The Interaction between Coffee: Caffeine Consumption, UCP2 Gene Variation, and Adiposity in Adults-A Cross-Sectional Study

Gene-Diet Interactions on Metabolic Disease-Related Outcomes in Southeast Asian Populations: A Systematic Review

Diabetes and obesity are chronic diseases that are a burden to low- and middle-income countries. We conducted this systematic review to understand gene-diet interactions affecting the Southeast Asian population's risk of obesity and diabetes. The literature search was performed on Google Scholar and MEDLINE (PubMed) search engines independently by four reviewers who evaluated the eligibility of articles based on inclusion criteria. Out of 19,031 articles, 20 articles examining gene-diet interactions on obesity and/or diabetes-related traits met the inclusion criteria. Three (Malaysia, Indonesia, and Singapore) out of eleven Association of Southeast Asian Nations (ASEAN) countries have conducted studies on gene-diet interactions on obesity and diabetes. From the 20 selected articles, the most common interactions were observed between macronutrients and genetic risk score (GRS) on metabolic disease-related traits in the Malay, Chinese, and Indian ethnicities. Overall, we identified 29 significant gene-diet interactions in the Southeast Asian population. The results of this systematic review demonstrate ethnic-specific gene-nutrient interactions on metabolic-disease-related traits in the Southeast Asian population. This is the first systematic review to explore gene-diet interactions on obesity and diabetes in the Southeast Asian population and further research using larger sample sizes is required for better understanding and framing nutrigenetic approaches for personalized nutrition.

In the context of the triple burden of malnutrition: A systematic review of gene-diet interactions and nutritional status

Genetic background interacts with dietary components to modulate nutritional health status. This study aimed to review the evidence for gene-diet interactions in all forms of malnutrition. A comprehensive systematic literature search was conducted through April 2021 to identify observational and intervention studies reporting the effects of gene-diet interactions in over-nutrition, under-nutrition and micronutrient status. Risk of publication bias was assessed using the Quality Criteria Checklist and a tool specifically designed for gene-diet interaction research. 167 studies from 27 populations were included. The majority of studies investigated single nucleotide polymorphisms (SNPs) in overnutrition (n = 158). Diets rich in whole grains, vegetables, fruits and low in total and saturated fats, such as Mediterranean and DASH diets, showed promising effects for reducing obesity risk among individuals who had higher genetic risk scores for obesity, particularly the risk alleles carriers of FTO rs9939609, rs1121980 and rs1421085. Other SNPs in MC4R, PPARG and APOA5 genes were also commonly studied for interaction with diet on overnutrition though findings were inconclusive. Only limited data were found related to undernutrition (n = 1) and micronutrient status (n = 9). The findings on gene-diet interactions in this review highlight the importance of personalized nutrition, and more research on undernutrition and micronutrient status is warranted.

Coffee constituents with antiadipogenic and antidiabetic potentials: A narrative review

Coffee consumption has been associated with the reduction of several chronic diseases, including type 2 diabetes mellitus (T2DM) and obesity. The aim of this review was to summarize the research conducted in the last five years (or older, when appropriate) on the relationship between the consumption of coffee bioactive compounds, obesity, and T2DM. A bibliographic search was performed using the Web of Sciences, Scopus, and Google Scholar. Keywords used were "caffeine," "coffee," "coffee consumption," "coffee extraction," "coffee bioactive components," "chlorogenic acid," "obesity," "antidiabetic," and "antiadipogenic." Epidemiological, clinical, animal, and cell culture studies were reviewed. Caffeine, chlorogenic acid, and diterpenes have been identified as potential bioactive compounds in coffee that exhibit antiadipogenic and antidiabetic effects. The concentration of these compounds in coffee depends on the coffee preparation method. The relationship between coffee consumption and obesity risk is inconsistent, as not all results report a positive association. The addition of sugar and cream may be responsible for these mixed results. The consumption of coffee and its constituents is consistently associated with a lower T2DM risk. Caffeine, chlorogenic acids, and diterpenes have antidiabetic properties and are associated with these effects. The available data do not allow us to draw a conclusion on the effect of coffee or its constituents on adipogenesis. Therefore, more tightly controlled human intervention studies are required for a deeper understanding about this relationship.

Associations of Blood Caffeine and Genetically Predicted Coffee Consumption with Anthropometric Measures of Obesity: A Two Sample Mendelian Randomization Study

OBJECTIVES

In observational studies, caffeine has been associated with a lower risk of obesity. However, whether the associations are causal and apply to coffee, which is a mixture of chemical compounds is unclear.

DESIGN

Two sample Mendelian randomization study.

