Dietary Intervention Effect on Metabolic Syndrome Essay (Article)

• Background: One-third of all adults in the developed world suffer from metabolic syndrome. This increases their risk to get cardiovascular diseases, diabetes type 2, and premature mortality. The term metabolic syndrome which is provided in the current study is based on the recommendations derived from the international Diabetes foundation. This study sought to establish the effects of dietary products curcumin, capsaicin, resveratrol, omega-3 polyunsaturated fatty acids and epigallocatechin-3-gallate combined on a randomly selected group of subjects diagnosed with metabolic syndrome.
• Methods: A triple-blinded experimental study design was used. The intervention was a 5-week trial. The subjects included in the study had been diagnosed with metabolic syndrome. Both men and women classified as either normal, overweight, or obese were included in the study.
• Results: There was no significant statistical difference between the trends of visceral adipose tissue (VAT) and liver fat in men and women. The results were adjusted for age, race, site, education, physical activity, smoking, alcohol intake and fat. However, a significant difference was evident between those subjects who had metabolic syndrome and those who did not have the syndrome.
• Conclusion: The dietary supplement mix had beneficial effects on the subjects. This can be explained by the fact that there was a significant (P≤0.05) decrease in total triglycerides, arachidonic acid, TNF-α, angiotensin, IL-6 and tissue macrophage count after the 5-week intervention trial. There was also a significant increase in HDL cholesterol and eicosapentanoic acid plasma levels. Therefore, dietary intervention can be applied to patients with metabolic syndrome.

Discussion

Most of the dietary intervention studies that have been carried out have focused on either one of the phytochemicals, or foods rich in phytochemicals like fruits and vegetables, and whole grains. This study is however unique in that it has combined specific substances that have been associated with beneficial effects regarding the metabolic syndrome. Resveratrol, curcumin, epigallocatechin-3-gallate, and capsaicin are phytochemicals. The study results revealed that the dietary intervention mix had beneficial health effects, as far as the metabolic syndrome was concerned. These results can be substantiated by other studies that have studied the effects of the various individual components making up the dietary intervention mix.

As it has been mentioned earlier in this paper, obesity and metabolic syndrome are closely associated with each other, hence the reason why a higher level of liver fat was associated with a diagnosis of metabolic syndrome is clear. The findings have been presented based on two groups: the experimental (those with metabolic syndrome) and those without the metabolic syndrome. There is a need to note that some normal-weight individuals have metabolic syndrome. This, therefore, creates an interesting area for research, away from what is generally known. Future researchers can therefore establish factors associated with metabolic syndrome in normal-weight individuals.

A substantial number of research studies^{1, 2, 3} have shown the beneficial effects derived from the consumption of whole, unprocessed plant foods because they are abundant in phytochemicals. These findings are comparable to the study results since the effects of the whole and unprocessed foods are similar to the combined effect of phytochemicals in the dietary supplement intervention. Phytochemicals are plant chemicals that are deemed to transfer their protective effects to human beings when consumed. They have a wide range of protective health benefits hence the need to establish substantially collective effects from those known to suppress the metabolic syndrome.

An omega-3 polyunsaturated fatty acid is a major constituent of the Mediterranean diet. This kind of diet has been known to uniquely address specific metabolic syndrome criteria. Some researchers have found out that the Mediterranean diet provides therapeutic benefits especially to individuals with metabolic syndrome by enhancing insulin sensitivity^{4, 5}, and is protective of total triglyceride levels^{6, 7}. These studies however did not factor in omega-3, but since it is a major component of olive oil, one cannot rule out its impact here. According to Carpentier, Portois & Malaisse⁸, consumption of omega-3 obtained from a healthy Mediterranean type of diet is indicated as a global strategy for suppressing metabolic syndrome.

In a study on rodents, epigallocatechin gallate (EGCG) treatment was found to attenuate the occurrence of “obesity, symptoms related to metabolic syndrome, and fatty liver”⁹. In obese mice, EGCG was seen to revert pre-existing high-fat-induced metabolic pathologies. Results from intervention trial studies in humans have shown equal potential benefits of EGCG in reducing body fat and weight¹⁰. One such study is a retrospective cohort study that enrolled 17,413subjects from Japan^{11, 12}.

Data on the intake of coffee and black, oolong, and green teas were collected. During a five-year follow-up, correlations between intakes of either one of the beverages and occurrence of diabetes type 2 were determined. The results of this study showed that EGCG supplementation from the teas led to reduced waist circumference and increased glucose tolerance. Various effects of EGCG have been noticed on insulin signalling. In vivo studies have shown that resveratrol can lower serum triglyceride, as well as low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) cholesterol¹³. When this happens, there is an increase in high-density lipoprotein cholesterol as presented in the current study results. This is because of the suggested ability of resveratrol to reduce the transfer of cholesteryl esters from HDL to VLDL/LDL, and promote reverse cholesterol transport (RCT) ^{14, 15}.

