Eating two handfuls of nuts a day makes fellas better in bed, according to new research.
The popular snack food boosts sexual desire and the quality of orgasms in men, say scientists.
The finding could help combat the alarming decline in sperm counts across the Western world owing to pollution, smoking and junk food.
It adds to a growing body of evidence that a healthy diet increases the chances of conceiving.
About one in seven couples have difficulty getting pregnant with up to half of infertility cases attributable to men.
A study of dozens of 18 to 35 year olds found those who ate about 2 ounces (60g) of mixed almonds, hazelnuts and walnuts daily for 14 weeks improved their prowess between the sheets.
Lead author Dr Albert Salas-Huetos, ,a nutritionist at Rovira i Virgili University, Reus, north east Spain, said nuts may boost blood flow to the penis.
The 83 participants were randomly divided into two sets – with 43 getting the nuts. Otherwise, they all followed their normal western diet. At the start, there were no major differences in sexual performance.
But Dr Sala–Huetos said: “However, compared to the control group, a significant increase in the orgasmic function and sexual desire was observed in the nut-supplemented group during the intervention.”
These were measured using a survey called the International index of erectile function (IIEF).
It examines both – along with erectile function and intercourse satisfaction – with a score of 0-5 awarded for each of 15 questions.
Dr Sala-Huetos said nuts are packed with nutrients. Their consumption has been linked to reducing the risk of a host of illnesses, including cardiovascular disease.
He said: “Specifically, hazelnuts, almonds and walnuts contain high amounts of vegetable protein and fat – mainly unsaturated fatty acids – are dense in antioxidants and vitamins and some minerals. They are also rich in dietary fibre.”
What is more, they contain quite high amounts of an amino acid called arginine that produces nitric oxide (NO) in the body.
The gas helps vessels relax, meaning more oxygen rich blood can circulate to the bodies extremities, including the penis.
Dr Sala-Huetos pointed out erectile dysfunction (ED) shares common causes with hardening of the arteries.
He said: “For that reason, several antioxidants and vitamins that are present in nuts have been suggested to be effective treatments for ED and at the same time are beneficial for the cardiovascular system.”
Previous studies have reported nuts help lower bad cholesterol and improve glucose metabolism, reducing the risk of heart attacks and strokes.
Dr Salas-Huetos said: “Therefore, we strongly believe in the necessity to develop similar trials with participants to accurately establish an effect of nut consumption on erectile function and cardiovascular risk.”
The study published in Nutrients forms part of a project dubbed FERTINUTS which is assessing the effects of regularly consuming nuts on the quality of semen.
Last year the same team, using a larger number of participants’, showed it increased their sperm count and had more viable “swimmers”.
Now they have built on this by demonstrating the positive effects of nuts on sexual function.
The prevalence of erectile and sexual dysfunction is thought to affect one in 50 men under the age of 40 years – and more than half of those aged 40 to 70. Risk factors also include drinking too much, a lack of physical exercise and stress.
Added Dr Salas-Huetos: “The findings show adding walnuts, hazelnuts and almonds to a healthy western diet can improve sexual desire and orgasm quality.”
He said they back a study five years ago that found men with erectuile dysfunction had better blood flow through the penis and much firmer erections after eating up to four handfuls of pistachios a day.
Dr Salas-Hueros and colleagues called for further studies involving more participants to confirm the results and to determine how these benefits arise.
Two ounces of nuts would be equivalent to about 24 hazelnuts, 48 almonds or 56 walnuts.