Wednesday, October 17, 2012

Six cups of coffee a day 'cuts risk of both womb and prostate cancer'

Here we go again.  The effects observed are too weak to support causal inferences.  And they are just correlations anyway.  Maybe richer people (who are healthier) can afford more coffee, for instance.  Or maybe they are more stressed and so need coffee more --  Or maybe lots of things

Women who drink four to six cups of coffee a day are less likely to suffer from womb cancer, while men who drink this amount are less likely to suffer prostate cancer, according to a study using 117,000 volunteers.

The effects were seen regardless of whether they drank regular or decaffeinated coffee, suggesting the effects are not linked to caffeine.

Although many people limit the amount of coffee they consume because it can cause a spike in blood pressure, recent studies suggest the drink may also offer health benefits.

Regular coffee drinkers also appear to have a lower risk of Type-2 diabetes, gallstones, colon cancer and even Parkinson’s disease.

In the latest research, a team from Harvard University looked at the drinking habits of 67,000 women whose health had been tracked for more than 20 years.

They found those who drank four or more cups a day reduced their risk of endometrial cancer by 25 per cent, compared with those who drank less than one cup a day.

A similar effect was found for decaffeinated coffee, but tea consumption had no impact. The researchers then looked at coffee intake among a group of 50,000 men over a 20-year period.

The results showed that those who drank six or more cups had an 18 per cent lower risk of suffering prostate cancer and a 60 per cent lower risk of developing its most deadly form.

One theory is that coffee may have a beneficial effect on insulin levels. Previous research has linked insulin levels with tumour growth, and coffee may help to limit this effect.

The drink can improve glucose processing and has anti-inflammatory and antioxidant effects, all of which play roles in cancer progression.

The researchers are warning against adding sugar and cream to each cup because the extra calories could offset benefits gained from the coffee.

Womb cancer is diagnosed in 8,000 women a year in the UK, while prostate cancer is diagnosed in about 40,000 men.


Cure or no cure, we’ll keep taking the tablets

Should echinacea fail against the common cold, a new 'remedy’ will not be far away

By Theodore Dalrymple

A study by the Common Cold Centre in Cardiff has found that the popular cold remedy echinacea can not only prevent colds but also shorten them once they start. If you take three daily doses for four months, your chances of catching a cold and the length of time you spend with it declines by 26 per cent, or 60 per cent if you are particularly susceptible to colds. Whether the benefit is large enough for people to take echinacea three times a day for four months is something for each person to decide: no answer is right for everyone.

Actually, these findings are not unexpected. A study from the University of Connecticut published in 2007 found that people who took a preparation of echinacea reduced the number of colds from which they suffered by 60 per cent; and if they did catch cold, the illness lasted 1.4 days fewer than if they did not take the preparation. It is only honest to point out, however, that other trials – for example, one led by a researcher from the University of Virginia in 2005 – have been negative. As is almost always the case, further research is needed.

If it turns out that echinacea really is valuable both as a prophylactic and a treatment, there will be rejoicing, not to say crowing, among enthusiasts of alternative medicine, for it will vindicate folk wisdom as a source of medical knowledge. Echinacea is extracted from a North American genus of plants of that name. Apparently, it was used by native Indians as a cure for a variety of conditions including snakebite. According to Wallace Sampson, a physician at Stanford University with an interest in alternative medicines, echinacea was first marketed for use in colds by a Swiss herbalist who had been told (mistakenly) that American Indians took it for that purpose.

In fact, several medical advances have resulted from doctors conducting experiments on folk remedies about which they had heard. William Withering discovered the use of digitalis in this way, and Edward Jenner the use of cowpox innoculation – which eventually led to the elimination of smallpox. But it is science that is required to distinguish between folk wisdom and folk superstition.

Why can’t we be immunised against colds as we can against, say, measles or yellow fever? Colds are caused by hundreds of strains of viruses, and immunity against one strain does not confer immunity against the others – which is why, according to American immunological data, elementary schoolchildren suffer from three to eight colds a year, and adults two or three.

Let us suppose for a moment that further scientific tests on echinacea show that, contrary to the hopes raised, it really does not work either to prevent or to cure colds: will that be the end of its career?

By no means. We each – man, woman and child – spend about £10 a year on cold remedies, most of which we know perfectly well will not shorten the duration of our colds (which, incidentally, are responsible for about 50 per cent of time lost at work through illness, so that colds are more economically than medically significant). But we are temperamentally incapable of saying to ourselves when ill, “There is nothing I can do about it”, and some of the remedies give us symptomatic relief, if only by making us drowsy.

About a third of people in Britain take vitamin supplements, too; we feel, in our bones rather than with our minds, that there must be a diet that will keep us healthy and free of disease. In my childhood I was given various disgusting concoctions of hot milk and honey for my colds. These days I prefer pills – provided that I can’t taste them.

The desire to take medicine, said the great 19th-century physician Sir William Osler, is what best distinguishes man from the animals. This is despite the fact that his near contemporary, Oliver Wendell Holmes, said that if the whole of the pharmacopoiea were thrown into the sea, it would be better for humanity but worse for the fish. The mere uselessness, or even harmfulness, of medicine has never prevented mankind from taking it.


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