Is a Handful an Effective Way to Guide Nut Recommendations?

Nut consumption is associated with a lower risk of depression in adults: A prospective analysis with data from the UK Biobank cohort

BACKGROUND & AIMS

Evidence on the association between nut consumption and depression is mainly based on cross-sectional studies. This study aims to analyse whether nut consumption is prospectively associated with the risk of depression in adults.

METHODS

This study was conducted using the United Kingdom (UK) Biobank resource. Data from middle-aged and older UK adults who participated in this cohort between 2007-2012 (baseline) and 2013-2020 (follow-up) were analysed. Baseline information on nut consumption was obtained with the Oxford WebQ 24-h questionnaire. Depression, defined as a self-reported physician diagnosis of depression or antidepressant use, was assessed at baseline and follow-up. Hazard regression models estimating the predictive ability of nut consumption for the risk of developing depression were adjusted for sociodemographic, lifestyle, and health confounders.

RESULTS

A total of 13,504 participants (mean age 57.5 ± 7.2 years, 50.7% female) free of depression at baseline were included in the analyses. After a mean follow-up of 5.3 ± 2.4 years, 1122 (8.3%) incident cases of depression were identified. Compared with no nut consumption, the daily consumption of >0 to 1 serving of 30 g of nuts was associated with a lower risk of depression (hazard ratio, HR = 0.83; 95% confidence interval, CI: 0.71-0.97) regardless of all potential confounders considered. In stratified analyses, a decreased risk of depression was more clearly observed in UK adults with adequate weight control, a healthy lifestyle, and better health status than in their counterparts (p < 0.05).

CONCLUSIONS

Low-to-moderate nut consumption (>0 to 1 serving of 30 g/day) was associated with a 17% lower risk of depression during a 5.3-year follow-up compared with no nut consumption in a large sample of middle-aged and older UK adults. This protective association is enhanced in the absence of other known risk factors for depression.

Occurrence of aflatoxins in nuts and peanut butter imported to UAE

Nuts are an important food group that contributes to maintaining health; however, they can be a source of exposure to aflatoxins. This study was conducted from 2017 to 2021 to assess the incidence of aflatoxins in nuts and nut products imported to the UAE from 57 countries. Associations between container type and processing technique and aflatoxin levels were also analyzed. A total of 5401 samples of pistachios, peanuts, peanut butter, and mixed nuts were examined using HPLC-FLD analysis in conjunction with immunoaffinity cleanup. In nuts, non-conformity was detected in samples imported from 32 different countries. Mean aflatoxin values for the non-compliant samples ranged from 81.0 to 92.7 μg/kg in pistachios, peanuts, and mixed nuts. A significant difference (p < 0.05) was found between mean aflatoxin levels in samples of peanut butter (29.3 μg/kg) compared to the other types of nuts. Nuts packed in containers made of fabric material had the highest mean aflatoxin levels of 108.1 μg/kg, while 29.7 μg/kg was the lowest mean level and was detected in nuts packed in glass. Ground samples had the highest aflatoxin levels (158.9 μg/kg) among processed products. This report will be valuable as a reference document in developing approaches to control nut importation and for establishing procedures that prevent food safety risks due to aflatoxin exposure. A need was underlined for the regulating authority to audit companies importing nuts, ensure safe practices are in place, and establish standards to minimize contamination and prevent the need for product rejection at the border.

Nuts and seeds consumption and risk of cardiovascular disease, type 2 diabetes and their risk factors: a systematic review and meta-analysis

Objectives

We aimed to systematically review studies and evaluate the strength of the evidence on nuts/seeds consumption and cardiometabolic diseases and their risk factors among adults.

