Lessons From the Great Antioxidant Lie
Antioxidants have been hailed as health game changers for over a quarter-century. When originally buzzed back in the early 1990s, the compounds, which include beta-carotene, Vitamin E, and glutathione, were predicted to protect against various cancers, heart disease, and neurodegradation. They'd do this by halting the spread of free radicals in the body, molecules with unpaired electrons that greedily rob other molecules of their electrons in order to stabilize. By stealing electrons to pair their own, however, they create more free radicals in the process, producing "oxidative stress." Antioxidants graciously lend their electrons to free radicals without turning ravenous themselves, thus halting the damaging chain reaction.
Early on, in vitro and observational studies showed promise, exciting scientists. Health "gurus" hyped the findings with books and articles. Supplement sellers had a new fad to fill their coffers. Food makers began slapping antioxidant claims on everything from yogurt and snack bars to chocolate and soda. The antioxidant craze was on.
But then, in the early 2000s, results from randomized, controlled trials on humans began flowing in, and the stream of positive results soon turned into a torrent of negative findings. Perhaps the trials weren't long enough, or were conducted on the wrong study populations, some scientists wondered. Over the next decade, more experiments concluded, with more inconclusive or outright negative results. Antioxidant intake didn't boost cognitive performance, or stall dementia, or halt heart disease, or prevent cancer, or lower the risk of Parkinson's.
Today, it's increasingly accepted in the scientific community that antioxidants are not the health promoters they were hoped to be.
"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 wrote in a 2012 review.
The health effects of antioxidants are a lie, one we told to ourselves. It's time to admit our failure and learn from the mistakes. Here are four takeaways:
1. In vitro is not in vivo. Results from a test tube rarely translate to humans, yet we always seem to forget that when discussing studies about human health.
2. Scientists can get too attached to ideas. Though negative findings about antioxidants started rolling in more than fifteen years ago, research and hope has persisted. Treasured ideas are hard to let go, even for supposedly rational scientists.
3. If something seems too good to be true... How many times has the public at large fallen for health panaceas? When will we learn that there is no simple pill-form or supplement solution to a healthy life?
4. Food marketing is mostly meaningless. Eat more protein! Take your vitamins! Antioxidant boost! If there's a hyped health call-out on a food label, you can probably disregard it.