Effect of a diet containing folate and hazelnut oil capsule on the methylation level of the ADRB3 gene, lipid profile and oxidative stress in overweight or obese women

Epigenetic Biomarkers of Metabolic Responses to Lifestyle Interventions

Studies have examined the possible utility of epigenetic phenomena (DNA methylation changes, covalent histone modifications, and miRNA expression patterns) in predicting individual responses to different lifestyle programs. Nonetheless, most available evidence is focused on identifying epigenetic marks eventually associated with body composition and adiposity outcomes, whereas their roles in metabolic endings remain less explored. This document comprehensively reviewed the evidence regarding the use of epigenetic signatures as putative biomarkers of metabolic outcomes (glycemic, lipid, blood pressure, and inflammatory/oxidative stress features) in response to different lifestyle interventions in humans. Although more investigation is still necessary in order to translate this knowledge in clinical practice, these scientific insights are contributing to the design of advanced strategies for the precise management of cardiometabolic risk, gaining understanding on metabolic heterogeneity, allowing for the prediction of metabolic outcomes, and facilitating the design of epigenome-based nutritional strategies for a more customized approach for metabolic alterations treatment under the scope of precision nutrition.

Nutrition, DNA methylation and obesity across life stages and generations

Obesity is a complex multifactorial condition that often manifests in early life with a lifelong burden on metabolic health. Diet, including pre-pregnancy maternal diet, in utero nutrition and dietary patterns in early and late life, can shape obesity development. Growing evidence suggests that epigenetic modifications, specifically DNA methylation, might mediate or accompany these effects across life stages and generations. By reviewing human observational and intervention studies conducted over the past 10 years, this work provides a comprehensive overview of the evidence linking nutrition to DNA methylation and its association with obesity across different age periods, spanning from preconception to adulthood and identify future research directions in the field.

Could Natural Products Help in the Control of Obesity? Current Insights and Future Perspectives

Obesity is a global issue faced by many individuals worldwide. However, no drug has a pronounced effect with few side effects. Green tea, a well-known natural product, shows preventive effects against obesity by decreasing lipogenesis and increasing fat oxidation and antioxidant capacity. In contrast, other natural products are known to contribute to obesity. Relevant articles published on the therapeutic effect of natural products on obesity were retrieved from PubMed, Web of Science, and Scopus. The search was conducted by entering keywords such as "obesity", "natural product", and "clinical trial". The natural products were classified as single compounds, foods, teas, fruits, herbal medicines-single extract, herbal medicines-decoction, and herbal medicines-external preparation. Then, the mechanisms of these medicines were organized into lipid metabolism, anti-inflammation, antioxidation, appetite loss, and thermogenesis. This review aimed to assess the efficacy and mechanisms of effective natural products in managing obesity. Several clinical studies reported that natural products showed antiobesity effects, including Coffea arabica (coffee), Camellia sinensis (green tea), Caulerpa racemosa (green algae), Allium sativum (garlic), combined Ephedra intermedia Schrenk, Thea sinensis L., and Atractylodes lancea DC extract (known as Gambisan), Ephedra sinica Stapf, Angelica Gigantis Radix, Atractylodis Rhizoma Alba, Coicis semen, Cinnamomi cortex, Paeoniae radix alba, and Glycyrrhiza uralensis (known as Euiiyin-tang formula). Further studies are expected to refine the pharmacological effects of natural products for clinical use.

