Polyphenols are phytochemicals, substances found in abundance in natural plant food sources that contain antioxidant properties. There are more than 8,000 identified polyphenols found in a wide range of foods, from fruits and vegetables to chocolate, tea, extra-virgin olive oil and even wine.
Polyphenols give fruits and veggies their vibrant hues, and contribute to the bitterness, flavor, astringency, aroma, and oxidative stability of the food. In the plant, they help to protect it against pathogens, oxidative damage, ultraviolet radiation and harsh climatic conditions. As there are so many polyphenols, they’ve also been broken down into four categories: lignans (found in flaxseeds, legumes, fruits and certain vegetables), flavonoids (found in fruits, vegetables, green tea, red wine and legumes), phenol acids (in tea, coffee, spices, apples, blueberries, cherries, plums and kiwis) and stilbenes (in red wine and peanuts.)
Antioxidants like these, among others, are important for protecting the body’s cells against damage from free radicals, which in turn, helps to control the rate at which you age. If you don’t get enough polyphenols in your diet, those free radicals become rampant, which results in poorer performing cells and can lead to tissue degradation, as well as raising your risk of developing diseases like cancer, Alzheimer’s and heart disease. It can even make you look more haggard and “aged” in appearance, as those fine lines, wrinkles and other signs of aging are more likely to appear.
In a nutshell, here is how polyphenols contribute to your better health and why you need them.
Lowering the risk of cancer
Polyphenols help by fighting cancer cells and inhibiting the growth of blood vessels that feed a tumor, something known as angiogenesis. According to the National Cancer Institute, about 40 percent of all men and women will experience cancer in their lifetime. Numerous studies have shown how polyphenols can help in the prevention of cancer. Experts believe the antioxidant properties of polyphenols help protect DNA from free radical damage, which is known to trigger cancer development. Polyphenols have also been known to reverse epigenetic markers in DNA, and are thought to decrease tumor growth.
Supporting weight loss
Studies on obese individuals have discovered that they typically have about 20 percent more of a type of bacteria called firmicutes, and nearly 90 percent less of a bacteria known as bacteroidetes, compared to those who are leaner. Firmicutes aid the body in extracting calories from complex sugars, and then help deposit the calories in fat. That may be how the microflora in one’s gut affects their weight. Research shows that both firmicutes and bacteroidetes are influenced by polyphenols. These bacteria are also helpful for managing weight and are known for keeping potentially harmful bacteria in check. In fact, one study showed that children with high numbers of bifidobacteria seemed to be protected from excess weight gain. The bifidobacteria counts were, on average, twice as high in children who had a healthy weight, as in those who became overweight by the age of 7.
Improving the health of the gastrointestinal tract
The gut plays a very important role in your overall health. Some 100 trillion fungi, bacteria, and viruses make up the microbiome and flora that live in your gut, and these organisms play an essential part in both mental and physical health, including everything from your mood, your weight and your brain to your skin, internal organs and neurological system. The gut microbiome is now considered to be one of the body’s most complex organs. Recent research on polyphenols shows that they can help microorganisms in your digestive system, and could extend your lifespan in the process.
In 2013, scientists from New Zealand’s Plant & Food Research found that polyphenols are beneficial for the digestive system and immunity in human health. Published in the journal Anaerobe, the study showed that polyphenols break down into molecules that positively influence beneficial microorganisms in the digestive system. In short, they can support gut health, something that’s now considered vital to our overall well-being.
Other research, published in the Journal of Nutrition found that large amounts of polyphenols can also boost longevity. Researchers found that those who consumed 650 milligrams each day experienced a 30% lower mortality rate, as compared to people who took in less than 500 milligrams per day. Much of the research has been conducted on green tea, which plays a key role in balancing gut flora. Improvements in gut flora have also been seen with the consumption of red wine and chocolate, in moderation.
Protecting the cardiovascular system
A healthy cardiovascular system means a lower risk of developing serious issues like heart disease and stroke. Polyphenols help by lowering cholesterol and blood pressure, improving artery function, preventing platelet clumping and improving arterial flexibility. The evidence on polyphenol-rich foods and heart benefits comes from hundreds of studies, including a large 2012 study in Europe which reported that a higher intake of polyphenols, particularly stilbenes from grapes and nuts and lignans from flax, was linked to a longer lifespan.
Flavonoid polyphenols help to lessen the clumping of platelets in the blood and improve the function of cells that line the arteries and veins. Platelet clumping is said to be one of the potential precursors for heart attack and angina. When it comes to the cardiovascular system, they’re also important by decreasing the inflammatory response and scavenging free radicals. Polyphenols can also inhibit vascular endothelial growth factor, which leads to complications with atherosclerotic plaque in the arteries, a significant factor in cardiovascular disease.
A 2007 study involving more than 34,000 postmenopausal women found that a higher intake of foods rich in flavonoids like strawberries, pears, apples, grapefruit, chocolate and red wine, was linked to a reduced risk of heart disease, and all-cause deaths.
Supporting brain health
Polyphenols promote better brain health and protect against dementia. Over 5 million Americans have been diagnosed with Alzheimer’s disease, according to the latest statistics. About one in nine people who are 65 and older have the disease, and about one-third of those 85 and older have it. Researchers say they’ve identified how polyphenols can help delay the onset of dementia and lower the risk of Alzheimer’s.
