Antioxidant supplements are popular and commonly considered healthy.
In part, this is because fruits and vegetables, which are rich in antioxidants , are associated with many health benefits, including a lower risk of disease.
However, there is strong evidence to suggest that you may be harming your health by supplementing with antioxidants.
This article explains what antioxidant supplements are and why it is best to get antioxidants from food.
What are antioxidant supplements?
Antioxidant supplements contain concentrated forms of antioxidants, which are substances that stabilize free radicals.
Your body naturally produces free radicals when you exercise and digest food.
Environmental factors, such as UV exposure, air pollutants, tobacco smoke, and industrial chemicals like pesticides, are also sources of free radicals.
If free radicals exceed your body’s ability to regulate them, a condition called oxidative stress occurs. Over time, this contributes to aging and the development of disease, including cancer.
The main antioxidants that help regulate free radicals in your body are vitamins A, C, and E and the mineral selenium.
Antioxidant supplements contain 70–1,660% of the Daily Value (DV) for these key nutrients.
Taking antioxidant supplements is often thought to prevent free radical damage to cells in the body, promoting longevity and preventing disease.
However, taking antioxidant supplements in high amounts can do the opposite.
Antioxidant supplements contain concentrated forms of antioxidants, which are substances that keep your body’s cells healthy by fighting free radical damage.
Taking high doses can be harmful
The health harms associated with taking antioxidant supplements outnumber its potential benefits.
Taking antioxidant supplements in large doses is not recommended for many reasons.
May decrease exercise performance
Your body naturally produces free radicals as a byproduct of energy metabolism during exercise. The harder and longer you exercise, the more free radicals your body produces.
Because free radicals can contribute to fatigue and muscle damage, it has been proposed that taking antioxidant supplements can mitigate their damaging effects, thereby improving exercise performance and muscle recovery.
However, several studies have shown that taking antioxidant supplements, specifically vitamins C and E, can interfere with the way your body adapts to exercise and even eliminate some of the health benefits associated with exercise.
May increase the risk of cancer
Oxidative stress caused by free radicals in body cells is believed to be a major contributor to the development of cancer.
Since antioxidants neutralize free radicals, it has been speculated that taking antioxidant supplements reduces the risk of developing or dying from cancer.
However, several meta-analyzes have shown that taking antioxidant supplements does not reduce the risk of many types of cancer or reduce the risk of dying from them once diagnosed. In fact, they can even increase the risk of certain types of cancer.
Additionally, several meta-analyzes have found that supplementation of beta-carotene, a precursor to vitamin A, increases the risk of bladder cancer and, in people who smoke, the risk of lung cancer as well.
The exception is selenium, which can help prevent cancer in people with low mineral levels or in people at high risk of cancer. However, more research is needed before selenium can be recommended for this purpose.
Can cause birth defects
Vitamin A is important for fetal growth and development, but at high doses, vitamin A supplements can increase the risk of birth defects.
Therefore, women who may be or are pregnant should not take high doses of vitamin A supplements.
These supplements are only recommended for pregnant women in areas where vitamin A deficiency is prevalent, such as Africa and Southeast Asia.
Beta-carotene, the precursor to vitamin A, has not been shown to cause birth defects. But since taking the supplement long-term is associated with cancer, pregnant women should check with their doctor before taking beta-carotene supplements.
While believed to be healthy, taking antioxidant supplements can reduce the health benefits of exercise and increase the risk of certain cancers and birth defects.
Vitamin C may benefit some people
Although antioxidant supplements are generally not recommended for a variety of reasons, antioxidant vitamin C may benefit people with the common cold or people who smoke.
Vitamin C for the common cold
Vitamin C has not been shown to prevent the common cold, but it can reduce its severity and duration.
In a meta-analysis of more than 11,000 people, taking vitamin C supplements was shown to decrease the duration of colds by 8%, while also decreasing their severity.
It is best to take vitamin C in smaller doses, usually less than one gram, as its absorption decreases with higher doses. Also, higher doses can cause an upset stomach.
Smoking increases vitamin C needs
Smoking causes many types of cancer, mainly because cigarette smoke contains toxins that cause oxidative damage to cells in your body.
Because of this increased exposure to free radicals, research suggests that people who smoke need 35 mg more of vitamin C per day than non-smokers. Similarly, exposure to secondhand smoke also increases vitamin C needs.
However, this additional need for vitamin C can be easily met through diet and without taking antioxidant supplements.
For the most part, the use of antioxidant supplements is discouraged, although antioxidant vitamin C may benefit people with the common cold or people who smoke. Still, needs can often be met with diet rather than supplements.
Get your antioxidants from food
Getting antioxidants from food instead of supplements is much safer and healthier.
All foods contain different antioxidants in varying amounts, so it is important to include a variety of foods in your diet.
While animal products, such as eggs and dairy products, have antioxidants, plant-based foods are particularly high in them.
These plant-based foods include:
- Vegetables : broccoli, bell peppers, spinach.
- Fruits: oranges, apples, berries.
- Whole grains: oatmeal, brown rice.
- Beans: kidney, pinto, red beans.
- Nuts : walnuts, walnuts, almonds.
- Drinks: coffee, tea.
Antioxidants are found in most foods, but plant sources, such as fruits and vegetables, are particularly rich in them.
The bottom line
- Antioxidant supplements are commonly considered healthy, but they can be problematic when taken in excess.
- They can decrease the benefits of exercise and increase your risk for certain cancers and birth defects.
- In general, it is much better to get the antioxidants your body needs through a healthy diet.