Tuesday, October 30, 2007

Antioxidants again.....

Just a quick heads up on a couple of recent bits of news about the alleged benefits of antioxidants in your diet.

Firstly a study that looks at the benefits of eating the herb Rosemary:

Rosemary not only tastes good in culinary dishes such as Rosemary chicken and lamb, but scientists have now found it is also good for your brain. A collaborative group from the Burnham Institute for Medical Research (Burnham Institute) in La Jolla, CA and in Japan, report that the herb rosemary contains an ingredient that fights off free radical damage in the brain. The active ingredient in rosemary, known as carnosic acid (CA), can protect the brain from stroke and neurodegeneration that is due to injurious chemical free radicals. These radicals are thought to contribute not only to stroke and neurodegenerative conditions such as Alzheimer’s, but also to the ill effects of normal aging on the brain.

And secondly one that looks at polyphenols:

In the study, French scientists describe how high and low doses of polyphenols have different effects. Most notably, they found that very high doses of antioxidant polyphenols shut down and prevent cancerous tumors by cutting off the formation of new blood vessels needed for tumor growth. Polyphenols are commonly found in red wine, fruits, vegetables, and green tea.

I liked this quote:

According to the authors, the amount of polyphenols necessary to obtain an anti-cancer effect is the equivalent of drinking about a bottle of red wine each day. This amount of daily alcohol consumption obviously is unhealthy......

While all these studies are coming out about the benefits of antioxidant consumption is seems almost heretical to question this now accepted wisdom. However there are those that do and Emma's posts on this are worth looking through.

It is also worth pointing out that Vilhjalmur Stefansson lived for years on the traditional Eskimo diet of fat and meat....no veggies.......and was, like the Eskimos he was living with, exceptionally healthy. Gary Taubes in his new and excellent book Good Calories, Bad Calories suggests that scurvy and other vitamin deficiency diseases are actually only found when people are eating diets low in meat, eggs and dairy. It seems to be the high levels of carbs that prompt the need for all the vitamins in the veggies.....


Kurt G. Harris MD said...

Hi Chris

I think your link to Emma is broken - it is now:


I think the jury is out on whether seeking out and eating antioxidants from plants is good or bad, I am leaning towards the latter. The important oxidation is what is going on inside your body, not on the grill. If you have high HBA1C, fructosamine and oxLDL that is what is important and these are not determined by eating "antioxidants" near as much as avoiding "oxidants" like fructose and avoiding things that are susceptible to oxidative damage and propagate it in your body like linoleic acid.

The ontology of the antioxidant idea is the near religious belief, against evidence of all randomized trials, that fruit and vegetable consumption is "good" and animal products are "bad". It is an ad hoc hypothesis that is seeking justification so that the standard paradigm of healthy fruits and vegetables can be promoted. It is only mildly biologically plausible and there is no good clinical evidence for it at all so far.

I am not a believer.

A far as alcohol, I think the health benefits are grossly exaggerated because the cultural bias of educated white people is that they like to have a few drinks. Is it an accident that we are looking at substances in red wine and not "40's" of malt liquor? There is no way resveratrol is more metabolically important than ethanol as a hepatotoxin. The idea is simply ludicrous.

Chris said...

Thanks Kurt