Tag Archives: cardiovascular health

The Effect of Red Wines with Varying Antioxidant Activities on the Cardiovascular Health of Rats

Posted on March 11, 2013 by Becca| Leave a comment

 

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Thickening of the arteries, or atherosclerosis, is a disease that is often associated with complications of heart attack and stroke. It is caused by LDL cholesterol (low density lipoprotein) which enters into the inner lining of the arteries which causes vascular oxidative stress. This oxidative stress occurs via the production of too many reactive free radicals that can’t be controlled by the antioxidative species that naturally reside in the body. When unable to control simply by altering diet and exercise habits, a way to reduce the oxidative stress (and thus the occurrence of too many harmful free radicals) is needed to reduce the risk of atherosclerosis and ultimately those cardiovascular events that are triggered by this disease.

As you all know by now, if you read this blog or have read one of the countless research articles related to the topic, that wine (particularly red wine) is loaded with polyphenols, which originate in the skins and seeds of the grape though a small fraction originates from the oak barrels that the wines are fermented and/or aged therein. Red wine typically has higher levels of polyphenols present, since red wine goes through a maceration step where the skins and seeds are left in the juice for a period of time, allowing the extraction of greater levels of polyphenols. White wines do not undergo this maceration step, nor do the skins and seeds typically remain in contact with the juice for any reason (of course there are exceptions), thereby resulting in a marked reduction in polyphenols in the finished white wine.

Polyphenols are known to have high antioxidant capacities, a fact by which has been studied over and over again in the literature. In studies of red wine and its effects on cardiovascular health, several mechanisms for possible protection have been described. Some studies showed that the cardio-protective nature of the wine is related to the high antioxidant capacities of the polyphenols present in the wine, while other studies claim that the polyphenols are acting in a more anti-platelet or anti-inflammatory fashion, which increases vasodilatation (i.e. opening of blood vessels) and improves cardiac function.

The study presented today aimed to examine the antioxidant activities of red wine in the rat model, while simultaneously determining whether or not results found in vitro (i.e. outside of the body, or in other words, in test tubes and petri dishes) correlated with what is found in vivo (i.e. inside the body). The latter is important for if it were found that in vitro results did not correlate with in vivo results, then making any assumptions or formulating implications for human health from in vitro studies would be much more difficult without an in vivo component.

By Patrick J. Lynch (1999), modified by Christian 2003 (Yale University - School of medicine) [CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons

By Patrick J. Lynch (1999), modified by Christian 2003 (Yale University – School of medicine) [CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons

Methods

The wines used in this study were: 1) a Chilean Syrah; 2) a Brazilian Cabernet Sauvignon; and 3) an Argentinean red blend. After purchase, the bottles were opened, put into test tubes, and stored at -80oC until ready for use in the experiment.

Rats were randomly split into 5 groups: 1) control rats fed a regular diet; 2) rats fed a high fat diet and 770-1360μL water; 3) rats fed a high fat diet and 800-1380μL of red wine with low antioxidant activity; 4) rats fed a high fat diet and 790-1170μL of red wine with intermediate antioxidant activity; and 5) rats fed a high fat diet and 820-1340μL of red wine with high antioxidant activity. The dose of wine was adjusted every week (for a total of 4 weeks) according to the body weight of the rats.

After the 4 week experiment, blood and liver samples were taken from the rats and analyzed for the following: plasma fatty acid composition, malondialdehyde concentration, plasma antioxidant activity, antioxidant enzyme expression (superoxide dismutase, catalase, and glutathione peroxidase), and antioxidant enzyme activity.

