Flavonoid can reduce platelet aggregation and reduce the risk of fatal coronary heart disease

Excessive platelet activation results in an increased susceptibility to aggregation and clotting. This can contribute to thrombosis, myocardial infarction and stroke.

The intake of tea within population may be one of many factors that can modify the risk of cardiovascular disease.

Flavonoids are a family of polyphenolic compounds. They are natural vitaminlike compounds. In vitro studies have shown that isolated flavonoids at high physiological concentrations can reduce platelet aggregation and markers of platelet activation (J. Nutr. 130, 2120S–2126S).

They make blood cells called platelets less prone to clotting, and act as antioxidants, countering the artery-damaging potential of highly reactive free radical chemicals.

In the study, men with a high flavonoid intake had a 73 percent lower risk of stroke during 15 years of follow-up, compared with men with a low intake of flavonoids. The men in the study got about 70 percent of their flavonoids from drinking black tea.

A meta-analysis of seven prospective studies of flavonoids in relation to coronary heart disease found that the highest tertile of flavonoid intake was associated with a 20% reduction in the risk of fatal coronary heart disease in comparison with the lowest tertile of flavonoid intake (Eur J Clin Nutr. 2003;57:904-8).
Flavonoid can reduce platelet aggregation  and reduce the risk of fatal coronary heart disease

Tea consumption and cardiovascular disease

Cardiovascular disease is a well-known global healthcare burden. It is thought that cardiovascular disease risk may be lowered by adjusting modifiable risk factors such as the diet, and this includes habitual intakes of tea.

Tea has long been regarded for its health promoting properties – helping to maintain cardiovascular and metabolic health since ancient times.

Polyphenols, particularly flavonoids, which are of great abundance in tea, have been experimentally demonstrated to inhibit oxidation reactions caused by free radicals and prevent or delay atherosclerosis. In green tea, the main flavonoids are the flavanols (catechins). Catechins are a group of flavonoids that include epicatechin (EC), epicatechingallate (ECG), epigallocatechin (EGC) and epigallocatechingallate.

Epidemiological data has also discovered that black and green tea may reduce coronary heart disease and stroke risk by between 10 and 20 per cent, respectively.

The effects of tea flavonoids to enhance nitric oxide status and to improve endothelial function may be at least partly responsible for benefits on risk of CVD.

Green tea polyphenols can protect against myocardial damage by modulating the contractile apparatus through altered myofilament Ca (2+) sensitivity in cardiac muscle.

More recent studies showed a cohort of 8,552 participants and observed a 28% reduction in death from cardiovascular disease for men and women consuming over 10 cups a day compared to those consuming less than 3 cups per day. Biofactors. 2000;13:49–54.
Tea consumption and cardiovascular disease

Phytochemicals in orange

Orange juice is a healthy, sweet drink. Some kinds of orange juice have pieces of orange in the juice.

Citrus fruits and juices are rich in flavonoid (phytochemicals) that help reduced overall rate of cancer occurrence. Ounce for ounce orange juice is the most nutrient dense juice consumed in the United States.

A glass of orange juice is thought to provide about 49 to 140 mg flavanone glycosides. Another flavonoid group is the anthocyanidins, the aglycone form of anthocyanins.

Phytochemicals have a wide variety of functions, some of which include antioxidant, hormonal actions, interactions with enzymes and DNA replication, and antibacterial effects.

Studies show that diets that are high in phytochemicals protect against cardiovascular disease, counteract inflammatory compounds, help to prevent cancer, and increase antioxidant status.
Phytochemicals in orange

Flavonoids in fruit juice

The term flavonoid denotes a large group of chemical compounds. Flavonoids contain a C6-C3-C6 carbon skeleton with sugar moity (in glucosides).

There are indications that flavonoids have a useful protective action, in particular against some respiratory disease.

It also has been implicated that a high intake of flavonoids reduces the risk of cancer.

The greatest contributors of flavonoids in human diets are fruits and vegetables with fruit juice, green tea, and dark chocolate being the richest sources in western diets.

They are four main types of flavonoids in fruit:

Flavonol 
For example quercetin glycosides in apple, plum and grape. The consumption of flavonoids has been estimated to average 190 mg/day in the US mostly as flavonols.

Anthocyanins 
Red and blue pigments such as cyaniding and delphinidin and their glycosides

Flavones 
Luteolin in lemon peel

Flavanones
For example, hesperidins in oranges and naringin in grapefruit. The cloudiness of juice and marmalade made from oranges is due to precipitation of hesperidins, which is less soluble in water. Naringin has a bitter taste and is soluble in water, some fresh grapefruits and pumelos taste slightly bitter.
Flavonoids in fruit juice

Flavonoids in tea

Researchers have unidentified a class of antioxidants called polyphenols that appear to be responsible for much of the health benefits of tea called flavonoids.

The term ‘flavonoid’ is generally used to describe a broad collection of natural products that include a C6-C3-C6 carbon framework, or more specifically a phenylbenzopran functionality.

Flavonoids known for their health promoting qualities and disease preventing dietary supplements, are found in whole grain, soy, vegetables, fruits, herbs, spices, teas, chocolate, nuts, olive oils and red wine.

Many flavonoids act as antioxidant and may protect against cancers.

93 per cent of tea phenolic compounds are flavonoids. Green tea contains more of simple flavonoids called catechins, while the oxidization that the leaves undergo to make black tea, coverts these simple flavonoids to more complex varieties called theaflavins and thearubigins. Green tea also contain epicatechin and gallic acid.

Epidemiological, in vitro and animal studies indicate that flavonoids exert protection against cardiovascular diseases.

Since green tea fight free radicals and reduce the risk of heart disease, it seems natural to assume that it is the ingredients contribute to health protection.

The cardio-protective effect of flavonoids can be attributed to its antioxidant, anti-thrombogenic and lipid lowering properties and also its effect on promoting endothelial function.

150 mgs of flavonoids, the amount found in a cup of brewed tea, is enough to have an immediate antioxidant effect.

Tea provides about 22 per cent of the total intake of flavonoids in the Unites States diet.

Flavonoids in tea