Effect of almond consumption on insulin sensitivity and serum lipids among Asian Indian adults with overweight and obesity- A randomized controlled trial

Nuts and seeds consumption impact on adolescent obesity: sex-specific associations from 2003 to 2018 National Health and Nutrition Examination Survey

The nutritional benefits and immunological advantages of consuming nuts and seeds are well-established. However, the link between nuts and seeds consumption and the susceptibility of being overweight or obese among adolescents is not clear. This study aims to explore this relationship in adolescents aged 12-19. Using a weighted multiple logistic regression model, we analysed data of the Food Patterns Equivalents Database and the U.S. National Health and Nutrition Examination Survey (NHANES) from 2003 to 2018. We found a significant association between nuts and seeds consumption and a reduced odds of being overweight or obese in females. Specifically, females who habitually consumed nuts and seeds had lower odds of being overweight or obese (OR = 0.55, 95% CI: 0.32-0.94). Additionally, we found an L-shaped relationship between nuts and seeds consumption and appropriate waist-to-height ratio in males. The findings suggest that nuts and seeds consumption may contribute to healthier physical development in adolescents.

Can different types of tree nuts and peanuts induce varied effects on specific blood lipid parameters? A systematic review and network meta-analysis

Tree nuts and peanuts have shown cardioprotective effects through the modulation of blood lipid levels. Despite the abundance of scientific evidence available, it remains uncertain whether the type of nut consumed influences these changes. The objective of this study was to evaluate and rank the effects of six types of nuts on total cholesterol (total-c), low-density lipoprotein (LDL-c), triglyceride (TG) and high-density lipoprotein (HDL-c) levels through a systematic search of randomized controlled trials (RCTs), a frequentist network meta-analysis (NMA), and the estimation of SUCRA values. A total of 76 RCTs were ultimately analyzed. The total c for pistachios, almond, and walnuts; LDL-c for cashews, walnuts, and almond; and TG for hazelnuts and walnuts significantly decreased, while only peanuts exhibited a significant increase in HDL-c levels. According to the rankings, the most effective type of nut for reducing total cholesterol was pistachio, cashew for LDL-c, hazelnut for TG, and peanut for increasing HDL-c levels. It should be noted that every type of nut analyzed exhibited a significant positive impact on some parameters, and specific types demonstrated enhanced advantages for particular blood lipids. These results endorse the use of personalized nutritional strategies to address and prevent dyslipidemia.Registration: PROSPERO database CRD42021270779.

High dietary intake of unsaturated fatty acids is associated with improved insulin resistance - a cross-sectional study based on the NHANES database

BACKGROUND

A moderate intake of unsaturated fatty acids (UFA) is associated positively with improved insulin resistance. The aim of this study was to investigate the relationship between the dietary intake of unsaturated fatty acids/total fats (UFA/TF) and insulin resistance.

METHODS

15,560 participants were selected from the National Health and Nutrition Examination Survey (NHANES) database enrolled between March 2017 and 2020, and excluded those under 20 years of age, pregnant, or with missing data for key research items. Finally, 7,630 participants were included in the study. R software was used for data analysis that included: (1) general descriptive statistics; (2) comparison of differences in baseline information of three UFA/TF groups, namely low, medium, and high ratios; (3) calculation of the correlation between the UFA/TF ratio and markers of insulin resistance: triglyceride-glucose index (TyG) and homeostatic model assessment for insulin resistance (HOMA-IR); (4) stratification of the study subjects into two groups, with or without insulin resistance, using a cut-off value of HOMA-IR ≥ 2, followed by logistic regression analysis to examine the relationship between UFA/TF and insulin resistance status in the two groups; and (5) further stratification of the subjects according to age, gender, body mass index (BMI), race, total energy intake, total protein, total carbohydrate, total sugars, total dietary fiber, total fat, alcohol consumption, diabetes, hypercholesterolemia to analyze the impact of UFA/TF on insulin resistance status in different subgroups.