Methods

A protocol was pre-registered in PROSPERO (CRD42021270554). We searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials and Scopus up to September 20, 2021 for prospective cohort studies and ≥12-week randomized controlled trials (RCTs). Main outcomes were cardiovascular disease (CVD), coronary heart disease (CHD), stroke and type 2 diabetes (T2D), secondary total-/low density lipoprotein (LDL)-cholesterol, blood pressure and glycaemic markers. Data extraction and risk of bias (RoB) assessments (using RoB 2.0 and RoB-NObS) were performed in duplicate. Effect sizes were pooled using random-effects meta-analyses and expressed as relative risk (RR) or weighted mean differences with 95% confidence intervals (CI); heterogeneity quantified as I ². One-stage dose-response analyses assessed the linear and non-linear associations with CVD, CHD, stroke and T2D. The strength of evidence was classified per the World Cancer Research Fund criteria.

Results

After screening 23,244 references, we included 42 papers from cohort studies (28 unique cohorts, 1,890,573 participants) and 18 RCTs (2,266 participants). In the cohorts, mainly populations with low consumption, high versus low total nuts/seeds consumption was inversely associated with total CVD (RR 0.81; 95% CI 0.75, 0.86; I ² = 67%), CVD mortality (0.77; 0.72, 0.82; I ² = 59.3%), CHD (0.82; 0.76, 0.89; I ² = 64%), CHD mortality (0.75; 0.65, 0.87; I ² = 66.9%) and non-fatal CHD (0.85; 0.75, 0.96; I ² = 62.2%). According to the non-linear dose-response analyses, consumption of 30 g/day of total nuts/seeds was associated with RRs of similar magnitude. For stroke and T2D the summary RR for high versus low intake was 0.91 (95% CI 0.85, 0.97; I ² = 24.8%) and 0.95 (0.75, 1.21; I ² = 82.2%). Intake of nuts (median ~50 g/day) lowered total (-0.15 mmol/L; -0.22, -0.08; I ² = 31.2%) and LDL-cholesterol (-0.13 mmol/L; -0.21, -0.05; I ² = 68.6%), but not blood pressure. Findings on fasting glucose, HbA1c and insulin resistance were conflicting. The results were robust to sensitivity and subgroup analyses. We rated the associations between nuts/seeds and both CVD and CHD as probable. There was limited but suggestive evidence for no association with stroke. No conclusion could be made for T2D.

Conclusion

There is a probable relationship between consumption of nuts/seeds and lower risk of CVD, mostly driven by CHD, possibly in part through effects on blood lipids. More research on stroke and T2D may affect the conclusions. The evidence of specific nuts should be further investigated.

Lifestyle, Eating Habits, and Health Behaviors Among Dietary Supplement Users in Three European Countries

Dietary supplements (DS) are used by about 30-50% of adults in developed countries. However, only a few studies have compared the characteristics of DS users in different nations. This study aimed to identify and compare selected health-related behaviors of DS users from three European countries. A total of 3,588 adults (32.08 ± 8.04 years) from Poland (1,030 females, 287 males), Germany (994 females, 190 males), and the United Kingdom (911 females, 176 males) were included in the analysis. The study was based on a self-administered survey consisting of 70 questions regarding baseline characteristics, lifestyle, eating, and health habits. The associations of the obtained results were compared using the Kruskal-Wallis test, Pearson Chi-Square test, and Cramer's V value. The highest percentage of DS users (56.98%, n = 2,044) had a correct body weight, while higher body weight values were observed in 39.19% (n = 1,406). In terms of lifestyle, statistically significant differences (p < 0.05) were noted for alcohol consumption and the level of physical activity. Fruit and vegetables were most often consumed a few times a weeks (34.67%, n = 1,244). A similar result was observed for the consumption of whole grain (37.76%, n = 1,355), dairy (39.99%, n = 1,435), eggs (49.67%, n = 1,782), and meat (51.45%, n = 1,846). Most DS users did not have a chronic disease (66.72%, n = 2,394). Among the other conditions, a frequent occurrence (a few times a weeks) of gastrointestinal problems (28.29%, n = 1,015) and concentration disorders (29.15%, n = 1,046) was noted. Cramer's V values (<0.3) indicated a weak (but significant p < 0.05) relationship between the country of residence and most of the analyzed variables. In conclusion, DS users were characterized by a healthy lifestyle with appropriate behaviors but not healthy eating habits.