The Superpowers of Polyphenols

Provides health benefits

Polyphenols can help with brain function and cognition. A systematic review published in Frontiers in Nutrition found that eating polyphenols for moderate and long periods may improve both working and episodic memory in middle-aged and older adults. One review published in the journal Antioxidants in 2022 hypothesized that polyphenols such as curcumin might help protect the brain by preventing the accumulation of the beta-amyloid plaques that are one of the hallmarks of Alzheimer’s disease.

Improves gut health

Many foods that contain polyphenols also have fiber, which is important for regular bowel movements. "Polyphenols can help with digestion, and that can help us in the restroom," says Goodridge.  

According to a study published in the Journal of Food Biochemistry in 2022, the gut microbiome transformed polyphenols into bioactive compounds that could have "therapeutic effects" on gut health. 

Helps with heart disease

Heart disease is the leading cause of death in the United States, according to the Centers for Disease Control and Prevention, with one person dying every 33 seconds. "One of the challenging things with heart disease is the inside of our arteries over the years can get rigid [and] stiff," says Goodridge. Arteries need to be elastic, yet oxidative stress can cause them to become rigid. "Polyphenols can be protective of heart health," Goodridge says.  

Prevents negative effects of cell death

Polyphenols can reduce cellular senescence. Cellular senescence occurs when cells die and accumulate in the body instead of leaving. They can leak harmful compounds, lead to inflammation and contribute to other coronary diseases, says Dieras. "The number of cells that are in that stage accumulates as you get older," she says. 

Polyphenol-rich foods 

Many fruits, vegetables, nuts, herbs, spices and beverages, such as green tea and coffee, contain polyphenols. The quantities of polyphenols vary based on the food or beverage, freshness, processing, and even the variety. Eating a healthy and varied diet helps ensure you're eating sufficient polyphenols. "You're probably getting these within your diet if you're eating a diverse diet with fruits, vegetables, nuts and seeds," says Dieras. There are also polyphenols in olive oil, whole grains and legumes. Plus, you get the additional benefits of fiber and vitamins when you eat these foods, she says. 

Brightly-colored fruits and vegetables, especially red-colored, are high in polyphenols, says Goodridge. Foods high in polyphenols include cranberries, pomegranates, red grapes, and berries, such as strawberries, blueberries, raspberries, and vegetables, like tomatoes, carrots, potatoes, and onions, she says. (See box.)

Eat a rainbow of colors for adequate nutrition throughout the week, says Goodridge. "All the different colors help the body in different ways," she says. "Color is mother nature's way of saying, 'I'm really good for you, whether that's a different polyphenol or a vitamin.'" 

Why freshness matters

Fresh produce has a higher nutrient content than fruits and vegetables that have been sitting in the fruit bowl or crisper drawer for a while. The longer it takes to consume fruit or vegetables after harvest, there's a steady decline in the bioavailability of the nutrients, says Dieras. "A lot of the nutrients, including the polyphenols, can oxidize and degrade over time," she adds. 

Have a lot of produce that you aren't going to eat quickly? Keep produce cool. "Polyphenols are delicate," says Goodridge. Store produce in the fridge to preserve some of the polyphenols, she says.

 Fresh produce has higher polyphenols than canned produce. "There's going to be a higher polyphenol content in foods that are fresh versus cans," says Goodridge. "Freshness definitely matters."

How much do you need?

There are guidelines for how quantities of macronutrients, such as protein, you should be consuming daily. So, you may wonder if polyphenols have similar recommendations. "There is no guideline yet for the amount of polyphenols that adults should eat every day," Goodridge says.  

In lieu of such recommendations, track the number of servings of fruits, vegetables and whole grains you eat in a day. "For example, you want to have at least a cup and a half of fruit a day and at least two and a half cups of vegetables or more," says Goodridge. Half of your consumption of grains, at minimum, should be whole grains, such as brown rice or wheat bread for your daily amount, she says. By doing this, you'll be including an adequate amount. of healthy polyphenols in your diet.

Should you take supplements?

People may reach for a supplement when they're concerned that they're not getting an adequate intake of a vitamin, mineral or, in this case, polyphenols.   Nutritionists recommend the best way to get polyphenols is with food.

When you eat foods with polyphenols, you're also getting important macronutrients, such as fiber and micronutrients, like vitamin C, says Goodridge. The body absorbs polyphenols better in food than when they are isolated in a supplement. "The other components in a food help those polyphenols to be digested and absorbed appropriately," says Goodridge. "You don’t get that when it’s just a supplement."

Be aware that medications can interact with polyphenol supplements.

"A significant part of the population above 50 is on multiple medications," says Dieras. "I don't know specifically how the individual polyphenols will interact with their medications." Before you seek out supplements, you should always speak to your medical provider about any risks or adverse effects that could occur. "It's important to speak to your provider to figure out all the medications that you're on, how they interact with each other, and how [a polyphenol] supplement would interact with those," says Dieras.