ANTIOXIDANTS help protect against oxidative stress. The First line of antioxidant defence in our body is the network of antioxidant enzymes. Antioxidant enzymes such as superoxide dismutase (SOD) and glutathione peroxidase play key functions in neutralizing excessive free radicals, thus preventing cell damage. The second line of antioxidants defence is non-enzymatic. The complex network of antioxidants in our body is influenced and supported by dietary intake of antioxidant vitamins and minerals such as beta-carotene, vitamin C, vitamin E, zinc, selenium and astaxanthin.
Beta-carotene, a carotenoid is a natural pigment that is synthesised by various kinds of brightly coloured fruits and vegetable. Also known as pro-vitamin A. Our body can convert beta-carotene to vitamin A when needed. Beta-carotene acts as an anti-oxidant and works better when combined with vitamin E Studies showed that beta-carotene supplementation protects LDL-cholesterol against oxidation. Supplemental beta-carotene intake at a dose level of at least 2mg a day was also associated with decreased prostate cancer risk in men with low dietary beta-carotene intake.
Vitamin C is a water-soluble antioxidant that is required for at least 300 metabolic functions in our body, including tissue growth and repair, maintaining healthy gums and reducing free radical damage. As an antioxidant, vitamin C is unique for its ability not only in quenching free radicals, but also in enhancing the activity of vitamin E. High doses of vitamins C (500mg a day) has also been shown to influence the ability of immune cells in reducing oxidative stress due to exercise. Some studies also demonstrated that vitamin C may help in speeding up recovery time in people suffering from colds.
Vitamin E, the most important lipid-soluble antioxidant, comprises two groups of family members, knows as tocopherols and tocotrienols. Out of these two families, tocotrienols have been shown to exert a greater antioxidant activity compared to tocopherols. Tocotrienols are more “fluid”, allowing for easy penetration into the skin and fatty layers of the brain and liver. Other health benefits that are unique to tocotrienols include their roles in blood cholesterol reduction and breast cancer protection in females.
Zine fights and prevents free radicals in many different ways. Zinc is also a constituent of the antioxidant enzyme SOD. Sufficient intake of zinc is necessary for optimum immune function, healthy reproductive system, healthy skin and wound healing.
Selenium works with vitamin E to protect tissues and membranes from damage caused by free radicals. It is also needed for the formation of the antioxidant enzyme glutathione peroxidase. The enzyme plays important roles in the protection against free radicals such as hydrogen peroxides and lipid peroxides. Besides that, selenium keeps the liver functioning optimally and strengthens the immune system, as well as maintains healthy eyes, skin, hair and heart.
Astaxanthin is a typeof fat-soluble pigment that is reddish-orange in colour. This pigment can be found mainly in microalgae, yeast, salmon, shrimps, lobster, crabs and trout. This natural carotenoid is essential for the proper growth and survival of these beings. In humans, supplemental astaxanthin inhibits lipid peroxidation in cell membranes by protecting the cells from free radical damage.
Astananthin is commonly used by athletes as this potent antioxidant helps reduce acid build-up and improves muscle endurance and stamina during intensive training. Astaxanthin is also well-sudied for its benefits on the skin by reducing effects due to ultraviolet damage such as line formation, age spots and freckles.