The Bottom Line: Is drinking a glass of red wine a day good for health?

Dietitians say there is insufficient evidence to support the health benefits of drinking red wine. PHOTO: ISTOCKPHOTO

Updated

SINGAPORE – Have you ever poured yourself a glass of shiraz or pinot noir thinking it is good for your health?

Many people believe that having a glass of red wine daily provides many health benefits, says Dr Naras Lapsys, a consultant dietitian at The Integrative Medical Centre.

And there seems to be quite a bit of research attesting to this.

A study published in 2018 in peer-reviewed scientific journal Molecules showed that drinking red wine in moderation is linked to a lower risk of medical conditions such as cardiovascular disease and cancer.

This is thanks to antioxidants, called polyphenols, found in wine.

One study published in 2009 in the International Journal of Angiology found that red wine contains a high concentration and a wide variety of polyphenols. Most of it comes from the extract derived from the skin and seeds of grapes during the fermentation process.

In particular, the process by which red wine is made allows more polyphenols to diffuse into the wine, giving red wine 10 times the polyphenol content of white wine, according to another study published in the American Journal of Clinical Nutrition in 2004.

Polyphenols – which are also found in fruit, vegetables and whole grains – can help manage blood pressure levels, reduce chronic inflammation and lower blood sugar levels, which is beneficial for those with Type 2 diabetes, says Dr Lapsys.

But dietitians tell The Straits Times there is insufficient evidence to support the health benefits of drinking red wine.

While red wine is known to contain antioxidants like resveratrol, Ms Natalie Yeo, a dietitian at the Singapore Heart Foundation, says the amount of resveratrol intake required to obtain health benefits remains debatable.

“To date, no research has established a direct cause-and-effect relationship between alcohol and better heart health,” she adds.

Ms Diane Seto, a senior dietitian at Mount Elizabeth Hospital, says there have been multiple observational studies in the past few decades which show that having one to two standard drinks a day, over four or more days a week, are associated with various health benefits.

A standard drink refers to 330ml of beer, 100ml of wine or 30ml of spirit.

These studies showed that the health benefits include reduced risk of heart disease, stroke, diabetes and death, compared with drinking large amounts of alcohol on fewer days in a week.

However, Ms Seto highlights that most of the previous research on alcohol intake was observational in nature and compared moderate drinkers, who tended to have healthier lifestyles, with non-drinkers who already had health problems.

Hence, she says, these studies likely overestimated the health benefits associated with moderate drinking, making it seem like moderate drinkers have better health than those who do not drink.

Drinking a light to moderate amount of one to two standard drinks a day does not harm your health, but it does not yield any further benefits either, says Ms Seto.

“If you want better health, it is better to focus on having a healthful diet and adequate physical activity instead of increasing your intake of alcohol,” she adds.

Dr Monika Arora, a member of the World Heart Foundation Advocacy Committee and co-author of the foundation’s 2022 policy brief, had said that claims of moderate drinking – such as a glass of red wine a day offering protection against cardiovascular disease – were “misinformed and at worst an attempt by the alcohol industry to mislead the public about the danger of their product”.

Drinking alcohol daily, including wine, can have ill effects on one’s health. It can contribute to obesity and high triglyceride levels, increasing one’s risk of heart attack and stroke, say dietitians.

Excessive alcohol intake can also raise one’s blood pressure, while binge drinking over time can result in persistent high blood pressure, which is a major risk factor for heart disease, notes Ms Yeo.

Rather than contemplating whether to go for that glass of wine, you would be better off consuming whole foods that are rich in resveratrol, she says.

“If you wish to reap the benefits of antioxidants like resveratrol, choose colourful fruit and vegetables in purple, blue, red, orange and yellow shades, such as grapes, blueberries, raspberries, broccoli, carrots, tomatoes and dark green leafy vegetables, instead of a glass of red wine,” advises Ms Yeo.

Does alcohol help you sleep better?

Drinking alcohol before bed is also commonly thought to help a person fall asleep.

But, in fact, it can interfere with restful sleep, say experts.

Alcohol has sedative effects, inducing relaxation and potentially making one fall asleep quicker. However, the consumption of alcohol, especially in excess, is also associated with sleep disruptions, particularly during the period of rapid eye movement, a stage of deep or restorative sleep, notes Ms Yeo.

Those who have insomnia or are experiencing difficulties sleeping should not drink alcohol before bed as a remedy, she cautions.

Doing so leads to poorer sleep quality and duration, affects concentration and causes daytime sleepiness. In addition, alcohol consumption is also associated with a higher risk of sleep apnea, adds Ms Yeo.

A 2018 study published in non-profit academic project Journal of Medical Internet Research Mental Health found that the greater the amount of alcohol consumed, the worse the sleep quality.

It showed a 24 per cent reduction in sleep quality for moderate drinkers, and 39.2 per cent decreased sleep quality for heavier drinkers.

Citing data from American online portal sleepfoundation.org, Ms Seto recommends that people stop drinking alcohol at least four hours before bedtime to give their bodies ample time to metabolise it before falling asleep.

The Bottom Line: Dietitians say there is insufficient evidence to warrant a glass of red wine daily for any potential health benefits. And it is not advisable to start drinking if you do not currently drink.