As part of the Naked Scientists Mythconception series, I question my choice of new year resolution as I investigates the science behind the infamous ‘free-radicals’ and their sworn enemy, the all-conquering antioxidants…
Tom – We’re now well into the new year – how are those resolutions going? If, like me, you’ve decided to eat more healthily, maybe you’ve been stuffing yourself with antioxidants. They’re good for you… right? And they attack free radicals, those naughty things flying around in your body causing damage to your cells and making you age faster. At least that’s what we’re told by the so-called ‘health experts’. Let’s see what science has to say on the subject…
The story begins in 1945, when the wife of chemist Denham Harman suggested that he read an article in Ladies Home Journal entitled “Tomorrow you may be younger.” This sparked his interest in the process of aging and a few years later whilst working at the University of California, Berkeley, he proposed that ageing is caused by reactive molecules that build up in the body as by-products of your body’s natural processes and lead to cellular damage. These are what he called “free radicals.” Harman himself described his discovery as ‘a thought out of the blue.’
Scientists began to rally around the theory of free radical ageing and that antioxidants such as vitamin C and beta-carotene were able to neutralise them. The antioxidant boom occurred in the 1990’s with the word entering into the public domain and supplements being added to foods and taken as tablets. It wasn’t until the early 2000’s, however, that scientists began testing the theory and they encountered some interesting results. Two separate studies compared mice, which were genetically engineered to overproduce either free radicals or antioxidants, with normal mice and they saw no change in the life span in each case. Further studies in humans found antioxidant supplements negate the health promoting effects of exercise and may even lead to a higher chance of death.
The increase in life expectancy which is often attributed to antioxidants is, in fact, likely to be a by-product of a generally healthier lifestyle. People that take antioxidant supplements tend to be more health conscious in general and as a result, are likely to live longer.
The bottom line is that scientists are still unsure of the exact roles of free radicals and antioxidants in the body and more studies are required. Most researchers do agree, however, that free radicals cause cellular damage but this is not necessarily a bad thing. In many cases is seems to be a normal part of the body’s reaction to stress. We are certainly not being oxidised and therefore do not require antioxidants to save us from impending doom as the health experts would like us to believe.
Nonetheless, the global antioxidant market was worth 2.1 billion dollars in 2013 and is expected to continue to grow by a further billion by 2020. I’ll leave you with a quote from Professor David Gems from University College London, which sums it all up quite nicely – “It’s a massive racket. The reason the notion of oxidation and ageing hangs around is because it is perpetuated by people making money out of it.”
You can listen to the full interview with the Naked Scientists here.