A new study paves the way to the possible health benefits of a tangerine flavonoid, nobiletin, in preventing obesity and atherosclerosis.

What are Flavonoids?

Flavonoids, or bioflavonoids as it is called when used in supplements, are a class of plant based compounds. They are polyphenols and a diverse group of phytochemicals that are mostly found in vegetables, fruits and herbs and are responsible for their different colors. They can be found in high amounts in foods such as grains, legumes, nuts, teas, onions, honey and many more. The teas, specifically black, green or white tea, are high sources of a flavonoid known particularly as quercetin. Furthermore, onions contain myricertin and kaempferol; honey has myricertin and quercetin. Other good sources of flavonoid include buckwheat, tangerines, strawberries, blueberries, beans and spinach. However, the composition and concentration of flavonoid in each plant may vary depending on certain factors such as maturity, growing condition, plant part and variety.

There are different types of flavonoids, which may vary depending on the plant source. One of the most important is the flavonoid quercetin as it acts as building blocks for other flavonoids and can be found in foods like apples and onions. There are also flavonoids that can be found in citrus fruits, and among these citrus flavonoids are the compounds hesperidin and rutin which are present in fruits like tangerines, grapefruits and oranges. There are other well known flavonoids that include compounds like PCO (proanthocyanins), polyphenols and genistein which can be found in a variety of food sources and has been known to give great health benefits. The polyphenols, primary source of a class of flavonoid called EGCG (epigallocatechin-gallate) is known to be an effective natural compound to fight cancer.

Health benefits of Flavonoids

Studies have been performed to prove that flavonoids are necessary for human health and may also show some healing potential. This is because flavonoids are known to perform antioxidant activities. Flavonoids are even considered to be more powerful than Vitamin C and Vitamin E in eradicating the body’s free radicals and in preventing cellular damage to the body. They also have anti-viral, anti-inflammatory, anti-tumor, vasodilatory and antiallergenic effects.

The flavonoid quercetin is the most known compound to provide many health benefits. It suggests delay of the onset of diseases like cancer that is triggered by free radicals. Clinical studies show low rates of pancreatic, lung and breast cancer brought about by the intake of foods with high amounts of quercetin. It can also slow down low density lipoprotein oxidation, thus preventing heart diseases. A recent study conducted in Finland and the Netherlands suggested that people who consume large amounts of flavonoids, especially quercetin, showed a reduced risk of heart disease and stroke. Quercetin also provides anti-inflammatory action, therefore reducing allergic reactions like sinusitis and chronic asthma. The anti-inflammatory properties of quercetin may also be ideal for the treatment of minor problems like eczema and bug bites, as well as disorders affecting joints, rheumatoid arthritis, fibromyalgia, chronic gout and the like.

Aside from flavonoids being acquired from the diet, it can also be beneficial as supplements as they strengthen blood vessels. The flavonoids PCO and citrus flavonoids help in repairing problems like chronic hemorrhoids and varicose veins.

Doses of flavonoid supplements will vary depending on the type consumed and the specific condition. However, if long term health is considered, a mixture of quercetin, rutin, and hesperidin will do the job. Instructions on the label must be always followed. To improve the flavonoid’s protective action and taste, it is usually combined with Vitamin C. But still, nothing beats natural sources like grape seeds and green tea where flavonoids are greatly found.

The Study

A new research reports that tangerine flavonoid does not only prevent obesity but also gives protection from type-2 diabetes and atherosclerosis. It suggests that nobiletin, high concentrations of which are found in tangerine’s white pith, helps maintain healthy levels of glucose, insulin and cholesterol, as well as preventing fat build up.

Dr. Murray Huff, from the Robarts Research Institute, University of Western Ontario, and USA vascular biology research group director said that mice treated with nobiletin were originally protected against obesity, but as the study progresses, it shows that it also protected the mice from build up of plaque in arteries which can cause atherosclerosis that can lead to heart attack and stroke.

Nobiletin was observed to prevent fat build up in human cells by the stimulation of gene expression involved in the burning of excess fat, as well as in slowing down the genes responsible for fat manufacture. The authors said that sensitivity to insulin and glucose tolerance in the peripheral tissues and liver were restored by nobiletin and the improvement in these parameters may lead to prevent atherosclerosis.

A second group where the western diet was administered with nobiletin, however, showed no rise or difference in cholesterol levels, glucose and insulin and a normal amount of weight was maintained. It was also monitored that mice fed with nobiletin were found to have less fatty livers and were more insulin sensitive.

According to the researchers, their studies give evidence, both in the physiological and molecular level, that nobiletin has the ability to regulate the metabolism of hepatic lipid and prevent insulin resistance abnormalities. It also corrects dyslipidemia, hepatic steatosis and glucose homeostasis and it protects the body from further development of atherosclerosis through a variety of mechanisms.

Dr. Huff cited that the study gives way for future studies in testing the many potential of nobiletin to reduce metabolic syndrome risks and related conditions. However, Huff suspects that tangerines lack enough nobiletin to transfer the same effects that it did to mice to the humans, adding that supplements are most likely required.

They also suggested that inflammation and foam cell formation reduction may as well help in reducing the risk of atherosclerosis, though it was not evaluated in their study.

The research of Dr. Huff was mostly focused on observing the properties of bioactive molecules that are naturally occurring. A research of his two years ago where he discovered a flavonoid called naringenin in grape fruit offered the same protection against obesity and other metabolic syndromes and drew attention internationally. This time, he said that what was interesting was that nobiletin is ten times more potent in its protective effects than naringenin, and this time they have proven that it can also prevent atherosclerosis.

Sources
herbs2000.com
dietaryfiberfood.com
nutraingredients.com