November 3, 2010
Men who eat foods, like burgers and fries, containing a lot of mono-unsaturated and saturated fats, may be harming their sperm.
Harvard researchers analyzed the sperm of more than 90 men attending the Massachusetts General Hospital Fertility Center in Boston.
These men answered questions about their diet and the types of fat they ate.
A number also had the levels of fatty acids in their sperm and semen measured.
They found men with the highest intake of saturated fat had 40% fewer sperm than those who ate the lowest amount.
Those with the highest intake of monounsaturated fats had 46% fewer sperm.
On the other hand, the men with the higher intake of poly-unsaturated fats produced much healthier sperm.
Saturated fat is the main dietary source of high blood cholesterol.
It can be found mostly in foods from animals such as beef, veal, lamb, milk, and cheese.
Mono-unsaturated fats are found in vegetable oils such as olive oil, canola oil, peanut oil, sunflower oil, and sesame oil.
Poly-unsaturated fats are found in fish, whole grains, and some seeds and nuts.
Study authors say the reasons for the apparent connection are not clear.
However, they acknowledged that different types of fats are treated differently in the body.