Tree Nut and Peanut Consumption and Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Cardiovascular disease (CVD) is the leading cause of death globally. Habitual consumption of tree nuts and peanuts is associated with cardioprotective benefits. Food-based dietary guidelines globally recommend nuts as a key component of a healthy diet. This systematic review and meta-analysis were conducted to examine the relationship between tree nut and peanut consumption and risk factors for CVD in randomized controlled trials (RCTs) (PROSPERO: CRD42022309156). MEDLINE, PubMed, CINAHL, and Cochrane Central databases were searched up to 26 September, 2021. All RCT studies that assessed the effects of tree nut or peanut consumption of any dose on CVD risk factors were included. Review Manager software was used to conduct a random effect meta-analysis for CVD outcomes from RCTs. Forest plots were generated for each outcome, between-study heterogeneity was estimated using the I2 test statistic and funnel plots and Egger's test for outcomes with ≥10 strata. The quality assessment used the Health Canada Quality Appraisal Tool, and the certainty of the evidence was assessed using grading of recommendations assessment, development, and evaluation (GRADE). A total of 153 articles describing 139 studies (81 parallel design and 58 cross-over design) were included in the systematic review, with 129 studies in the meta-analysis. The meta-analysis showed a significant decrease for low-density lipoprotein (LDL) cholesterol, total cholesterol (TC), triglycerides (TG), TC:high-density lipoprotein (HDL) cholesterol, LDL cholesterol:HDL cholesterol, and apolipoprotein B (apoB) following nut consumption. However, the quality of evidence was "low" for only 18 intervention studies. The certainty of the body of evidence for TC:HDL cholesterol, LDL cholesterol:HDL cholesterol, and apoB were "moderate" because of inconsistency, for TG were "low," and for LDL cholesterol and TC were "very low" because of inconsistency and the likelihood of publication bias. The findings of this review provide evidence of a combined effect of tree nuts and peanuts on a range of biomarkers to create an overall CVD risk reduction.

New Moms Wellness Study: the randomized controlled trial study protocol for an intervention study to increase fruit and vegetable intake and lower breast cancer risk through weekly counseling and supplemental fruit and vegetable box delivery in breastfeeding women

Background

Laboratory studies indicate that chemicals in fruits and vegetables have anti-carcinogenic and anti-inflammatory activities that can lower breast cancer risk. However, epidemiologic studies of the association between fruit and vegetable intake and breast cancer risk have produced mixed results. Measurement error, confounding, and an emphasis on diet in later adulthood may contribute to weak associations. This paper describes a randomized controlled diet intervention trial in breastfeeding women to examine the effect of high fruit and vegetable intake on breast cancer risk factors, including weight, DNA methylation and inflammatory markers.

Methods

Eligible breastfeeding women who reside within a 35-mile radius of Amherst, MA are enrolled at five to six weeks postpartum and randomly assigned to a Fruit and Vegetable Intervention Arm (target n = 200) or to a USDA MyPlate Control Arm (target n = 200). The Fruit and Vegetable Intervention group receives weekly telephone or video-based counseling to encourage intake of at least eight to ten daily servings of fruits and vegetables and a weekly delivery of a supplemental box of fruits and vegetables for 20 weeks, and less intensive counseling for up to one year. Breastmilk and infant fecal specimens are collected at baseline, 10 and 20 weeks. Anthropometric measurements are obtained at these timepoints and at the 1-year follow-up. The primary outcomes are change in DNA methylation in breast epithelial cells and change in inflammatory markers in breastmilk from randomization to 20 weeks; and change in weight, waist circumference, and fruit and vegetable intake for the period from randomization to 20 weeks and 1 year.

Discussion

This 1-year randomized diet intervention trial in breastfeeding women will assess whether intake of at least eight to ten daily servings of fruits and vegetables per day improves biomarkers of breast cancer risk directly in the breast (i.e., DNA methylation and inflammatory markers) and helps women maintain a healthy weight.

Trial registration: ClinicalTrials.gov Identifier: NCT04374747. Registered May 5, 2020. https://www.clinicaltrials.gov/ct2/show/NCT04374747.

The impact of nutrition and lifestyle modification on health

The main recommendations from public health entities include healthy diets and physical activity as the main lifestyle factors impacting the development of chronic diseases such as cardiovascular and metabolic diseases, cancer, and even neurological diseases. Randomized clinical trials have been designed to demonstrate those lifestyle modifications can change the pattern of chronic diseases development and progression. Among these, nutrition is one of the most impacting factors. Therefore, nutrition and diets were also included in different randomized clinical trials, and most of them showed a favorable impact of nutrition modification on the participant's health. Nevertheless, study designs were considerably different, and future studies are needed to support nutrition modifications further. The choice of a healthy considered diet, like the Mediterranean diet, was shown to impact chronic diseases, cardiovascular risk, and adult life expectancy mainly due to its anti-inflammatory and antioxidant properties. Furthermore, a high intake of fibers, fruits, and vegetables together with a low intake of fat and energy-dense, processed foods contribute to an inflammation reduction and a more robust immune system leading. Besides these well-known properties, all lifestyle modifications must be personalized according to the availability of foods, geographic localizations, and the healthy status of the patient.

