Polyphenols are chemical compounds that are found in plants. Many of which are responsible for the attractive colours of the, fruits, flowers and leaves. Polyphenols involved in defense against ultraviolet radiation or aggression by pathogens. The 2 classes of polyphenols are flavonoids (anthocyanins, flavanones, flavones, catechins, isoflavones) and non-flavonoids (ellagic acids). Polyphenols are found in maximum concentrations in the skin.
Several thousand molecules having a polyphenol structure have been identified in higher plants, and several hundred are found in edible plants. Evidence strong supports a contribution of polyphenols to the prevention of cancers, cardiovascular diseases, and osteoporosis and suggests a role in the prevention of neurodegenerative diseases. Many plant polyphenolic compounds have been shown to have cancer preventive effects in lab experiments. Polyphenols have been shown to inhibit the abnormal platelet aggregation that cause most sudden heart attacks and strokes, while fighting inflammation and supporting healthful blood lipids.
Polyphenols Foods List
Blueberries, cherries, cranberries, pomegranate, apples, apricots, grapefruits, oranges, elderberry, red grapes, raspberry, strawberries, blackberries, gooseberry, dark plums, kiwi, ligonberries, marionberries, acai berry juice, black or red currants, green tea, Oolong tea, Cocoa beans, onions, garlic, turnip, watercress, cashews, peanuts, soybeans.
According to some research, ellagic acid reduces the effect of estrogen on cancer cell growth in breast tissue and promotes the breakdown and removal of cancer-causing substances in the blood via the liver. Ellagic acid prevents the destruction of P53 gene by cancer cells. Can bind with cancer causing molecules, therefore making them inactive. Also shown to induce apoptosis and potentiate all-trans retinoic acid myeloid differentiation therapy in human leukemia HL-60 cells.
Isoflavones are polyphenolic compounds that are talented of exerting estrogen-like activity. Therefore, they are classified as phytoestrogens plant-derived compounds with estrogenic effect. Soybeans are the most important source of isoflavones and the main isoflavones in soybean are daidzein and genistein. Epidemiological studies demonstrated a preventive activity of soy protein on breast tissue as evidenced by the lower rates of breast cancer in East Asian countries where soy is a part of the diet. A new study has showed that isoflavones have strong antioxidant effects, comparable to that of the vitamin E. The antioxidant properties of isoflavones can decrease the long-term risk of cancer by preventing free radical damage to DNA.The main sources of isoflavones in diet include soybeans, soy milk, tofu, and bean curd.
Quercetin works as an antioxidant by scavenging damaging particles in the body known as free radicals. Antioxidants are chemical substances that donate an electron to the free radical and convert it to a harmless molecule. Quercetin has powerful antioxidant properties and works to protect the body from free radical damage which can damage DNA and cause ageing, heart disease and cancer. Quercetin has demonstrated significant activity in helping with inflammation of direct activity of several initial pathways that can lead to an inflammatory response. Studies done in cell cultures have shown that quercetin has activity against some types of cancer cells. Quercetin significantly inhibits the growth of precancerous cells affecting the liver, according to a study published in 2011 issue of Nutrition and Cancer.
The antioxidant effect of resveratrol helps to avoid damage to DNA, influences the transcriptions of genes responsible for redox metabolism and inhibits proliferartion of cancer cells. Resveratrol dilates blood vessels to develop blood flow and increases nitric oxide production, which is a important Resveratrolpart of healthful blood flow and heart health.That includes the inhibition of synthesis and release of pro-inflammatory mediators, modifications of eicosanoid synthesis, inhibition of some activated immune cells, or inhibiting the enzymes, such as COX-1 or COX-2, which are responsible for the synthesis of pro-inflammatory mediators through the inhibitory property of resveratrol on transcription factors like nuclear factor kappaB or AP-1.
Anthocyanins may help prevent cardiovascular disorders, inflammatory responses, cancer, and degenerative diseases. Anthocyanins also improve neuronal and cognitive brain functions, ocular health as well as protect genomic DNA integrity. Crude anthocyanin extracts have been administered both orally and via injection to reduce capillary permeability. The anthocyanins cyanidin and delphinidin have been shown to prevent the expression of vascular endothelial growth factor, a compound that has stimulates atherosclerosis.
The importance of green tea lies in the fact it is rich in catechin polyphenols, particularly epigallocatechin gallate. Some researchs have found an association between consuming green tea and a reduced risk for several cancers, including, lung, breast, colon, esophageal, and bladder. Green tea contains chemicals recognized as polyphenols, which have antioxidant effects. Catechins are antioxidants with the ability to scavenge reactive oxygen species such as superoxide, the hydroxyl and peroxyl radicals. Green tea’s anticancer effects include its ability to inhibit the overproduction of the enzyme cyclooxygenase (COX)-2, a protein whose overproduction has been implicated as a factor in many diseases, including cancer. A study of 18,000 Chinese men found that men who drank green tea frequently had a 50% lower risk of developing stomach cancer as compared to men who did not drink tea.