Hip
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Just watched a BBC Horizon documentary from 2018 on vitamins and minerals by Dr Giles Yeo.
This documentary questions some of the long-held beliefs about the benefits of antioxidant supplements, and details studies in which antioxidant supplements are shown to increase the risk of death by up to 12%.
The first half of this BBC documentary a bit slow, but it gets interesting from timecode 27:30 onwards, where it delves into the historical origins of the idea that antioxidant supplementation may offer health benefits.
The documentary says the grandfather of the "antioxidant miracle" and the anti-aging movement was biochemist Prof Denham Harman, who in the 1950s began to focus on the secrets of living a longer and healthier life.
Prof Harman proposed that oxidative stress and free radicals might be a major factor in aging and the development of disease. Harman was a sober scientist, and never sensationalized his work. But his ideas nevertheless sparked off a whole antioxidant vitamin evangelist health movement, and a supplement industry promoting antioxidants.
Fast forward to 2007: the BBC documentary (at timecode 41:00) focuses on the work of Dr Christian Gluud, who meta-analyzed dozens of studies on humans taking antioxidants.
From his research, Dr Gluud found that antioxidant supplements actually increased all-cause mortality by as much as 12%! Gluud's paper is here.
An article on Dr Gluud's research into antioxidants says that:
Though the article also offers some criticism of Dr Gluud's work:
Another interesting finding detailed in the BBC documentary was Prof Michael Ristow's research on the effect of taking antioxidant supplements with exercise (timecode 35:18).
Exercise is known to generate oxidative stress and free radicals, so the theory was that taking antioxidants as you exercise would be a good thing.
But Prof Ristow's studies found that supplementing with antioxidants during exercise actually blocks and cancels out some of the health-promoting effects of exercise!
Exercise improves insulin sensitivity and glucose metabolism, but Ristow found that if you take antioxidants when you exercise, your insulin sensitivity is not improved.
So it seems that the free radicals produced during exercise are actually responsible and required for obtaining certain benefits from exercise.
(This reminds me of the theory of why ozone therapy may be beneficial: because the transient oxidative stress caused by ozone gets the body to actually ramp up its own antioxidant defenses. So with ozone therapy, the theory is a short exposure to oxidative stress can bring benefits.)
This article about Prof Michael Ristow's research has some interesting content:
The article on Ristow also distinguishes between direct antioxidants, and indirect antioxidants, with the latter being beneficial (as they actually cause transient healthy oxidative stress):
So it seems indirect antioxidants such as green tea EGCG work like ozone to temporarily increase oxidative stress in the body, thereby training the body to better handle oxidative stress.
I find this interesting, as I was not aware that EGCG boosts antioxidant defenses by actually being a pro-oxidant.
(BBC Horizon incidentally also covers the fact that on very rare occasions, high dose EGCG supplements will destroy the liver, requiring an emergency liver transplant).
This documentary questions some of the long-held beliefs about the benefits of antioxidant supplements, and details studies in which antioxidant supplements are shown to increase the risk of death by up to 12%.
The first half of this BBC documentary a bit slow, but it gets interesting from timecode 27:30 onwards, where it delves into the historical origins of the idea that antioxidant supplementation may offer health benefits.
The documentary says the grandfather of the "antioxidant miracle" and the anti-aging movement was biochemist Prof Denham Harman, who in the 1950s began to focus on the secrets of living a longer and healthier life.
Prof Harman proposed that oxidative stress and free radicals might be a major factor in aging and the development of disease. Harman was a sober scientist, and never sensationalized his work. But his ideas nevertheless sparked off a whole antioxidant vitamin evangelist health movement, and a supplement industry promoting antioxidants.
Fast forward to 2007: the BBC documentary (at timecode 41:00) focuses on the work of Dr Christian Gluud, who meta-analyzed dozens of studies on humans taking antioxidants.
From his research, Dr Gluud found that antioxidant supplements actually increased all-cause mortality by as much as 12%! Gluud's paper is here.
An article on Dr Gluud's research into antioxidants says that:
- Vitamin A supplements increased the risk of death by 16%
- Beta-carotene supplements increased the risk of death by 7%
- Vitamin E supplements increased the risk of death by 4%
- Vitamin C supplements did not have any effect on risk of death
Though the article also offers some criticism of Dr Gluud's work:
Shao says it just isn't fair to study antioxidants in this way.
"What these authors have done is combine studies that are incredibly dissimilar in all sorts of ways," he says. "These studies looked at different nutrients at different doses at different durations with different lengths of follow-up -- and in different populations, ranging from folks who were incredibly healthy to people with cancer and other diseases."
Another interesting finding detailed in the BBC documentary was Prof Michael Ristow's research on the effect of taking antioxidant supplements with exercise (timecode 35:18).
Exercise is known to generate oxidative stress and free radicals, so the theory was that taking antioxidants as you exercise would be a good thing.
But Prof Ristow's studies found that supplementing with antioxidants during exercise actually blocks and cancels out some of the health-promoting effects of exercise!
Exercise improves insulin sensitivity and glucose metabolism, but Ristow found that if you take antioxidants when you exercise, your insulin sensitivity is not improved.
So it seems that the free radicals produced during exercise are actually responsible and required for obtaining certain benefits from exercise.
(This reminds me of the theory of why ozone therapy may be beneficial: because the transient oxidative stress caused by ozone gets the body to actually ramp up its own antioxidant defenses. So with ozone therapy, the theory is a short exposure to oxidative stress can bring benefits.)
This article about Prof Michael Ristow's research has some interesting content:
Right, the “free radical theory of aging” – where is that theory at now?
It’s dead. Well, let’s be a bit more precise. The free radical theory of aging dates back to the 1950s, and then there were decades of research on it, which was all very good research scientifically speaking, but it was always in artificial settings with high doses of free radicals that never occur in real life.
In real life, in healthy model organisms or humans, free radicals occur in very low doses, and they have very different functions from high doses of free radicals, where they serve as signaling molecules that increase our body’s defense mechanisms against external stressors. So it works like a vaccination–repeated low doses of free radicals will increase stress resistance.
The article on Ristow also distinguishes between direct antioxidants, and indirect antioxidants, with the latter being beneficial (as they actually cause transient healthy oxidative stress):
There are direct antioxidants that really react with free radicals, like vitamin C and E and a few others, and then there are indirect antioxidants, which actually induce oxidative stress.
A prime example is polyphenols, like EGCG from green tea, or the compounds that make berries blue or purple or red, which are all pro-oxidants because they cause oxidative stress. So these guys induce antioxidant defense in the body like exercise does, and they really are healthy.
So it seems indirect antioxidants such as green tea EGCG work like ozone to temporarily increase oxidative stress in the body, thereby training the body to better handle oxidative stress.
I find this interesting, as I was not aware that EGCG boosts antioxidant defenses by actually being a pro-oxidant.
(BBC Horizon incidentally also covers the fact that on very rare occasions, high dose EGCG supplements will destroy the liver, requiring an emergency liver transplant).
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