Male diet associated with fertility and sperm quality

The study of 99 men in the USA suggests that diet – in particular the amount and type of different fats that men consume – could be associated with semen quality. However, the researchers, led by Professor Jill Attaman of Harvard Medical School, warned that the current results come from a small study, and therefore such findings need to be replicated by further research in order to be sure about the role of dietary fat in male fertility.

Writing in the journal Human Reproduction​, Attaman and her team reported an association between a high total fat intake and lower total sperm count and concentration. The research also found that men who consumed higher levels of omega-3 polyunsaturated fats (PUFA’s) had better formed sperm than those who ate less.

“If men make changes to their diets so as to reduce the amount of saturated fat they eat and increase their omega-3 intake, then this may not only improve their general health, but could improve their reproductive health too,”​ said Attaman.

“At a global level, adopting these lifestyle modifications may improve general health, as high saturated fat diets are known to be a risk factor for a range of cardiovascular diseases; but, in addition, our research suggests that it could be beneficial for reproductive health worldwide,”​ she confirmed.

Fat and fertility​

Attaman said a number of previous research studies have investigated a potential link between body mass index (BMI) and semen quality – with mixed results.

However, she noted that little is known about a potential role of dietary fats and semen quality – and so she and her colleagues set out to investigate how diet affected fertility in men attending a fertility clinic.

The team questioned 99 men about their diet in addition to analysing samples of their semen. Levels of fatty acids in sperm and seminal plasma were also measured in 23 of the 99 men taking part.

Research findings​

Attaman explained that the men were divided into three groups, according to the amount of fats they consumed.

Those in the third with the highest fat intake had a 43% lower total sperm count and 38% lower sperm concentration than men in the third with the lowest fat intake.

The researchers said that the relationship between dietary fats and semen quality was largely driven by the consumption of saturated fats. Men consuming the most saturated fats had a 35% lower total sperm count than men eating the least, and a 38% lower sperm concentration.

“The magnitude of the association is quite dramatic and provides further support for the health efforts to limit consumption of saturated fat given their relation with other health outcomes such as cardiovascular disease,”​ said Attaman.

Meanwhile, men consuming the most omega-3 fats had slightly more sperm (1.9%) that were correctly formed than men in the third that had the lowest omega-3 intake.

“To our knowledge, this is the largest study to date examining the influence of specific dietary fats on male fertility,”​ said the researchers.

However, they concluded that several limitations in the study – in particular the fact that it was a cross-sectional analysis – mean that it is essential to for future research to confirm the findings.