Results

• Rats fed a high fat diet showed increased levels of malondialdehyde in their blood plasma.
• Rats fed a high fat diet ate less food than the control diet group, though there were no differences in weight gain between the groups.
• Rats supplemented with high antioxidant wine had the lowest malondialdehyde levels in the liver and plasma antioxidant activity compared with all other groups and the low antioxidant wine group, respectively.
• A correlation was found between in vitro antioxidant activity measurements in the wine and in vitro measurements in the blood plasma of rats.
• Catalase and glutathione peroxidase were highest in rats supplemented with the low antioxidant activity wine.
• The only difference in enzyme activities was: superoxide dismutase was higher in the high antioxidant wine group compared with the medium antioxidant wine group.
• The only differences in plasma fatty acid profiles were the following: 1) palmitoleic acid was higher in the high antioxidant wine group compared with the medium antioxidant wine group; and 2) cis-13,16-docosadienoic acid was higher in all wines groups compared with the non-wine control.
• Rats supplemented with the low antioxidant wines had increased activity in all enzymes measured compared with rats supplemented with the high antioxidant wine.
• Trans-resveratrol, quercetin, and anthocyanidin levels were highest in rats supplemented with high antioxidant activity wines.

Conclusions

The authors of this study claimed that based on the results, rats supplemented with wines with high antioxidant activities were better able to protect against blood plasma and liver oxidative stress than wines with lower antioxidant activities. They also suggested that resveratrol, quercetin, and anthocyanidins play an important role in the protection against oxidative stress due to their high abundance in the rats supplemented with the high antioxidant activity wines. It was also noted that higher levels of trans-resveratrol were associated with lower levels of malondialdehyde, which further supports the idea that this compound plays a major role in protection against oxidative stress in the body.

The take-home given by the authors was that since there are differences between rats and human in regards to their response, further studies should only focus on wines with medium to high antioxidant activities, because wine with low antioxidant activities may not provide much protection against oxidative stress and atherosclerosis than would be ideal.

Photo by Nick Savchenko: http://farm8.staticflickr.com/7160/6495446227_33a3f9dfe1.jpg

Photo by Nick Savchenko: http://farm8.staticflickr.com/7160/6495446227_33a3f9dfe1.jpg

I’d love to hear what you all think about this topic. Do you really care about the antioxidant capacity of wine? Does this factor into your buying behavior when it comes to purchasing wine? Or, is this all just interesting for science’s sake and you’re going to drink wine anyway knowing you might be getting a nice little cardio-protective bonus? Please feel free to leave comments!

Source: Macedo, L.F.L., Rogero, M.M., Guimarães, J.P., Granato, D., Lobato, L.P., and Castro, I.A. 2013. Effect of red wines with different in vitro antioxidant activity on oxidative stress of high-fat diet rats. Food Chemistry 137: 122-129.

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The Effect of Wine Consumption on Repeat Cardiovascular Events after Heart Attack

Posted on January 2, 2013 by Becca| 7 Comments

 

We’ve all seen the reports suggesting that wine consumption, particular red wine, is beneficial for many aspects of one’s health, with the most studied probably being wine’s affect on cardiovascular health.  Studies have shown that red wine consumption may have cardiovascular health benefits by way of cardioprotective properties.  Of course, there are other studies that suggest there is no link between red wine consumption and cardiovascular health benefits; however, when in consumed in moderation, there does appear to be something going on.

Most of the studies to date have examined animals or people with or without cardiac disease risk factors prior to any adverse events occurring.  According to

By Patrick J. Lynch (1999), modified by Christian 2003 (Yale University - School of medicine) [CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons

By Patrick J. Lynch (1999), modified by Christian 2003 (Yale University – School of medicine) [CC-BY-2.5 (http://creativecommons.org/licenses/by/2.5)], via Wikimedia Commons

the authors of the short study presented today, very few studies have examined the effect of red wine consumption on people who have recently experienced a cardiac event and how their risk changes with continued red wine consumption post cardiac event.

Methods

A total of 11,323 Italian participants were enrolled in this study.  Questions regarding demographics, cardiovascular risk factors, medications, dietary habits, and medical history were answered.  After cardiac events, participants were given advice and instructions on how they should eat and/or drink and general lifestyle changes.

Participants were followed over time at clinic visits to update information on any lifestyle and health changes.  Clinic visits were 0.5, 1.5, and 3.5 years after the initial cardiac event.  Heart attack was considered the initial cardiac event.