Monitoring of Hazelnut oil quality during thermal processing in comparison with extra virgin olive oil by using ATR-FTIR spectroscopy combined with chemometrics

Hazelnut oil (HO), which is not widely used because its healthy properties are not fully known yet, is an excellent nutrient due to its high content of monounsaturated fatty acids and antioxidants. In this study, the effects of thermal processing on the quality of HO in comparison to extra virgin olive oil (EVOO), which is one of the healthiest and heat-resistant oils, were investigated using Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) spectroscopy. Oil samples were heated at a frying temperature (180 °C) for 24 h in periods of 8 h per day and alterations in the spectra of these oils sampled every 2 h were evaluated. The heating process caused decreases in the areas of the bands at 3007 and 722 cm^-1 and the area ratios of 3007/2854 and 722/2854 cm^-1 and increases in the areas of the bands at 987 and 965 cm^-1 and the area ratio of 965/2854 cm^-1 in both oils suggesting the conjugation and cis-trans isomerization of unsaturated fatty acids. In addition, heating caused increases in the areas of the bands at 3475 and 1744 cm^-1 and the ratios of 3475/2854 cm^-1 and 1744/2854 cm^-1, a shift to a lower value in the wavenumber and a broadening of the 1744 cm^-1 band indicating the formation of primary and secondary oxidation products in the heated oils, which were also supported by chemical studies. Most of these changes began earlier in EVOO and all occurred to a higher extent, revealing that HO has a higher thermal stability than EVOO. Principal component analysis and hierarchical cluster analysis confirmed that HO is more resistant to heat than EVOO. These results showed that HO is superior to EVOO and it could be used for frying as a healthier and cheaper oil alternative. This study also indicated that oil oxidation could be monitored easily and rapidly via ATR-FTIR spectroscopy.

Role of Vitamin B12 and Folate in Metabolic Syndrome

Metabolic syndrome (MS) is a collection of pathological metabolic conditions that includes insulin resistance, central or abdominal obesity, dyslipidemia, and hypertension. It affects large populations worldwide, and its prevalence is rising exponentially. There is no specific mechanism that leads to the development of MS. Proposed hypotheses range from visceral adiposity being a key factor to an increase in very-low-density lipoprotein and fatty acid synthesis as the primary cause of MS. Numerous pharmaceutical therapies are widely available in the market for the treatment of the individual components of MS. The relationship between MS and vitamin B complex supplementation, specifically folic acid and vitamin B12, has been a subject of investigation worldwide, with several trials reporting a positive impact with vitamin supplementation on MS.

In this study, an all-language literature search was conducted on Medline, Cochrane, Embase, and Google Scholar till September 2021. The following search strings and Medical Subject Headings (MeSH) terms were used: “Vitamin B12,” “Folate,” “Metabolic Syndrome,” and “Insulin Resistance.” We explored the literature on MS for its epidemiology, pathophysiology, newer treatment options, with a special focus on the effectiveness of supplementation with vitamins B9 and B12.

According to the literature, vitamin B12 and folate supplementation, along with a host of novel therapies, has a considerable positive impact on MS. These findings must be kept in mind while designing newer treatment protocols in the future.

Which Diets Are Effective in Reducing Cardiovascular and Cancer Risk in Women with Obesity? An Integrative Review

Women are more affected by obesity than men which increases their risk of cancer and cardiovascular disease (CVD). Therefore, it is important to understand the effectiveness of different types of diet in the context of women's health. This review aims to summarize the scientific evidence on the effects of different types of diet for women with obesity and their impact on CVD and cancer risk. This review included epidemiological and clinical studies on adult women and different types of diets, such as the Mediterranean (MED) diet, the Traditional Brazilian Diet, the Dietary Approach to Stop Hypertension (DASH), intermittent fasting (IF), calorie (energy) restriction, food re-education, low-carbohydrate diet (LCD) and a very low-carbohydrate diet (VLCD). Our main findings showed that although LCDs, VLCD and IF are difficult to adhere to over an extended period, they can be good options for achieving improvements in body weight and cardiometabolic parameters. MED, DASH and the Traditional Brazilian Diet are based on natural foods and reduced processed foods. These diets have been associated with better women's health outcomes, including lower risk of CVD and cancer and the prevention and treatment of obesity.

