06/22/2001 - Updated 05:18 PM ET
LYON, France (June 23) - Eating lots of preserved meats such as salami, bacon, cured ham and hot dogs could increase the risk of bowel cancer by 50 percent, early results of a major new study have suggested.
However, when it came to fresh red meat - beef, lamb, pork and veal - there seemed to be no link.
Previous studies have linked high meat intake to colorectal cancer, but almost all the studies grouped fresh and processed meats together.
The latest findings come from an ongoing study experts say is the most reliable research into the influence of diet on cancer to date - an investigation involving almost half a million people, from southern Greece to northern Norway. However, that does not mean red meat has been cleared of suspicion, said Dr. Arthur Schatzkin, chief of nutritional epidemiology at the U.S. National Cancer Institute.
``These results are very preliminary,'' said Schatzkin, who was not involved in the study. ``There's more narrowing down that has to be done before we can draw any conclusions.''
The study, presented Friday in Lyon at the European Conference on Nutrition and Cancer, is being coordinated by the World Health Organization's International Agency for Research on Cancer.
Experts say the findings show the issue is more complex than previously thought, and that it's not as simple as meat being either cancer-promoting or not. Scientists are learning that factors such as cooking methods and duration, and cuts of meat must also be considered.
Some research has suggested that frying or barbecuing may add cancer-promoting chemicals to meat and that a crispy lamb chop or a well-done steak may contain undesirable compounds.
``This points us in the direction we need to go. The only firm conclusion is that lumping fresh and processed meat together is inappropriate,'' said Martin Wiseman, a professor at the Institute of Human Nutrition in Southampton, England, who was not involved with the research.
``But now, what about hamburgers? Are they processed or fresh meat? And meatballs? Where do they fit in? We are just starting to disentangle all this,'' Wiseman said.
The study's coordinator, Dr. Elio Riboli, chief of the nutrition division at the International Agency for Research on Cancer, told scientists no link was seen when all red meat was examined as one group.
But when the processed meat, which is usually red meat, was investigated alone, those who ate an average of 2 ounces per day - the equivalent of a thick slice or two of smoked ham, four slivers of Parma ham or one giant hot dog - had a 50 percent greater chance of developing cancer of the colon or rectum than those who ate no preserved meat.
``However, we could not, so far, take into account cooking methods in our analysis,'' Riboli said. ``So we could not, for the time being, separate red meat consumption depending on whether it was consumed well done or rare. Therefore, these are just intermediate results.''
Study Links Processed Meat to Cancer
The design of our digestive organs and digestive enzymes today shows that mankind is basically a carnivorous (meat eating) species with the ability to digest carbohydrates from fruit and vegetables. Health is damaged by the consumption of these carbohydrates in ratio to the percentage ingested.
