Burgers, fries, pizza and high energy drinks impact testicular function in young men, new research suggests. Specifically, the sperm counts for men who typically eat “Western” meals of high fat foods were 25.6 million lower, on average, than the counts of men noshing on fish, chicken, fruits, vegetables and other more “prudent” foods, a new Harvard study found.
Sperm is the male reproductive cell. A man is considered to have a low sperm count if he has fewer than 15 million sperm per milliliter or less than 39 million sperm per ejaculation. A low sperm count can negatively impact a man’s ability to get a partner pregnant.
Declining sperm counts in Western nations
“Sperm count has been declining in the Western countries over the past few decades,” wrote the researchers in a presentation of their results at the 2019 annual meeting of the European Society of Human Reproduction and Embryology in Vienna on Tuesday. By one recent calculation, sperm counts of men in North America, Europe, Australia and New Zealand have plunged 59% over a nearly 40-year period ending in 2011.
Plummeting counts have coincided with poorer diet quality. How, if at all, do typical diets chosen by northern European men influence testicular function?
To find out, the researchers studied the menus and semen quality of nearly 3,000 healthy young Danish men who underwent a compulsory military-readiness medical exam between 2008 and 2017.
A “prudent” pattern of eating – characterized by lots of fish, chicken, vegetables, fruit, and water – was associated with the highest sperm counts. This was followed by “vegetarian” (veggies, soymilk and eggs) and then “smørrebrød” (cold processed meats, whole grains, mayonnaise, condiments and dairy) patterns.
The “Western” diet, including red meat, chips and other high fat foods, was linked to the lowest sperm counts. Men who ate western had sperm counts between 8.86 million and 42.3 million lower than men who ate prudently, the researchers found after adjusting for outside factors that might influence testicular function, such as smoking.
“Our findings support the growing evidence that adhering to generally healthy diet patterns, including local variations, is associated to higher sperm counts and more favorable markers of sperm function,” noted the researchers.
Both the goose and the gander
Dr. Peter N. Schlegel, a urologist at Weill Cornell Medicine, told CNN in an email that the new study “helps to solidify that dietary patterns in the father affect sperm production and quality. Indeed, some of these dietary effects are passed on to children as genetic changes referred to as ‘imprinting’,” said Schlegel, who was not involved in the new study.
Charles Lindemann, a professor emeritus and researcher at Michigan’s Oakland University who also did not participate in the research presented this week, said the new study “could be an important clue if it holds up to scrutiny.” A high processed food diet “may be responsible for the known trend that has been recorded over the recent past of progressively decreasing sperm counts,” he told CNN in an email.
“Stress is harmful and vitamin or mineral deficiencies can also reduce sperm quality,” said Lindemann. “My advice to men who contact me is that a well balanced diet which includes dairy and fresh vegetables combined with adequate sleep and exercise may improve sexual health.”
Similar advice applies equally to women concerned about fertility.
Women who eat more fast food and those who eat very little fruit take longer to get pregnant than women whose diets include several portions of fruit, according to a recent study of more than 5,500 women.
Get CNN Health's weekly newsletter
Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.
Women who made a meal of fast food four or more times a week took nearly a month longer to get pregnant than women who ate several portions of fruit a day, the Australian researchers found. Women who ate fruit less than three times a month also took longer to conceive than those who ate fruit three or more times a day.
Lindemann concluded, “There is no magic food combination to cure infertility to my knowledge.”