Lipid Phenotypes and DNA Methylation: a Review of the Literature

PURPOSE OF REVIEW

Epigenetic modifications via DNA methylation have previously been linked to blood lipid levels, dyslipidemias, and atherosclerosis. The purpose of this review is to discuss current literature on the role of DNA methylation on lipid traits and their associated pathologies.

RECENT FINDINGS

Candidate gene and epigenome-wide approaches have identified differential methylation of genes associated with lipid traits (particularly CPT1A, ABCG1, SREBF1), and novel approaches are being implemented to further characterize these relationships. Moreover, studies on environmental factors have shown that methylation variations at lipid-related genes are associated with diet and pollution exposure. Further investigation is needed to elucidate the directionality of the associations between the environment, lipid traits, and epigenome. Future studies should also seek to increase the diversity of cohorts, as European and Asian ancestry populations are the predominant study populations in the current literature.

Relationship between BsmI polymorphism and VDR gene methylation profile, gender, metabolic profile, oxidative stress, and inflammation in adolescents

BACKGROUND

the biological activity of vitamin D depends on the activity of its receptor or VDR. On the other hand, the activity of this receptor is influenced by its state of methylation. The objective of this study was to verify if the BsmI polymorphism of the VDR gene influences its methylation profile in adolescents. Secondly, it was to verify if the status of some metabolic factors (oxidative stress, inflammation, lipid profile, and glycemia) in the serum, and gender-adjusted vitamin D levels are independent factors with an influence on the VDR methylation profile.

METHODS AND RESULTS

the study included 198 adolescents of both sexes, aged 15-19 years, who underwent testing for VDR gene methylation polymorphisms, serum vitamin D levels, and metabolic, oxidative stress, and systemic inflammation markers. It was observed that the BB genotype was less methylated than the other groups (26.1 % versus 30.3 %, and 29.3 % for Bb and bb, respectively), although without statistical differences between them. The odds ratio indicated a protection of 13 % (partially methylated) for vitamin D status, while alpha glycols increased the risk ratio (of being partially methylated) by 3 %. MDA was protective at a 28 % chance of risk that adolescents with higher levels of lipid peroxidation would be hypomethylated.

CONCLUSION

we conclude that the methylation profile of the VDR gene is not influenced by the different BsmI polymorphism genotypes, and that serum vitamin D and serum markers of oxidative stress and inflammation can modulate this profile.

The direct correlation between oxidative stress and LDL-C levels in adults is maintained by the Friedewald and Martin equations, but the methylation levels in the MTHFR and ADRB3 genes differ

Low-density lipoprotein (LDL-C) concentrations are a standard of care in the prevention of cardiovascular disease and are influenced by different factors. This study compared the LDL-C concentrations estimated by two different equations and determined their associations with inflammatory status, oxidative stress, anthropometric variables, food intake and DNA methylation levels in the LPL, ADRB3 and MTHFR genes. A cross-sectional population-based study was conducted with 236 adults (median age 37.5 years) of both sexes from the municipality of João Pessoa, Paraíba, Brazil. The LDL-C concentrations were estimated according to the Friedewald and Martin equations. LPL, ADRB3 and MTHFR gene methylation levels; malondialdehyde levels; total antioxidant capacity; ultra-sensitive C-reactive protein, alpha-1-acid glycoprotein, homocysteine, cobalamin, and folic acid levels; usual dietary intake; and epidemiological variables were also determined. For each unit increase in malondialdehyde concentration there was an increase in the LDL-C concentration from 6.25 to 10.29 mg/dL (p <0.000). Based on the Martin equation (≥70 mg/dL), there was a decrease in the DNA methylation levels in the ADRB3 gene and an increase in the DNA methylation levels in the MTHFR gene (p <0.05). There was a positive relation of homocysteine and cholesterol intake on LDL-C concentrations estimated according to the Friedewald equation and of waist circumference and age based on the two estimates. It is concluded the LDL-C concentrations estimated by the Friedewald and Martin equations were different, and the Friedewald equation values were significantly lower than those obtained by the Martin equation. MDA was the variable that was most positively associated with the estimated LDL-C levels in all multivariate models. Significant relationships were observed based on the two estimates and occurred for most variables. The methylation levels of the ADRB3 and MTHFR genes were different according to the Martin equation at low LDL-C concentrations (70 mg/dL).