Daily wine intake was determined and consumers were separated into the following categories: 1) never/almost never; 2) up to 0.5L per day (0.1-3.3 glasses); 3) between 0.5L and 1L per day (3.4-6.8 glasses); and 4) greater than 1L per day (greater than 6.8 glasses).

Photo by isante_magazine: http://farm5.staticflickr.com/4086/5057195715_74f63d6cca.jpg

Photo by isante_magazine: http://farm5.staticflickr.com/4086/5057195715_74f63d6cca.jpg

Results

  • 85.4% of participants were male and 14.6% were female.
  • After heart attack, those participants drinking higher amounts of wine tended to be younger, more likely have lower systolic blood pressure, able to perform an exercise stress test, current smoker and less likely to have had more than one heart attack, diabetes, or hypertension.
  • Wine consumption as associated with consumption of butter, cheese, coffee, and oils and negatively associated with consumption of fish, fruit, vegetables, and olive oil.
  • During the first 6 months after heart attack, the proportion on non-drinkers increased.
    • 21.6% of wine drinkers reported giving up drinking after heart attack.
    • 24% of those drinking less than 0.5L and 15% of those drinking greater than 0.5L stopped drinking wine completely.
    • For those drinking greater than 0.5L of wine per day, 80% of them reduced their wine consumption by 6 months after heart attack.
    • Only a small number of participants increased wine consumption after heart attack.
  • After 37,021 person-years after the initial heart attack, there were 1168 cardiovascular events including 671 deaths related to cardiovascular events, 456 heart attacks (nonfatal), and 119 strokes (nonfatal).
  • The rate of new cardiovascular events was lower in participants who consumed higher levels of wine.
    • The rate of new cardiovascular events was lowest in participants who consumed moderate levels of wine (up to 0.5L per day).
  • The risk of new cardiovascular events decreased by 13% for those consuming up to 0.5L of wine per day compared with nondrinkers.
  • No significant differences between wine consumption and cardiovascular events were found when other confounding factors were included (i.e. sex and compliance with advised treatment).
  • Pharmacological treatments did not affect the results of the study.
  • After the long-term follow up (between 5.7 and 7.3 years) and 60,022 person-years, 1659 participants had died (1400 men and 259 women).
  • Wine consumption up to 0.5L and more than 0.5L per day was associated with a lower risk of death than nondrinkers.

Results

According to the authors, the results of this study suggest that moderate wine consumption was associated with a new cardiovascular event after a prior heart attack.  However, once changing in drinking habits and other confounding factors were taken into consideration, this association was no longer significant.  The authors noted that since they were not able to include the highest level of alcohol consumption (greater than 1L per day) due to too few participants actually consuming that much on a regular basis, there could have been some weakening in power of the analysis.

If you don’t take the confounding factors into consideration, the results suggest that there is a negative association between moderate wine consumption and

By Alex Proimos (Flickr: The Stethoscope) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

By Alex Proimos (Flickr: The Stethoscope) [CC-BY-2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

cardiovascular events and death due to new cardiovascular events.  According to the authors, those Italian individuals with prior cardiovascular history may have reduced risk of repeat events if they consume moderate amounts of wine.

Taking confounding factors into consideration is very important, so I’m not sure why the authors would still focus on the positive results they found prior to taking these results into consideration.  The fact of the matter is that confounding factors are important, and if including them in the model result in insignificant results, well then that should be the result you present.  There were other factors that were not taken into consideration that limited the study, including data on physical activity and other types of alcohol consumed by participants.  Both of these could have significant impacts on the results of the study.

The authors concluded by saying that light to moderate wine consumption was not associated with increased risks of cardiovascular events or cardiovascular-related deaths, which is a result I can get on board with based on the statistics.  While it is true wine consumption did not increase the risk of further cardiovascular events, it is not clear whether or not wine consumption actually decreases this risk.  The study should be repeated with more confounding factors taken into consideration.  Also, the study should be repeated in other locations, since the dietary habits of Italians and people from other corners of the world are different and thereby the cardiovascular risks will likely be different.

