Centuries ago, wine was used treat various health conditions. Medieval monasteries were convinced that their monks lived longer than the rest of the population partly because of their moderate, regular consumption of wine. In recent years, science has indicated that this could be true.
However, any health benefits only apply to moderate drinking. The United States (U.S.) Dietary Guidelines 2015 to 2020 define moderate drinking as: "Up to one drink per day for women, and up to two drinks per day for men, and only by adults of legal drinking age."
Some people should not drink at all. It is best to discuss any planned increase in consumption with a doctor.
Here are some key points about red wine and health. More detail is in the main article.
- Red wine is high in resveratrol, and it may offer various health benefits.
- Resveratrol may boost heart health, protect against some kinds of cancer, and prevent some types of vision loss.
- Grapes and berries are a better source of resveratrol than red wine, so eating these is likely to be more healthful than drinking wine.
- However, if you are going to drink, red wine appears to be more healthful than some kinds of alcoholic beverage.
- Women should not drink more than one glass a day, and men, two glasses.
Red wine contains resveratrol, which appears to have a number of health benefits.
Research indicates that red wine can boost a range of health factors.
Several of these are based on the presence of resveratrol, a compound that is believed to offer a number of benefits.
Resveratrol is a compound that some plants produce to fight off bacteria and fungi, and to protect against ultraviolet (UV) irradiation.
The resveratrol in wine comes from the skins of red grapes. Blueberries, cranberries, and peanuts are also sources of resveratrol, and it is available in supplement form.
Evidence suggests that in some forms, resveratrol may boost cardiovascular health, protect against cancer, and help treat acne, among others.
Red wine contains resveratrol, but it may not be the best way to consume it, because the intake of alcohol brings it own risks.
1. Gut microbiome and cardiovascular health
2. Raising levels of omega-3 fatty acids
Omega-3 fatty acids, believed to protect against heart disease, are usually derived from eating fish.
Researchers found that, in 1,604 adult participants, regular, moderate wine drinking was linked to higher blood levels of omega-3 fatty acids.
3. Heart health and type-2 diabetes
One study has shown that drinking a glass of red wine with dinner "modestly decreases cardiometabolic risk" in people with type-2 diabetes, and that a moderate intake of red wine is safe.
The scientists believe that the ethanol in wine plays a key role in metabolizing glucose, and that the nonalcoholic ingredients may also contribute. They call for more research to confirm the findings.
Anyone with diabetes should check with their doctor before consuming alcohol.
4. Healthy blood vessels and blood pressure
In 2006, scientists from the United Kingdom (U.K.) found that procyanidins, compounds commonly found in red wine, help keep the blood vessels healthy. Traditional production methods appear to be most effective in extracting the compounds, leading to higher levels of procyanidins in the wine.
5. Brain damage after stroke
Results from tests on mice showed that resveratrol increased levels of heme oxygenase, an enzyme known to protect nerve cells in the brain from damage. When a stroke occurs, the brain is ready to protect itself because of higher enzyme levels.
It remains unclear whether the health benefits are due to the resveratrol itself, or if the alcohol in the wine is needed to concentrate the levels of the compound.
6. Preventing vision loss
Resveratrol in red wine may help prevent vision loss caused by out-of-control blood vessel growth in the eye, according to findings published in 2010.
Diabetic retinopathy and age-related macular degeneration are leading causes of blindness among Americans aged 50 years and above. This is due to an overgrowth of blood vessels in the eye, known as angiogenesis.
If further research confirms findings, the scientists believe it could help not only people with vision problems due to diabetes, but those with atherosclerosis, cardiovascular disease, and other causes of retinal detachment.
7. Preventing colon cancer
However, other experts point out that alcohol is strongly linked to different types of cancer, and that any benefit from resveratrol is likely to be outweighed by the negative effects of the alcohol.
8. Preventing breast cancer
Regular consumption of most alcoholic drinks increases the risk of breast cancer. However, thanks to chemicals in the seeds and skins of red grapes, women who drink red wine in moderation may be spared this risk.
Red grapes and nonalcoholic red wine also offer the benefits of resveratrol.
Normally, alcohol increases a woman's estrogen levels, and this encourages the growth of cancer cells. However, the aromatase inhibitors (AIs) that are present in red wine, and to a lesser extent white wine, reduce estrogen levels and increase testosterone in women approaching menopause.
It is the grape rather than the wine that primarily provides these beneficial compounds, so eating red grapes is more healthful than drinking red wine.
Nevertheless, if a woman is going to choose an alcoholic drink, red wine might be a better option, compared with other beverages.
Scientists have questioned the claims of this study and insist that "alcoholic beverages cause breast cancer independent of beverage type."
