Natural Obesity Fighters: How Coffee, Tea and Cocoa Fight Weight Gain

Natural Obesity Fighters: How Coffee, Tea and Cocoa Fight Weight Gain

A review article published in the journalCurrent research in food sciencedescribes the effectiveness of bioactive compounds in coffee, tea and cocoa against obesity.

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Obesity has become a major public health problem worldwide due to its gradually increasing prevalence. Obesity is characterized by excessive accumulation of body fat due to altered fat metabolism. The condition can potentially increase the risk of various health complications, including cardiovascular disease, diabetes, dyslipidemia, hypertension, atherosclerosis, and inflammatory metabolic diseases.

Drugs used to treat obesity, including mitochondrial uncouplers, sympathomimetics, serotonergic agonists, lipase inhibitors, cannabinoid receptor antagonists, and gastrointestinal peptides, often do not provide optimal benefit and are associated with many harmful side effects.

Coffee, tea and cocoa are the most commonly used herbal drinks with potential anti-obesity effects. Several studies have highlighted the effectiveness of the bioactive compounds contained in these drinks in preventing obesity.

In this review article, the authors comprehensively analyzed 183 studies that examined the effects and mode of action of coffee, tea and cocoa in obesity treatment.

Coffee, tea and cocoa in the treatment of obesity

Adipocytes, the primary cell type in adipose tissue, are responsible for storing body fat and regulating metabolism. White adipocytes store and mobilize triglycerides and secrete various lipid and protein factors to control energy balance.

Excessive adipogenesis and white adipocyte hypertrophy are associated with the development of obesity. In contrast, reactivation of brown and beige adipocytes provides metabolic health benefits and prevents obesity.

Therefore, effective obesity treatment strategies should focus on inhibiting white adipocyte adipogenesis and promoting brown and beige adipocyte development and lipid catabolism (lipolysis).

Bioactive compounds contained in functional foods such as coffee, tea and cocoa can inhibit the formation of white adipogenesis and promote the formation of brown adipogenesis and lipolysis, thereby preventing obesity. While some compounds, including caffeine and chlorogenic acid (CGA), are found in all three drinks, some are specific to each type. Some of these specific compounds include trigonelline and cafestol in coffee, theaflavins and thearubigins in tea, and theobromine and quercetin in cocoa.

Coffee in obesity treatment

The main anti-obesity active ingredients in green and roasted coffee include caffeine, CGAs, trigonelline, diterpenoids, cafestol and kahweol.

caffeine

Existing evidence suggests that caffeine can increase metabolic rate and promote the breakdown of fat tissue, leading to a reduction in body weight. Caffeine may also increase fat oxidation during submaximal exercise.

Studies examining the mode of action of caffeine show that it affects the AKT/GSK3β signaling pathway and inhibits the expression of adipogenic proteins during adipocyte differentiation. There is also evidence that caffeine promotes thermogenesis by upregulating uncoupling proteins, increases lipolysis by increasing catecholamine secretion, inhibits lipogenesis, suppresses appetite, and reduces inflammatory responses.

Existing evidence on the health benefits of caffeine suggests that this bioactive compound may prevent obesity, nonalcoholic fatty liver disease, and hepatic steatosis. Caffeine and epigallocatechin-3-gallate (EGCG) have been found to work synergistically to prevent obesity.

Chlorogenic acid

Studies examining how CGA works have found that the compound can improve body weight, fat metabolism and obesity-related hormone levels in mice fed a high-fat diet. CGA can inhibit fat accumulation by regulating the activities of enzymes related to fat metabolism in the liver. CGA can promote brown adipogenesis through the activation of AMPK.

CGA and caffeine synergistically promoted brown adipogenesis via the AMPK- and PPARα/γ-mediated pathways. CGA has also been found to prevent obesity by modulating the composition of the gut microbiota.

Trigonelline

Trigonelline has been found to prevent obesity by lowering lipid levels, increasing insulin sensitivity index and insulin content, upregulating antioxidant enzyme activity, and reducing lipid peroxidation.

Mechanistic studies have shown that trigonelline promotes brown adipogenesis by stimulating the p38 MAPK/ATF-2 signaling pathway. The compound was also found to prevent white adipocyte differentiation and excessive white adipocyte hypertrophy.

Cafestol and Kahweol

Cafestol has been found to have an anti-obesity effect by increasing fat oxidation and energy expenditure. Regarding kahweol, there is evidence that the compound inhibits adipogenesis by activating the AMPK signaling pathway.

Decaffarrolide B is an oxidation product of cafestol that has been shown to have a stronger anti-adipogenesis effect than cafestol or kahweol.

Tea to treat obesity

Compounds with anti-obesity effects in tea include catechins, L-theanine, theaflavin, thearubigin and theabrownine.

Tea extracts have been found to prevent obesity by increasing brown adipogenesis, inhibiting white adipogenesis, increasing energy expenditure, and inhibiting lipid synthesis.

Mechanistic studies have revealed that tea EGCG prevents adipogenesis by inducing cell cycle arrest in adipocytes. EGCG has been found to inhibit pancreatic lipase, salivary alpha-amylase, and starch digestion to reduce metabolic factors associated with obesity.

Other anti-obesity actions of EGCG include increased fecal excretion of free fatty acids, inhibition of lipogenesis-related enzymes, and modulation of gut microbiota composition.

Another tea-derived compound, theaflavin, has been found to improve glycolipid metabolism and obesity by activating the SIRT6/AMPK/SREBP-1/FAS signaling pathway. Further evidence suggests that the compound may prevent liver lipid accumulation by activating AMPK.

Other tea-derived compounds, including thearubigin and theabrownine, have been found to have anti-obesity effects by increasing adipogenesis, improving blood lipid profile, and reducing pro-inflammatory cytokines.

Cocoa in obesity management

Cocoa polyphenols, including flavanols (epicatechin, catechin and procyanidins), flavonol (quercetin), anthocyanins, phenolic acids and stilbenes, are known to have anti-obesity effects.

Cocoa polyphenols have been found to have anti-obesity effects by increasing energy expenditure and thermogenesis, improving blood lipid profile, and reducing oxidative stress and inflammation.

Results from animal studies have shown that cocoa extracts can reduce blood cholesterol levels, regulate glucose metabolism and inhibit visceral obesity. Peroxisome proliferator-activated receptors (PPARs), liver X receptors, adiponectin genes and uncoupling proteins are the main targets of cocoa polyphenols in the treatment of obesity.

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