Is red wine good for you? What the odd glass does for your health

The health benefits of red wine

1. Heart health

“Moderate and regular intakes of red wine are thought to be good for the heart by raising ‘good’ HDL cholesterol, preventing artery damage and improving blood vessel function,” says Professor Aedin Cassidy, the chair in nutrition and preventative medicine and director for interdisciplinary research at Queen’s University Belfast’s Institute for Global Food Security.

This could be down to the substances found swirling around your wine glass such as polyphenols and quercetin that, in small doses, can be beneficial for cardiovascular health, says Adrian Baranchuk, a professor of medicine at Queen’s University in Ontario.

“Even small doses of ethanol can improve vessel function by improving the endothelium (inner part of the vessel),” he explains. “Larger doses may have the opposite effect, so staying in small doses is key.”

One recent paper, from researchers at the University of Barcelona, found moderate drinkers who consume up to one bottle of wine a week had a 50% lower risk of heart disease compared to those who had one glass or less. For comparison, taking statins for five years lowers the risk of heart disease by about 25%.

However, Cassidy notes that research into the effects of alcohol on health is controversial. “There is evidence on the other side, too, saying they have not found clear evidence that people who take a drink a day are less likely to develop heart disease than those who don’t drink,” she notes.

“If a person does not drink, they should not start due to these possible benefits given the risks of complications in other organs (even drinking at small doses),” Baranchuk says.

2. Gut health

While too much red wine can leave your stomach churning, a moderate intake may support the health of your gut microbiome — the collection of microbes living in your digestive system.

“In a 2020 study, my colleagues and I found that people who drink moderate amounts of red wine had a more diverse gut microbiome” compared to people who didn’t drink red wine, Spector says.

That research, which looked at the gut health of nearly 1000 sets of female twins, did not see the same effect among those who drank white wine, beer or spirits.

This finding may be a result of the concentration of polyphenols found in red wine, including anthocyanin, resveratrol and gallic acid, Spector says. “These so-called phytochemicals have a range of benefits throughout the body and feed the ‘good’ bacteria in your gut.”

3. Blood sugar

Drinking too much alcohol over time undoubtedly raises the risk of Type 2 diabetes. However, a moderate amount of wine with meals could help maintain healthy blood sugar levels, compared to drinking at other times.

Research from a team at Tulane University Obesity Research Centre in New Orleans, found women who drank up to one glass of wine with meals daily, and men who drank up to two glasses, had a 14% lower risk of developing type 2 diabetes. The effect wasn’t seen with other types of alcohol.

“In short-term clinical studies, alcohol lowers blood glucose levels and there is some evidence from large population studies that it lowers Type 2 diabetes risk,” says Cassidy. “So the combined evidence both point in a direction to suggest benefit. However, to date, the health effects of alcohol have never been tested in a long-term, randomised trial.”

What is red wine made of?

Red wine is made from grapes that have been picked, crushed (with their skins still on) and fermented for about a week, with the latter process creating the drink’s alcohol content.

The grapes are then pressed to extract the juice, which is then left to mature in vats, barrels or tanks before it is eventually bottled.

As the skin is left on the grapes during this process, a high concentration of polyphenols is contained within the drink.

These powerhouse chemicals — which are also found in apples, tea and berries — have been associated with a reduced risk of heart disease, Type 2 diabetes and dementia, says Cassidy.

Resveratrol is one polyphenol thought to have heart-protecting and anti-ageing effects, based on studies conducted in mice, she says.

However, you would need to drink vast quantities of red wine, which would not be good for health, to get enough resveratrol to replicate the effect seen in animal studies, she adds.

What’s in a medium (175ml) glass of red wine:

Red wine vs white wine

“The health benefits specifically attributed to red wine have generally been thought to be due to the presence of polyphenols,” says Dr Hassan Vally, an associate professor in epidemiology at Deakin University.

They are more concentrated in red wine as they are found in high levels in the skins and seeds of grapes. “Because the grape skins are removed when making white wine, there are far fewer polyphenols than in red wine,” says Spector.

“When making rosé wine, the skins are left on a little longer than white wine, so rosé has slightly more polyphenols than white, but much less than red,” he adds.

How much red wine do you need to see its health benefits?

“Some experts would argue that there is no truly safe level of alcohol to consume,” Spector says. While the UK guidance is to drink no more than 14 units a week (14 single shots of spirit, six medium glasses of wine or six pints of beer), scientists have found health problems can occur even from light drinking.

“However, in my opinion — and there is evidence to support this — a small glass a few nights each week is probably fine and may impart some health benefits,” he says.

If you already drink alcohol, switching to an occasional glass of red wine is probably sensible, Spector says. “However, if you don’t already drink alcohol, you shouldn’t start — you can get polyphenols from a wide range of non-alcoholic plant sources.”

Vally notes the most recent studies are aligned on alcohol consumption not being good for us. Despite this, “consumption of red wine in moderate levels is probably not all that unhealthy either”.

“What this suggests is that if someone likes red wine and this brings significant joy to their lives then they should feel comfortable consuming this drink, but in the full understanding that for them the benefits such as bringing pleasure outweigh the risks,” he says. “Red wine should not be considered a health food and it does come with some costs to your health, and the more you drink the greater those risks are.”

FAQs

What’s the healthiest way of drinking red wine?

“It’s likely that enjoying your wine with or just after a meal is better for your health,” says Spector. “Many of us have experienced the suboptimal outcomes of drinking alcohol on an empty stomach.”

He recommends drinking alcohol earlier in the evening rather than later, as it will interfere with how rested you feel the next day. “It might help you nod off quicker, but your sleep will be of a lower quality.”

Does red wine raise cholesterol?

So far, studies have suggested that resveratrol, a polyphenol found in red wine, can lower cholesterol as well as blood pressure. Researchers have also found moderate alcohol consumption can raise “good” HDL cholesterol.

Is red wine high in iron?

A 150ml glass of red wine contains about 1.5mg of iron. For context, men and women aged 50 and over need 8.7mg a day, while women aged 19 to 49 need 14.8mg.

However, the tannins in red wine are known to bind to iron during digestion, which means less is available for the body to absorb.