What are polyphenols?
These little known nutrients do most of the hard work of creating a healthy body
In our previous post we started with “bad food kills you” yet “good food can give you a long and healthy life”. For this, we introduced polyphenols to you. In this post we will tell you more about what polyphenols are.
In the coming weeks, we will dive deeper into the impact polyphenols have on health (specifically the cardiovascular system, joints, muscles and the neural system), beauty (such as skin, wrinkles and hair), ageing (or actually anti-ageing) and disease prevention. It turns out that polyphenols fight inflammations, hypertension and hypercholesterolemia. Certain polyphenols protect against cancer, prevent dementia and Alzheimer’s and are linked to a number of other health issues. In short, there are many proven and assumed links between polyphenols and longevity, ageing and health.
What are polyphenols?
Polyphenols are a class of secondary metabolites widely found in plants with two or more phenolic hydroxyl groups. Polyphenols are particularly abundant in fruits, vegetables, extra vergine olive oil, herbs, tea, coffee and ... red wine. Depending on their chemical structure, polyphenols can be classified into flavonoids, phenolic acids, stilbenes, lignans, and other polyphenols. Flavonoids possess functions such as antioxidation and anti-inflammation. Phenolic acids have the ability to be antioxidative and are beneficial to aspects such as vision. Stilbenes have certain anti-cancer effects. Lignans have an impact on hormone regulation.
Polyphenols are phytochemicals, i.e they are found in plant-based foods, Numerous studies have indicated that polyphenols possess a range of biological activities, including anti-inflammatory effects, promotion of cellular repair, and antioxidant capability.
Let’s first deal with this concept of antioxidant capability. Our body produces free radicals, which are unstable molecules and the root-cause of many diseases. But what are free radicals? Remember from high school that burning (oxidating) propane gas leads to CO (yellow flame leading to soot; that is carbon monoxide, which is poisonous) and CO2 (carbon dioxide, which can be safely (I know ...) released into the atmosphere? Well, something similar is happening when the cells in your body need energy. Most oxidation goes perfectly okay, but a few molecules lack an oxygen atom. These “free radicals” cause oxidative stress, leading to cellular damage and inflammation. Polyphenols, acting as powerful scavengers, protect cells from oxidative stress. In other words, polyphenols (akin to other nutrients with antioxidant properties) carry a “spare” oxygen atom, enabling the dismantling of the free radical.
But polyphenols are more than (powerful) antioxidants. Beyond their antioxidative prowess, polyphenols can also regulate immune function, inflammatory response, and oxidative stress and improve the resistance to diseases including systemic lupus erythematosus, rheumatoid arthritis and multiple sclerosis. In the aspect of the nervous system, polyphenols have potential protective effects on cognitive functions and alleviate neurodiseases through enhancement of mitochondrial function, prevention of cellular damage, and proper functioning of the DNA repair pathway. At the same time, polyphenols also play an important role in regulating metabolic processes, such as improving blood glucose and blood lipid levels. A diet rich in polyphenols leads to lower blood pressure, insulin resistance and LDL oxidation. Polyphenols have many benefits targeting the anti-aging process on various organs and tissues, such as the brain, muscle, skin, heart, liver, and intestine. A number of studies have linked polyphenols to improved gut-health and improved weight management.
(I’m trying to avoid footnotes and referecnes, so please leave a comment if you’re interested to get access to some or all of the studies).
Where to find polyphenols?
Polyphenols are found in herbs, fruits and vegetables. They express themselves sometimes as pigments (i.e. colourful food, hence the benefits of the “rainbow” diet). They frequently taste bitter, prickly or peppery. Some polyphenols are astringent.
Berries are rich in polyphenols, but many berries have an astringent effect. Carrots, tomatoes and many fruits display bright colours. Olive oil that is rich in polyphenols should display a pleasant bitter taste and a significant peppery afterdrink effect. Cacao (including chocolate with over 70% cacao content) is rich in polyphenols, yet bitter. Coffee is both bitter and astringent. Green tea is rich in polphenols and astringent. Blessed are those who appreciate these tastes. But even when you don’t there are many ways to get sufficient polyphenols through healthy and delicious meals. We will come back to this later.