Higher dairy intake lowers semen quality – Harvard study

A team of scientists at the Harvard School of Public Health in Boston, Massachusetts conducted a study involving nearly 200 young men, which examined the association between dairy intake and semen quality.

They discovered that men who eat even three portions of cheese a day had poorer quality sperm than those with a lower daily intake of full-fat dairy products.

Harvard researcher Myriam Afeiche, who led the study, told DairyReporter.com that the sperm produced by men that consumed between 1.3 and 7.5 servings of dairy per day was of less quality than those with a lower dietary intake of dairy products.

The study defined a serving of full-fat dairy as ounce of cheese, a teaspoon of cream, a scoop of ice cream or a glass of full-fat milk.

Semen quality​

“We examined whether dairy food intake was associated with semen quality,”​ said Afeiche.

Afeiche and her team examined the association between dairy intake and semen quality by comparing the diets of 189 young men from the Rochester Young Men’s Study.

“Men aged 18-22 were recruited for the Rochester Young Men’s Study in 2009-2010. The relationship between dairy intake and semen quality parameters was evaluated using linear regression models.”​

The Harvard School of Public Health team found that the percentage of men with morphologically normal sperm decreased as the daily intake of full-fat dairy products such as milk, cheese and cream increased.

“We found that men with the highest intakes of full-fat dairy (1.3 to 7.5 servings per day) had 2.7% lower morphologically normal sperm compared to men with the lowest intakes (0 to 1.2 servings per day),” ​Afeiche said.

Health recommendations​

The team’s findings were presented at the American Society for Reproductive Medicine’s (ASRM) annual conference in California earlier this month.

Afeiche added, however, that further research would be vital before any health recommendations could be made.

“While we know that some semen quality parameters relate to the probability of conception, we did not directly assess whether the observed differences in semen quality had any influence in fertility. Moreover, since the data on this topic is very limited, it is important that further studies address this question before making any recommendations to men looking to conceive,” ​she said.