Why do we still believe in Antioxidants? - healthuncut.com
One of the controversies we lay bare in our recent book The Health Delusion is the substantial body of evidence showing that the indiscriminate use of high dose antioxidant supplements (namely vitamins A, C and E, and beta carotene), touted as modern day panaceas, is at best useless and at worst, harmful to health. It’s fair to say that our coverage of the antioxidant debacle met with a mixed response (understatement…).
Well, if you’re not going to take our word for it (backed up by plenty of studies, we hasten to add), then perhaps you might listen instead to a Nobel laureate? In a compelling paper published this week in Open Biology Nobel laureate James D. Watson PhD presents his hypothesis regarding the role of oxidants and antioxidants, and eloquently argues that antioxidants actually promote the progression of late-stage (metastatic) cancers.
One of the things that shocked people most about our expose in The Health Delusion was the assertion (again, based on the scientific literature) that reactive oxygen species (commonly referred to as ‘free radicals’) are not the pantomime villains that they are universally caricatured as, but actually a natural, normal, and intrinsic part of our biology. Watson’s paper sums this up perfectly, referring to reactive oxygen species as “a positive force for life”. On the one hand, he argues, they are notorious “for their ability to irreversibly damage key proteins and nucleic acid molecules”, which is the side of the coin we always hear about, but the flipside is that they have a fundamental role in apoptosis, the process by which stressed, damaged or worn out cells commit suicide, thus effectively getting rid of them before they become dysfunctional and cause us trouble.
So once again, I find myself asking, why do we still have a love-affair with antioxidants? And why do we cling to the naïve and simplistic notion that antioxidants are ‘good’ and free radicals are ‘bad’? Once you see the nuances of this aspect of our biology, the idea that we should try to snuff out free radicals with the indiscriminate use of high dose antioxidant supplements is crude, ignorant, and dangerous in equal measures. Yet, you can walk into Boots today (or any number of pharmacies and health food shop) and readily pick up a vitamin E supplement providing a massive dose of 800 IU per capsule (which bizarrely appears to be classified as part of their ‘beauty’ range…), a dose that almost certainly has the potential to cause harm to some people. As Watson comments, “In light of the recent data strongly hinting that much of late-stage cancer’s untreatability may arise from its possession of too many antioxidants, the time has come to seriously ask whether antioxidant use much more likely causes than prevents cancer…All in all, the by now vast number of nutritional intervention trials using the antioxidants b-carotene, vitamin A, vitamin C, vitamin E and selenium have shown no obvious effectiveness in preventing gastrointestinal cancer nor in lengthening mortality. In fact, they seem to slightly shorten the lives of those who take them. Future data may, in fact, show that antioxidant use, particularly that of vitamin E, leads to a small number of cancers that would not have come into existence but for antioxidant supplementation.” Roughly translated, popping into Boots for your 800IU Vitamin E supplement doesn’t seem very smart.
As an aside, we dare to pull the Nobel laureate up on two issues. Firstly, to include selenium on this list is unjust. As we covered in detail in The Health Delusion, selenium is widely deficient from the diets of the UK (and much of Europe) and there is a compelling case for correcting this deficiency with a modest selenium supplement to diminish our cancer risk (although it is certainly true that more is not better, and indiscriminate use of higher dose selenium supplements run their risks too). Secondly, Watson doesn’t quite grasp contemporary thinking about why fruits and vegetables are good for us when he writes “blueberries best be eaten because they taste good, not because their consumption will lead to less cancer.” It’s horribly reductionist to think that fruits and vegetables could be good for us solely because of their antioxidant content. The reality is that phytonutrients from plant foods may interact with our biology in multiple ways to influence health, none of which have much to do with antioxidant effects. Ironically, the antithesis could be true, and the benefits of phytonutrients from fruits and vegetables may actually be because they act as weak toxins (due to naturally occurring pesticide compounds within plants), ingestion of which stresses our cells, forcing them to ‘toughen up’ and be more resilient as a result. We might think of this in terms of ‘a little bit of poison is good for us’, or, what’s known as the ‘hormesis effect’, a far cry from the simplistic notion of antioxidants.
But that is rather splitting hairs and deflecting from the main point here. If you haven’t done so already, it’s time to re-think your relationship with antioxidants.
Comments (2)
The problem here is that you don't know if the science that you're quoting is correct, or is just a load of prejudice and opinion that has been transformed into something that looks like a proper scientific analysis/experiment by someone who knows he'll get published. And what about all the studies that show antioxidants are useful? Are you saying that one study of intestinal cancer automatically invalidates all the previous studies? Maybe you're playing devils advocate, Glenn, but for me all you've done is point out how unreliable science is at providing useful guidance on diet. Read one study - chips are good for you, read abother and they are more fatal than arsenic. We can choose our food at random or we can choose our scientific evidence at random and then use that to formulate a "healthy" diet. It's far easier to just choose option 1.
