The hidden health benefits of drinking a glass of red wine

“It’s medicinal.” How many times has an utterance of this type accompanied a glug of red wine? And justifiably so: studies have long shown that the presence of polyphenols, plant-based micronutrients, give red wine a healthy edge over other forms of alcohol. 

According to research from Dr Rudolph Schutte of Anglia Ruskin University in 2021, the health benefits derive from the grapes, which are packed full of the wonder micronutrients, which can reduce the risk of developing type 2 diabetes, heart disease, blood clots and cancer, as well boost our gut health and sharpen mental acuity, guarding against dementia. 

Here is everything you need to know.

What are other polyphenols sources?

Of course, wine – or grapes – is by no means the only source of polyphenols available to us: they are easy enough to come by in a well-balanced diet containing plenty of fruits and vegetables. Look out, in particular, for foods with red, blue and purple pigments: these are anthocyanins, a sub-category of polyphenols known as flavonoids, which have an anti-inflammatory function and help to protect cells from the oxidative stress that can heighten the risk of disease. Examples include all kinds of berries, red cabbage, chilli peppers, cherries, aubergines, pomegranates, purple potatoes and beetroot.

“Dark green leafy vegetables are another excellent source of polyphenols: think broccoli, kale, spinach and ruby chard,” says Alex Glover, senior nutritionist at Holland & Barrett. “Even so, there are some exceptions to the ‘colourful’ rule, such as olive oil, which is rich in several phenolic compounds – one of the main factors in the documented benefits of extra virgin olive oil consumption.” Whole grains, seeds, legumes, turmeric and a variety of herbs and spices are other good sources.

Why are polyphenols good for you?

Polyphenols have a role to play in digestive health, which you’d likely expect from a diet rich in wholefoods, but it’s not just about keeping things moving – it’s also a question of promoting healthy gut bacteria. Polyphenols not only help to encourage the growth of the useful bifidobacterium strains but also help to inhibit ‘bad’ bacteria such as c.difficile, which can cause bowel irritations and diarrhoea. Good gut health also helps to keep blood sugar stable and the immune system in good working order – plus, there’s increasing evidence to suggest that gut health has an impact on the brain and mental wellbeing; a relationship known as the gut-brain axis. 

According to dietician Jo Travers, consuming foods that are high in polyphenols has been shown to boost cognition – and a study published in Neurology in 2021 demonstrated that polyphenols – in particular, flavonoids – support cognitive function.

How much should you consume to reap its benefits?

According to Glover, “there’s no daily reference value for dietary intake” since polyphenols aren’t considered ‘essential’ in the way that vitamins and minerals are: aim for a well-balanced diet, comprising foods rich in colour and variety, and you should be on the right track. Even so, a study published in the Journal of Nutrition in 2013 found that individuals who consumed 650mg of polyphenols per day (around three-quarters of a cup of blueberries) had a 30 per cent lower mortality rate than those who took in less than 500mg.

Essentially, it’s easy enough to get adequate amounts of polyphenols by eating a varied diet that contains plenty of plant-based foods – even those with a treat-like appeal. A few squares of dark chocolate, a handful of nuts – even starting your day with a coffee clocks up around 35mg. As for the wine? In moderation is best, says Glover, advising that drinkers “stick to one to three glasses per week.”

What about supplements? 

Since polyphenols are most effective when interacting with the other nutrients naturally found in food, it’s unlikely that taking them in an ‘isolated’ form is as beneficial. For example, vitamin C, which supports the immune system and immune cell function, has a mutually beneficial relationship with polyphenols, with each enhancing the role of the other: kale, raspberries, blackberries, blackcurrants, spinach and broccoli are all high in both. 

Various dried herbs and spices, including ginger, oregano and cumin, tend to contain nutrients such as magnesium, which can help to ward off migraine and muscle cramps, as well as lowering blood pressure and reducing the risk of heart disease. In addition, there are concerns over the unfeasibly high amounts of polyphenols contained in supplements: they don’t mirror food’s natural amounts and animal studies have indicated that such high doses could be associated with kidney damage, thyroid imbalance and may even heighten the risk of stroke.