What are polyphenols? Benefits, polyphenol foods and why they matter

And there isn’t just one type. Scientists have identified more than 8,000 polyphenols, which are usually grouped into four main families:³

Our bodies don’t necessarily absorb every polyphenol in the same way or amount, and many are metabolised and removed from the body.⁴ That’s one reason why, when it comes to polyphenols, it’s worth thinking about the variety of plant foods in your diet, rather than focusing on just one source.

Antioxidants and polyphenols go hand in hand.² Research has explored how they interact with processes linked to oxidative stress – an imbalance between free radicals and the body’s antioxidant defences.⁵ Our bodies naturally produce molecules called free radicals and we're also exposed to them through things like pollution and UV light. When they build up faster than the body can manage them, this is known as oxidative stress, which can damage cells.⁶ Researchers are interested in how polyphenols interact with these processes. . Researchers are interested in how polyphenols interact with these processes.

Scientists are interested in how certain polyphenols may interact with the way our bodies digest carbohydrates and manage glucose. Research has looked at everything from fasting blood glucose to insulin sensitivity, although findings vary depending on the type and source of polyphenol studied.^7,8 So, what does the research actually say? One large review looked at 46 clinical trials and found mixed results across different health measures but didn’t find a significant effect on fasting blood glucose. This suggests any effects may depend on the type and source of polyphenols.⁷

Your heart may be another reason to put polyphenol-rich foods on your radar. Research is exploring how they may influence markers of heart health, such as blood pressure and cholesterol.⁹ But it’s not as simple as ‘more polyphenols = a healthier heart’ – different sources can have different effects and there’s still more to learn.

Here’s where things get particularly interesting. Your gut bacteria help break down polyphenols into other compounds – but research suggests the relationship may work both ways, with polyphenols potentially influencing the make-up of the gut microbiome too. Scientists are still working out exactly what these changes mean for our health, but it’s an emerging area of research worth watching.^10,11 an emerging area of research worth watching.

Could what you eat have an impact on how sharp you feel? Researchers are exploring that question, including the role of polyphenols. One review of studies in healthy young and middle-aged adults found that polyphenol-rich interventions were associated with improvements in some measures of cognitive performance, including reaction time and mental fatigue. However, research is still developing, and different polyphenols, doses and study lengths can produce different results.¹² However, research is still developing, and different polyphenols, doses and study lengths can produce different results.

Polyphenols are an exciting area of research, but there’s still plenty to learn and their effects aren’t necessarily the same across every polyphenol, food or person.

So, is there one best polyphenol food? Not really. Variety is more useful than focusing on a single ‘superfood’. An easy place to start is by adding more colour and variety to your plate. There are plenty of foods high in polyphenols to choose from, whether it’s berries with breakfast, a handful of nuts for a snack, herbs and spices with dinner or a cup of tea, these all offer different ways to bring more polyphenol-rich foods into your everyday diet.

Interested in more food knowledge? Start with learning about functional mushrooms or rock salt vs sea salt – what's the difference?