Red wine and grape skins contain resveratrol, a type of polyphenol that offers neuroprotective effects. Other research has shown the progression of dementia was slowed after polyphenols were introduced into the daily diet.
Lifting your mood
Certain lactobacillus strains have also been associated with an improved mood and reduced anxiety and depression-related behavior. Chocolate has famously been associated with an ability to lift one’s mood, and much of that may be due to its high polyphenol count. According to a 2013 study published in the Journal of Psychopharmacology, those who drank a polyphenol-rich chocolate drink once daily (about 1.5 ounces of dark chocolate) reported feeling calmer and more content than those who did not.
Supporting healthier bones
Osteoporosis is a devastating bone disease. In this condition, you lose bone density, which can then lead to bone fractures. Research has found that polyphenols have a positive effect on bone metabolism and lower one’s potential risk of developing osteoporosis while promoting bone strength. Oxidative stress, which occurs as a result of free radical activity, leads to oxidative damage in the cells and bones. But foods rich in polyphenols, like green tea, have been shown in studies to reduce the damage of oxidative stress on bones and improve femoral bone mineral density.
Supporting normal blood sugar levels
High blood sugar levels predispose one to diabetes, which affects some 29 million people in the U.S. Polyphenols have been shown to help stabilize blood sugar and fat metabolism while also lowering inflammation and reducing insulin resistance, which can help prevent serious, long-term complications like neuropathy, retinopathy, and cardiovascular disease.
The immune system attacks anything in the body that it considers foreign, like chemicals, plant pollen and invading microbes. That process is known as inflammation, and in intermittent bouts, they are directed at invaders who truly pose a threat to protect your health. But when chronic inflammation persists, meaning even when the body isn’t threatened by a foreign invader, that inflammation can lead to just about every major disease, including heart disease, hypertension, inflammatory bowel disease, arthritis, cancer, asthma, diabetes, depression and more.
On the flip side are foods and beverages that have been found to lower the risk of inflammation, and with it, chronic disease. Food high in natural antioxidants and polyphenols are said to be particularly helpful
Protecting the skin against harmful UV radiation
While it’s been awhile since many of us have seen the sun, it won’t be long before those scorching rays return. Perhaps just in time for the warmer season, the word is out that polyphenols may help protect your skin from harmful UV rays. That’s due to their ability to scavenge harmful free radicals in the body and, as new research reports, on the skin. Researchers from the University of Witten-Herdecke in Germany found that “consumption of dietary flavonoids from tea may confer photoprotection and improve skin quality.”
Published in the June 2011 issue of the Journal of Nutrition, the researchers found that, in addition to topical application, drinking large amounts of green tea, which is high in polyphenols, conferred similar protective benefits against UV radiation and visible signs of aging. The researchers concluded that regularly consuming beverages rich in flavonoids like tea, contributed photoprotection against harmful UV radiation and helped maintain skin structure and function. The flavonoids, again a type of polyphenol, may also help to absorb harmful UV rays before they can harm the skin’s surface, resulting in a sunburn. Not only can sunburns accelerate skin aging, but repeated and unprotected exposure to ultraviolet light can harm cells and compromise the body’s tissues. This study demonstrates, consuming a diet that’s rich in polyphenols can help to fight the sun-induced signs of aging while protecting one from the inside out.
Foods that contain the highest levels of polyphenols
There’s really no doubt that food can act as a natural medicine, which means your meals can even determine your destiny. Polyphenol-rich foods offer a healthy, natural pharmacy to enhance the body’s health. But which foods are the highest in polyphenol?
The European Journal of Clinical Nutrition states that star anise, dried peppermint, and cloves are the seasonings with the highest concentrations of polyphenols. Fruits with the highest levels of polyphenols include black chokeberries, black elderberries, strawberries, red raspberries, blueberries, plums, and black currants. Cocoa powder, dark chocolate, coffee, tea, and flaxseed meal are also high in polyphenols.
Black chokeberries or Aronia melanocarpa are particularly high in polyphenol, with five times more flavonoids than cranberries. The nutrients in chokeberries may even prevent harmful mutations in cell cultures, help regulate immune function of human white blood cell cultures and in patients with breast cancer, as well as to suppress the growth of human colon cancer cells.
In order, here are the foods that contain the highest amount of polyphenols:
- Dried peppermint
- Star anise
- Cocoa powder
- Mexican oregano, dried
- Celery seed
- Black chokeberry
- Dark chocolate
- Black elderberry
Drinks with the highest amount of polyphenols include:
- Black tea
- Red wine
- Green tea
- Pure apple juice
- Pure pomegranate juice
- Pure blood orange juice
- Pure grapefruit juice
- Pure lemon juice
As you can see, nature’s bounty of polyphenols offer a wealth of beneficial effects that combat free-radical damage and other degenerative processes, thereby potentially reducing the risk of cardiovascular disease, diabetes, high blood pressure, cancer, allergic conditions, and much more.
But as with so many things, variety is the spice of life – that means, you should consume a variety of polyphenol-rich foods to get the maximum benefits. The vital nutrients in these foods often work together so the sum is greater than the whole of its parts when it comes to protecting the body from the ravages of disease and aging. And, unlike pharmaceuticals like antihypertensives and statins that are used to prevent and treat disease, polyphenols come with no known adverse effects.