There’s a new health buzzword: polyphenols. While scientists have been studying plant compounds for years, the term has now captured the public imagination – and for good reason.
Growing evidence shows that a diet rich in these smart natural chemicals provides numerous health benefits, improving everything from heart and metabolic health to reducing the risk of neurodegenerative diseases, like Alzheimer’s. .
Some research also suggests that eating more polyphenols may slow the signs of skin aging and reduce waistline.
Polyphenols are a group of phytonutrients (although the terms are often used interchangeably), chemicals naturally found in plants that help protect them in nature from threats such as insects and UV light and, in Ultimately, also help protect us when we eat them.
They are found in high concentrations in deep or brightly colored fruits and vegetables 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 powerful pigment. The same goes for strong tastes: the more cough-inducing an extra virgin olive oil is, 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—like resveratrol in red wine, ellagic acid in nuts, and catechins in tea. And the individual ingredients contain several phytonutrients: Tomatoes contain polyphenols (flavonoids and flavanones) as well as carotenoids (lycopene, phytoene and beta-carotene).
Trials have shown that they all have different effects on our health. “Flavanols in cocoa are linked to a reduced risk of stroke and heart attack,” says Dr. Federica Amati, chief nutritionist at Zoe Health Sciences Application and researcher at the School of Public . HealthImperial College London. “Catechins found in green tea can positively affect your metabolism, waistline, and body mass index. And I really like the research on polyphenols in hibiscus (which reduce) 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 vast 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 intake of dietary polyphenols is associated with reduced risk of many chronic diseases. » For example, one study found that those who reported eating a diet high in polyphenols had a 46% lower risk of developing heart disease than those who ate the least.
There is evidence that consuming polyphenols can increase blood flow to the brain and reduce inflammation in the body, which is why they are thought 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 act in our bodies remain under study, and many researchers approach this question from the wrong perspective, neglecting how these compounds are significantly modified by our bodies,” Del Rio says. “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 processed by our gut microbes, which effectively use them as food. Working with colleagues from Parma and the University of Glasgow, Del Rio showed that our gut microbes transform 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 actually do to protect us,” he says.
after newsletter promotion
In fact, it’s likely that the public’s new appetite for all things gut health has propelled polyphenols into the spotlight. “There was a huge boom of interest in the 90s, particularly in red wine and the ‘French paradox,’ which led to a lot of research into the polyphenol resveratrol,” says Amati.
Today, with more widespread awareness of the microbes in our guts and increased attention paid more generally to the role that diet plays in our health, polyphenols are being re-entered into the debate.
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 hype around polyphenols, but the truth is they contain seven times less than the more affordable black bean – 4,800 mg/100 g.
Del Rio has been fascinated by “incredible molecules” since he began studying them for his doctorate 23 years ago. “From that point on, I never stopped researching them to try to understand their chemistry and their effects on human health. I guess there’s a lot of hype right now, and some researchers like to use it to do easy science, which isn’t real science.
“However, if studied rigorously, I believe polyphenols will teach us new ways to take care of ourselves and our health through a balanced diet. These are not miracle compounds that solve the problem of chronic diseases, but they can certainly help prevent chronic diseases.