The body of evidence about nuts and health continues to grow. These local and international papers, outlining new nut research published around September 2021, corroborate decades of research about the importance of a regular handful of nuts in a healthy diet.

Are fatty nuts a weighty concern? A systematic review and meta-analysis and dose–response meta-regression of prospective cohorts and randomized controlled trials. (2021).
This systematic review and meta-analysis of six prospective cohort studies and 86 randomised controlled trials (RCTs), involving more than half a million study participants. It found nut consumption does not lead to increased adiposity. Nuts were linked with a 7% lower rate of overweight/obesity in long-term prospective cohorts, and RCTs showed a ‘high certainty’ of no adverse effect of nuts on body weight. The researchers conclude that “the concern that eating nuts contributes to increased adiposity appears unwarranted”.

Association of nut consumption with risk of stroke and cardiovascular disease: The Million Veteran Program. (2021).
In this prospective cohort study, researchers tracked 179,827 US-based veterans (male and female adults of any race and age) over a median of 3.5 years. They found frequent nut consumers (having around 30g nuts, ≥ 5 times per week) were 19% less likely to have a stroke, 22% less likely to suffer from coronary artery disease, and 24% less likely to die from cardiovascular disease, compared with those who rarely or never ate nuts. Consumption of peanut butter was not linked with risk of stroke.

Intake of nuts and seeds is associated with a lower prevalence of non-alcoholic fatty liver disease in US Adults: Findings from 2005–2018 NHANES. (2021).
This cross-sectional study is the first to look into the link between nut and seed intake and non-alcoholic fatty liver disease (NAFLD) in a non-Mediterranean, Western population. The researchers used data from 25,360 US-based adults. They found daily consumption of nuts and seeds (at 15–30 g/day) was linked with a lower prevalence of NAFLD. And for females, any level of nut intake seemed to be beneficial, compared with not eating nuts.

Effects of walnut consumption for 2 years on lipoprotein subclasses among healthy elders: Findings from the WAHA randomized controlled trial. (2021).
The Walnuts and Healthy Aging (WAHA) randomised controlled trial looked at the effects of walnut-supplemented diets for two years, in 628 healthy older people (63-79 years of age) based in Spain and the US. Participants were allocated to either a walnut-free (control) or walnut-supplemented diet (≈15% of energy, 30-60 g/day). The ‘walnut diet’ significantly decreased total cholesterol, LDL-cholesterol and intermediate-density lipoprotein by 4.4%, 3.6%, and 16.8%, respectively. Triglycerides and HDL-cholesterol were unaffected.

Pecan-enriched diets decrease postprandial lipid peroxidation and increase total antioxidant capacity in adults at-risk for cardiovascular disease. (2021).
This randomised controlled trial looked into the impact of daily pecan consumption for eight weeks on lipid peroxidation, total antioxidant capacity (TAC), and tocopherols in adults at higher risk for cardiovascular disease (CVD). There were three treatment groups: the ADD group (n = 15) ate pecans as part of a free-living diet, the SUB group (n = 16) substituted the pecans for isocaloric foods from their habitual diet, and a control group (n=16). In the ADD and SUB groups, postprandial lipid peroxidation was suppressed and TAC was elevated, compared to baseline. And there was an increase in γ-tocopherol within the ADD group. These findings suggest that daily pecan consumption protects against oxidative stress that occurs following a high-fat meal in adults at risk for CVD.

Evaluation of dietary patterns and all-cause mortality: A systematic review. (2021).
This systematic review, which focussed on dietary patterns and all-cause mortality, included one randomised controlled trial and 152 observational studies. It found that dietary patterns characterised by increased consumption of vegetables, fruits, legumes, nuts, whole grains, unsaturated vegetable oils, fish, and lean meat or poultry (when meat was included), among adults and older adults (aged 17-84 years at baseline), were associated with a decreased risk of all-cause mortality. The evidence review informed the latest Dietary Guidelines for Americans.

The association between insulin resistance and the consumption of nut including peanut, pine nut and almonds in working-aged Korean population. (2021).
This retrospective cross-sectional study assessed the link between nut consumption and insulin resistance, among more than 379,000 Korean adults. Among the findings, the odds of elevated insulin resistance were 10% lower in those who ate (15g) nuts at least monthly, compared with less often. And the association was more remarkable in women and people aged younger than 40 years.  

Peanut consumption and risk of stroke and ischemic heart disease in Japanese men and women: The JPHC Study. (2021).
This study investigated the link between peanut consumption and risk of cardiovascular disease in 74,793 Japanese men and women, aged 45 to 74 years. Study participants were tracked for an average (median) of 14.8 years. Higher peanut consumption was associated with a 16% reduced risk of total stroke, compared to the lowest consumption. A higher intake was also linked with a lower risk of ischemic stroke, but was not associated with ischemic heart disease.