SOYA-BASED DIET may leave a man less fertile, suggests a study, which found a link between soya-rich food and lower sperm counts. “Our
findings suggest that the greater the soya food intake is, the lower the sperm concentration, compared with men who never consume soya food,” said lead researcher Jorge Chavarro, at Harvard school of public health in Boston.
The study, which appears
in the journal Human Reproduction, found 41 million fewer sperm per millilitre of semen after just one portion every two days. It is thought that soya compounds called isoflavones, which mimic the female sex hormone oestrogen, are behind the effect. Earlier animal studies have linked a high consumption of isoflavones with infertility.
In the latest study on 99 men, who visited a fertility clinic between 2000 and 2006, the US researchers led by Chavarro at Massachusetts General hospital found that men who consumed at least half a portion of
soya food a day had the lowest sperm counts.
The “normal” sperm concentration for a man is between 80 and 120 million per millilitre, and the average of men who ate on average a portion of soya-based food every other day was 41 million fewer, the study said.
The apparent fall in sperm count is unlikely to make healthy men infertile, but some experts said it could have a significant impact on those already with lower than average sperm counts. Soya-based products are now found in two-thirds of manufactured food including biscuits, sweets, pasta and bread, according to the Institute of Food Research in Norwich.
Male fertility has been in decline in the west for several decades, with about 20 per cent of young Europeans having a low sperm count, while levels of soya have risen steadily in the western diet since the 1940s because it is a cheap source of protein, the study said.
Middle-aged men are happier than women, suggests a study, which found that the glow of adult life among females wears off with time. “In later life, men come closer to fulfilling their aspirations, are more satisfied with their family lives and financial situations, and are the happier of the two,” said Anke Plagnol, a researcher at the University of Cambridge,
The study, “Aspirations, Attainments, and Satisfaction: Life Cycle Differences Between American Women and Men”, by Plagnol and Richard Easterlin, Professor of Economics at University of Southern California, looked specifically at the role of unfulfilled desires in a person's sense of well-being.
In their study, published in the latest issue of the Journal of Happiness Studies, the researchers concluded that after the age of 48, men are generally happier than women. They found that overall happiness is most heavily linked to the stability of a person’s family and finances, the British daily said. Men are most miserable in
their 20s, but grow more satisfied as they get older, marry and earn more money, the researchers found.
Women on the other hand
are happier than men in early adulthood, but the glow wears off with time.