Lillegard, K., A. Widmer, J.R. Koethe, H.J. Silver, 2025. Consuming tree nuts daily as between-meal snacks reduces food cravings and improves diet quality in American young adults at high metabolic syndrome risk. Nutrients. 17, 3778. https://doi.org/10.3390/nu17233778.
Background: Daily energy intake from snacking behaviors has increased over the past few decades, during which the prevalence of obesity and metabolic syndrome has risen to epidemic proportions. There remains considerable room for improvement in the overall quality of dietary intakes of the U.S. population when compared to national recommendations. Food cravings may contribute to the types of snacks chosen for consumption, and thus, the frequency of foods and food groups consumed, and the overall nutritional quality of the diet. Methods: Eighty-four young (28.5 ± 4.3 years) adults with at least one metabolic syndrome risk factor participated in a parallel-arm single-blind randomized trial designed to compare effects of consuming a mix of tree nuts versus typical high-carbohydrate food items as between-meal snacks for 16 weeks. Cravings for 28 common foods via the Food Craving Inventory, short-term dietary intakes via 24 h multi-pass methodology, food group frequency via the Rapid Eating Assessment for Participants, usual hunger and fullness via visual analog scales, appetite-regulating hormones, and diet quality via the Healthy Eating Index-2015 were measured at baseline and end of study. Results: Participants in the TNsnack group had significant decreases in cravings for high sweet items and fast-food items, which were associated with decreased frequency of desserts and salty foods along with increased intake of higher protein items. In contrast, no significant reductions in food cravings or preference for sweets were observed in the CHOsnack group. Decreased cravings for sweets by TNsnack participants were associated with increased total GLP-1 levels: cake (r = −0.35, p = 0.03), brownies (r = −0.44, p = 0.02), candy (r = −0.36, p = 0.03) and ice cream (r = −0.33, p = 0.04). Overall, the total diet quality score improved by 19% among TNsnack participants. Conclusions: Replacing more typical between-meal snacks with tree nuts may reduce food cravings, particularly for sweeter food items that are likely to be nutrient poor and energy dense. By reducing cravings and frequency of intake, consuming tree nuts as snacks could facilitate having a higher quality, more nutrient-dense diet and mitigate potential negative effects of snacking on metabolic health in young adults.
Suprono, M.S., D.J. Shavlik, F.M. Butler, J. Sabaté, G.E. Fraser, M.J. Orlich, 2025. Nut consumption and risk of cardiovascular disease and ischemic heart disease mortality: The Adventist Health Study 2. J Nutr. https://doi.org/10.1016/j.tjnut.2025.10.022
Background: Cardiovascular disease (CVD) and ischemic heart disease (IHD) are leading causes of mortality worldwide. Nut consumption has been associated with reduced risk. Objectives: To examine the associations between total nut and tree nut intake with CVD and IHD mortality, and to explore the potential benefits of substituting nuts for less heart-healthy foods. Methods: This prospective cohort study followed 80,529 Adventist participants for an average of 11.1 y. During this period, 4258 CVD deaths, including 1529 IHD deaths, were recorded. Dietary intake was assessed using a validated food frequency questionnaire. We examined total nut intake (combining tree nuts, peanuts, and peanut butter) as well as tree nut intake specifically (including almonds, cashews, walnuts, and mixed nuts). Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for demographic, dietary, and lifestyle factors. Results: Participants with higher nut intake tended to be older, more educated, and reported healthier lifestyle behaviors. After multivariable adjustment, higher total nut intake was significantly associated with lower CVD (HR: 0.86; 95% CI: 0.79, 0.94) and IHD mortality (HR: 0.81; 95% CI: 0.70, 0.94) when comparing the 90th with the 10th percentile of intake. Stronger inverse associations were observed with tree nut intake and CVD (HR: 0.83; 95% CI: 0.74, 0.92) and IHD mortality (HR: 0.73; 95% CI: 0.62, 0.87). Substitution analysis revealed that replacing unprocessed red meats and processed meats with total nuts and tree nuts was associated with lower risk of CVD and IHD mortality. Conclusions: Higher intakes of total nuts and tree nuts are associated with significantly lower risk of CVD and IHD mortality. These findings support dietary recommendations to increase nut consumption as part of a heart-healthy diet.
