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Forget tight pants and pollution, it's smoking that harms the chances of fit sperm.
The most recent research on male fertility comes from one of the most macho areas of the UK. A 2004 study by the Aberdeen Fertility Centre based on 16,000 semen samples taken from 7,500 Scottish men showed that between 1989 and 2002, Scottish sperm counts had plummeted by a huge 29 per cent. When the study began, the average normal sperm count from the men on the program was 87 million sperm per millilitre.
Thirteen years later, that had dropped by nearly a third, to 62 million sperm per millilitre. In their efforts to determine whether this dramatic decline related specifically to Scotland, everything from the local penchant for deep fried Mars Bars to the impact of acid rain after the Chernobyll disaster was scrutinised under a microscope. To date, there have been no conclusions drawn, but when there are any, one thing is for sure. They will have enormous global significance.
The Scottish research follows on from a Danish study published in the British Medical Journal in 1992 that suggested male sperm counts were falling by about 1 per cent a year worldwide. Three years later a study of 1,300 fertile French semen donors, published in the New England Journal of Medicine, indicated that sperm counts had been falling by an average of 2 per cent every year for the previous two decades.
Infertility affects more than one in seven couples attempting to get pregnant, and although women normally feel the burden of responsibility for this, male problems contribute to around 40 per cent of cases and in 15 per cent of cases, a couple’s inability to conceive will be solely down to the man.
The most common causes of male infertility are obstructions in the tubes carrying sperm or testicular injury. It can also be caused by sperm disorders, genetic irregularities, hormonal problems, erectile dysfunction, disease, ill health and as a side effect of medication. Needless to say, the usual suspects, poor diet, smoking, drinking alcohol and using recreational drugs play a part too.
Men, and women, are notoriously unwilling to take personal responsibility for the impact these lifestyle choices have on their health. In fact, ask any group of men or women why they think global male sperm counts might be declining and they won’t hesitate to tell you that estrogen in the water is turning fish into women and men into Pete Burns.
There is certainly plenty of evidence to support the theory that the industrial chemicals with unpronounceable names that are used in plastics, paints, detergents and pesticides can, and indeed do, disrupt normal hormonal functions. And it is probably no coincidence that Finland, a country with minimal agriculture has, until now, had the highest fertility rates in Europe.
However, agricultural pesticides such as DDT have been banned or restricted for two decades in the developed world and unless the hazard from any of these is occupational, it is unlikely that the average bloke would be exposed to any of them in large enough quantities to make them a cause for general concern.
Though society certainly needs to maintain the pressure on governments and industry to minimise the potential long-term damage that chemicals and pollutants have on us and our environment, men and women who want to maximise their immediate fertility are probably better off focusing on the things they can actually change personally. Such as smoking.
Last year a British Medical Association study showed that smoking caused impotence in men, reduced the chances of women conceiving by 40 per cent and was responsible for 5,000 miscarriages a year, while a Scandinavian study published in the American Journal of Epidemiology found lower sperm counts and smaller testes among men whose mothers smoked during pregnancy. And smokers who manage to impregnate their partners put their babies at an increased risk of childhood leukemia and sudden infant death syndrome. In fact, 80 per cent of all sudden infant deaths occur in families where one or both parents smoke.
Cutting down on alcohol and cutting out recreational drugs should be a no-brainer for anyone trying to have a baby, but maintaining a healthy body weight appears to be just as important. It is clearly not the root cause of declining fertility levels, because sperm counts are dropping twice as fast in Europe as they are in the US, but countless studies have proven a direct correlation between obesity and a lower sperm count.
Since Scotland has one of the worst diets in the western world (a Scottish health survey from 1998 shows that 62 per cent of Scottish men are either overweight or obese), it is probably no coincidence that the results of the Aberdeen fertility study were so poor. If the chips are down for the overweight, obese men who keep their mobiles in their pockets have no hope of breeding at all. In research that may have grave implication for the potent Finns (Nokia is Finland’s largest employer), Hungarian studies have shown that men who kept their phone handsets on standby in their trousers produced a third less live sperm than other men.
There is some good news though. A major survey carried out by experts at Imperial College London shows that despite declining male fertility, the average time it takes for a couple wanting a child to conceive has actually decreased. Between 1961 and 1965, 65 per cent of couples managed to conceive within six months, but between 1991 and 1993, this figure had risen to 72 per cent. Though this improvement probably only reflects greater awareness of the window of opportunity during which pregnancy can occur.
For a man to increase his chance of creating a heir, the best option is to crush their cigarette habit.
