We all know fruits and vegetables are good for us, but what is it about them that makes them healthy? Is it simply their vitamin content, and can we get the same results from taking vitamins?

The short answer is “no.” While fruits and vegetables do provide many essential vitamins and minerals, there are additional benefits to eating a diet high in plant foods, many of which science still doesn’t fully understand. Blueberries, for example, lower blood pressure and improve the flexibility of arteries, effectively restoring more youthful arterial function. This may be due to increased production of nitric oxide, a compound that helps expand blood vessels, increase blood flow, and decrease plaque growth and blood clotting.

Part of what makes plant foods so powerful is something known as polyphenols, which are groups of plant-based compounds. One group of polyphenols is known as phenolic acid, which is found in the seeds and skin of fruits and the leave of vegetables. Another broad group is known as flavonoids, which are phytonutrients (plant nutrients) that give fruits and vegetables their vibrant colors. This is why plant foods with similar colors often offer many of the same health benefits. For example, blueberries, blackberries, prunes, and plums all contain antioxidants called anthocyanins that help prevent blood clots.

Another well-known polyphenol is resveratrol — found in grapes and red wine — which may help burn fat.

Health benefits of polyphenols

In general, polyphenols help protect against age-related disease in several ways:

Numerous studies support the health benefits of polyphenols. A study of middle-aged Finnish men found that a high intake of flavonoids was associated with a lower rate of atherosclerosis (a risk factor for heart disease.) A study of more than 34,000 postmenopausal women founds that eating flavonoid-rich foods such as bran, apples, pears, red wine, grapefruit, strawberries, and chocolate was associated with lower rates of cardiovascular disease and a lower risk of death from all causes. Another large European study found that polyphenol consumption — this time in the form of grapes and flax — was associated with a longer lifespan.

Another study found that flavonoid intake helped protect against cognitive decline over a ten-year period.

Research also indicates that polyphenols help block the action of enzymes and other substances that promote the growth of cancer cells.

Evidence also suggests that polyphenols from different plants have additional benefits when consumed together — further supporting the need to include a variety of different plant foods in the diet.

Best sources of polyphenols

One of the best sources of polyphenols is actually cocoa. Polyphenols occur in higher concentrations in cocoa than in any other food, and cocoa contains more antioxidants than broccoli or red wine. When buying cocoa, look for unsweetened, raw cocoa powder — preferably organic — or the darkest chocolate you can find. Anything with additives such as sugar or milk will have fewer health benefits. The only ingredient should be cocoa. Avoid “ground chocolate,” which is likely to contain sweeteners and other additives.
Other foods that are high in polyphenols include:

  • Spices and herbs, including cloves, oregano, celery seed, dried peppermint, parsley, sage, rosemary, and thyme
  • Dark berries, including black chokeberries and black elderberries (blueberries, blackberries, strawberries, and raspberries are also on the list)
  • Flax seed
  • Nuts, such as chestnuts and hazelnuts
  • Olives and capers

View the full list of 100 richest dietary sources of polyphenols.

You can further reduce your risk of age-related disease through periodic, prolonged fasting. When followed for five consecutive days, the ProLon fasting mimicking diet has been shown to reduce risk factors such as blood pressure, inflammation, and cholesterol. ProLon is an all-inclusive meal program consisting of plant-based, polyphenol-rich foods such as olives, nuts, seeds, and vegetable soups. Learn more and find out if ProLon is right for you.