Wednesday, October 17, 2007

Sperm count: More accepted "wisdom" crumbles

Men who suffer fertility problems because of low sperm quality may be able to improve their chances of fatherhood by having sex every day, research has suggested. While those trying for a baby are often told to refrain from ejaculating too often to protect their sperm count, Australian scientists have shown that this can be counterproductive and may lower male fertility.

Among men whose fertility problems stem from genetic damage to their sperm rather than a low sperm count, abstaining from sex can make their difficulties worse, research led by David Greening, of Sydney IVF, has shown. The pilot study of 42 men whose sperm showed significant DNA damage found that daily ejaculation reduced this by 12 per cent. While the results are preliminary and no direct effect on fertility has yet been measured, they suggest that certain men could benefit from having sex more often, or from abstaining less before providing semen for use in IVF.

Dr Greening, who presented his results at the American Society for Reproductive Medicine conference in Washington yesterday, said: "I'm convinced that ejaculating more frequently, ie daily, improves sperm DNA damage in most men by a decent amount. "Prior to IVF, for example, men are abstaining a lot more than normal and perhaps sperm DNA increases more than usual. Men think if they abstain for longer times before, say, ovulation that their sperm will be better. [There may be] more volume and numbers but DNA damage may increase."

Abstaining from sex does increase the number of sperm that are ejaculated, and this has led to advice that couples trying for a baby should have sex every two to three days. Longer periods of abstinence, however, achieve little because while the quantity of sperm might increase, its quality declines. As sperm is produced, it is stored in the epididymis at the top of the testicle, but the longer it sits there the more damage it accumulates from exposure to free radicals. Regular ejaculation empties this sperm reservoir, making sure that newly produced sperm of higher genetic quality can get out.

Allan Pacey, a senior lecturer in andrology at the University of Sheffield, said that clearing the reservoir was more important when sperm had high levels of genetic damage. "If you get above 30 to 40 per cent damaged DNA, a man is highly likely to be infertile," he said. "When you put people on a daily ejaculation regime, it reduces that figure for DNA damage. If you can go from 30 per cent down to 20 per cent that is quite a big shift, that should have implications for fertility. "There is a trade-off between genetic damage and quantity, so when a couple are first trying to get pregnant a wait of two to three days is probably advisable. But if you are a guy who has high DNA damage and a decent sperm count, it is probably in your interest to ejaculate every day. "I remember one couple in which the woman would only let the man ejaculate when she was in her fertile period, so the poor chap was going without for almost a month at a time. "Even leaving aside the frustration that must have caused, it would have had no benefits."


The government cannot stop us from being overweight

Yesterday the outward problem of obesity got it with both barrels at the conference of the gold-standard organisation in the field, the National Obesity Forum. The chairman of the forum argued that "levels of childhood obesity will lead to the first cut in life expectancy for 200 years. These children are likely to die before their parents." Some have called for what I suppose would become known as a Lard Czar to coordinate the fight against flab.

I have to admit that, knowing what I know (and I know quite a lot about fat), I find this debate, as it is carried out in public, intensely irritating. The campaigners for change are always on the edge of exaggeration ("worse than climate change"), so fearful are they of inaction. This gives credence to the deniers who will invariably claim that the whole idea of obesity is a scare got up by the Government so as to deprive the public of its pleasures....

Lordy, though, how we do look for the quick fix. Every year for the past decade there have been several stories in which scientists have either discovered the part of the brain, or the chemicals, responsible for our gluttony, and therefore the route to the possible magic cure, which will miraculously deprive us of our appetites and cause us to turn away the offered nibbles or pass by the cake-shop door. This summer fatties-in-denial everywhere were cheered by the suggestion from Louisiana that a virus might be changing stem cells into fat cells, thus helping to cause obesity.

All that was needed was the remedy, and I have lost count of the number of times that this or that antidepressant has been touted as an appetite suppressor, or the claim that - within a few years - a spray or a pill will be marketed to save us from ourselves. And then disappointment attends the realisation that the only tangible result from that magic fat-replacement food substitute is something distressing called "anal leakage".

Yet we know the truth, just like Alice did: if you stick in more calories than you use up, you will get fatter; if you use up more calories than you consume you will get thinner. A fatter society tends to be one where people eat more high-density calorie foodstuffs and take less exercise. And that's it folks, there is no more. No cure. No magic.

Of course, at this point it all gets complicated, because changing highly engrained and destructive patterns of behaviour is the hard part. As an educated man I allowed my weight to rise to nearly 19 stone three years ago, committing slow suicide with the aid of Lindt chocolates, until packing myself off to an American reeducation institution to be told inescapably what I should already have known.

This amazing deliberate blindness doesn't deter the easy-answers brigade. Some blame the food industry, as if they forced us to consume pizzas against our will. "It is the Government," said the Lib Dem health spokesthing, Norman Lamb, at the weekend, "that must take responsibility for failing to do enough to halt the rise of this public health crisis." Mr Lamb demanded urgent, though unspecified, action by the Government "to encourage healthier eating". Something, perhaps, like the Indian Government's sterilisation campaign of the 1970s, with forcible stomach-clamping for the recalcitrant. Nor is the answer "more school sports". One part of the solution is certainly more exercise, and that could just as well be tap-dance as rounders. In fact tap-dance would be better.

Here's a measure of the problem. The National Childhood Obesity Database, the largest database of its kind in the world, has found it difficult to garner accurate statistics because, it is thought, "heavier children" fail to turn up for weighing. Meanwhile, following Jamie Oliver's campaign on school meals, Ofsted has discovered that the numbers of children taking the improved school meals has fallen. Analyse that for a second: the meals are healthier so the kids turn away from them. Instead their parents furnish them with lunchboxes, comprising, according to Oliver, "a cold, half-eaten McDonald's, multiple packets of crisps and a can of Red Bull. We laugh and then want to cry."

It is obvious that the problem is what is going on at home. Public policy can take down the barriers to healthier living by doing something to promote, say, safe cycling and walking at the expense of the bloody all-conquering motor car. But the message about obesity and lifestyle has to be internalised, as it eventually was over cigarettes, in order to work. We are going to have to convince ourselves that overfeeding and underexercising the kids amounts to neglect.

Best of all is the power of example. I am not a model for virtue when it comes to food, and the battle - as my colleagues can attest - is continual. But when I started running in 2005 I had no idea what would happen. Two years on, out of a family of five, three of us run regularly, and a fourth is about to begin. No mystery, just one bloody foot in front of the other.



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].


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