by up to 40%. Simply eating less may not only add years to life, but also may improve cardiovascular health, lessen the chances of such diseases as diabetes and cancer, and slow neurodegeneration due to aging.