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

Association of prostate cancer with nuts, seeds, alcohol and processed meats: A worldwide population-based study. (2020).
This population-based study, which looked at data from 170 countries, including Australia, found consumption of nuts and seeds was linked with a reduced risk of prostate cancer and a reduced risk of death from the disease, while alcohol and processed meat increased these risks. It showed each 1g increase in nut and seed intake was associated with a 2.0% lower incidence, 3.2% lower prevalence, and 0.8% lower mortality of prostate cancer. The researchers stated that ‘nuts may affect carcinogenesis by inhibiting proinflammatory cell signalling pathways and thanks to their high dose of antioxidant. The main components suggested to be preventive agents against cancer are phytoestrogens, ellagic and oleic acids’.

The effect of tree nuts on glycaemic outcomes in adults with type 2 diabetes mellitus: A systematic review. (2020).
This research pulled together the available research on the effectiveness of tree nuts on glycaemic outcomes in adults with type 2 diabetes. Fifteen randomised controlled trials were included, with a total sample size of 667. Consumption of mixed tree nuts showed reduction in both fasting blood glucose and glycated haemoglobin (mean differences of −0.26 mmol/L and −0.11%, respectively) at three months or earlier follow-up. Consumption of pistachios showed a significant reduction in triglyceride levels at three months or earlier follow-up (MD −0.28mmol/L). Specific tree nuts (walnuts, almonds and hazelnuts) reduced fasting blood glucose and glycated haemoglobin by varying degrees.

Sperm DNA methylation changes after short‐term nut supplementation in healthy men consuming a Western‐style diet. (2020).
This randomised controlled trial looked at the effect of short-term (14 weeks) consumption of 60g/day tree nuts on sperm DNA myelination in 72 healthy men. They found that adding nuts to a regular Western‐style diet subtly impacts sperm DNA methylation in specific DNA regions, showing that there are some sperm epigenome regions that could respond to diet. The authors point out that ‘nuts contain significant amounts of folic acid and other nutrients with potential ability to change DNA methylation’.

Effects of pistachios on anthropometric indices, inflammatory markers, endothelial function, and blood pressure in adults: A systematic review and meta-analysis of randomized controlled trials. (2020).
This study pooled the data of available randomised controlled trials (RCTs) to determine if pistachios offer benefits to anthropometric indices, inflammatory markers, endothelial dysfunction, and blood pressure. The meta-analysis of 13 RCTs, collectively involving 563 participants, found that pistachio consumption significantly decreased systolic blood pressure, whereas all other indicators were not statistically significant.

Effects of 2-year walnut-supplemented diet on inflammatory biomarkers. (2020).
In this randomised controlled trial, 634 healthy adults, aged 63 to 79 years, were assigned to either a control diet, without walnuts, or a diet incorporating daily ‘doses’ of walnuts at ≈15% of energy (or 30 to 60g walnuts) for two years. Those who ate walnuts daily had reduced concentrations of several inflammatory biomarkers, compared to the control group. This anti-inflammatory effect of long-term walnut intake could help explain how these nuts reduce cardiovascular disease risk – beyond that of lipid lowering.