Red meat has almost certainly featured in the human diet for a large portion of our evolution, and its primal nature is one reason why I believe it can assume some place in a 'healthy' diet today. Yet I am well aware that red meat is viewed as unhealthy fare. One common warning concerns its supposed ability to cause cancer in the colon. Earlier this year, the British Medical Journal (BMJ) reported on a study that it claimed 'confirmed' the link between red meat and colon cancer. Such reports give the impression that those who eat red meat are like lambs to the slaughter.
The study, published in the Journal of the American Medical Association, assessed the relationship between diet and cancers of the colon and rectum (the last part of the colon) in 150,000 individuals. Consumption of processed meat (such as bacon, sausage, hot dogs, ham and salami) and red meat was assessed in 1982 and then in 1992/93; participants were followed until 2001. High red-meat consumption as assessed in just 1992/93 (shorter term) or in 1982 and 1992/93 (longer term) was not associated with an increased risk of colon cancer. However, high consumption of red meat in the shorter term was associated with a significant increased risk of cancer of the rectum. Curiously, this effect seemed to wane, with longer-term consumption only 'marginally associated' with rectal-cancer risk. This rather unconvincing link was not strengthened by the fact that higher intakes of processed meat did not seem to increase rectal-cancer risk. Yet high-processed meat consumption in the longer term was associated with a somewhat increased risk of colon cancer.
It is worthwhile viewing these findings in the context of the wider evidence: a review in the European Journal of Clinical Nutrition found that of 44 relevant studies, 31 found no apparent association between red-meat intake and colon-cancer risk. Despite the assertion of the BMJ, it is clear that the link between red meat and colon cancer is anything but 'confirmed'.
Those wishing to eat red meat might do well to avoid processed meats that are more likely to be laced with carcinogenic chemicals. Some evidence comes from a study published in the International Journal of Cancer in 2002 which found that processed meat has more cancer-causing potential in the colon than red meat. To further avoid disease-making substances, opt for organic meat. While my appetite for occasional quality red meat remains undiminished, I suggest that de-emphasising processed and non-organic meats is a good strategy for those wishing to save their bacon.
Dear John
I was recently sailing on the Irish Sea. I became very seasick and, as a result, hypothermic and dehydrated. Could you give me some advice on how to deal with this problem in the future?
RGS Hankin
Certain natural remedies may help reduce or prevent the nausea and sickness that is characteristic of travel- or seasickness. Perhaps the most widely used is ginger. It is said that the ancient Chinese mariners would ward off seasickness by keeping a slice of fresh root ginger between their cheek and gum. You may find it more convenient to take it in capsule or tablet form (available from health-food stores). It seems that ginger is most effective taken prior to any sickness setting in. Take 1g four hours before travel, and again half an hour before setting sail. On long journeys, you may go on to take more ginger at a dose of 500mg, three times a day. As a back-up measure, you might want to invest in the elasticated wristbands designed for reducing the risk of sickness (available in pharmacies). These contain a plastic bead to stimulate the acupressure point in the wrist that controls nausea.
Nutrition news
Insulin, the chief hormone responsible for tempering blood-sugar levels, is essential to life. However, in excess, insulin may predispose to a number of health issues including weight gain, heart disease and diabetes. Evidence in recent years suggests that excesses of insulin may also increase the risk of certain cancers, perhaps through its ability to stimulate the proliferation of the body's cells. In a study published in the International Journal of Cancer, the link between the overall glycaemic index (GI) of the diet (which gives a broad guide to the tendency of the diet to induce insulin secretion) and breast-cancer risk was assessed in a group of about 1,500 women over an average of 16 years. The glycaemic index of the diet appeared to have no bearing on breast-cancer risk prior to the menopause. However, after menopause, compared to those eating the lowest-GI diets, the women eating the highest-GI diets were found to have an 87 per cent increased risk of breast cancer. This study adds further weight to the notion that eating a diet low in relatively high-GI foods (including sugar-sweetened foods and most breads, pasta, white rice, breakfast cereals and potato) may help to reduce the risk of cancer in time.
· If you have any issues you would like Dr Briffa to address in his column, please email him on john.briffa@observer.co.uk. Please note that Dr Briffa cannot enter into any correspondence. You can also visit www.drbriffa.com.Before following any recommendations in this column, you should consult your own medical adviser about any medical problems or special health conditions