I’d love to hear what you all think of this study.  Please feel free to leave your comments!

Source: Levantesi, G., Marfisi, R., Mozaffarian, D., Franzosi, M.G., Maggioni, A., Nicolosi, G.L., Schweiger, C., Siletta, M., Tavazzi, L., Tognoni, G., and Marchioli, R. 2011. Wine consumption and risk of cardiovascular events after myocardial infarction: Results from the GISSI-Prevenzione trial. International Journal of Cardiology, doi: 10.1016/j.ijcard.2011.06.053.

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Enzymatic Extracts from Wine Industry Waste May Provide Cardiovascular Benefits in the Rat Model

Posted on October 18, 2012 by Becca| 2 Comments

Wine industry wastes are a topic we’ve covered a few times before on The Academic Wino.  We’ve discussed papers on how water waste from the wine industry may be used as an alternative biofuel or biogas as well papers discussing how grape seed extract could be used as a meat preservative.  Grape pomace has also been investigated as a potential protein supplement for Tilapia fish, and in humans, grape pomace has been investigated as a potential supplement to help those suffering from diabetes.

Grape pomace, or marc, can be problematic in the environment when it is accumulated in large quantities.  Recycling grape pomace may provide the winery with economic gains by creating new products from it, in addition to protecting the environment from further damage or industrial pollution.  Grape pomace is full of bioactive polyphenolic compounds which could be beneficial for products aimed at providing some sort of health benefits for animals or humans.  Since the vast majority of these polyphenolic nutrients are located in the skins and seeds of the grapes, the grape pomace; which is basically pressed

Photo by Klearchos Kapoutsis; http://farm7.staticflickr.com/6182/6077347562_94e958e71f.jpg

skins and seeds left after the winemaking process is complete; is a huge source of nutrition that could be utilized in a sort of functional food or “nutraceutical” (think ‘vitamin’ or ‘supplement’).

Polyphenolic compounds have previously been extracted from grape pomace by way of organic solvents, which themselves may be a health risk and also concerning for environmental contamination.  One alternative that has been designed for this purpose is enzymatic extraction.  This method results in a more environmentally-friendly water-soluble by-product which is nontoxic.

These polyphenolic compounds that are found in wine are well documented to be beneficial to human health, including (but not limited to) cardiovascular benefits, antioxidant properties, and anticarcinogenic benefits.  Studies have shown that grape seed extracts also possess similar health benefits as wine, and have been shown to have cardiovascular and vasodilator benefits in the rat model.  Specifically, grape seed (and skin) extracts improve vascular function by increasing nitric oxide (NO), a vasodilator and antiplatelet factor, to the vessels endothelial cells.

Though grape seed extracts and grape skin extracts have been frequently studied for their potential health benefits, no studies have actually examined entire grape pomace extract to determine its ability to provide health benefits to animals or humans.  The goal of the study presented today was to chemically characterize grape pomace extract using enzymatic extraction methods, and to test its effects on the vascular system of rats.  The results could provide information regarding the usability of grape pomace as a functional food or dietary supplement for protecting against cardiovascular diseases.

Methods

Grape pomace consisted of pressed Verdejo grapes from Yllera wineries in Rueda, Valladolid, Spain, which contained the skins, pulp, seeds, and stems.  Polyphenolic compounds were extracted using an enzymatic extraction process then completely dried.  The extract was then lyophilized to a fine red powder.  For every 100 grams of wet pomace, 12 grams of lyophilized extract was made.

The grape pomace extract was analyzed for the following: total protein, crude fat, phytochemical content (kaempferol, quercetin, procyanidin and catechin), oxygen radical absorbance capacity (ORAC), and DPPH radical scavenging activity.

Photo by Nick Savchenko: http://farm8.staticflickr.com/7160/6495446227_33a3f9dfe1.jpg

Male rats were used and were fed a normal laboratory diet.  For the testing vascular function, the thoracic aorta, and second- or third-order branches of small mesenteric arteries were isolated.

For vascular function, the following for measured/analyzed: mechanical activity, relaxation and contraction, NO involvement, and O2- production in arterial sections.

