Antioxidants are molecules that prevent oxygen
molecules from interacting with other molecules in a
process called oxidation.
In the body, antioxidants
combine with potentially damaging molecules called
free radicals to prevent the free radicals from causing
damage to cell membranes, DNA, and proteins in the
cell.
Common antioxidants important to human
health are vitamins A, C, E, beta-carotene, and selenium.
In the mid-2000s, about 20% of North Americans
and Europeans were taking at least one
antioxidant dietary supplement.
The role of antioxidants in the body is complex
and not completely understood. Antioxidants combine
with free radicals so that the free radicals cannot
react with, or oxidize, other molecules.
In this way,
antioxidants help slow or prevent damage to cells.
Damage caused by free radicals is thought to cause
or contribute to cardiovascular disease, cancer, Alzheimer’s
disease, age-related changes in vision, and
other signs of aging.
However, no direct cause and
effect relationship between antioxidant intake and disease
prevention has been proven. Antioxidants unrelated
to those of importance in the body have
commercial uses in the preservation of processed
food and in many industrial processes.
Health benefits of antioxidants and their food sources
Selenium
Helps maintain healthy hair and nails, enhances immunity,
works with vitamin E to protect cells from damage. Reduces the
risk of cancer, particularly lung, prostate, and colorectal.
Food sources
Garlic, seeds, Brazil nuts, meat, eggs, poultry, seafood, whole
grains. The amount in plant sources varies according to the
content of the soil.
Beta-carotene
Keeps skin healthy, helps prevent night blindness and infections,
promotes growth and bone development.
Food sources
Red, yellow-orange, and leafy green vegetables and fruits,
including carrots, apricots, cantaloupe, peppers, tomatoes,
spinach, broccoli, sweet potatoes, and pumpkin.
Vitamin E
Acts as the protector of essential fats in cell membranes and red
blood cells. Reduces risk of cancer, heart disease, and other
age-associated diseases.
Food sources
Peanut butter, nuts, seeds, vegetable oils and margarine, wheat
germ, avocado, whole grains, salad dressings.
Vitamin C
Destroys free radicals inside and outside cells. Helps in the
formation of connective tissue, the healing of wounds, and iron
absorption, and also helps to prevent bruising and keep gums
healthy. May reduce risk of cataracts, heart disease, and cancer.
Food sources
Peppers, tomatoes, citrus fruits and juices, berries, broccoli,
spinach, cabbage, potatoes, mango, papaya.
Some important human antioxidants must be
acquired through diet, while others can be made by
the body. Vitamin C (ascorbic acid), vitamin E (alphatocopherol),
vitamin A (retinol), and beta-carotene are
the most important antioxidants the body must obtain
from food sources.
