Living longer is the dream of many, and strategies to stunt or even reverse the aging process exist in both traditional and alternative medical treatments. Aging is affected by genetic factors, diet, social conditions and environmental factors, according to "Pathologic Basis of Disease," and it occurs at least in part as a result of oxidative stress caused by free radicals. Antioxidants, particularly the vitamins A, C and E and the mineral selenium, neutralize free radicals and may play a role in increasing longevity. Before starting any new diet or treatment, talk to your doctor.
Aging and Free Radicals
Free radicals are reactive oxygen and nitrogen molecules that form continuously in your body as byproducts of metabolism and through exposure to environmental toxins. Free radicals destabilize surrounding molecules and cause chain reactions of destruction that can lead to cell damage and death. Cells divide to replace damaged cells, and each division decreases a cell's life span. Antioxidants help to prevent damage caused by free radicals, prolonging the lifespan of your cells and thereby increasing longevity.
Vitamin A
Vitamin A, a group of related chemicals that functions like a hormone, maintains normal vision and enhances immunity to infections. Important dietary sources of vitamin A are animal derived and include liver, fish, eggs, milk and butter. Yellow and leafy green vegetables such as carrots, squash and spinach supply large amounts of this carotenoid group of vitamins, the most important of which is beta-carotene.
Vitamin C
As an antioxidant, vitamin C helps protect your cells from damage that can lead to cell dysfunction and death. Active in collagen synthesis, it is also required for healthy skin. Ascorbic acid, as vitamin C is also called, is present in milk and some animal products and is abundant in a variety of fruits and vegetables. Bell peppers, broccoli, strawberries, cauliflower and Romaine lettuce are all excellent sources of vitamin C. The antioxidant properties of vitamin C are potentiated by vitamin E.
Vitamin E
As a free radical scavenger, vitamin E breaks down cellular metabolites before they can damage your cells. Specifically, nerve cells and blood cells depend on adequate vitamin E levels for integrity; deficiency puts cells at risk for oxidative injury. A group of eight closely related fat-soluble compounds, vitamin E is abundant in vegetables, grains, nuts and their oils, dairy products, fish and meat.
Selenium
The mineral selenium protects against damage to your cell membranes, just as does vitamin E. It is a component of the enzyme glutathione peroxidase that neutralizes free radicals. Animal foods, most notably sardines, salmon and shrimp, contain the highest amounts of selenium. Tofu, mushrooms, garlic and broccoli are good plant-based sources.
Warning
Clinical trials with vitamins A, C and E as dietary supplements have failed to show clear beneficial effects. Thus, the health-promoting effects of diets high in these antioxidants probably reflects a complex interaction among many naturally-occurring compounds, some as yet undiscovered. In other words, choose whole-food sources of antioxidants over dietary supplements. According to the USDA, diets rich in fruits and vegetables are an excellent source of vitamins and antioxidants.
References
- "Pathologic Basis of Disease"; Vinay Kumar; 2005
- "Biochemistry: Pamela C. Champe et al; 2005
- USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2
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