A recent trial in Spain known as the Fertinuts study involved over a hundred healthy men in their reproductive prime (18-35 years of age), had their sperm put under the microscope!! All these men ate a usual Western diet. For the study half of these men continued to eat their usual diet (without nuts), and the other half had a couple of handfuls of nuts (60 g) a day! The nut group were shown to have not only more sperm, but better looking sperm (morphology) that had far more vitality and could swim better! To add to this, the trial only went for 14 weeks. If you are wanting your nuts to be fertinuts and produce happy strong good looking and fast swimming sperm, then perhaps make sure to be dosing up on your walnuts, almonds and hazelnuts! This of course is in conjunction with a well balanced diet. Please seek advice from your dietitian before permanently changing your diet in any major way.
For full article: Effect of nut consumption on semen quality and functionality in healthy men consuming a Western-style diet: a randomized controlled trial.
Albert Salas-Huetos, Rocío Moraleda, Simona Giardina, Ester Anton, Joan Blanco, Jordi Salas-Salvadó, Mònica Bulló
The American Journal of Clinical Nutrition, 2018 Nov 1;108(5):953-962. doi: 10.1093/ajcn/nqy181