Every Tuesday I am going to address one specific myth, urban legend, conspiracy theory or piece of pseudo-science. This time we take a closer look at one of the most popular myth among adults: the cardio-protectivity of red wine consumption.
Research is Hell
A few days ago, I created a contest, which should have provided me with some more ideas for topics of this series I can dig into.
The amount of entries was…not even mediocre, to put it mildly. And I got some posts by users about stuff I was not even able to understand – no price for you, sorry lads. But, that’s alright. The few useful ideas some people came up with are going to be rewarded as promised. Thanks a lot for the input guys.
This week’s topic was inspired by @fragmentarion. It’s indeed quite an interesting one and I should be ashamed, I didn’t think of it myself. I have probably already killed too many brain cells during my career as a bartender. But that’s alright, this way you petty mortals don’t have to be intimidated as much by my sheer awesomeness as people were used to. Good for you.
But because I still want to appear smarter than I am, I used a Latin title for this week’s topic – since we all know: the everyday usage of random Latin phrases and words make people aware of your superior intelligence. You know all these fancy words, after all.
But back to the fun part. Alcohol, or to be more precise: red wine. It’s a bit difficult to nail down the exact source of the idea that drinking red wine will protect you against cardiovascular diseases.
My guess is, a team of researchers wrote something like:
The results of moderate red wine consumption found in rats MIGHT explain SOME of the protective effects against cardiovascular diseases in humans as well.
And professional journalists suddenly came up with this kind of headline:
Scientifically proven: red wine protects your heart!
Because #yolo and fuck research. What do these petty scientists know anyway? Life as a researcher must be frustrating as hell. I envy you guys not.
Update: @sco rightfully mentioned in a comment below the German version of this article, that I should have talked a bit about the French Paradox, which is likely the origin of the belief regarding health benefits of red wine consumption. So feel free to check out the Wiki article about this, it's quite interesting.
But luckily, I have no greedy company sitting behind and forcing me to come up with a catchy headline – no matter the actual research. So, I have the liberty to do the things, most journalists are apparently not willing (or capable) to do these days: I can read the studies (and lucky me, I got a decent education in methodology and statistics, thus can understand them) and discuss with you guys, whether a headline is misleading or not. Spoiler alert: it’s not as easy as it may appear.
Let’s go back in time a bit. It’s the year 1995 and a research team around Cecil R. Pace-Asciak conducted a study about the effects of trans-resveratrol on coronary heart disease(1).
They came up with quite a fascinating conclusion. According to their findings, a higher resveratrol intake could have a beneficial therapeutic effect on one’s eicosanoid (molecules which are, among other functions, responsible for the regulation of blood pressure and flow) metabolism. They suggested a consumption of 350ml of red wine per day, which should provide a sufficient amount of resveratrol to have a significant impact.
Could. Suggest. Probably. Maybe. Whatever.
You can see the problem. Without knowing about further details of the study, these words should already be huge warning signs.
But there is another, even bigger issue: the protective effects were only studied in vitro - which means, any suggestions for humans are basically worthless. This may sound harsh, but to jump from in vitro experiments to human administration is an incredibly big leap to take. There are way more variables involved.
Well, apparently, the idea of red wine protecting against cardiovascular diseases has been indeed around for quite some time. But it would be foolish to conclude a general recommendation for an increased red wine consumption based on these findings.
Fast forward a couple of years. It’s 2009 and this is where things are getting interesting. One name seems to be the centre of one of the biggest frauds in recent scientific history: Dipak K. Das(2).
He and his colleagues published several papers concerning the benefits of wine consumption. Especially about effects on cardiovascular diseases and longevity(3). It seemed, he was able to show significant evidence for positive effects of wine consumption. Well, if only it were true.
Until today, many of his papers have been retracted due to evidence of data manipulation(4).
It seems to be the case, that the idea of beneficial effects of wine consumption on human health is mainly there because of one dishonest scientist. But once an idea like this is born, it’s incredibly hard to kill.
But does that mean, there is really no benefit in drinking red wine?
I tend to say yes. But. Since I’m a slave of my intellectual honesty, I will give you some insights about the research which suggests otherwise.
In 2001, Fernandez et al.(5) were able to show cardiovascular protective effects of long-term consumption of red wine – at least in mice. They assumed, that the impact on human health is probably similar, although more human trials are still needed to come to any sort of satisfying conclusion.
Now comes the sad part: although they were able to show benefits of red wine consumption, they still recommended a diet without it, noting the severe side-effects of long-term alcohol consumption might outweigh the possible benefits. Thus, a diet containing other sources of resveratrol is still the healthier way to go.
In general, resveratrol appears to be quite helpful to treat certain cardiovascular diseases – this is something, which seems to be quite evident. Especially women suffering from hypertension (high blood pressure) show significant improvements in comparison to a placebo group when treated with high dosages of isolated resveratrol(6). Take note, the treatment occured with isolated resveratrol – and not wine or something similar, which might have confounded the effect. So, don’t get too excited.
Similar positive results concerning resveratrol were shown by Yan et al. (2017)(7). They were able to show improvements of the cardiovascular system of rats suffering from diabetes – but, yet again, the researchers administered isolated resveratrol in high dosages. Something you will not get from your daily diet and since the study was only conducted with mice, it’s still not sure how to recreate the same effects in humans.
More research needs to be conducted.
