The occurrence of overweight and obesity and their related metabolic disease and disorders are considered a significant risk to the public’s health. Although numerous diet and exercise regimens are available for weight loss, fat loss and avoidance of weight regain, progress is often slow and unsatisfactory. Recently, natural bioactive phytochemicals present in foods stuff have discovered for their potential antioxidant and other health benefit effects on the refusal of chronic disorders such as cardiovascular disease, cancer, inflammatory and metabolic diseases including obesity and diabetes.

Polyphenols are a broad class of naturally-occurring phytochemicals, of which some such as anthocyanins, resveratrol catechins, Pyrocatechol, Resorcinol, Pyrogallol curcumin, and phloroglucinol have been shown to modulate physiological activities and molecular pathways that associated with energy metabolism, adiposity, and obesity. Since several decades many research carried out and found the potential in vivo, beneficial effects of these polyphenols on obesity and adiposity as complementary agents in the up-regulation fat oxidation and energy expenditure have developed by investigating these compounds in cell various cultures, animal models of obesity and in some human clinical and epidemiological studies. In this article, the efficacy of the above-title polyphenols and their potential effectiveness to modulate obesity and some associated disorders discussed in brief.

 We all are well known for cholesterol which helps in our regarding insulate nerves, body build new cells and precursors of hormones. The liver produces all the cholesterol which demands by the body. But cholesterol also enters into our body through food, such as animal-based foods like eggs, meat and milk, and even high intake of cholesterol in our body is a risk factor for obesity, blood pressure and heart disease.so to control the absorption of dietary cholesterol we can various natural compounds are such as polyphenols. When high cholesterol level present in our blood, situation causes atherosclerosis a form of heart disease.  In this situation, our blood arteries become narrowed due to that the blood flow to the heart muscle is slowed down, the blood transmits oxygen to the heart, and if not reach it according to the demand of cardiac cells may suffer chest pain and convert into the ischemia. If the blood supply to a part of the heart is cut off by an obstacle, the result is a heart attack.There are mainly two forms of cholesterol high-density lipoprotein (HDL or "good" cholesterol.) and Low-density lipoprotein (LDL or "bad" cholesterol) these are the form in which cholesterol travels in the blood. LDL is the primary cause of artery-clogging plaque. HDL manages to clear cholesterol from the blood and it good for health.Various invitro and invivo studies suggest that natural phenolic compounds such as catechins in green tea guggulsterones in guggul, allicin and S-allyl cysteine in garlic curcumin in turmeric lignans and omega-3 fatty acids in flax seed and monacolin K in red yeast rice and other polyphenol containing products may reduce dietary cholesterol absorption along with antioxidant activity which also minimise the risk of different cardiovascular diseases (CHD),by lowering the plasma levels of cholesterol and triglyceride^.

Polyphenols Benefits

The knowledge of polyphenols foods and their health benefits is at an earlier stage than foods with fibre or omega three fats, but what we know is very exciting.

Among the several polyphenols benefits, possibly most vital is the substantial evidence for their ability to control gene expression, precisely the genes that control inflammation.

Pharmacological effects of polyphenols:

1.    In cardiovascular disease, polyphenols improve blood lipids, reduce platelet aggregation, and reduce blood pressure.

2.    In diabetes, polyphenols can help decrease blood glucose levels.

3.    Numerous polyphenols have been shown to block processes in individual cells that drive arthritis.

4.    Polyphenols also help to reduce bone density loss and reduce the risk for cancer aging-related factors.

5.    Polyphenols benefit from various diseases, they also perform an essential role in weight loss by increasing energy expenditure, decreasing dietary fat absorbance and metabolic rate, which slow when we lose weight.

 The mechanism underlying such effect of polyphenolic compounds is yet to be discovered, it is apparent from in vitro and in -vivo studies that polyphenolic compounds inhibit the intestinal absorption of dietary lipids by inhibiting pancreatic lipase activity, and lowers the postprandial serum triglyceride and also significantly inhibit pancreatic phospholipase A2 (PLA2). A critical step in the uptake and absorption of lipids by the enterocyte by the micellar solubilization of hydrolyzed lipids, which facilitates the relocation of lipids via the unstirred water layer to the enterocyte.

The cellular studies established that these dietary polyphenols decrease the viability of adipocytes and proliferation of preadipocytes, triglyceride accumulation, and suppress adipocyte differentiation encourage lipolysis and fatty acid β-oxidation, and diminish inflammation. Concurrently, the polyphenols modulate signaling pathways including the AMP-activated protein kinase, peroxisome proliferator-activated receptor γ, PPAR gamma activator 1-alpha, CCAAT/enhancer binding protein α, sirtuin 1, uncoupling proteins 1 and 2, sterol regulatory element binding protein-1c, and nuclear receptor factor kappa B that regulate antioxidant adipogenesis, and anti-inflammatory responses in the cell.Also polyphenolic compounds significantly dropped the lymphatic absorption of dietary cholesterol in a dose-dependent way in the animal system with the mesenteric lymph-duct cannula. Likewise, crude green tea extracts strongly inhibited the intestinal absorption of α-tocopherol, another lipid of which are highly hydrophobicity; however, the absorption of dietary fat (fatty acids) was transformed in a biphasic manner, with a significant increase at a low dose of the green tea water extract and a reasonable decrease with higher dose in various studies its revels that of water extract of catechins from Japanese green tea lowered the absorption of triglyceride and cholesterol in the animal system with the thoracic lymph-duct cannula.

 The researchers observed that the mixture of epigallocatechin and epigallocatechin gallate was highly effective than a mixture of epigallocatechin and epicatechin in lowering the absorption of dietary cholesterol, these observations suggesting that the gallate esters of green tea catechins were more effective inhibitors of dietary cholesterol absorption. In some, another study,observed that heat-treated catechins high in catechingallate and gallocatechingallate were highly effective in the inhibiting dietary cholesterol absorption than a catechin mixture high in epigallocatechin and epigallocatechin gallate. It seems that tea catechins are less effective in inhibiting fat absorption. The observations are in keeping with the findings that polyphenols are the potent inhibitor of cholesterol absorption but have the reasonable inhibitory effect on fatty acid (fat) absorption. Based on the information available thus far, it is evident that different polyphenols effectively lowers the intestinal absorption of lipids by interfering with the luminal processes of emulsification, hydrolysis, micellar solubilization, and subsequent uptake of dietary lipids^.

High Polyphenol Foods