Antioxidant Vitamins and Ageing.

Area of Science:

• Gerontology
• Biochemistry
• Cellular Biology

Background:

• The free radical theory of aging (FRTA) posits that accumulated cellular damage from reactive oxygen species (ROS) drives aging.
• Antioxidants, which neutralize free radicals, were hypothesized to slow aging when supplemented.
• This chapter reviews the efficacy of antioxidant supplementation for health and longevity.

Purpose of the Study:

• To critically evaluate the effectiveness of antioxidant supplementation in preventing aging and disease.
• To explore the complex, often dichotomous, roles of antioxidants and ROS in cellular processes.
• To discuss the implications of both oxidative stress and "antioxidative stress" on aging.

Main Methods:

• Review of in vitro and in vivo studies on antioxidant efficacy.
• Analysis of human trial data regarding antioxidant supplements and health outcomes.
• Examination of the biochemical mechanisms of antioxidant action and ROS involvement in physiology.

Main Results:

• Many antioxidants effective in vitro show unclear in vivo effects.
• Human trials suggest antioxidant supplements do not extend lifespan and may increase disease incidence.
• Antioxidants can act as oxidants at high concentrations, and ROS are vital for physiological processes.

Conclusions:

• Antioxidant supplementation is ineffective for improving health and longevity.
• Excessive antioxidants ("antioxidative stress") can be as damaging as oxidative stress.
• A balanced cellular environment, not antioxidant excess, is crucial for healthy aging.