WHAT ARE THE FLAVAN-3-OLS?
The flavan-3-ols (also known as catechins or flavanols) are a group of health boosting nutrients that are mainly found in cocoa beans and tea but can also be sourced from other plant based products. They were discovered and isolated in 1929 by Dr Michiyo Tusjimura at the institute of Physical and Chemical Research in Japan and make up part of the flavonoid group of phytonutrients (a group of chemical compounds which occur naturally in plants and have numerous health benefits but are not considered essential nutrients).
Although the flavan-3-ols are not considered essential to human health there are still plenty of reasons to include them in your diet. They are all powerful antioxidants which protect your body’s cells from dangerous free radicals (harmful by-products of oxygen related reactions). Additionally, the flavan-3-ols act in a healing and protective capacity throughout the body by fighting disease, preventing disorders and reducing cellular damage.
In this article I will be providing a full overview of 7 key flavan-3-ols:
Functions:- Catechin is a powerful antihistamine (a substance that counters the effects of histamine and fights against allergies and inflammation) and antioxidant. It has also been linked with cancer prevention and can be used to treat hepatitis (inflammation of the liver) and mental disorders such as Alzheimer’s disease (a condition which destroys your brain cells) and Parkinson’s disease (a degenerative brain disease which causes loss of mobility and speech). Additionally, it may help prevent acquired immune deficiency syndrome (a disease also known as AIDs that slowly destroys the human immune system) and brain damage caused by strokes but more research needs to be done to confirm this.
Recommended Daily Allowance (RDA):- There is currently no RDA for catechin.
Food Sources:- Catechin can be found in a wide variety of foods. Some of the richest sources include blackberries (37.06 milligrams (mg) per 100 grams (g)), black diamond plums (17.55mg per 100g), blueberries (37.24mg per 100g), cocoa beans (88.45mg per 100g), dark chocolate (11.99mg per 100g) and green tea (2.55mg per 100g).
Overdose Symptoms:- There are no reported overdose symptoms associated with catechin consumption.
Deficiency Symptoms:- There are no reported deficiency symptoms associated with catechin consumption.
Functions:- Epicatechin is a potent antioxidant that keeps the heart healthy and can help treat diabetes (by reducing blood glucose levels and acting in a similar way to insulin). An observational study of the Kuna Indians revealed that epicatechin may also prevent cancer, heart failure and strokes (a loss of blood flow to the brain which causes brain damage) but more research needs to be done to validate this.
RDA:- There is currently no RDA for epicatechin. However, a number of studies suggest that eating 45g of dark chocolate a day (which contains 18.68mg of epicatechin) will allow the epicatechin health benefits above to be realised.
Food Sources:- Epicatechin can be found in a large selection of plant based foods. Some of the best epicatechin foods include apple skins (28.73mg per 100g), blueberries (13.69mg per 100g), cocoa beans (99.18mg per 100g), dark chocolate (41.5mg per 100g) and green tea (8.29mg per 100g).
Overdose Symptoms:- There are no reported overdose symptoms associated with epicatechin consumption.
Deficiency Symptoms:- There are no official reported deficiency symptoms associated with epicatechin consumption. However, it has been suggested by Dr Norman Hollenberg that epicatechin deficiency may actually contribute to cancer, diabetes, heart failure and stroke.
Functions:- Gallocatechol (also known as epigallocatechin) is a powerful antioxidant but its other health benefits have not yet been confirmed. It may potentially boost the immune system, prevent arthritis (inflammation of the joints), prevent cancer, prevent heart disease and reduce blood levels of low density lipoprotein (LDL) cholesterol (a type of cholesterol which can cause blockages in the arteries and increase your heart disease risk) but further research needs to be performed to validate this.
RDA:- There is currently no RDA for gallocatechol.
Food Sources:- Cocoa beans (156.67mg per 100g) are the richest food source of gallocatechol. However, black diamond plums (13.06mg per 100g), black tea (7.93mg per 100g) and green tea (16.71mg per 100g) are also good gallocatechol sources.
Overdose Symptoms:- There are no reported overdose symptoms associated with gallocatechol consumption.
Deficiency Symptoms:- There are no reported deficiency symptoms associated with gallocatechol consumption.
