Massachusetts ? Ben & Jerry might help you get pregnant, but not in the usual way. A diet rich in ice cream and other high-fat dairy foods may lower the risk of one type of infertility, a study suggests.

It sounds too good to be true and probably is, some doctors say.

But the findings are bound to get attention because they are from the well-known Nurses Health Study at the Harvard School of Public Health and were published today in the European journal Human Reproduction.

Researchers found that women who ate two or more low-fat dairy products a day were nearly twice as likely to have trouble conceiving because of lack of ovulation than women who ate less than one serving of such foods a week.

Conversely, women who ate at least one fatty dairy food a day were 27 percent less likely to have this problem.

Even the researchers say women should not make too much of these results, which are based on reports of what women said they ate over many years – not a rigorous, scientific experiment where specific dietary factors could be studied in isolation.