9. Improving lung function and preventing lung cancer
10. Protection from prostate cancer
A study published in 2007 reported that, in men who drink moderate amounts of red wine, the chance of being diagnosed with prostate cancer is around half that of men who never drink red wine.
The researchers defined moderate drinking as an average of four to seven glasses of red wine per week.
Those who drank one glass a week were 6 percent less likely to develop prostate cancer than those who never drank it.
11. Preventing dementia
A long-term study of data from 19 nations found a statistically significant lower risk of dementia among regular, moderate red wine drinkers in 14 countries.
Resveratrol, explained the investigators, is key to this benefit. By reducing the stickiness of blood platelets, it helps keep the blood vessels open and flexible, and this promotes a good supply of blood to the brain.
Red and white wines both contain resveratrol, but red wine has more. The skin of red grapes has very high levels of resveratrol. The manufacturing process of red wine, involves prolonged contact with grape skins.
The researchers note: "We don't recommend that nondrinkers start drinking. But moderate drinking, if it is truly moderate, can be beneficial."
A 2015 study found that a high dose of resveratrol appeared to stabilize a key biomarker for Alzheimer's.
The amount needed, however, is far higher than anyone would get from a glass of wine. The participants took a-1 gram (g) supplement by mouth twice a day, equivalent to the amount in 1,000 bottles of wine.
12. Reducing risk of depression
A study of data for around 5,500 men and women aged from 55 to 80 years over a 7-year period showed that those who drank between two and seven glasses of wine each week were less likely to receive a diagnosis of depression, even after taking lifestyle factors into consideration.
13. Protecting from severe sunburn
Wine and grape derivatives can help protect the skin from the damaging effects of UV light from the sun, according to scientists from Spain.
The team found that when UV rays make contact with human skin, they activate reactive oxygen species (ROS), which oxidize fats, DNA, and other large molecules. These, in turn, stimulate other enzymes that harm skin cells.
Wine and grapes contain flavonoids. These inhibit the formation of the ROS in skin cells that are exposed to sunlight.
Rather than drinking more wine, however, the researchers suggest incorporating grapes and grape derivatives into sun protection products.
14. Preventing liver disease
Modest wine consumption may cut the risk of nonalcoholic fatty liver disease (NAFLD) by half in those who are at risk of the condition, compared with never drinking wine.
The finding, published by researchers from the University of California San Diego School of Medicine, is controversial. They note that only moderate consumption will bring benefits, and they suggest a maximum of one glass a day for people at risk of coronary heart disease and NAFLD.
Those who regularly and moderately drink beer or liquor, say the scientists, have a four-times higher risk than those who drink red wine.
Anyone who already has hepatitis or any other kind of liver disease should avoid alcohol altogether.
15. Preventing dental cavities
Red wine may help prevent dental cavities by getting rid of bacteria on the teeth, according to research published in 2014, in the Journal of Agricultural and Food Chemistry (ACS).
16. Treating acne
Research has indicated that resveratrol, with its antioxidant and anti-inflammatory action, could help treat acne. The scientists suggest combining it with benzoyl peroxide and applying it directly to the skin, to maximize antibacterial activity.
However, there is no evidence that drinking red wine has the same effect.
Red or white wine?
Resveratrol appears to underlie many of the health benefits of red wine. Red wine contains more resveratrol than white wine, because it is fermented with the skins, but white wine is not. Most of the resveratrol in grapes is in the seeds and skin.
Non-alcoholic red wines may also include beneficial amounts of resveratrol. Other good sources are grapes, blueberries, raspberries, bilberries, and peanuts.
Wine consumption may have some health benefits, but drinking too much of any kind of alcoholic drink increases the risk of:
- mental health problems
- fatty liver
- alcoholic hepatitis
- several cancers
Many other chronic diseases can result from excessive alcohol consumption.
In 2016, the U.K. government issued a warning that there is no safe level of alcohol. They advise people to achieve better health through "eating less and exercising more."
What about resveratrol?
Even the benefits of resveratrol have been questioned.
A 2014 study suggested that the health benefits of resveratrol, applied to rodents in high doses, may not translate to humans.
The study found no link between resveratrol levels and inflammatory markers, cardiovascular disease, cancer, and longevity.
Should I drink more red wine?
Before looking at the potential benefits of drinking red wine, it is worth noting what the U.S. Dietary guidelines 2015-2020 say about alcohol:
"The Dietary Guidelines does not recommend that individuals begin drinking or drink more for any reason. The amount of alcohol and calories in beverages varies and should be accounted for within the limits of healthy eating patterns. Alcohol should be consumed only by adults of legal drinking age. There are many circumstances in which individuals should not drink, such as during pregnancy."
Ultimately, many of the benefits linked to red wine are really benefits of resveratrol. Eating grapes and berries may be a more healthful option.