Obese men can double their sperm count
Men all throughout the globe are experiencing declining semen quality, which is commonly referred to as an outright fertility crisis.
However, there may be some good news for some of the males who are having difficulties.
Researchers from the University of Copenhagen and Hvidovre Hospital reveal in a new clinical study that men who lose weight improve their sperm quality – if they keep the weight off.
“It was surprising to us that such a big improvement can be shown in the semen quality in connection with a weight loss. And as 18 percent of Danes have obesity, this new knowledge may actually make a difference,” says Professor Signe Torekov who headed the study together with Professor Romain Barres at the Novo Nordisk Foundation Center for Basic Metabolic Research.
The new results may be excellent news for fertility since a correlation between increased sperm count and faster pregnancy attainment has already been shown.
The study was published in the prestigious journal Human Reproduction, which is highly ranked in the area of fertility research. A total of 56 obese males aged 18-65 years with a BMI between 32 and 43 took part in the study.
Sustained weight loss is necessary
Signe Torekov explains that it has long been known that obesity is associated with reduced semen quality. Previous studies have also suggested a link between weight loss and increased semen quality, but these studies have had so few participants or such modest weight loss that it has been difficult to draw conclusions from them, she explains.
“But now we are ready to do just that. This is the first long-term randomized study, where we have shown that semen quality in men with obesity improves with a sustained weight loss,” says Signe Torekov at the Department of Biomedical Sciences.
“The men lost an average of 16.5 kg which increased the sperm concentration by 50 percent and the sperm count by 40 percent eight weeks after the weight loss. During the 52 weeks, the trial lasted following the weight loss, the men maintained the improved semen quality. But only the men who maintained the weight loss: after a year, these men had twice as many sperm cells as before their weight loss. The men who regained weight lost the improvements in semen quality,” she explains.
Part of a larger study
The study is a sub-study of a major publication on weight loss, which was published in the New England Journal of Medicine in May 2021. A total of 215 Danes with obesity participated in the larger study. It was among these participants that 56 of the men also provided semen samples to investigate whether semen quality and weight loss could be related.
In the trial, all participants first followed an eight-week regimen with a low-calorie diet, resulting in weight loss. Then the participants were randomly divided into four groups.
Two of the groups received placebo medication, while the other two groups received obesity medication. Among the two placebo groups, one group had to follow an exercise program where each week, they had to do a minimum of 150 minutes of moderate physical training or 75 minutes of hard training – or a combination.
The other group did not change their usual level of physical activity. The two groups that received obesity medication were divided in the same way, into a group with and a group without an exercise program.
After a year, it was shown that the group that only exercised and did not receive medication, as well as the group that only received obesity medication and did not exercise, maintained a weight loss of 13 kg. The group that both received obesity medication and exercised lost additional weight and improved health. The placebo group – those who thought they were given medication but did not exercise – had regained half of the weight loss with aggravation of many of the risk factors related to the development of type 2 diabetes and cardiovascular disease.
Reference: “Sperm count is increased by diet-induced weight loss and maintained by exercise or GLP-1 analogue treatment: a randomized controlled trial” by Emil Andersen, Christian R Juhl, Emma T Kjøller, Julie R Lundgren, Charlotte Janus, Yasmin Dehestani, Marte Saupstad, Lars R Ingerslev, Olivia M Duun, Simon B K Jensen, Jens J Holst, Bente M Stallknecht, Sten Madsbad, Signe S Torekov and Romain Barrès, 17 May 2022, Human Reproduction.