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Health effects of red wine: Where do we stand

Story highlights

  • Current research says it's safe for most people to have a glass of red wine every day
  • While there are likely some heart health and other benefits, there are risks, too

(CNN)Red wine, you have been many things to us over the years. A drink for royalty, a forbidden beverage for women, fuel for a bachelor weekend bender in the movie "Sideways."

But through it all -- with the exception of Prohibition and other dark spots in history -- wine has been medicine.
    A lot of the excitement over red wine in recent years has been around resveratrol and whether it can extend life, prevent cancer, cure Alzheimer's -- you name it. But that has obscured some of the more tried-and-true health benefits of wine. Since nearly the dawn of mankind, wine has been added to drinking water to kill bacteria, or consumed as a more hygienic alternative. More recently, the antimicrobial properties of wine, especially red wine, are being studied for cavity prevention.
    In the 1980s, the heart health benefits of red wine began to emerge. Numerous studies have by now found a connection between imbibing vino and lower rates of heart attack, stroke and death caused by heart disease.
    "The evidence is more firmly in place for red wine preventing heart disease, diabetes and a few other vascular (conditions) compared to cancer and dementia," said Dr. Howard Sesso, associate professor of medicine at Brigham and Women's Hospital in Massachusetts.
    But subsequent research revealed a twist to the happy story of red wine and healthy hearts. Other alcoholic drinks, beer and hard liquor, also seemed to provide heart benefits.
    "That's not to say that there might not be some special quality of red wine like resveratrol that could confer additional benefits," Sesso said. At least for now, though, attribute it to the alcohol.
    The story of red wine's effect on cancer and dementia is cloudier -- some studies found it increased the risks, other studies suggested a decrease. The most recent addition to the research found that people who drink red wine had a higher risk of cancers that are related to alcohol consumption, such as breast and liver. But the rub with all these studies is that people who drink red wine, or any kind of alcohol, might be different from non drinkers in other ways, such as diet, exercise level and smoking status.
    Based on the research so far, it seems safe to have a glass of red wine or alcoholic beverage a day, unless you have a medical condition or a history of alcoholism, and it may even provide some heart health benefit, Sesso said. However the risks of drinking too much, such as liver disease, drunken driving and domestic violence, are all very clear, making it difficult for doctors to prescribe drinking even a small amount of red wine in the age of modern medicine.
    Here's a look at how our views on wine have changed over the years.

    3000 B.C.: Wine is the best medicine

    Millennia before Jesus turned water into wine, the ancient Egyptians turned wine into medicine. Researchers found a jar in the tomb of King Scorpion I dating back to 3150 B.C. that contained traces of wine along with residue from balm, coriander, sage and mint. The finding suggests that ancient Egyptians dissolved herbs in wine, and then drank the cocktail to treat stomach problems, herpes and other ailments.

    750 B.C.: Wine does not pair well with womanhood

    Any wife found drinking wine could be put to death, according to the laws of Romulus, King of Rome. Concerns about the "weaker sex" imbibing wine continued for centuries. By 14 A.D., a Roman writer described how vino could cause women to "slip into some disgrace" and spiral downward "usually towards illicit sex."

    400 B.C.: Hippocrates prescribes red wine for digestion

    The father of medicine agreed with the ancient Egyptians that wine could soothe stomach ills. He specifically prescribed red wine for digestion and white wine for bladder problems. Wine in general could also serve as a disinfectant for wounds, according to Hippocrates, but the beverage was not appropriate for those with nervous system diseases because it could cause headaches.

    1250: Sip some grog to clear your mental fog

    Hundreds of years before studies suggesting that red wine may help protect against the common cold, Arnaldus de Villa Nova, a physician in southern France, detailed how wine can help sinus problems. De Villa Nova was also ahead of his time in writing about the benefit of wine for dementia. Current research supports the possibility that red wine in moderation could reduce the risk of Alzheimer's disease.

    1850: Don't drink the water, drink the wine instead

    Water is now considered the healthiest beverage choice, but it was often contaminated with cholera and typhus in the 1800s. A glass of milk, another healthy favorite, might also serve a helping of tuberculosis. As a result, Louis Pasteur, the father of microbiology himself, said that wine was "the most healthful and hygienic of all beverages."
    Wine can also make other beverages healthier. As far back as ancient Greece, it was used to sanitize water for drinking. Then in the late 1800s a Viennese professor demonstrated scientifically that wine can actually kill cholera and typhoid bacteria -- possibly explaining why Hippocrates concluded that wine could help indigestion! Experts began to recommend mixing red or white wine with water six to 12 hours before drinking, a practice that continued through parts of Europe until at least World War II.

    1920: Beware the evils of vino

    Hard alcohol started to get a bad rap with the temperance movement of the 1820s as religious groups in the United States and Europe spoke out about the threat of drunkenness and alcoholism. Red wine got a pass at least through the 1800s because it was viewed as hygienic, and less toxic than white wine. But then evidence started to pile up that red wine might also cause health problems, such as high blood pressure and organ damage.
    Over the next few decades, it became clear that red wine, just like white wine, beer and liquor, should be consumed in moderation -- which was the original position of the temperance movement. However, these nuances were lost on the prohibition movements that started cropping up across the United States in the late 1800s.

