The media seems to be very keen indeed to tell us all about the wonderful properties of red wine. Here is their latest effort. A Doctor who owns a vineyard is apparently producing red wine high in antioxidants and the Independent reports that he “calls them “vascular pipe-cleaners”, saying the antioxidant they contain – resveratrol, which occurs naturally in grapes – helps to keep blood vessels free of fatty deposits”, which made me wonder how good the evidence was for the claim that resveratrol in wine clears the arteries. I also began to wonder just how many stories the media was going to print about resveratrol and/or red wine and health. The third thing I wondered was why the papers are so obsessed with resveratrol in red wine – after all, it occurs naturally in other foodstuffs that do not contain alcohol. Are they all trying to be the paper that brings us the good news that booze is good for us? I think they’ll find it’s a little more complicated than that – telling us (on the basis of a paper about the actions of a component of red wine) that drinking red wine is good for us ignores the dangers of alcohol and the reality that most people probably won’t be drinking a healthy amount of red wine in terms of the alcohol they consume. [*See bottom of page for more on this.] These are the same newspapers that report on binge-drink Britain, but expecting joined-up thinking from the media is woefully optimistic in my humble opinion.
Anyway, back to the first couple of points I pondered. I reckon my second though (working out how many stories the media is going to print on red wine and health) is a blog post in itself. But my first thought on reading the Independent piece related to the claim that red wine will clear your arteries. Let’s have a quick look at that. Looking for reviews on Pubmed using ‘wine’ and ‘atherosclerotic’ as search terms brings up 27 papers. A quick glance through the abstracts yields some interesting points. This one tells us that “several epidemiological studies suggest that moderate alcohol intake, especially red wine, decrease cardiac mortality due to atherosclerosis”, but adds that while “moderate red wine drinking, in the absence of contraindications, may be beneficial to patients who are at risk of atherosclerotic cardiovascular events […] a diet based on fruits and vegetables containing flavonoids may be even more beneficial.” I don’t recall reading that headline in the Independent. Here, the authors tell us that “on the basis of epidemiological studies, moderate intake of alcoholic beverages, including red wine, reduces the risk of cardiovascular, cerebrovascular, and peripheral vascular disease in populations.” Wait. There’s more. “Definitive data from a large-scale, randomized clinical end-point trial of red wine intake would be required before physicians can advise patients to use wine as part of preventative or medical therapies.” It’s just a shame the papers won’t wait for such data before advising red wine to clear your arteries. The authors of another paper inform us that “alcohol intake from any type of alcoholic beverage appears beneficial, but red wine seems to confer additional health benefits because of the presence of red wine polyphenolic compounds (RWPC).” but again there’s a caveat. Although “red wine might be of therapeutic benefit in cardiovascular diseases, prospective controlled clinical studies are still lacking.” The other relevant papers generally carry similar notes regarding the lack of data, or the point that a diet based on fruit and veg would be even more beneficial, or relating to the increase in cardiovascular risk with three or more drinks per day. While they seem to be broadly positive, none of them are remotely as optimistic as the newspaper version of the wondrous effects of red wine. So there may be reason to think that red wine (or some of the components in red wine) may have specific beneficial effects, but anyone hoping to extend their lifespan by drinking red wine may be thinking wishfully. Particularly if they like to drink more than just the occasional single glass.
Encouraging people to drink red wine to improve their health might be counter-productive. Here’s one good example of that scenario: Telegraph nutriwoo. Basically, a compound in that is found in red wine increases the activity of a particular enzyme in the body. This enzyme “recycles” a metabolite of oestrogen back into oestrogen and the metabolite that is recycled can damage DNA. As DNA damage can lead to cancer-causing mutations, it is assumed by the Telegraph that drinking red wine containing this chemical can recycle the oestrogen derivative, thereby preventing DNA damage, thereby preventing mutations and thereby prevent cancer. Specifically breast cancer. As you can read in the Bad Science post on nutriwoo that I have linked to above, red wine doesn’t contain just resveratrol, it also contains alcohol, which is metabolised to acetaldehyde – a substance that causes DNA damage. The upshot is that half a glass of red wine a day increases your risk of breast cancer by 10%. So recommending red wine to prevent breast cancer is advice that, if taken seriously by enough readers, could lead to an increase in cases. The Telegraph aren’t alone, of course, in over-emphasising the potential health benefits of red wine or in ignoring the potential negative effects of red wine. You won’t be surprised to learn that aside from the Telegraph and the Independent, the Daily Mail have done their bit for public miseducation in this area too.
Interesting study from 2003 showing that wine drinkers live longer than those who prefer beer or spirits: it remains unclear whether this reduced risk is due to non-alcoholic wine ingredients, drinking pattern, or associated traits. Let’s not forget that alcohol is bad for blood pressure too. Not that any of this is going to stop me enjoying a couple of glasses when I fancy it, mind.
* “The upswing in CVD risk with three or more drinks per day is sharp and emphasizes that benefit from alcohol is limited to moderate consumption only. This upswing also cautions against any public health recommendation to drink alcohol, since many persons will not or cannot limit their intake to moderate levels.” Link to abstract. [My italics]