The importance of antioxidants for health is unclear. Plenty of marketing claims will tell you antioxidants are important for preventing everything from cancer to heart disease, but the science is less definitive. This article will briefly cover a high-level understanding of what do antioxidants do for your body, and how you should view the importance of antioxidants.
Many supplement manufacturers and food producers heavily market the importance of antioxidants. We’ve heard this claim for decades.
But how accurate are these claims?
What do antioxidants do for your body?
To understand the importance of antioxidants, it’s useful to look at the underlying biochemical claims and broader health research that has investigated those claims.
Free radicals are molecules that readily react with other molecules by taking their electrons. One class of free radicals are reactive oxygen species.
Free radicals are the natural byproduct of metabolism within your cells. In other words, when you eat, the food gets metabolized into energy and free radicals are produced in the process.
In and of themselves, free radicals are naturally present at all times. They help regulate many biochemical processes and aspects of health like blood pressure.
But free radicals also can impart potentially negative consequences on health.
When they react with other molecules, stealing their electron, it can disrupt the activity of that now electron-less molecule. Free radicals can damage other molecules, like DNA and RNA, as well.
Free radicals have been implicated in our health, therefore, through mechanisms linked to high blood pressure, cancer, eye health, and many others.
This is where the importance of antioxidants theoretically enters the equation.
Antioxidants are molecules that react with these free radicals by donating an electron.
In essence, the importance of antioxidants is supposedly derived from this willingness to donate their electrons, “neutralize” the free radical, and thus preventing it from causing any potential harm such as damage to your DNA.
Does the ability for antioxidants to neutralize free radicals result in improved health?
The science, here, is far from definitive.
As is usually the case in nutrition science, more studies need to be done. There are always caveats with respect to the quality of the current studies, such as the number of people studied, their health prior to the study, the length of the study, and so forth.
Nevertheless, the consensus among researchers is that what antioxidants do for the body is rather inconclusive.
A series of systematic reviews published in the Cochrane Database of Systematic Reviews assess the overall state of the academic literature regarding the importance of antioxidants.
These reviews help develop a larger view of the science, helping to smooth out variation among individual studies.
With respect to liver disease, these authors “found no evidence to support or refute antioxidant supplements in patients with liver disease.”
Regarding gastrointestinal cancers, the authors “could not find convincing evidence that antioxidant supplements prevent gastrointestinal cancers. On the contrary, antioxidant supplements seem to increase overall mortality.”
And when studying a range of diseases and analyzing 78 randomized control trials and over 296,000 patients, the authors “found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A.”
Other reviews and meta-analyses from other journals investigating other roles have come to similar conclusions.
A systematic review and meta-analysis from the British Medical Journal declared “there is insufficient evidence to support the role of dietary antioxidants, including the use of dietary antioxidant supplements, for the primary prevention of early [age-related macular degeneration].”
A meta-analysis from the journal Respirology states “this meta-analysis does not support the hypothesis that dietary intake of the antioxidants vitamins C and E and beta-carotene influences the risk of asthma.”
So are antioxidants important at all?
It’s difficult to say.
We do have strong evidence that free radicals contribute to diseases such as cancer. But that doesn’t necessarily mean antioxidants will correct this.
And indeed, we don’t have strong evidence to support that hypothesis.
Nevertheless, antioxidants are prevalent in fruits and vegetables that do promote many of the health benefits these researchers are investigating.
There may be synergistic, nutrient-nutrient interactions that we haven’t identified that help catalyze health-promoting activity.
Or it could simply be that the studies performed have not been strong enough to capture their effect.
Despite what you may read on your drink label, we unfortunately don’t have a good answer. And as Harvard Health points out, some studies have even identified potential negative effects of over-supplementation for certain individuals.
As with most things related to nutrition, aim for moderation and a well-balanced diet. While antioxidant supplementation has yet to provide clear benefits, eating plenty of healthy fruits, vegetables, and whole grains has.
Intake’s mission is to improve global health through data-driven nutrition. Our blog provides information, education, tools, and tips about all things related to nutrition, including healthy eating, disease prevention, peak performance, and personalization. Sign up for alerts on new posts and product updates!