    1988: Migraine sufferers, put down your glass

    All of you who complain that red wine gives you migraines got some vindication from science. A small 1988 study in London found that nine out of 11 people with this complaint did indeed develop a migraine within a few hours of sipping a Spanish red, whereas another eight people served vodka with lemonade remained migraine free. Both beverages were served chilled and in a dark bottle to disguise their identity. The authors of the study concluded that alcohol on its own is not to blame, and that ingredients in red wine such as flavonoids could precipitate the debilitating headaches.

    1992: The French secret to heart health? Red wine, bien sûr!

    In the early 1990s, the French paradox made headlines, and forever more (at least, so far) put red wine in a healthy light. Doctors described the paradox that the French had lower death rates from heart disease in the 1980s than countries such as the United States and the United Kingdom, even though they had similar rates of smoking, blood pressure and other risk factors. The doctors suggested the reason could be that the copious amounts of wine -- in particular, red wine -- protects from heart disease.
    Many have questioned whether red wine deserved credit back then for lowering heart disease deaths. For one thing, the French actually had less fatty diets in the decades before the 1980s than the UK, which could have been what brought down death rates. But even if the role of red wine in the French paradox was overhyped, other studies in the 1980s and 1990s backed up the link between red wine and increased levels of good cholesterol and antioxidants.

    1995: Drink to your longevity

    Danish researchers found that, among 6,000 men and 7,000 women, those who drank three to five glasses of wine a day had a 49% lower rate of death over a 10-year period. Drinking the same amount of beer was not associated with lower death rate, and three to five glasses of hard alcohol increased the death rate by 34%. The researchers did not look at lifestyle factors, though, so it is possible that wine drinkers live longer because they eat healthier or exercise more, for example
    Fast forward another few years to 2003 and scientists started getting excited about the possibility that resveratrol, that magic ingredient in red wine and foods such as berries and chocolate, could extend the human life span by 30%. We are still waiting, science.

    2005: Can red wine put a cork in prostate cancer?

    Around the turn of the century, reports started to pour in of links between red wine and cancer risk. A 2005 study is one of the first to find a possible benefit, albeit small, for prostate cancer. It found that each additional glass of red wine that men consumed per week was associated with a 6% decrease in prostate cancer risk. However a larger study of moderate drinkers several years later failed to find a link between red wine and prostate cancer risk, so the jury is still out.

    2007: Smile: Red wine fights cavities

    Although it's been known since the late 1800s that red wine can kill bacteria in contaminated water, it took scientists until 2007 to show that it has a similar effect on the bugs that colonize our mouth. The study found that both red and white wine could block the growth of Streptococcus, a common culprit in cavity formation. Red wine had a stronger effect than white, possibly because of the acids it contains. Researchers used wine in which the alcohol had been removed, but it's possible that the alcohol in the real stuff may make it an even more potent bacteria buster.

    2013: Men, liquoring up may help your libido but hurt your fertility

    It may seem unlikely, but a 2013 study suggests that a component in red wine that acts like estrogen could give sperm a fertility boost. After taking a short bath in this compound, sperm excelled in categories such as moving toward an egg compared with the non-exposed little swimmers. The catch is that higher levels of the compound impaired sperm, and these levels might be closer to the actual dose that the sperm of moderate drinkers are exposed to.
    A point against alcohol consumption in general comes from a 2014 study that found that men who consumed at least five drinks a week had fewer sperm and lower testosterone levels. On the other hand, a study presented at a scientific conference in 2014 found that men who are moderate drinkers had better erections than teetotalers.

    2015: Does the next Alzheimer's treatment hang on a vine?

    Resveratrol was shown a decade ago to break up amyloid-beta protein, whose buildup has been linked to Alzheimer's disease, at least in cells growing in a Petri dish. In the newest chapter of this research, a 2015 study provided indirect evidence that a resveratrol pill may be able to prevent amyloid-beta accumulation in the brains of people with Alzheimer's. But many questions remain, most importantly, perhaps, whether resveratrol can reverse symptoms of the disease. And there's some bad news for oenophiles: you would have to drink 1,000 bottles of red wine to get the amount of resveratrol used in this study.

    2015: A closer look at cancer risk

    The story of red wine and cancer has been a complicated one, but it took a turn for the worse this year. In the past, studies have suggested that red wine may be able to reduce the risk of prostate, as well as lung and colon cancer, but probably only for light to moderate drinkers. A preponderance of research suggest that heavy drinking, on the other hand, increases the risk of lung, colon, liver, stomach and breast cancers, among others.
    This year, a large study by Harvard researchers shook the notion that moderate alcohol consumption is probably harmless. Healthy middle-aged women who had about a half a glass to a glass of wine a day, or the equivalent amount of beer or liquor, had a 13% higher risk of certain types of cancer, particularly breast cancer. For men, drinking a couple glasses of alcohol a day was associated with 26% increased risk of cancers such as liver, colon and esophagus. For both men and women, heavier drinking carried higher risk. Experts reacted to the findings by urging the importance of keeping alcohol consumption in close check.