As a result of this, a recent study showed the satin-like effects of resveratrol through its ability to down-regulate HMG-CoA reductase in a hyperlipidemia model and elevate the ratio of apolipoprotein (Apo) A1 to Apo B (which attributed to metabolic syndrome and cardiovascular risks) ¹⁶. In an animal study of obese dogs, administration of a green tea extract was associated with higher insulin sensitivity and lower total triglycerides¹⁷. EGCG is the main polyphenol in green tea hence the main extract¹⁸.

It has been recently found that curcumin, which is a naturally occurring anti-inflammatory phytochemical, is associated with hypoglycemic activity in type 2 diabetic KK-A (y) mice¹⁹. In addition, it has been shown to reduce obesity-induced inflammation and diabetes in mice with hereditary and diet-induced obesity. Curcumin’s action is due to its ability to reverse adipocytokine dysregulation²⁰. According to these research findings on capsaicin, curcumin’s antidiabetic activity is due to its inhibitory effects on inflammation and adipocytokine production.

Capsaicin is a spicy component of hot pepper and has been yield to have anti-inflammatory effects. In a recent in vitro study of obese adipose tissues and isolated adipocytes, capsaicin inhibited the expression of inflammatory adipocytokines and the release of corresponding proteins like IL-6 and MCP-1²¹. It however enhanced the expression and release of adiponectin. Capsaicin also inhibited macrophage responses, whose importance is exhibited in the augmentation of adipose tissue inflammation²². As a result, of these findings together with those of this study, capsaicin is very important in addressing obesity-related complications, which are also metabolic syndrome elements, such as insulin resistance.

Capsaicin has also been associated with reduced insulin resistance and increased glucose tolerance as seen in a recent study on mice²³. In a study by Kim and others²⁴, dietary capsaicin was effective in alleviating obesity-related metabolic disorders like liver diseases and insulin resistance. It also lowers total triglycerides in the plasma and liver. Its beneficial effects against obesity-induced glucose intolerance/insulin resistance and liver steatosis are due to its dual action on the proliferator-activated receptor (PPARα /PPARγ) and transient receptor potential vanilloid type-1 (TRPV-1) expression/activation. Increases in the levels of free fatty and leptin in the systemic tissues and simultaneous decreases in adiponectin levels are evident occurrences in obesity. They are also largely responsible for insulin resistance ²⁵. The positive results obtained from the study show that the combined effect of the various specific phytochemicals is greater.

Research Translation

This is one of the most important and successful researches because it has focused on a health issue that affects a large part of the population, globally. The study aimed at investigating the effect of a dietary mix intervention that consisted of 4 types of phytochemicals: capsaicin, resveratrol, curcumin and epigallocatechin gallate and one essential fatty acid: omega-3 on metabolic syndrome. Metabolic syndrome is a serious health issue because it leads to increased healthcare costs. Metabolic disorders affect obese individuals and therefore there is a need to address the issue of body weight since more than half of the adult population in the United States is overweight.

The results obtained indicated that there was no significant statistical difference in the trends of VAT and liver fat in men and women; subjects with metabolic syndrome generally demonstrated higher VAT and liver fat than those without. Therefore, in both sexes, there was a significant difference in the amount of VAT between those with metabolic syndrome and those without. The amount of liver fat showed a significant difference in overweight and obese individuals between those with metabolic syndrome, and those without. The normal weight subjects even though they had the metabolic syndrome or not did show significant differences concerning the amount of liver fat.

Several changes were derived following the 5-week intervention. Generally, the study results demonstrated that there was a decreased likelihood of metabolic syndrome following the 5-week trial dietary intervention. There was a decreased likelihood of metabolic syndrome for thigh subcutaneous fat in men and women. The total triglycerides in the hepatic tissue were significantly reduced. There was no significant change for glycated hemoglobin.

Fasting insulin in plasma significantly reduced while the glucose tolerance test showed significant improvement. MCP-1 in the hepatic and adipose tissues and leptin in the plasma showed a significant decrease. There was a significant increase in the levels of adiponectin in plasma and adipose tissues. Arachidonic acid, alpha tumor necrosis factor (TNF-α), IL-6, CRP showed a significant decrease. The study, therefore, was a successful intervention study that showed that the dietary intervention supplement can be used to improve the quality of life of patients with metabolic syndrome.

According to this study, there is a chance of enhancing the well-being of people. If the use of this dietary supplement is endorsed, then patients with metabolic disorders will have an increased likelihood of survival and obese persons will have a reduced risk of obtaining these metabolic disorders. The study results also indicate the essence of ideal and normal body weight.

Conclusion

This study established that the dietary supplement mix had greater beneficial health effects on all the subjects. This is because, after the 5-week intervention trial, there were significant (P≤0.05) decreases in total triglycerides, arachidonic acid, TNF-α, angiotensin, IL-6, and tissue macrophage count. There was a significant (P≤0.05) increase in HDL cholesterol and eicosapentanoic acid plasma levels. The positive and significant effect of this mix could be attributed to the combined effect of all the constituents of the dietary supplementation milk. Therefore, this dietary intervention can be used on patients to address the negative health-impacting effects of metabolic syndrome.

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