We've all heard about the purported benefits of drinking red wine for heart health. But, is red wine really good for heart health?
No organization recommends drinking red wine over other types of alcohol, including the American Heart Association. The evidence supporting the claim that red wine is heart-healthy is much less clear-cut than you might expect. Let’s take a dive into what the research says and how this claim came to be.
The Origin: How Red Wine Rose To Fame
Though wine has been consumed for centuries, the theory that red wine consumption may have cardioprotective effects originated from data from the 1980s, which suggested that despite high intake of foods rich in saturated fats, French people had a lower mortality rate from coronary heart disease relative to individuals from the U.S. and the U.K. . Because individuals from France also consume more red wine relative to individuals from these other countries, it was posited that red wine consumption might explain this “paradox.” Thus, this observation spurred countless studies on red wine and forever changed the marketing of red wine.
The Mediterranean diet has also been extensively studied in the context of cardiovascular disease, with ample data supporting its cardioprotective effects. The Mediterranean eating pattern is rich in plant foods, like whole grains, beans, fruits and vegetables, healthy fats from nuts, olive oil, and fish, and includes moderate amounts of dairy, poultry, and red wine . Similarly, red wine is consumed “moderately and regularly” by individuals who live in four of the so-called “blue zones,” regions across the world that are home to a high proportion of centenarians .
Although individuals in all of these regions consume moderate amounts of red wine, it is important to note that red wine comprises only one aspect of their eating patterns, which also includes foods high in fiber and healthy fats. Wine is also often consumed slowly, socially, and with meals in these regions. It is extremely difficult to tease out the effects of individual components of these diets on health, and more likely than not, the real benefits come from the synergy of these parts in addition to other lifestyle factors.
What are the “heart-healthy” nutritional components of red wine?
Wine is produced from the fermentation of grapes, and the type of grape used to make wine impacts the chemical composition of the wine. In addition to water and alcohol (ethanol), wine contains polyphenols, a class of antioxidants that includes quercetin and resveratrol. The latter is the compound that has been most extensively investigated for its potential cardioprotective effects. Red wine has ten times the polyphenol content of white wine as well as lower sugar content .
Potential mechanisms by which resveratrol might exert positive effects on heart health include reductions in platelet aggregation, improved fibrinolysis, and vasodilation . Interestingly though, resveratrol itself, like many polyphenols, has a very low bioavailability and isn’t absorbed well into our bloodstream. Furthermore, resveratrol is actually a poor antioxidant, meaning it doesn’t do a good job fighting stress and inflammation in the body. In fact, resveratrol’s metabolites, or breakdown products, likely mediate any potential antioxidant effects of polyphenols . An evolving area of research examines how the gut microbiota contributes to the production of these metabolites.
Interestingly, a prospective study of older adults living in the Chianti region of Italy did not find an association between resveratrol metabolite concentration and inflammatory markers, cardiovascular disease, cancer, or overall risk of mortality. The authors concluded, “Resveratrol levels achieved with a Western diet did not have a substantial influence on health status and mortality risk of the population in this study.”
Resveratrol and other polyphenols are not unique to red wine. Other sources of these compounds include peanuts, pistachios, grapes, blueberries, cranberries, and cocoa, and dark chocolate . Several foods, including grape juice, frozen strawberries, and frozen cranberries, have a resveratrol content comparable to red wine (per serving).
Information obtained from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3141184/
The relationship between red wine and heart disease
Previous observational and experimental studies suggested that red wine consumption may have cardioprotective effects. For example, a systematic review and meta-analysis of 84 prospective cohort studies revealed that alcohol consumption between 2.5–14.9 g/day (about ≤1 drink a day) was associated with a 14–25% reduction in the risk of outcomes, including cardiovascular disease mortality, coronary heart disease, coronary heart disease mortality, and stroke.
However, recent research using a more sophisticated design that can account for genetic variations in a study population (also known as Mendelian randomization) challenges this notion of a cardioprotective effect of alcohol. For example, a 2014 study including over 260,000 participants of European descent found that individuals with a genetic variant associated with non-drinking and lower alcohol consumption had a more favorable cardiovascular profile and a reduced risk of coronary heart disease than those without the genetic variant. The researchers concluded that “reduction of alcohol consumption, even for light to moderate drinkers, is beneficial for cardiovascular health.”
Is red wine good for blood pressure and the prevention of heart disease?
Research from human studies does not suggest a clear benefit of red wine consumption for blood pressure. A recent systematic review and meta-analysis compared the effects of red wine polyphenols in animal versus human studies on vascular health, namely blood pressure. Human studies indicated significant improvements in systolic blood pressure (-2.6 mmHg), with a greater improvement in pure-resveratrol studies versus those that used whole grape or grape seed extract.
The researchers observed improvements in blood pressure in 84% of the animal studies included in this analysis, while the benefits in human studies were “not as prevalent.” This is a common theme for many endpoints of studies investigating the relationship between red wine consumption and health. Differences between animal and human studies of resveratrol can be explained by variations in metabolism and metabolic rate between species. Furthermore, other factors, such as the “background diet,” can be more tightly controlled in animal studies. Not only is there more variability in human versus animal diets, but there is also greater variability in polyphenol consumption from other dietary sources than wine or supplements. Importantly, doses of resveratrol administered in animal trials are often much higher than a human could consume via diet alone and far exceeds the resveratrol content of a glass or two of red wine .
What are the limitations of the research to date on alcohol and health?
Purported benefits of drinking red wine are numerous and include reduced risk of heart disease, diabetes, dementia, and weight gain. However, it is important to note that no studies have definitively shown that moderate alcohol consumption, wine or otherwise, positively impacts health.
As with most nutrition research, it is challenging to study the effects of alcohol on health. Many of the studies examining these effects are observational, meaning that individuals are followed over time. In this type of study design, associations can be revealed between two variables, but conclusions about causation can’t necessarily be drawn. In addition, it can be difficult to determine whether other positive lifestyle factors, such as diet and exercise, influence any observed associations between moderate alcohol intake and health. Furthermore, individuals who drink wine are more likely to be more affluent, to be more highly educated, and to live healthier lifestyles . The relationship between moderate alcohol consumption and health is evolving and the current guidelines suggest that drinking less alcohol is better for health.
Potential risks of drinking wine
Even if there are unique cardioprotective benefits of red wine, which are up for debate, these positive effects need to be put into the context of the risks of drinking alcohol as well as one’s individual health. Any amount of alcohol consumption increases the risk of certain types of cancer. Based on the available evidence, The American Cancer Society and American Institute for Cancer Research recommend that it is “best” to avoid alcohol for cancer prevention. Furthermore, excess alcohol consumption increases the risk of alcohol use disorder, liver disease, and even heart disease; excessive alcohol consumption has been shown to raise blood pressure, increase the risk of stroke, etc.
So, should you drink wine?
No organization recommends drinking red wine over other types of alcohol, including the American Heart Association. If one chooses to drink red wine, they should only do so because they enjoy it, and it shouldn’t be thought of as a “health food” or a means of getting one’s “daily dose of polyphenols.” Those who choose to drink wine should follow the guidelines for moderate alcohol consumption. Moderate alcohol consumption, as defined by the U.S. Dietary Guidelines for Americans, is 2 standard drinks per day for men, and one standard drink per day for women. Always speak with a healthcare provider about whether any alcohol consumption is appropriate for you.
Looking for wine alternatives? Order a copy of Mocktail Party for recipes like Zero-Proof Sparkling Wine, Sweet Wine-Not Slushie, and Red Sans-gria!