For decades, there’s been speculation about the supposed health benefits of red wine. Now, for the first time, research has proved that drinking three glasses of red wine a week can in fact help lower blood pressure.
The analysis was carried out by scientists at Queen’s University in Belfast and Kiel University in Germany and published in Hypertension, an American Heart Association journal, in August 2021. Researchers worked with over 900 study participants in Germany and concluded that higher intakes of flavonoid-rich foods, including berries, red wine, apples and pears, were linked to lower systolic blood pressure – the force at which the heart pumps blood around the body.
It’s all down to flavonoids – compounds found mainly in fruits and vegetables, as well as dark chocolate and red wine, that are high in antioxidants. Antioxidants help protect the bodys cells against free-radical damage, also known as oxidative stress.
The study focused on how microbes in the gut break down flavonoids, which then work to lower blood pressure. For the first time, scientists looked at six different subclasses of flavonoids and the link between their intake, microbial diversity, and blood pressure. Data suggested that up to 15.2% of the association between flavonoid-rich foods and systolic blood pressure could be explained by the gut microbiome.
Previous research has shown flavonoids can improve heart health, but researchers said this was the first time they had been able to explain their connection to lower blood pressure.
Lead investigator Professor Aedin Cassidy said: “Our gut microbiome plays a key role in metabolising flavonoids to enhance their cardioprotective effects, and this study provides evidence to suggest these blood-pressure-lowering effects are achievable with simple changes to the daily diet.”
Wondering how much red wine will lower blood pressure? Not surprisingly, moderation is key. Researchers found that about three glasses of red wine a week was optimal. For berries, the suggested amount was 80g a day.
Resveratrol is a type of compound that functions like an antioxidant and is found in the skin of red grapes. You may well have heard about it – it’s gained a lot of attention in recent years for its reported health benefits and is available in nutritional supplements as well as found in anti-ageing skincare.
In a 2019 study, researchers from the King’s BHF Centre of Excellence gave a dose of resveratrol to mice with induced high blood pressure, causing the blood vessels of the mice to relax and blood pressure to drop. The same effect was found in human blood vessel cells.
But while this sounds promising, King’s Professor of Molecular Cardiology and Associate Medical Director at the British Heart Foundation, Metin Avkiran, warns: “To get the human equivalent dose of resveratrol used here, you’d need to drink an impossible amount of red wine every day – which is both unfeasible and inadvisable.
“The real value of this study is in revealing the surprising way in which resveratrol exerts its effects, and with it the possibility of new blood pressure drugs which work in a similar way.”
Research is making excellent headway, and the greater our understanding of the links between diet and blood pressure, the more effectively we’ll be able to use dietary approaches to control and prevent hypertension.
Despite positive research findings, red wine isn’t a magic cure. If you enjoy it, be sure to limit yourself to moderate amounts, and remember the best way to control your blood pressure is through a combination of factors, including a healthy lifestyle, a balanced diet and prescribed medication. Always speak to your doctor to get the best guidance on the dietary choices that are right for you.