Move over red roses. If you’re nuts about someone, why not say it with… nuts? If you’re a couple trying for a baby, then even more reason to do so; a new study[i] shows that almonds, along with other tree nuts, may help support male fertility and in turn the 3.5 million British couples facing infertility[ii]. The researchers found that eating 60 grams (about two portions) of nuts daily – including almonds – significantly improves the total sperm count and the vitality, motility and morphology (size and shape) of the sperm.
This recent study – with a combination of almonds (15g), hazelnuts (15g) and walnuts (30g) – showed similar sperm quality results as previous walnuts-only research[iii] demonstrated, but additionally increased sperm count by 16%. So, it seems that a mix of nuts may be key. Further, almonds are rich in zinc, which contributes to normal fertility and reproduction.
Previous research on infertility has suggested that poor eating habits, among other unhealthy behaviours and environmental factors, may be a contributor to declining sperm counts and sperm quality in industrialised countries. The new FERTINUTS study, was first presented at the 2018 European Society for Human Reproduction and Embryology meeting.
This study was funded by the International Nut and Dried Fruit Council (INC) who have created a short informative video explaining the results, highlighting the fact that fertility is an issue that affecting about 1 in 7 couples worldwide, with male factors responsible for 40-50% of these cases[iv].
This study builds on a previous finding on walnuts alone (75g/day for 12 weeks) that found improvements in sperm vitality, motility and morphology, but not in total sperm count. The addition of almonds and hazelnuts to the study diet resulted in improvements in the same measures of quality, but increased sperm count as an added benefit. The researchers note that this current study agrees with the results from the walnuts-only study and “extends the seminal improvements obtained from eating walnuts to other types of nuts.”
Consultant Dietitian Juliette Kellow comments: “Having a healthy diet is an important, but often-overlooked piece of the fertility puzzle. This study shows that adding tree nuts like almonds offers a potentially easy way to boost male fertility and may help support couples trying to conceive.”
In this 14-week randomized controlled parallel trial, researchers from the Universitat Rovira i Virgili in Spain split 119 healthy males between the ages of 18 and 35 into two groups. One group was asked to eat nuts – a combination of 15 grams of almonds, 15 grams of hazelnuts and 30 grams of walnuts per day – in addition to their regular Western-style diet. Those in the second group ate their same Western-style diet but avoided all nuts. Sperm and blood samples were collected from participants in both groups at the end of the study.
The nut group saw improvements as follows:
- 16% higher sperm count
- 6% improvement in sperm motility (sperm cells’ ability to swim)
- 4% higher sperm vitality (the amount of live, healthy sperm cells found in semen)
- 1% improvement in sperm morphology (which refers to the sperm cells’ normal healthy size and shape)
Importantly, those in the nut-eating group also had less sperm DNA fragmentation, showing that genetic integrity was better preserved in the sperm of nut-eaters. (When sperm DNA is too fragmented, fertility declines or miscarriage risk is higher.)
The researchers suggest that the nutritional makeup of the nuts in this study could improve specific seminal parameters including antioxidant vitamin E, omega-3 and omega-6 fatty acids, and folate. Almonds are high in zinc, which contributes to normal fertility and reproduction. The inclusion of nuts in a Western-style diet significantly improves the total sperm count and the vitality, motility, and morphology of the sperm. These findings could be partly explained by a reduction in the sperm DNA fragmentation.
- Results cannot be extrapolated to the general population since this trial focused on healthy and apparently fertile men.
- The effect on sperm parameters was seen with an intake of 60 grams of nuts daily. It is unknown whether
- larger or smaller amounts of nuts would have a different effect on sperm parameters.
- Study participants ate a Western diet but in a Mediterranean area (Spain), so the diet could differ from that followed in other countries and impact results.
- The sample size of this study may not be sufficient to determine other possible mechanisms that might explain results at the molecular level.
- More than 10% of study participants dropped out from the initial number recruited for the study, so there is a risk of bias.