Results

  • The enzymatic extraction process increased the carbohydrate and protein content of the pomace extract.
    • The insoluble fibers, cellulose, hemicellulose, and lignine, all decreased after extraction.
    • Pectin concentrations increased after extraction.
    • There was an overall reduction in fat content after extraction.
  • Polyphenolic compounds present in the extract included kaempferol, catechin, quercetin, and procyanidins B1 and B2.
    • Only trace amounts of resveratrol, gallocatechin, and anthocyanidins were found.
  • The antioxidant activity (ORAC) of the grape pomace extract was 4238.9 +/- 731.0 nmol TE/mg.
  • Addition of grape pomace extract elicited relaxation in the endothelium-intact vasculature of rats.
    • After removing the endothelial layer, this relaxation (a.k.a. vasodilation) was no longer observed.
  • When exposed to nitric oxide synthase inhibitors, vasodilation of the arteries was significantly reduced.
    • The NO synthase inhibitors prevented the synethsis (production) of NO, which had a negative effect on the vasodilatory properties of the blood vessels.
      • After adding grape pomace extract, this inhibitory effect was reversed.
    • After adding the α-adrenergic agonist Phe, concentration-dependent contractions were induced.
      • Exposure to grape pomace extract reduced the maximum concentration elicited by Phe.
  • ET-1 and DETCA, both of which are known to promote the vascular production of O2-, elicited and sustained a contraction in the rat aortas.
    • By exposing the aortas to grape pomace extract, these vascular contractions elicited by the ET-1 and DETCA were reduced.
  • After 3 hours, there was a significant increase in O2- production brought on by ET-1.
    • Grape pomace extract prevented this significant increase in O2- production.

Conclusions

First and foremost, this paper showed that processing grape pomace using an enzymatic extraction process may serve as a good mechanism for extracting the beneficial polyphenols from grape pomace and potentially other foodstuffs which may be recycled into functional foods, dietary supplements, or other

Photo by GreenFlames09: http://farm1.staticflickr.com/43/74296211_4acbdb3934.jpg

uses.  The antioxidant activity of the grape pomace extracted in this manner was at similar levels to pomaces extracted using more traditional chemical methods.

Exposure of rat vasculature to grape pomace extract resulted in a reduction in superoxide anion elicited by ET-1.  At the same time, the vascular contraction caused by ET-1 was reduced due to grape pomace exposure.  Exposure to grape pomace also prevented O2- production in the vasculature of the rats.

What do these results suggest?

The authors of the study state that these results are the first of their kind showing the vascular vasodilatory properties of grape pomace extract.  According to the authors, it appears as though grape pomace extract (processed by enzymatic extraction) induces endothelium-dependent vasodilation and reduces vascular constriction brought on by NO-dependent mechanisms.

In plain English, it seems as though like grape seed and grape skin extract, grape pomace extracts also possess significant health benefits, in particular cardiovascular benefits.  Of course, this study focused on the rat model, therefore to be certain similar results will be seen in humans, clinical research trials would need to be performed.

I would also like to see a study that directly compares the vasodilatory properties of blood vessels after exposure by grape pomace extracts produced from traditional organic solvent methods with extract produced from enzymatic extraction methods.  Does one extraction method result in an extract with superior health benefits to the other?  Or is this simply a matter of environmental soundness (which is extremely important in and of itself).

Using the information gathered from this study, what sorts of studies would you like to see performed in the future?  What is the next step?  Do you have any other ideas for using grape pomace that have not been investigated yet in the scientific literature?

Please leave your comments!

Source: Rodriguez-Rodriguez, R., Justo, M.L., Claro, C.M., Vila, E., Parrado, J., Herrera, M.D., and de Sotomayor, M.A. 2012. Endothelium-dependent vasodilator and antioxidant properties of a novel enzymatic extract of grape pomace from wine industrial waste. Food Chemistry 135: 1044-1051.

