The body of evidence about nuts and health continues to grow. These local and international research papers, published around July 2024, corroborate decades of research about the importance of a regular handful of nuts within a healthy diet.

Nut consumption, gut microbiota, and body fat distribution: Results of a large, community-based population study. (Shi et al, 2024).
This research, involving 2,255 Chinese adults, utilised food frequency questionnaires (to assess nut intake), dual-energy x-ray absorptiometry (to look at body fat distribution), and 16s ribosomal RNA sequencing (for gut microbial analysis). It found nut consumption was associated with beneficial body fat distribution, and greater gut microbiota diversity and taxonomy. In addition, the microbial features related to a high nut intake (including α diversity) were linked with a favourable pattern of fat distribution.

Cashew nut (Anacardium occidentale L.) and cashew nut oil reduce cardiovascular risk factors in adults on weight-loss treatment: A randomized controlled three-arm trial (Brazilian Nuts Study). (Meneguelli et al, 2024).
In this randomised controlled-feeding study, involving 68 adults with overweight/obesity, all participants ate an energy-restricted diet (−500kcal/day) and were also randomly assigned to either a control (no nuts), cashew nut (30g/day), or cashew nut oil (30 mL/day) group. After 8 weeks, all groups significantly reduced body fat, body weight, and waist and hip circumferences. But those in the cashew nut and cashew nut oil groups had additional reductions in atherogenic markers, liver function biomarkers, and cardiovascular risk factors (neck circumference and apolipoprotein B levels).

Postprandial appetite responses to a pecan enriched meal: A randomized crossover trial. (Prater et al, 2024).
In this acute meal challenge study (using a double-blinded randomized crossover design), 31 young, healthy adults ate a meal containing either 68g of pecans, or an energy- and macronutrient-matched control meal, on separate testing days. It found a greater peptide YY response, and a greater suppression of ghrelin at two hours after eating a pecan-containing meal, compared with control. The pecan meal also increased feelings of fullness, and suppressed appetite later in the day, more so than the control meal.

Brazil nut (Bertholletia excelsa H.B.K.) consumption in energy-restricted intervention decreases pro-inflammatory markers and intestinal permeability of women with overweight/obesity: A controlled trial (Brazilian Nuts Study). (Souza Silveira et al, 2024).
In this 8-week trial, 56 women with overweight or obesity followed an energy-restricted diet (-500 kcal/day), and either had no nuts (control group) or 8g Brazil nuts/day, providing ~350μg of selenium. The Brazil nut group showed lower values of inflammatory markers, including CRP, TNF, IL1-β, IL-8, compared to the control group – and this corresponded with changes in serum selenium concentrations. It suggests that eating Brazil nuts regularly may help control low-grade inflammation and improve intestinal permeability – and these effects seem to be dependent on selenium status.

Pistachio (Pistacia vera L.) consumption improves cognitive performance and mood in overweight young adults: A pilot study. (Landaverde-Meija et al, 2024).
This study evaluated the impact of pistachio consumption (28g for 28 days) on cognitive performance and mood in overweight, young adults. Among the findings, pistachio supplementation improved risk tolerance and decision-making strategy, executive functions, and selective and sustained attention. Mood state, measured via anxiety, anger-hostility, and sadness-depression markers, was also improved. Pistachios consumption also significantly reduced waist circumference, total and LDL-cholesterol, and triglycerides, and increased plasma antioxidant activity.

The effects of almond consumption on cardiovascular health and gut microbiome: A comprehensive review. (Singar et al, 2024).
This review found that almond consumption can improve cardiovascular health markers and positively modulate the gut microbiome. Specifically, almond consumption has been linked with improvements in endothelial function, lipid profiles, and body composition (including reductions in body fat percentage and central adiposity). And it’s also been shown to increase the production of beneficial short-chain fatty acids, particularly butyrate, and change faecal microbiota composition. The dosages of almonds used in these studies varied, but were typically around 56g/day.

A cross-sectional study on the association of walnut consumption with obesity and relative fat mass among US adolescents and young adults in NHANES (2003-2020). (Gletsu-Miller, 2024).
This study, of 8,874 adolescents (12–19 years) and 10,323 young adults (20–39 years), used data from the (US-based) National Health and Nutrition Examination Survey to investigate the links between consumption of walnuts, as well as other nuts, and measures of obesity. It found that, despite nuts being energy-dense, consumption of tree nuts (specifically, walnuts with other nuts) was associated with a lower prevalence of obesity and a lower relative fat mass, compared to not eating nuts, especially in adolescent girls and young women.

Unveiling the ‘hidden quality’ of the walnut pellicle: A precious source of bioactive lipids. (Abbattista et al. 2024).
The aim of this analysis was to isolate and quantify compounds in pellicle-enriched waste by-products of walnut processing. Results showed an array of unusual lipids, including oxylipins and endocannabinoids, in significant concentrations. These lipid classes have known potent bioactivities – including as mammalian signalling molecules and homeostatic regulators. This ‘hidden quality’ of the walnut pellicle may offer an additional explanation for the health benefits of walnut consumption.   

Dietary patterns to promote cardiometabolic health. (Pagidipati et al, 2024).
The authors of this review article highlight that the Mediterranean and DASH dietary patterns have high-quality evidence to support improved cardiometabolic health. And they say that, although there is no one dietary pattern that is appropriate for all people, emphasizing the similarities, rather than the differences, of health-promoting dietary patterns – which include an emphasis on vegetables, fruits, legumes, nuts, whole grains and minimally-processed protein foods, such as fatty fish or plant-based proteins – can help simplify guidance.

Impact of quantity and type of dietary protein on cardiovascular disease risk factors using standard and network meta-analyses of randomized controlled trials. (Yao et al, 2024).
This meta-analysis research assessed the impacts of quantity and type of dietary protein on cardiovascular risk factors. It found favourable effects of higher protein diets on lowering blood pressure and improving flow-mediated dilation, without altering lipid-lipoprotein profiles. And plant-protein-rich diets showed significant improvements in the lipid-lipoprotein profiles, compared with animal-protein-rich diets – particularly in reducing total cholesterol, LDL-cholesterol, and triglyceride levels, while increasing HDL-cholesterol levels.

Adherence to the EAT-Lancet diet and incident depression and anxiety. (Lu et al, 2024).
This study investigated the prospective association of adhering to the EAT-Lancet reference diet with depression, anxiety, and their co-occurrence, in 180,446 UK Biobank participants. Over 11.62 years of follow-up, participants within the group with the highest adherence to the Eat-Lancet diet had lower risks of depression, anxiety, and their co-occurrence, compared to those in the lowest adherence group. It suggests that following the EAT-Lancet Planetary Health Diet may be linked with a reduced risk of depression and anxiety.