A Daily Quart

Every schoolchild knows that milk is a natural source of the calcium needed to build strong bones and healthy teeth. Now grownups may also have a good reason to drink (fat-free) milk. A study published last week in the New England Journal of Medicine suggests that calcium may help protect adults from cancer of the large intestine, a sometimes fatal disease that has afflicted some 138,000 Americans this year--including President Reagan, who had surgery to remove a cancerous growth from his colon last July.

Colon cancer has been linked to high-fat diets; fatty foods increase the production of bile acids, which may irritate the lining of the colon and trigger abnormal cell growth. This could explain why the disease is found less frequently among vegetarians and in countries where people eat less fat than typical Americans.

In the new study, conducted by Dr. Martin Lipkin and Harold Newmark at the Memorial Sloan-Kettering Cancer Center in New York City, ten people with typical Western-style high-fat diets and family histories of colon cancer were given 1.2 grams, 1½ times the recommended daily allowance, of calcium, which acts to neutralize bile acids. After only two to three months, tests of their colon linings showed that the number of fast-growing cells associated with cancer had significantly decreased. More study is needed, but at least one expert has already urged adults to drink a quart of fat-free milk a day.