SETTING AND PARTICIPANTS

Genetic instruments predicting caffeine were extracted from an existing GWAS of serum metabolites in 1960 individuals of European descent. For coffee consumption up to 91,462 individuals of European ancestry with top SNPs followed-up in ~30,062 coffee consumers and up to 375,833 individuals of European ancestry were taken from two separate studies. Genetic associations with obesity classes (n= 263,407), waist-to-hip ratio (WHR) (n=210,086), waist circumference (WC) (n= 231,355), and hip circumference (HC) (n=211,117) were obtained from summary statistics of individuals of European ancestry from the Genetic Investigation of Anthropocentric Traits (GIANT).

METHODS

The inverse-variance weighted method (IVW) was used as the main analysis. We also employed the weighted median approach (WM) and MR-Egger regression as sensitivity analyses. To gauge evidence of directional pleiotropy, we used Cochrane's Q test, and MR-PRESSO global test, as measures of heterogeneity between ratio estimates of variants.

RESULTS

There was little evidence to support an association between blood caffeine and any anthropometric measure of obesity in the primary and sensitivity analyses. However, genetically predicted coffee consumption was positively associated with higher class I obesity and WHR. Furthermore, this association was maintained after correction for multiple testing (P < 0.05/6 = 0.008). Results from the GWAS of coffee consumption were in tandem with results from the GWMA, but associations with class I obesity and waist to hip ratio (WHR) were not maintained after correction for multiple testing.

CONCLUSION

We found little evidence that caffeine or coffee consumption protects against obesity, adding to growing literature suggesting that previous observational studies may have been confounded. This study demonstrates the dangers of ignoring genetic testing for targeted interventions and basing dietary policy recommendations solely on observational studies restricted to specific populations.

The interaction between energy intake, physical activity and UCP2 -866G/A gene variation on weight gain and changes in adiposity: an Indonesian Nutrigenetic Cohort (INDOGENIC)

The present study aimed to investigate an interaction between energy intake, physical activity and UCP2 gene variation on weight gain and adiposity changes in Indonesian adults. This is a prospective cohort study conducted in 323 healthy adults living in the city of Yogyakarta, Indonesia. Energy intake, physical activity, body weight, BMI, percentage body fat and waist:hip ratio (WHR) were measured at baseline and after 2 years while UCP2 -866G/A gene variation was determined at baseline. We reported that after 2 years subjects had a significant increment in body weight, BMI, body fat and reduction in WHR (all P < 0·05). In all subjects, total energy intake was significantly correlated with changes in body weight (β = 0·128, P = 0·023) and body fat (β = 0·123, P = 0·030). Among subjects with the GG genotype, changes in energy intake were positively correlated with changes in body weight (β = 0·232, P = 0·016) and body fat (β = 0·201, P = 0·034). These correlations were insignificant among those with AA + GA genotypes (all P > 0·05). In summary, we show that UCP2 gene variation might influence the adiposity response towards changes in energy intake. Subjects with the GG genotype of UCP2 -866G/A gene were more responsive to energy intake, thus more prone to weight gain due to overeating.

Type 2 Diabetes Prevention Diet and Hepatocellular Carcinoma Risk in US Men and Women

OBJECTIVES

Adherence to a healthy diet has been associated with a reduced risk of type 2 diabetes (T2D). Hepatocellular carcinoma (HCC) may have overlapping mechanisms with T2D, such as inflammation and insulin resistance. Thus, we examined the association between a previously developed T2D prevention dietary pattern and HCC risk.

METHODS

We followed 87,943 women in the Nurses' Health Study and 49,665 men in the Health Professionals Follow-up Study for up to 32 years. The dietary diabetes risk reduction score, which includes dietary glycemic index, cereal fiber, ratio of polyunsaturated to saturated fats, trans fat, sugar-sweetened beverages, nuts, coffee, and red and processed meats, was obtained using validated food frequency questionnaires and updated every 4 years. The Cox proportional hazards regression model was used to calculate multivariable hazard ratios and confidence intervals (95% CIs).

RESULTS

During over 1.9 million person-years, a total of 160 incident HCC cases were identified. The dietary diabetes risk reduction score was associated with a lower risk of HCC (top vs bottom quartile; hazard ratio: 0.57, 95% CI: 0.34-0.95; Ptrend = 0.03). All the individual food and beverage items were associated with the risk of HCC in the expected direction, although the association was weaker than the overall dietary pattern.

DISCUSSION

Greater adherence to the T2D prevention diet was associated with a lower risk of developing HCC among US men and women. Further studies are needed to confirm and extend our findings.