Why Science Is Anti-Antioxidant Supplements
In the 1990s, preliminary studies showed that people who regularly consume antioxidant-rich fruits and vegetables have lower rates of cancer, cardiovascular disease, and vision loss compared to people who eat fewer of those foods. The rest, as they say, is media hype and marketing.
Today, a great many consumers down antioxidants as if they were candy. Sales of antioxidant supplements account for $500 million of the massive $32 billion supplement industry.
For the uninitiated, antioxidants, including Vitamin C, Vitamin E, beta-carotene, selenium, manganese, and coenzyme Q10, are chemicals that corral potentially harmful free radicals. Free radicals are a fixture of life. They're everywhere: in your food, in the air, inside you. They come in many shapes and sizes, but what they all share in common, as described by the Harvard School of Public Health, is a "voracious appetite for electrons, stealing them from any nearby substances that will yield them." This "theft" can alter the instructions in a strand of DNA, potentially leading to a cancerous mutation, or cause "bad" LDL cholesterol to become trapped in a cell wall, increasing the risk of cardiovascular disease. Free radicals are like raucous, mischievous six-year-olds: you don't want them running amok.
That's where antioxidants come in. They appease free radicals by selflessly donating their own electrons.
So... more antioxidants is better... right?
Here is where the science gets lost in translation. It's ever alluring to view optimal health as attainable via a simple fix, pill, or diet -- that's what the supplement industry capitalizes on. But it's not that one-dimensional.
The same goes for antioxidants. They all perform complex roles in differing niches; their mission isn't solely to combat free radicals. Analyses have demonstrated that, in certain circumstances, antioxidants may actually serve as pro-oxidants, grabbing electrons instead of giving them up. A couple of the factors that determine how they act include the chemistry of their surroundings and the amount of antioxidants present.
Other scientists also raise the point that oxidative stress from free radicals isn't as detrimental as it's been made out to be.
"Oxidative stress is not only an inevitable event in a healthy human cell, but is responsible for the functioning of vital metabolic processes, such as insulin signaling and erythropoietin production," a team of researchers wrote in 2012.
Moreover, pretty much all of antioxidants' supposed benefits, optimistically touted decades ago, have not materialized. Antioxidant supplements do not improve cognitive performance or reduce the risk of dementia. There's little to no evidence that they reduce cancer risk. None of them is a "silver bullet" against cardiovascular disease, although Vitamin E might have a tenuous benefit.
To the contrary, antioxidant supplements may do more harm than good. Examining longitudinal studies of beta-carotene, Vitamin A, and Vitamin E supplementation, scientists were surprised to discover a small, but noticeable increase in mortality.
Make no mistake, consuming antioxidants via a diet rich in fruits and vegetables seems to be nothing but healthful. But available evidence shows that further supplementation is entirely unwarranted.
"In the light of recent physiological studies it appears more advisable to maintain the delicate redox balance of the cell than to interfere with the antioxidant homeostasis by a non-physiological, excessive exogenous supply of antioxidants in healthy humans," researchers from Gottfried Wilhelm Leibniz University in Germany wrote.
In layman's terms, that translates to "don't waste your money on those Vitamin A pills."