Researchers still do not know why people age. However, one theory claims that oxygen radicals tend to chip away on healthy cells, damaging them in the process, before totally destroying them. Even though scientists carry out vast research on calorie restriction, nutritional supplements and drugs for the sole purpose of making people live longer, medical experts argue that the secret behind living a long and healthy life lies in what one eats. Eating anti-oxidant foods is believed to prevent the cellular wear and tear from the unstable molecules of oxygen generated by the biochemical process of the body.

This theory is evident in the diets of communities known to have long life spans. For instance, in the San Blas islands, chocolate is their longevity secret.  It is rich in the compounds responsible for maintaining healthy blood vessels. Greeks avoid heart diseases by consuming olive oil, while the diet of the Alaskan native Inuit is rich in fish, which offers cardiovascular protection. The Okiwan diet mostly consists of bitter lemon, sanpin tea and sweet potatoes, which contain anti-oxidants that flush out oxygen radicals from the body. When compared to other religious faithful, the Seventh Day Adventists live longer by more than four years. This is mainly because they maintain a vegetarian diet comprising of nuts, fruits, whole grains and vegetables. All are rich in anti-oxidants.

After 18 years of study, it has been noted that vegetables and fruits play a major role in human longevity and anti-aging and reduce the development of heart disease. Blueberries are also believed to prevent brain impairments that come about because of age advancements. Other than vegetables, saturated fats and fruits, there are health and dietary recommendations such as eating fish and lots of whole grains, eliminating trans fats, not smoking and consuming a moderate amount of wine during dinner.