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Lower Alcohol Wines Do Not Alter Cardiovascular Benefits in the Rat Model: Study Results and Personal Thoughts

Posted on October 2, 2012 by Becca| 4 Comments

A few weeks ago, I sent out a tweet and shared on Facebook an article from CBS News describing a new study which found that red wine may reduce blood pressure in men, but only if it is non-alcoholic.  Sure, this makes sense to me: component of red wine (particularly polyphenols) have been shown to have many health benefits, including cardiovascular health benefits, and alcohol has been shown to have negative health effect when consumed heavily.

Reading the article further, some of the limitations of the study were addressed, which put into question for me the validity of the results.  Specifically, there was no control group for this study.  That right there is a major red flag, and for anyone who has ever worked in research, you know you must have a control group in order to make ANY sort of comparison or come to any sort of conclusion.  The study also mentioned that it is well known that blood pressure goes up after one stops drinking alcohol, even if they weren’t drinking that much to begin with, so the overlap between this possible increase and the next phase of the experiment could have muddled the results.

Photo by gandhiji40: http://farm1.staticflickr.com/128/395241000_68fd86f260.jpg

Dissatisfied with these huge limitations in the study protocol, I wanted to see if any other studies have focused on this idea of non-alcoholic or at least low alcohol wines, and if they are any better for us than wines with the “standard” amount of alcohol present.  As luck would have it, I stumbled upon an article that was published in June of this year that examined the effects of low alcohol wines on cardiovascular health.  Unlike the aforementioned article, this article was performed on rats instead of humans, which makes the comparison an indirect one, but potentially important nonetheless.

In addition to blood pressure benefits, the polyphenols in red wine have also been shown to have protection against ischemia/reperfusion events (that’s doctor talk for “heart attacks”).  Though it is known that these polyphenols have protective effects against heart attacks, it is not yet known the proportion to which this effect is attributable to the alcohol or the polyphenols in red wine.  The study presented today aimed to answer that question by comparing antioxidant and cardio-protective properties of wine with “standard” levels of alcohol, and wines with lowered levels of alcohol.

Methods

French red, rosé, and white wines with 12% alcohol by volume were used in this study.  In order to create the same wine with lower alcohol, alcohol was removed via the lirisation process, which the authors confirm did not alter the chemical composition of the wine, other than the alcohol level.

Antioxidant characteristics of each wine were measured using the oxygen radical absorbance capacity (ORAC) assay with fluorescein.

Male Long Evans rats(age not reported) were utilized for this study.  There were

Photo by Dawn Huczek: http://www.flickr.com/photos/31064702@N05/4386334680/

a total of 4 general treatment groups to which these rats were assigned: Control group (no wine); 12% v/v wine group; 6% v/v wine group; 12% v/v alcohol extract group; or 6% v/v alcohol extract group. The alcohol extract groups were to compare to the red wine and control groups in order to determine if the alcohol contributed to changed in cardio-protective properties, or if it was something else attributable to the non-alcohol components of the wine.  Reminder:  red, rosé, and white wines were tested for each alcohol level.

Alcoholic solutions were created by adding one part red wine or alcohol extract to 7 parts drinking water.  This corresponds to about 2 glasses of wine per day, relative to body weight.  Rats were fed these red wine, alcohol, or water solutions for 10 consecutive days, then rats were harvested for analysis.

Rat cardiac function was monitored and analyzed by measuring heart rate, left ventricular developed pressure, and coronary flow.  If you’re curious to know, left ventricular developed pressure is calculated as the difference between left ventricular end systolic pressure and left ventricular end diastolic pressure.  Rate pressure product was calculated by multiplying the heart rate and the left ventricular developed pressure at a given time point.

All rat hearts underwent 30 minutes of ischemia (closing of the blood vessels—like a clot causing a heart attack) and 30 minutes of reperfusion (opening on the blood vessels—short term recovery from the heart attack).

