14/03/2012 09:55 GMT | Updated 14/03/2012 14:04 GMT

Junk Food ‘Lowers Sperm Count And Quality'

Men who love eating junk food could be slowly killing their sperm count with every bite, research has revealed.

A study by Harvard Medical School, Boston, discovered that men with a diet high in saturated fats produce significantly less sperm (and weaker quality sperm) than men who ate a healthy, balanced diet.

Researchers studied results from men attending a US fertility clinic who were questioned about their diet and fat intake.

They discovered that junk food not only carries other health risks like heart disease, obesity and cholesterol, but it destroys sperm count and quality.

Men who regularly ate junk food had a 43% lower sperm count and 38% lower sperm concentration (this the number of sperm per unit volume of semen) compared to men who ate healthy.

During the study, researchers discovered that a diet rich in omega-3 fatty acids are best at boosting sperm quality, as men who ate lot’s of fish and plant-based oils had 1.9% more correctly formed sperm than men with lower levels of omega-3 in their diet.

Foods rich in omega-3 fatty acids include oily fish (sardines, tuna, mackerel, salmon), flax seeds, tofu and leafy greens (kale, spinach, collard).

Researcher, Professor Jill Attaman said as reported by the Press Association: "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."

This study follows a previous study that linked infertility to a junk food diet in men.

According to the World Health Organisation (WHO), a healthy sperm count is considered to be at least 20m per ml and at least 75% of the sperm should be alive in the ejaculate. Around 30% should be of normal shape and form.

Researchers added that the sperm count of participants in the study varied between 39m per ml to 15m per ml.

Dr Allan Pacey from the University of Sheffield told the Press Association: "This is a relatively small study showing an association between dietary intake of saturated fats and semen quality. Perhaps unsurprisingly there appeared to be a reasonable association between the two, with men who ate the highest levels of saturated fats having the lowest sperm counts and those eating the most omega-3 polyunsaturated fats having the highest.

"Importantly, the study does not show that one causes the other and further work needs to be carried out to clarify this. But it does add weight to the argument that having a good healthy diet may benefit male fertility as well as being good general health advice."

Fertility expert Emma Cannon told HuffPost Lifestyle: "A good diet is the building blocks for good fertility in both men and women. This research, although small, is important as it encourages men as well as women to improve their general health prior to conceiving.

“In most relationships it is the woman who drives the healthy eating campaign and sometimes it is difficult to persuade their partners to improve their eating and drinking habits. I see women needlessly go through IVF because of poor semen quality, so anything that demonstrates that changing bad habits improves sperm is a good thing.”

It’s estimated that around 20% of young men suffer from poor quality semen and of the couples who opt for IVF, 30 to 50% have male-related fertility problems.

Other lifestyle factors that kill sperm:


Being overweight and having a high BMI can increase the temperature of the testicles through the formation of fat deposits in the groin area. It also increases the level of oestrogen circulating in the body, which affects sperm count.


A heavy drinking session will temporarily reduce your sperm count but regular heavy drinking damages the tubes that carry semen and increases the number of abnormal sperm cells.


Tobacco smoke contains chemicals that weaken sperm function and deplete the antioxidants, especially vitamin C, that neutralise the damaging free radicals.

Zinc deficiency

Zinc is an essential nutrient for proper sperm production. A deficiency may result in lowered testosterone levels.

Sexually transmitted diseases

Conditions like chlamydia can lead to epididymitis, which can cause obstruction of the sperm ductal system, which can affect fertility.

Fertility-Boosting Foods