RESULTS

(1) A high UFA/TF level was associated with a low TyG index and HOMA-IR [β (vs. TyG index) = -0.559, 95% CI: (-0.821~-0.297), P < 0.001; β (vs. HOMA-IR) = -0.742, 95% CI: (-1.083~-0.402), P < 0.001]. This negative relationship became more pronounced when UFA/TF exceeded 57.9% (i.e., the higher group). (2) Logistic regression analysis showed that a higher UFA/TF level was associated with a lower risk of developing insulin resistance [Q3 vs. Q1: 0.838 (95%CI: 0.709 ~ 0.991); P for trend = 0.038]. After adjusting for covariates such as gender, age, and BMI, this protective effect remained significant (P value < 0.05). (3) Analysis also showed that increased UFA/TF intake reduced the risk of developing insulin resistance (OR = 0.266, 95% CI: (0.075 ~ 0.946), P = 0.041). Subgroup analysis showed that although elevated UFA/TF intake showed no statistically significant difference in its effect in most subgroups, the large study population in this study provides valuable insights on potential changes. Increased UFA/TF intake may confer relatively greater benefits within specific subgroups, particularly among the elderly [Q3 age group, OR = 0.114, 95%CI: (0.012 ~ 1.078), P = 0.058], females [OR = 0.234, 95%CI: (0.041 ~ 1.333), P = 0.102], those with a BMI ≤ 25 kg/m²[OR = 0.191, 95%CI: (0.016 ~ 2.344), P = 0.196], and individuals without hypercholesterolemia [OR = 0.207, 95%CI: (0.042 ~ 1.013), P = 0.0519]. The impact of high UFA/TF levels within subgroups based on the presence or absence of coronary heart disease and stroke displayed contrasting trends. In those without coronary heart disease, there was a significant protective effect against insulin resistance [OR = 0.254, 95% CI: (0.07 ~ 0.929), P = 0.0384], while in the stroke subgroup, a significantly protective effect against insulin resistance was observed [OR = 0.002, 95%CI: (0 ~ 0.695), P = 0.0376].

CONCLUSION

A high dietary intake of UFA relative to total fat consumption could be a protective factor against the risk of developing insulin resistance.

Study protocol for a cluster randomized controlled trial for 16 weeks to assess the effect of almond consumption on glycemic control and gut health in prediabetes adults in rural settings of India.. [DOI: 10.1101/2023.06.21.23291579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Introduction

Almonds have prebiotic potential to maintain gut health and regulate glycemia. Western studies have shown their positive effects in preventing non-communicable diseases like diabetes and CVDs. However, there is a lack of well-designed studies involving Asian Indians, who have a higher predisposition to diabetes due to their unique ‘Asian phenotype’. Therefore, this study aims to evaluate the impact of almond supplementation on glycemic control and gut health in prediabetic adults in rural India through a randomized clinical trial.

Methods and Analysis

A parallel cluster randomized controlled trial with 178 prediabetic participants aged 20-50, both genders, with a BMI of 18.9-25 kg/m2, will be conducted in rural areas of Chikkaballapur, Kolar, and rural Bangalore districts in India. The intervention group will receive 56g of almonds as mid-morning snacks for 16 weeks, while the control group will receive cereal pulse based traditional isocaloric snacks under the closed supervision of the study investigators. Anthropometry, clinical, and biochemical parameters will be measured at 0, 8th, and 16th weeks, and a subgroup of 120 participants will undergo gut health analysis. GLP 1 analysis will be conducted on 30 participants at 0 and 16th week. Statistical analysis will be performed using SPSS for Windows V 27.0, and both ITT and per-protocol analyses will be conducted.

Ethics and Dissemination

Ethics approval was obtained from the Institutional Ethics Committee at Ramaiah Medical College, Bangalore, Karnataka, India (DRPEFP7672021). Results from this trial will be disseminated through publication in peer-reviewed journals, national and international presentations.

Trial Registration Number

The trial is registered in the clinical trial registry of India (CTRI/2023/03/050421).

ARTICLE SUMMARY

Strengths and Limitations:

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The study is the first field-based trial in rural settings to assess the effect of almond consumption versus traditional cereal pulse-based snacks on prediabetes adults’ glycemic control and gut health.

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The compliance management is crucially designed by performing an intervention on one-to-one closed supervision, assessment of serum tocopherol levels, and regular follow up of any adverse events.

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The upcoming metagenomic analysis and the gut metabolites like short chain fatty acids (SCFA) and GLP 1 will significantly advance our understanding of the impact of almonds on the gut health of prediabetes adults.

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A potential limitation of the study is that it will not be feasible to follow the participants after the post intervention period.