The body of evidence about nuts and pregnancy and fertility continues to grow, with new local and international research papers regularly published.

Body of evidence

Soy foods and nuts consumption during early pregnancy are associated with decreased risk of gestational diabetes mellitus: A prospective cohort study. (Pang et al, 2022).
Consumption of soy foods and nuts were independently inversely associated with the risk of gestational diabetes mellitis (GDM) during early pregnancy (6-14 weeks) among women based in China. Specific to nuts, it found that, compared with those who didn’t consume nuts, those who ate the most (that is, women in the highest tertile of nut intake) had a 35% reduced risk of GDM in early pregnancy. This prospective cohort study involved 1,495 pregnant women, of which 529 were diagnosed with GDM.

Modeling the effect of environmentally sustainable food swaps on nutrient intake in pregnant women. (Wang et al, 2021).
This research looked at the impact on nutrient intakes of replacing commonly-consumed foods in pregnancy with environmentally-sustainable alternatives. With the highest gashouse gas emissions (GHG), beef was selected as the reference food. The most pronounced reductions in CO₂ emissions were from replacing beef with tofu, legumes, and nuts. For instance, replacing 1 serve/week of beef with an isocaloric serve of nuts (18g) during pregnancy could reduce GHG emissions by 383kg CO₂ equivalents, and increase folate (+10.2µg/serve) and fiber (+1.1g/serve) – with a small decrease in iron intake (-1.1mg/serve). The researchers say simple dietary swaps can noticeably reduce environmental impact, without compromising nutrient intake in pregnancy.

Effect of nut consumption on erectile and sexual function in healthy males: A secondary outcome analysis of the FERTINUTS randomized controlled trial. (Salas-Huetos et al, 2019).
Compared to the control group, a significant increase in the orgasmic function (p-value = 0.037) and sexual desire (p-value = 0.040) was observed during the nut intervention. No significant differences in changes between groups were shown in peripheral concentrations of NO and E-selectin. Including nuts in a regular diet significantly improved auto-reported orgasmic function and sexual desire.

Effect of nut consumption on semen quality and functionality in healthy men consuming a Western-style diet: a randomized controlled trial. (Salas-Huetos et al, 2018).
Snacking on a handful of nuts can improve male fertility. The study demonstrated that men who snacked on nuts every day experienced significant improvement in sperm quality parameters. The RCT showed that these improvements resulted from consuming 60 grams per day of nuts (30g of walnuts, 15g of almonds and 15g of hazelnuts), compared to consuming no nuts.

Hazelnut consumption improves testicular antioxidant function and semen quality in young and old male rats. (Kara et al, 2019).
Hazelnut supplementation in the diets of young and old rats significantly improved testicular function and semen quality.

Maternal nut intake in pregnancy and child neuropsychological development up to 8 years old: A population-based cohort study in Spain. (Gignac et al, 2019).
In the first of its kind, a study led by the Barcelona Institute for Global Health found children, whose mothers ate more nuts during the first trimester of pregnancy, achieved the best results in tests measuring cognitive function, attention capacity and working memory.