The effect of diet on oxidative stress and metabolic diseases-Clinically controlled trials

Oxidative stress is associated with several chronic diseases. It is acknowledged that molecules damaged by reactive oxygen species activate the inflammatory process and that this response increases the production of free radicals. Modifications in a diet can improve or decrease redox state markers. The aim of this revision was to provide an update of clinical controlled trials, to assess changes in diet and markers of oxidative stress in subjects with metabolic diseases. They were investigated randomized controlled intervention studies (RCTs) published in MEDLINE (U.S. National Library of Medicine, National Institutes of Health) that were conducted in subjects with obesity, hypertension, diabetes, or dyslipidemia; with dietary intervention; where markers of oxidative stress have been evaluated and published in the last 5 years. Food antioxidants, hypocaloric diets with loss of adipose tissue, substitution of animal protein by vegetable, and changes in the microbiota improve antioxidant status in people with chronic disease. PRACTICAL APPLICATIONS: Hyperglycemia in diabetes mellitus and adipose tissue in obesity are known to trigger oxidative stress. Oxidative stress, in turn, decreases insulin sensitivity and favors an inflammatory state producing adhesion molecules. Oxidative stress and adhesion molecules, can increase blood pressure and oxidation of lipoproteins, that ultimately could lead to a cerebrovascular event. Consumption of high-antioxidant and polyphenol foods increases plasma antioxidant capacity and decreases oxidative stress markers in people with diabetes, obesity, hypertension, and hypertriglyceridemia. In addition, weight loss caused by caloric restriction with or without exercise increases the endogenous antioxidant capacity. Therefore, it is likely that the combination of a hypocaloric diet with a high content of antioxidants and polyphenols will have a greater effect. Other dietary changes with antioxidant effect, such as the substitution of animal for vegetable protein or the addition of fiber, might be mediated by changes in the microbiota. However, this aspect requires further study.

Maize extract rich in ferulic acid and anthocyanins prevents high-fat-induced obesity in mice by modulating SIRT1, AMPK and IL-6 associated metabolic and inflammatory pathways

The aim was to compare the antiobesity efficacy of different concentrations of a phenolic-rich water extract from purple maize pericarp (PPE) in a murine model of obesity for 12 weeks. Forty C57BL/6 mice (n=10/group) were randomized: standard diet (SD), high-fat diet (HFD), HFD+200 mg PPE/kg (200 PPE) and HFD+500 mg PPE/kg (500 PPE). PPE contained mainly ferulic acid, anthocyanins and other phenolics (total phenolics: 448.5 μg/mg dry weight, DW). Body weight (-27.9%), blood glucose (-26.5%) and blood triglycerides (-22.1%) were most attenuated (P<.05) in 500 PPE group compared to HFD group. Also, 500 PPE group had reduced (P<.05) plasma levels of TNF-α, MCP-1, resistin and leptin compared to HFD group. Fatty liver disease scores were highest for HFD (8.4), followed by 200 PPE (6.1), 500 PPE (2.7) and SD (0.4) groups. Relative adipose tissue was lower (P<.05) in 200 PPE (7.6%), 500 PPE (8.0%) and SD (0.8%) compared to HFD (12.1%) group. In 500 PPE group, compared to HFD group, important genes were modulated related to adipogenesis (Mmp3, fold-change [FC]=7.4), inflammation (Nfkb1, FC=-1.8) and glucose metabolism (Slc2a4, FC=23.6) in adipose tissue. In liver, 500 PPE group showed modulation of genes related to gluconeogenesis (Pck1, FC=-2.9), lipogenesis (Fasn, FC=-2.4) and β-oxidation (Cpt1b, FC=3.1). Maize rich in ferulic acid and anthocyanins prevented obesity through the modulation of TLR and AMPK signaling pathways reducing adipogenesis and adipose inflammation, and promoting energy expenditure.