Moussa, M.R., N. Fan, J. Birk, A.A. Provatas, P. Mehta, Y. Hatano, O.K. Chun, M Darooghegi Mofrad, A. Lotfi, A. Aksenov, V.N. Motta, M. Zenali, H. Vaziri, J.J. Grady, M. Nakanishi, D.W. Rosenberg, 2025. Systemic inflammation and the inflammatory context of the colonic microenvironment is improved by urolithin A. Cancer Prev Res (Phila). https://doi.org/10.1158/1940-6207.capr-24-0383
Diet affects cancer risk and plant-derived polyphenols exhibit cancer-preventive properties. Walnuts are an exceptional source of polyphenolic ellagitannins, converted into urolithins by gut microflora. This clinical study examines the impact of urolithin metabolism on inflammatory markers in blood and colon polyp tissue. We evaluate the effects of walnut consumption on urinary urolithins, serum inflammatory markers and immune cell markers in polyp tissues obtained from 39 subjects. Together with detailed food frequency data, we perform integrated computational analysis of metabolomics data combined with serum inflammatory markers and spatial imaging of polyp tissues using imaging mass cytometry. LC-MS/MS analyses of urine and fecal samples identifies a widely divergent capacity to form nine urolithin metabolites in this patient population. Subjects with higher urolithin A formation exhibit lower levels of several key serological inflammatory markers, including C-peptide, sICAM 1, sIL6R, Ghrelin, TRAIL, sVEGFR2, PDGF and MCP2, alterations that are more pronounced in obese individuals for siCAM-1, ENA-78, Leptin, GLP-1 and MIP-1D. There is a significant increase in levels of PYY associated with urolithin A formation, whereas TNF-α levels show an opposite trend, recapitulated in an in vitro system with ionomycin/PMA-stimulated PBMCs. Spatial imaging of colon polyp tissues shows altered cell cluster patterns, including a significant reduction of vimentin and CD163 expression associated with urolithin A. The ability to form urolithin A is linked to inflammation, warranting further studies to understand the role of urolithins in cancer prevention.
Bell, L., G.F. Dodd, M. Jeavons, D.R. Fisher, A.R. Whyte, B. Shukitt-Hale, C.M. Williams, 2025. The impact of a walnut-rich breakfast on cognitive performance and brain activity throughout the day in healthy young adults: a crossover intervention trial. Food Funct. 16(5):1696-1707. https://doi.org/10.1039/d4fo04832f
A healthy diet is essential for optimal brain health and many bioactives from food are linked to cognitive benefits. To examine whether walnuts led to cognitive improvements throughout the day, 32 healthy young adults, aged 18-30, were tested in a double-blind, crossover pilot study, to compare the effects of a breakfast containing 50 g walnuts with a calorie-matched control containing no nuts. Cognition, mood, blood, and EEG measures were recorded at baseline and 2, 4, and 6 hours postprandially. Mood ratings for negative affect appeared worse following walnuts compared to control, possibly due to a general dislike of the intervention. However, walnuts elicited faster reaction times throughout the day on executive function tasks. Memory recall performance at 2 hours was worse for walnuts compared to control, but by 6 hours this finding was reversed with walnuts outperforming the control. EEG PSD analysis revealed differences in frontoparietal activity in the walnut condition compared to the control condition during memory recall and during executive function performance. These results may reflect between-treatment differences in cognitive effort or attentional processes while performing the tasks. Blood analysis revealed lower circulating non-esterified fatty acids and small increases in glucose availability following consumption of walnuts compared to control, suggesting enhanced glucose availability as one possible mechanism of action. Further investigations of other potential mechanisms are needed. Overall, these findings provide evidence for reaction time benefits throughout the day following a walnut-rich breakfast, while memory findings were mixed with benefits only observed later in the day. However, more research is needed into how diets containing walnuts might regulate cognitive improvements in humans postprandially and over the longer term.