Functions:- Epigallocatechin gallate (also known as EGCG or epigallocatechin-3-gallate) is a powerful antioxidant and 1 of the most potent flavan-3-ols. It has numerous health benefits which include preventing arteriosclerosis (hardening and loss of elasticity within the arteries), arthritis, heart disease and hepatitis whilst also protecting the body’s deoxyribonucleic acid (DNA) and nervous system from damage. Additionally, epigallocatechin gallate can keep the blood healthy (by reducing blood levels of LDL cholesterol and reducing high blood pressure), treat diabetes and treat various types of cancer (including bladder cancer, brain cancer, breast cancer, cervical cancer, prostate cancer and skin cancer). Epigallocatechin gallate may also prevent Huntington’s disease (a neurodegenerative disorder which affects cognitive function and muscular coordination), Sjögren’s syndrome (an autoimmune disorder where the immune cells attack the glands which produce tears and saliva) and help treat the human immunodeficiency virus (HIV) but more research needs to be done before these benefits are confirmed.
RDA:- There is currently no RDA for epigallocatechin gallate. However, some sources suggest that relatively high amounts of this flavan-3-ol are needed to unlock the health benefits listed above. These sources recommend consumption of at least 2,000mg per day and suggest that it is safe to consume up to 4,000mg of epigallocatechin gallate each day.
Food Sources:- Carob flour (109.46mg per 100g) is extremely rich in epigallocatechin gallate. However, black tea (9.26mg per 100g), green tea (77.81mg per 100g) and oolong tea (34.48mg per 100g) also contain high levels of this flavan-3-ol.
Overdose Symptoms:- Ingesting too much epigallocatechin gallate can inhibit its antioxidant and cancer fighting action by accelerating the rate of oxidative damage caused by free radicals, interfering with the action of cancer fighting drugs and increasing cancer risk amongs neonatal infants (children aged between 1 and 4 weeks old). To avoid these overdose symptoms it is recommended that you limit your intake of epigallocatechin gallate to 4,000mg per day.
Deficiency Symptoms:- There are no reported deficiency symptoms associated with epigallocatechin gallate consumption.
Functions:- Epicatechin gallate (also known as ECG or epicatechin-3-gallate) is a potent antioxidant which protects against ultraviolet (UV) damage and prevents various types of cancer (including breast cancer and skin cancer).
RDA:- There is currently no RDA for epicatechin gallate. However, most sources suggest that you limit your consumption of this flavan-3-ol to 200mg per day.
Food Sources:- Tea is the best source of epicatechin gallate with black tea (7.24mg per 100g), green tea (20.95mg per 100g) and oolong tea (6.73mg per 100g) all containing high levels. Black grapes (2.81mg per 100g) are also a good source of this flavan-3ol.
Overdose Symptoms:- Overdosing on epicatechin gallate is believed to promote tumour growth, hence the reason a lot of sources recommend that you consume no more than 200mg per day of this flavan-3-ol.
Deficiency Symptoms:- There are no reported deficiency symptoms associated with epicatechin gallate consumption.
Functions:- Theaflavin (also known as TF) has a number of potential health benefits. It is a powerful antioxidant that may boost heart health, prevent cancer, prevent dementia (a type of mental deterioration), prevent replication of the HIV virus and reduce LDL cholesterol levels. However, it is not clear how well this flavan-3-ol is absorbed in the human body so more research needs to be performed to directly link these benefits with theaflavin.
RDA:- There is currently no RDA for theaflavin. However, some research suggests that consuming 5 cups of tea per day (which will supply you with around 8mg of this flavan-3-ol) will give your body adequate amounts of this nutrient.
Food Sources:- Black tea is the main source of theaflavin with a 100mg serving containing 1.58mg.
Overdose Symptoms:- There are no reported overdose symptoms associated with theaflavin consumption.
Deficiency Symptoms:- There are no reported deficiency symptoms associated with theaflavin consumption.
Functions:- Thearubigins are powerful antioxidants which also have a number of further potential health benefits. These potential health benefits include possibly preventing cancer, possibly reducing blood levels of LDL cholesterol and possibly treating diabetes. However, they require additional research before they can be confirmed.
RDA:- There is currently no RDA for thearubigins.
Food Sources:- Black tea (8.13mg per 100g) and green tea (1.03mg per 100g) are the 2 main food sources of thearubigins.
Overdose Symptoms:- There are no reported overdose symptoms associated with thearubigins consumption.
Deficiency Symptoms:- There are no reported deficiency symptoms associated with thearubigins consumption.
Although the phytonutrients are not thought to be essential in humans, there is very strong evidence that eating these plant based nutrients can massively boost your health. Additionally, they can protect you from many serious health conditions including cancer, diabetes and mental disorders. So make sure your diet is rich in these powerful flavan-3-ols by drinking more tea, eating more fruits and allowing yourself to indulge in dark chocolate.