NEW YORK • Young men who adopt a heart-healthy diet may have better-quality sperm than their peers who dine mostly on junk food, a study suggests.
The American Heart Association recommends the Dietary Approaches to Stop Hypertension (Dash) diet or a Mediterranean-style diet to help prevent cardiovascular disease.
Both diets emphasise cooking with vegetable oils, eating nuts, fruit, vegetables, low-fat dairy products, wholegrains, fish and poultry, and limiting red meat and added sugar and salt.
In the study of 209 male college students, aged 18 to 23, those who most closely followed a Dash diet had total sperm counts 65 per cent higher than those who did not.
Eating patterns that stuck more closely to a Dash diet were also associated with a 74 per cent higher total motile sperm count, a measure of the amount of moving sperm, and 31 per cent more sperm with a normal size and shape, which are the sperm most likely to fertilise an egg.
"Even in young, healthy men with overall good semen quality, we still see an association between a healthier diet and better semen quality," said Ms Audrey Gaskins, a researcher at the Rollins School of Public Health in Emory University in Atlanta.
"Young men are not invincible to the consequences of a poor diet," she added.
For the study, Ms Ana Cutillas-Tolin of the University of Murcia School of Medicine in Spain and her colleagues used food questionnaires to see how much the participants consumed of the main foods that make up heart-healthy diets.
They also examined how often the students ate foods that are known to help minimise the risk of common chronic diseases.
Men who most closely followed a Dash diet consumed more total calories and alcohol and got more exercise than men who did not follow this diet.
Eating habits did not appear to impact reproductive hormone levels, however, the researchers note in the journal Human Reproduction.
The study, however, cannot prove whether or how diet impacts semen quality in young men.
Beyond its small size, another limitation of the study is that researchers relied on men to accurately report their eating habits.
"The findings of this study cannot be generalised due to various limitations such as small sample size and healthy volunteers, and the study should be extended to other populations," said Dr Muhammad Imran Omar, a researcher at the University of Aberdeen in Britain, who was not involved in the study.
"However, there is enough scientific evidence to suggest that fruit, vegetables and low-fat dairy foods are important for a healthy lifestyle and reproductive health," he added.
"In addition, people should be encouraged to get regular exercise and avoid smoking and excessive drinking."