Skimmed milk linked to prostate cancer

Low-fat milk is better for you than the full fat version. Everyone knows that. But everyone, it seems, is wrong. Low-fat milk may be linked with, amongst other health problems, prostate cancer.

Yes, these are interesting times for those who believe that meddling with nature has unpredictable consequences. We've heard campaigners argue this time and again in the debate on genetically-modified food. And now they can point to good old-fashioned skimmed milk, one of our most popular dairy products and a low-fat marketing triumph, to support their argument.

This year two major studies supporting the established link between high consumption of 'diary products' and prostate cancer are to be published. As a result we'll probably assume that cutting down on dairy or switching to low-fat is the best way to reduce the risk. But is that right? 'Dairy products' is a vague description; what researchers are really talking about is milk — our major source of dairy.

For the real story we need to go back two years. (And if you're wondering why you haven't read this before on malehealth, you're not alone. So am I.) In 2005 a major US study following 3,600 men over 10 years reported that those who ate or drank a lot of dairy were twice as likely to develop prostate cancer as those who ate or drank less. So far, so familiar. But the 2005 study went into a bit more detail. It found that the risk depended on what sort of milk the men drank. The risk was only higher with low-fat milk not whole milk. Prostate cancer: an unpredictable consequence of meddling with milk if ever there was one.

Detective work by Joanna Evans of the magazine What Doctors Don't Tell You has discovered that this was not the only study to suggest this link. She cites studies of 20,000 American men published in 2001 and of 25,000 Norwegian men published in 1997.

So why haven't we heard about this before? After all, the 2005 research, published in the American Journal of Clinical Nutrition, was not just your everyday academic study but part of a major long-term follow-up study in the US called the NHEFS.

Part of the answer is that we can't yet explain exactly why skimmed milk might increase cancer risk. The authors of the 2005 study speculated that 'removal of fat from milk may remove other components with potentially cancer-protective properties, such as conjugated linoleic acid.' It is also suggested that the fat in milk is there for a reason, namely to helps the body absorb the milk's calcium and Vitamin D; improperly absorbed calcium can, as Evans puts it, be 'toxic'.

But perhaps the real problem is that this research challenges both received public health wisdom that fat is bad and received food industry wisdom that natural food can be modified to make it healthier.

Whatever the explanation the finding may go some way towards explaining the higher levels of prostate cancer among richer men. Traditionally put down to stress, the difference may actually reflect the higher consumption of skimmed and low-fat milk among better-off families.

Evans's archive research has also linked skimmed milk with ovarian cancer, infertility and acne. One commentator has even argued that it is worse for the heart than the full-fat version because all the B vitamins have been stripped out.

If you're concluding that full-fat milk might be a better bet than skimmed, you might be right. But don't guzzle too much. All processed milk contains added hormones and antibiotics. The pasteurisation process also eliminates beneficial bacteria, vitamins and proteins.

The rule of thumb for milk therefore appears to be no different than for other foods: the least processed, freshest version is, if used properly, usually best. That's why, in the USA at least, they are witnessing something similar to our Campaign for Real Ale with a Campaign for Real - or raw — Milk.

Despite attempts to make it illegal, some 200 producers sell raw milk in the UK. You can find some of them here. (Health warning: Make sure you know what you're buying and how to keep it properly.)