What are polyphenols?
Polyphenols are natural compounds used by plants that work as a defense system against various stresses. They can act as antioxidants and neutralize the free radicals that increase risk for certain diseases. More than 8,000 types have been identified, and are classified into four groups, flavonoids, phenolic acids, polyphenolic amides, and other polyphenols. However, the most common type are the flavonoids, which account for 60% of polyphenols. And what do all polyphenols have in common? They are found in plant based foods.
Health benefits of polyphenol for PCOS
Although there are currently not many studies specifically focusing on polyphenols and PCOS, many studies have been done on the general health benefits of polyphenols. Polyphenols have been studied for their cardioprotection, anti-carcinogenic, anti-oxidant, and anti-inflammatory properties. Here is where it gets interesting – They can help to enhance your overall health by the mechanisms below:
Decreases inflammation
Oxidative stress occurs in the body and leads to inflammation. This part gets a little “sciency”. Studies show that the ability of dietary polyphenols to reduce inflammation is due to its ability to act as antioxidants, interfering with oxidative stress signaling, and thirdly, suppressing the proinflammatory signaling pathways. ROS, reactive oxygen species, are molecules that signal inflammation. Studies show that polyphenols can interfere with these molecules, inhibiting the pathway that triggers inflammation.
Improves insulin resistance
Insulin resistance is at the heart of PCOS for the majority of people. Diet and lifestyle can help to improve insulin resistance. Check out our blog post on 8 Foods that Improve Insulin Resistance. Polyphenol rich foods can also improve insulin resistance. 
Studies show that polyphenols can stimulate insulin secretion, and enhance insulin dependent glucose uptake in the tissues. In a clinical study done to examine the effects of polyphenols on insulin resistance in insulin resistant patients, one group took two anthocyanin (a type of flavonoid) capsules twice a day for 24 weeks. Compared to the placebo group, those taking the anthocyanin had a significantly lower insulin resistance index.
Another study looking specifically at people with PCOS, those consuming 1,500mg resveratrol (a type of polyphenol) daily, showed an increase of the Insulin Sensitivity Index by 66.3%.
Improves gut health
Studies have shown that dietary polyphenols have been shown to have influence on the gut microbiota composition and function, having the ability to interfere with gene expression. With only about a 5-10% absorption, most polyphenols are malabsorbed in the small intestine. The leftover 90-95% may accumulate in the large intestine, where they can promote beneficial effects on the gut microbiota.
A different study explains how polyphenols may also inhibit harmful bacteria while stimulating the growth of beneficial bacteria. In a study done to examine polyphenols and the gut microbiome, those drinking a blueberry extract drink throughout the study promoted beneficial bifidobacteria in their gut, and those drinking green tea extract were able to help suppress harmful bacteria such as Clostridium Difficile.
May lower the risk for heart disease
Women with PCOS have an increased risk of heart disease. The good news is that certain foods, including those rich in polyphenols, may help decrease this risk.
A randomized control study looked at the effects of quercetin, which is a type of flavonoid. Those receiving the quercetin after six weeks had a significantly decreased blood pressure compared to the placebo. LDL cholesterol levels, also known as the bad cholesterol, were also significantly decreased, while HDL cholesterol, the good cholesterol, was increased. It is believed that these heart healthy benefits are due to the antioxidant properties of polyphenols.
Polyphenols can help regulate the host immune system as well as directly target the pathogens in the body. Different types of polyphenols bind to one or more receptors on the immune cells.
One study showed that polyphenols enhance intestinal mucosal immunity (our first line of intestinal defense) by increasing the populations of cells that evoke rapid immune protection. As mentioned previously, polyphenols can alter the gut microbiota which may also change our immune capacity.-
What foods are rich in polyphenols?
Tea, red wine, coffee, dark chocolate, and berries are some of the best known sources of polyphenols. A study examined the richest sources of polyphenols in the diet – and are the “winners”:
-Fruits: Apples, apricots, black grapes, blackberries, blueberries, grapes, cherries, grapefruit, lemon, peaches, pears, plums, strawberries, and raspberries
-Vegetables: artichokes, asparagus, broccoli, carrots, potatoes, red/yellow onions, spinach, shallots
-Legumes: black beans, tofu, soy milk, white beans
-Nuts and seeds: flaxseeds, almonds, hazelnuts, pecans, walnuts
-Herbs and spices: Caraway, cinnamon, cloves, cumin, rosemary, sage, thyme, dried basil, dried parsley
-Drinks: Black tea, green tea, red wine, coffee
Martha’s note: Pay attention to how your body feels with caffeine. It make some feel jittery and more anxious – so moderation is your best bet. Consume wine (and any alcohol) in moderation as well.
-Other: cocoa powder, dark chocolate, ginger, vinegar, olives
Bottom line
Start thinking about the “little guys” when it comes to nutrition for PCOS. Find ways to add in polyphenol rich foods and beverages into your diet.
Which are your favorite polyphenol rich foods?