ZNF577 Methylation Levels in Leukocytes From Women With Breast Cancer Is Modulated by Adiposity, Menopausal State, and the Mediterranean Diet

The methylation levels of ZNF577 in breast tumors has been previously identified as a possible epigenetic mark of breast cancer associated with obesity. The aim of the current study was to investigate differences in methylation levels of ZNF577 depending on obesity, menopausal state and dietary pattern in blood leukocytes, a non-invasive sample. The methylation levels of ZNF577 of two CpG sites (CpGs) located in promoter and island previously identified as differentially methylated according to adiposity and menopausal state by 450 k array (cg10635122, cg03562414) were evaluated by pyrosequencing in DNA from the blood leukocytes of breast cancer patients [n = 90; n = 64 (71.1%) overweight/obesity and n = 26 (28.9%) normal-weight] and paired tumor tissue biopsies (n = 8 breast cancer patients with obesity; n = 3/5 premenopausal/postmenopausal women). Differences in methylation levels were evaluated at each CpGs individually and at the mean of the two evaluated CpGs. Adherence to the Mediterranean diet was evaluated using the MEDAS-validated questionnaire, and the consumption of food groups of interest was also evaluated using the recommended intakes of the Sociedad Española de Nutricion Comunitaria. The methylation levels of ZNF577 were correlated between paired leukocytes and breast tumor biopsies (r = 0.62; p = 0.001). Moreover, higher methylation was found in leukocytes from patients with obesity (p = 0.002) and postmenopausal patients (p = 0.022) than patients with normal-weight or premenopausal, respectively. After adjusting for the body mass index and age, higher levels of ZNF577 methylation were also found in women with greater adherence to the Mediterranean diet (p = 0.017) or specific foods. Relevantly, the methylation levels of ZNF577 showed a good ability for fish consumption detection [area under the ROC curve (AUC) = 0.72; p = 0.016]. In conclusion, the association between methylation of ZNF577 and adiposity, menopausal state, and adherence to the Mediterranean diet can be detected in the blood leukocytes. The results guarantee the need of performing further studies in longer longitudinal cohorts in order to elucidate the role of ZNF577 methylation in the association between breast cancer, adiposity and dietary patterns.

Dietary Supplementation with Hazelnut Oil Reduces Serum Hyperlipidemia and Ameliorates the Progression of Nonalcoholic Fatty Liver Disease in Hamsters Fed a High-Cholesterol Diet

Objective: Hazelnut oil (HO) is rich in monounsaturated fatty acids and polyunsaturated fatty acids. This study intended to analyze the effects of hazelnut oil supplementation on the serum lipid profile and nonalcoholic fatty liver disease in hamsters fed a high-cholesterol (HC) diet. Methods: Hamsters were fed a basic diet (control group) and an HC diet (HC group) for 16 weeks (n = 10 in each group). Hamsters were fed an HC diet for four weeks to induce hyperlipidemia and were then fed an HC diet enriched with 5% (low-dose HC + HO group; n = 10) and 10% HO (high-dose HC + HO group; n = 10) for 12 weeks. Serum lipid levels, hepatic changes (including steatosis, inflammation, and fibrosis), and hepatic prooxidant-antioxidant status (malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione S-transferase (GST)) were evaluated after the treatment period. Results: Hamsters in the control group showed normal serum lipid profiles, normal liver function, and moderate glycogen storage without hepatic steatosis. Hamsters in the HC group showed severe hyperlipidemia, severe hepatic steatosis, and moderate steatohepatitis (mononuclear cell and neutrophil infiltration, oval cell hyperplasia, and fibrosis). Compared to the HC group, both the low-dose and the high-dose HC + HO groups showed a significant reduction of hyperlipidemia (serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and very-low-density lipoprotein cholesterol (VLDL-C levels)) and improved liver function (serum glutamic-oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT)). Additionally, compared to the HC group, intrahepatic triglyceride accumulation (IHTC) was significantly higher in the HC + HO group, while the incidence of steatohepatitis was significantly lower. The intake of the HC diet was associated with a higher level of lipid peroxidation (malondialdehyde, MDA) and a lower concentration of hepatic antioxidant enzymes (SOD, GPx, and GST), and all these factors were partially improved in the low-dose and high-dose HC + HO groups. Conclusions: Our findings indicate that the intake of HO reduced serum hyperlipidemia and oxidative stress and ameliorated the progression of nonalcoholic fatty liver disease in hamsters fed a high-cholesterol diet.

