Tuesday, 15 January 2013

High-fat diet could reduce sperm count – Study


A new study carried out by Danish researchers has shown that eating high-fat diet can reduce a man’s sperm count by up to 40 per cent.
The study published in www.righospitalet.com found out that, in the sample studied, people who ate the most saturated fat had significantly lower sperm counts and poorer quality sperm than those who consumed the least.
The finding comes amid concerns that quantity and quality of sperm appears to be declining in Western countries, with some studies showing average sperm counts have fallen by more than half over the past 60 years.
Also, the researchers say that estimates suggest around 30 per cent of men in couples seeking IVF treatment are what is called sub-fertile while 2 per cent are ‘totally’ infertile.
In the study, a team from Rigshospitalet in Copenhagen, Denmark surveyed and examined 701 young Danish men who were about 20 years old and getting checkups for the military between 2008 and 2010.
They were asked about the food they ate over the prior three months, and then asked for a semen sample. The men who ate the most saturated fats had a 38 per cent lower concentration of sperm (45 million sperm per millilitre) and 41 per cent lower sperm counts (128 million) in their semen than those who ate the least fat.
Those eating the least fat had an average sperm concentration of 50 million per millilitre of semen and a total sperm count of about 163 million.
Study author, Tina Jensen, said, “We cannot say that it has a causal effect, but I think other studies have shown that saturated fat intake has shown a connection to other problems and now also for sperm count.”
Significantly, the participants were not seeking fertility treatment, unlike previous studies looking at diet and fertility.
Although the study cannot determine whether other lifestyle factors might account for the link, Jensen said her team’s findings may partially explain studies that have found sperm counts decreasing around the world.
“I think obesity is another cause, but (saturated fats) could also be a possible explanation,” she said.
Last year, French researchers reported that the number of sperm in one millilitre of the average 35-year-old Frenchman’s semen fell from about 74 million in 1989 to about 50 million in 2005.
Jensen said that the next step is to find the mechanism by which saturated fat could influence sperm count, and then to see whether counts improve when men cut down on saturated fat in their diets.
This new research is not the first to connect diet and other lifestyle factors to sperm production and quality.
In 2011, Brazilian researchers found eating more grains – such as wheat, oats or barley – was associated with improved sperm concentration and motility, while fruit was also linked to a speed and agility boost in sperm.
But this study, among many others, only looked at these associations using data on men seeking fertility treatments, which may not be representative of all men.
Saturated fats are found in butter, processed meats, fried foods and other junk food containing hydrogenated oils. Too much saturated fat has also been proven to increase the amount of cholesterol in the blood, increasing the risk of heart disease.
According to the World Health Organisation, anything above 15 million sperm per millilitre of semen is normal. In the study, 13 per cent of men in the lowest-fat group and 18 per cent of men in the highest-fat group fell below that level.
Various researchers note that 40 years ago, fertility problems were almost unheard of. But today, it is so widespread that if fertility rates continue to drop at the current rate, the world’s fertility will fall below the global replacement rate in the next 10 to 40 years.
Although much of the blame is placed on women, various studies now show that more than half of all cases of infertility may be related to male factors. A Danish study in the British Medical Journal Open in 2012, shows that just one in four men has optimal semen quality.
By some estimates, sperm counts around the world may have dropped by 5o per cent since the 1930s. While no one knows the reason behind this disturbing decline, it is clear that some of the factors that plague the modern world in general are at least partly to blame. For example, research shows toxic chemicals that act as endocrine disrupters, such as insecticides, flame retardants and phthalates from plastics affect hormones responsible for sperm production while excessive oxidant stress can damage DNA and impair sperm function. Obesity is an additional factor.
Despite the alarming increase in male infertility, the good news is that in many cases it is completely reversible. Numerous studies demonstrate that certain nutrients can directly affect sperm quality — and can ultimately result in improved pregnancy rates.
Between 1989 and 2005, average sperm counts fell by a third in a study of 26,000 men, increasing their risk of infertility. The amount of healthy sperm was also reduced, by a similar proportion.
The latest research was conducted in France but British experts say it has global implications. The scientists said the results constituted a “serious public health warning” and that the link with the environment “particularly needs to be determined.”
The findings confirm research over the past 20 years that has shown sperm counts declining in many countries across the world. Reasons ranging from tight underwear to toxins in the environment have also been advanced to explain the fall, but still no definitive cause has been found.
The decline occurred progressively throughout the 17-year period, suggesting that it could be continuing.
The worldwide fall in sperm counts has been accompanied by a rise in testicular cancer rates, which have doubled in the last 30 years and in other male sexual disorders such as un-descended testes, which are indicative of a “worrying pattern”, scientists say.
There is an urgent need to establish the causes so measures can be taken to prevent further damage, they add.
Punch Nigeria

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