Results

  • Red wine contained higher levels of antioxidants than white or rosé wines (to be expected).
  • The reduction of alcohol to 6% v/v in wines did not alter the antioxidant levels of any of the wines.
  • Giving rats wine or alcohol extract prior to ischemia/reperfusion did not alter the functional character of the rat hearts.
  • Treatment with wine at 12% v/v and 6% v/v alcohol improved left ventricular developed pressure function after reperfusion compared with controls.
  • No differences were seen in cardio performance after ischemia/reperfusion in 12% v/v and 6% v/v alcohol wines.
  • Treatment with wine at 12% v/v and 6% v/v alcohol significantly improved rate pressure product compared with the controls.
  • Treatment with alcohol extract did not improve any of the cardiac functions measured compared with the control group.

What does this all mean?

This was a pretty brief study, and the results are fairly straight forward.  According to the authors of the study, it is the first to show that chronic and moderate consumption of red wine for 10 days in rats is protective against ischemia/reperfusion (recall: heart attack).

Photo by David Wilbanks: http://www.fotopedia.com/items/flickr-2201098920/slideshow

Bringing the focus back to the low-alcohol quality of some of the wines, the results of the study show that lower alcohol wines do not affect the antioxidant properties of the wine, nor do they provide any extra cardiovascular benefit that wines with twice as much alcohol provide.  This result is seemingly inconsistent with the results of the blood pressure study described in the introduction to this post.

The study results indicate that while red wine solutions provide cardio-protective benefits to rats, alcohol extracts alone do not.  By eliminating all other components of the wine, the result indicates that alcohol is not responsible for providing any positive cardiovascular benefit but rather the remaining components of the wine (likely the polyphenols) provide this benefit.

So which study is correct?

I certainly cannot say that this study disproves the earlier study, since many of the methods were different between each publication.  First of all, this study used rats, while the study mentioned earlier used actual humans.  Second, that this study did use controls (good!!), while the previous study mentioned had no controls (bad!!).  Third, the study mentioned previously just monitored blood pressure, while this study measured several cardiac function parameters.  Of course I can’t directly compare these two studies, but it certainly gets one thinking!  Neither study mentioned how getting rid of the alcohol altered the aroma/flavor/quality of the wine, nor do I have time to elaborate more now on that important topic.

However, I can say with confidence that this study provides results that call into question the validity of the first study, or that perhaps the entire story is much more complicated than a simple “yes or no” answer.  Maybe the level of alcohol in wine doesn’t matter to some groups, but does matter to others.  Maybe it has certain positive health benefits with some groups, but not with others.

One thing about medicine is that it’s complicated: ridiculously complicated.  Sure, we can say that drinking a handle of vodka isn’t going to be good for any individual, but can we say with certainty that two glasses of wine are or are not good for each individual?  No, because each every human body is different.  Take antidepressant medications, for example: one antidepressant medication will work famously for one patient, but when given to another patient, it may not have any effect or even have an opposite effect (*note: I qualify this example based on my first hand experience working in the Neurology clinic at my place of employment*).

My guess is that wine behaves in the same way.  For some people, moderate wine consumption will be great for their overall health, whereas for other people, wine may not be as beneficial.  The complicated nature of both wine and the human body will make many blanket statements about the health benefits of wine near impossible.  We have seen it happen so much already, with one study claiming one result and another coming out a few weeks later saying the opposite.

While I believe this type research is very important and should continue to be funded and performed, each individual person should certainly talk things over with their doctor if there is any concern whatsoever about possible positive or negative health benefits of the wine that they consume.  Of course, for me, I enjoy drinking wine for reasons other than potential health benefits, so regardless of what study results come forth, I likely will not alter my consumption habits.

I’d love to hear what you all think of this topic, and of the topic of the health benefits of wine in general.  Please leave your comments and engage in the discussion!

Sources:

CBS article: http://www.cbsnews.com/8301-504763_162-57508191-10391704/red-wine-may-reduce-mens-blood-pressure-but-only-if-its-non-alcoholic/   Last accessed 10/01/2012.

Article presented today:  Lamont, K., Blackhurst, D., Albertyn, Z., Marais, D., Lecour, S. 2012. Lowering the alcohol content of red wine does not alter its cardioprotective properties. South African Medical Journal 102 (6): 565-567.

 

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