The Antioxidant Hoax

To put it mildly, I claim no expertise on the subject of antioxidants. I have never paid very much attention to the hype about antioxidants. We have long been assaulted with supposedly scientific studies telling us what to eat and what not to eat. The great scientists who float these ideas tend to change their minds after a time. One suspects that these scientists like the feeling of dictating food consumption to masses of people. It makes them feel strong and powerful.

If you ignore them all, it will save you a lot of time and stress. And, don’t we know, the stress you experience by worrying about what you should or should not eat will probably compromise the positive benefits of even… antioxidants. Or, it would if antioxidants lived up to the hype. The truth is, they don't.

As I said, I am sorely underinformed about antioxidants, so I am relying on Ross Pomeroy’s illuminating article from Real Clear Science. (via Maggie's Farm)

He opens by presenting the hype:

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.

Whether or not it’s good science, at least it’s a good story. And you don’t want to argue with a good story, do you?

Anyway, once the theories were tested, the results were less than encouraging. The antioxidant effect proved to be a mirage:

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.

More recently, one researcher presenting at a grand rounds admitted that the lack of effectiveness of antioxidants is the greatest disappointment of their career.

So, antioxidants are not going to prevent cancer or to help you to live forever.

Pomeroy concludes with some salient observations:

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.

Amen.