Polyphenols: The natural chemicals that can give you a small waist, a healthy heart and low blood pressure

There’s a new buzzword when it comes to health: polyphenols. Although scientists have been studying the plant compounds for years, the term has now captured the public imagination – and for good reason.

A growing body of evidence shows that eating a diet high in these clever natural chemicals provides numerous health benefits, improving everything from heart health and metabolism to lowering the risk of neurodegenerative diseases, such as diabetes. Alzheimer’s.

There is also research suggesting that eating more polyphenols can slow the signs of skin aging and reduce waist size.

Polyphenols are a group of phytonutrients (although the terms are often incorrectly used interchangeably), naturally occurring chemicals in plants that in nature help protect them from threats such as insects and UV light, and, as it turns out, also help protect plants. us when we eat them.

They are found in high concentrations in fruits and vegetables with deep or vibrant colors, such as beetroot, blackberries, black olives, very red tomatoes and dark leafy greens. In addition to protecting the plant, phytonutrients – including polyphenols – also provide it with a strong pigment. The same goes for strong flavors: the more cough-inducing extra virgin olive oil, the higher the likely concentration of polyphenols. Tea, coffee and dark chocolate are excellent sources.

There are thousands of types of phytonutrients – we haven’t discovered them all – such as resveratrol in red wine, ellagic acid in walnuts and catechins in tea. And individual ingredients contain multiple phytonutrients: tomatoes contain polyphenols (flavonoids and flavanones) and carotenoids (lycopene, phytoene and beta-carotene).

Trials have shown that they all do different things for our health. “The flavanols in cocoa are linked to a reduced risk of stroke and heart attack,” explains Dr Federica Amati, chief nutritionist at health science app Zoe and research fellow at the School of Public Health, Imperial College London. “Catechins in green tea can have a positive influence on your metabolism, waist circumference and body mass index. And I really like the research on the polyphenols in hibiscus (which lower blood pressure).

Polyphenols, she says, are amazing and reveal the complexity of the plants we eat. “Plants don’t just provide us with fiber and vitamins – there is a huge world of compounds that have a beneficial impact on our health.”

Daniele Del Rio, professor of human nutrition at the University of Parma, Italy, says: “Several observational studies have shown that higher dietary intake of polyphenols is associated with a reduced risk of numerous chronic diseases.” For example, one study found that those who reported eating diets rich in polyphenols had a 46% lower risk of developing heart disease than those who ate the least.

There is some evidence that consuming polyphenols can increase blood flow to the brain and reduce inflammation in the body. Therefore, they are believed to have the potential to fight neurodegenerative diseases.

However, our understanding of exactly how these compounds work is not yet complete.

“The mechanisms by which they work in our bodies are still under investigation, and many researchers approach this issue from the wrong perspective, ignoring how these compounds are significantly changed by our bodies,” says Del Rio. “There is still a lot of work to be done.”

Polyphenols may be good for us because of the way they interact with and are transformed by our gut microbes, which effectively use them as food. Together with colleagues from Parma and the University of Glasgow, Del Rio has shown that our gut microbes convert polyphenols into “smaller, more absorbable metabolites” that help support the body. “This research has paved the way for more rigorous studies aimed at understanding what they really do to protect us,” he says.

In fact, it’s likely that a new public interest in all things gut health has put polyphenols back in the spotlight. “There was a huge interest in red wine and the ‘French paradox’ in the 1990s, which led to a lot of research into the polyphenol resveratrol,” says Amati.

As we become more aware of the microbes in our gut and more attention is paid to the role food plays in our health in general, polyphenols have re-entered the conversation.

Experts say the best approach is to eat a variety of plants to get a wide range of phytonutrients. This means fruits, vegetables, legumes, whole grains, nuts, seeds, herbs and spices.

“Herbs and spices are among the most concentrated sources, with cloves containing 16,000 mg of polyphenols per 100 g and cinnamon 9,700 mg per 100 g,” says microbiome expert Emily Leeming. “It doesn’t have to be expensive. Wild blueberries – 650 mg/100 g – get a lot of polyphenol hype, but the truth is they contain seven times less than the cheaper black beans – 4,800 mg/100 g.”

Del Rio has been fascinated by the “incredible molecules” since he started studying them for his PhD 23 years ago. “From then on, I never stopped researching them to understand their chemistry and their health effects on humans. I think there’s a lot of hype right now, and some researchers like to use it to do easy science, which isn’t real science.

“But if studied carefully, I think polyphenols will teach us new ways to care for ourselves and our health through a balanced diet. They are not the miracle cures that solve the problem of chronic diseases, but they can certainly contribute to the prevention of chronic diseases.”