Genetics and epigenetics in obesity

Obesity is among the most threatening health burdens worldwide and its prevalence has markedly increased over the last decades. Obesity maybe considered a heritable trait. Identifications of rare cases of monogenic obesity unveiled that hypothalamic circuits and the brain-adipose axis play an important role in the regulation of energy homeostasis, appetite, hunger and satiety. For example, mutations in the leptin gene cause obesity through almost unsuppressed overeating. Common (multifactorial) obesity, most likely resulting from a concerted interplay of genetic, epigenetic and environmental factors, is clearly linked to genetic predisposition by multiple risk variants, which, however only account for a minor part of the general BMI variability. Although GWAS opened new avenues in elucidating the complex genetics behind common obesity, understanding the biological mechanisms relative to the specific risk contributing to obesity remains poorly understood. Non-genetic factors such as eating behavior or physical activity strongly modulate the individual risk for developing obesity. These factors may interact with genetic predisposition for obesity through epigenetic mechanisms. Thus, here, we review the current knowledge about monogenic and common (multifactorial) obesity highlighting the important recent advances in our knowledge on how epigenetic regulation is involved in the etiology of obesity.

Decrease of the DNA methylation levels of the ADRB3 gene in leukocytes is related with serum folate in eutrophic adults

Background

DNA methylation has been evidenced as a potential epigenetic mechanism related to various candidate genes to development of obesity. Therefore, the objective of this study was to evaluate the DNA methylation levels of the ADRB3 gene by body mass index (BMI) in a representative adult population, besides characterizing this population as to the lipid profile, oxidative stress and food intake.

Methods

This was a cross-sectional population-based study, involving 262 adults aged 20–59 years, of both genders, representative of the East and West regions of the municipality of João Pessoa, Paraíba state, Brazil, in that were evaluated lifestyle variables and performed nutritional, biochemical evaluation and DNA methylation levels of the ADRB3 gene using high resolution melting method. The relationship between the study variables was performed using analyses of variance and multiple regression models. All results were obtained using the software R, 3.3.2.

Results

From the stratification of categories BMI, was observed a difference in the average variables values of age, waist-to-height ratio, waist-to-hip ratio, waist circumference, triglycerides and intake of trans fat, which occurred more frequently between the categories “eutrophic” and “obesity”. From the multiple regression analysis in the group of eutrophic adults, it was observed a negative relationship between methylation levels of the ADRB3 gene with serum levels of folic acid. However, no significant relation was observed among lipid profile, oxidative stress and food intake in individuals distributed in the three categories of BMI.

Conclusions

A negative relationship was demonstrated between methylation levels of the ADRB3 gene in eutrophic adults individuals with serum levels of folic acid, as well as with the independent gender of BMI, however, was not observed relation with lipid profile, oxidative stress and variables of food intake. Regarding the absence of relationship with methylation levels of the ADRB3 gene in the categories of overweight, mild and moderate obesity, the answer probably lies in the insufficient amount of body fat to initiate inflammatory processes and oxidative stress with a direct impact on methylation levels, what is differently is found most of the times in exacerbated levels in severe obesity.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1529-0) contains supplementary material, which is available to authorized users.

Influence of the C677T Polymorphism of the MTHFR Gene on Oxidative Stress in Women With Overweight or Obesity: Response to a Dietary Folate Intervention

The C677T polymorphism of the methylenetetrahydrofolate reductase gene (MTHFR) is related to folate metabolism and can alter the levels of biochemical markers.Objective: Investigate the influence of the MTHFR C677T polymorphism on the effects of a dietary folate intervention on oxidative stress in women with overweight or obesity.Methods: Forty-eight adult women with overweight or obesity were subjected to a 24-hour dietary recall, anthropometric measurements, biochemical analysis, and genotyping of the MTHFR C677T polymorphism. They were allocated by convenience sampling to 2 groups, which received 300 g of folate-rich vegetables containing 191 µg/d (Group 1) (n = 24) or 95 µg/d (Group 2) (n = 24) of folate for 8 weeks.Results: The dietary intervention increased the serum folic acid levels in the 2 analyzed groups. The intervention with 191 µg/d of folate led to relevant results in terms of homocysteine levels (p = 0.0005) and total antioxidant capacity (p = 0.0261); the effect was larger among carriers of the TT genotype.Conclusions: The study demonstrated the beneficial effect of folate intake in terms of a TAC elevation for the CC and TT genotypes of the MTHFR C677T polymorphism, an increase in folic acid levels for all genotypes, and a reduction in the Hcy levels for the TT genotype in response to an intervention consisting of an intake of 191 µg/d of folate supplied by vegetables.