Although we might already have an idea where this will lead:
Every time, one wants to investigate a claim which has been the topic of different studies, it’s incredibly helpful to take a look at meta-analyses. One of the most recent ones was conducted by Zhao et al. in 2017(8), titled: Alcohol Consumption and Mortality From Coronary
Heart Disease: An Updated Meta-Analysis of Cohort Studies.
They analysed 45 different studies connected to this topic and came to some interesting conclusions. 38 of these studies were confounded by methodical weaknesses, especially when it came down to measure former and/or occasional drinkers. In addition to that, 16 studies were using an unusual way of measuring the average amount of alcohol intake per day.
These weaknesses led, among other things, to the conclusion that the idea of cardio-protective effects of alcohol consumption is still not more than an interesting hypothesis, which should be met with scepticism.
But, yet again, there are researchers who say quite the opposite. Haseeb et al. (2017)(9) argue in favour of a moderate consumption (in accordance to the WHO guidelines), since the available evidence seem to suggest protective effects against cardiovascular diseases. Take note though, they did only a review of the available research and not an in-depth analysis of the conducted studies (like Zhao et al. did) including possible weaknesses.
End of the Road?
This whole topic is incredibly complex. I have spent way more time with researching and reading today than I usually need to finish an article for this series. This is why today’s one is longer than usual as well.
But I felt, it was necessary to provide you with a comprehensive idea about this piece of research.
And what’s the take-away?
It’s tough. Some evidence indicates there are indeed cardio-protective effects of red wine (although some researchers argue, it’s still not clear whether this is solely due to resveratrol or ethanol in general(10)), especially the human trials were quite often methodological weak.
Another issue is, the amount of resveratrol one needs to consume to achieve (possibly) significant beneficial effects are so high, it’s almost impossible to get it with a daily diet alone. Lachenmeier et al. criticized this and the conclusion for humans based on animal trials already in 2013(11) (These pesky Germans must spoil all the fun, eh?).
Scepticism might be the healthier choice after all.
In addition to that, it’s important to be aware of one of the main problems regarding alcohol consumption:
Even if there are some beneficial effects regarding the protection against cardiovascular diseases, the intake of alcohol has several side-effects, which are indeed quite detrimental to one’s health.
It’s probably not worth being protected against heart diseases when you die from liver failure or cancer, which was caused by long-term alcohol consumption.
Alcohol is most likely not healthy and can lead to severe implications for your own health.
Feel always free to discuss my ideas and share your own thoughts about the things I’m writing about. Nobody is omniscient and if we all walk away a bit smarter than before, we’ll have achieved a lot.
Thanks for reading and stay sceptical.
Make sure, to check out #steemstem for more science related content.
(1) Cecil R. Pace-Asciak, Susan Hahn, Eleftherios P. Diamandis,
George Soleas, David M. Goldberg. The red wine phenolics trans-resveratrol and
quercetin block human platelet aggregation and eicosanoid synthesis: Implications for protection
against coronary heart disease. 1995. Clinica Chimica Acta 235. 207-219
(3) Subhendu Mukherjee, Istvan Lekli, Narasimman Gurusamy, Alberto A. A. Bertelli, Dipak K. Das. Expression of the longevity proteins by both red and white wines and their cardioprotective components, resveratrol, tyrosol, and hydroxytyrosol. Volume 46, Issue 5, 1 March 2009, Pages 573-578
(5) Francisco Orallo, Ezequiel Alvarez, Mercedes Camina, Jose Manuel Leiro, Eva Gomez, Pilar Fernandez. The Possible Implication of trans-Resveratrol in the Cardioprotective Effects of Long-Term Moderate Wine Consumption. 2001. MOLECULAR PHARMACOLOGY Vol. 61, No. 2
(6) B.C.A.A Marques, M Trindade, J.C.F Aquino, A.R Cunha, R.O Gismondi, M.F
Neves & W Oigman. Beneficial effects of acute trans-resveratrol supplementation in treated hypertensive patients with endothelial dysfunction. 2017. Clinical and Experimental Hypertension
Volume 40, 2018 - Issue 3
(7) Fuqin Yan, Xiaomeng Sun, Chun Xu. Protective effects of resveratrol improve cardiovascular function in rats with diabetes. 2017. Experimental and Therapeutic Medicine 15: 1728-1734
(8) Jinhui Zhao. Tim Stockwell. Audra Roemer. Timothy Naimi. Tanya Chikritzhs. Alcohol Consumption and Mortality From Coronary Heart Disease:An Updated Meta-Analysis of Cohort Studies. J Stud Alcohol Drugs. 2017 May;78(3):375-386.
(9) Sohaib Haseeb, Bryce Alexander, Adrian Baranchuk. Wine and Cardiovascular Health A Comprehensive Review. 2017. Circulation. October 10, 2017, Volume 136, Issue 15
(10) John C Barefoot, Morten Grønbæk, John R Feaganes, R Sue McPherson, Redford B Williams, Ilene C Siegler. Alcoholic beverage preference, diet, and health habits in the UNC Alumni Heart Study. The American Journal of Clinical Nutrition, Volume 76, Issue 2, 1 August 2002, Pages 466–472
(11) Dirk W. Lachenmeier, Rolf Godelmann, Barbara Witt, Kerstin Riedel, Jürgen Rehm. Can resveratrol in wine protect against the carcinogenicity of ethanol? A probabilistic dose‐response assessment. International Journal of Cancer. Volume134, Issue1 1 January 2014