The chances of a successful in-vitro fertilisation increase if men have a diet high in fruit and grains, and low in red meat, alcohol and coffee, a Brazilian study on the male sperm said.
While female reproductive problems have been linked to body weight as well as smoking and drinking, it hasn't been clear before now if the same applies to men during IVF treatment.
"The sperm concentration was negatively influenced by body mass index (BMI) and alcohol consumption, and was positively influenced by cereal consumption and the number of meals per day," wrote Edson Borges, from the Fertility-Assisted Fertilization Center in Sao Paolo in the Fertility and Sterility journal.
"The sperm motility was also negatively influenced by BMI, alcohol consumption and smoking habit, whereas it was positively influenced by the consumption of fruits and cereals."
BMI, or body mass index, is a measure of weight against height.
The study involved 250 men who, with their partners, were undergoing a type of fertility treatment called intracytoplasmic sperm injection (ICSI) at one center. Researchers asked the men how often they ate a range of foods, including fruits and vegetables, beans, grains, meat and fish, as well as how much they drank and smoked.
They also got semen samples from the men to analyze how healthy and well concentrated their sperm were, and kept track of how every step of the IVF process went for each couple.
Eggs were successfully fertilized in about three-quarters of the treatments, and just under four in ten women got pregnant during the study.
From the speed of their sperm to their partner's chance of pregnancy, men who imbibed and ate poorly were slowed down on the fertility front, researchers found.
Being overweight and drinking alcohol were linked to lower sperm concentration and motility, or how well sperm swam, while smoking was tied only to negative effects on motility. Alcohol and coffee were both linked to a lower chance of fertilization.
In addition, embryo implantation rates and pregnancy rates were significantly lower when men ate a lot of red meat.
On the other hand, eating more cereal grains -- such as wheat, oats or barley -- was associated with improved sperm concentration and motility. Fruit was linked to a speed and agility boost in sperm.
"We talk about having a healthy lifestyle and trying to eliminate any of these things that are bad for health, but I think most of the emphasis tends to be on making sure the woman is as healthy as possible," said Lynn Westphal, a women's health and fertility specialist at Stanford University Medical Center in Palo Alto, California.
"I think this is really interesting data that lifestyle factors for men, even when you're doing ICSI, are significant. This is probably more of a difference than most people would have thought."
The findings are consistent with the idea that certain vitamins, minerals and amino acids may help maintain or improve semen quality, while too much alcohol and certain hormones in processed meat could be harmful to sperm, Borges wrote.
In couples undergoing fertility treatment, both men and women should know that their diets and lifestyles may affect their chance of having a successful pregnancy, he added. SOURCE: bit.ly/vJVFYj
(Reporting from New York by Genevra Pittman; editing by Elaine Lies)