Washington ? The Department of Health and Human Services Thursday issued a revised recommendation urging women to get mammograms every one to two years beginning at age 40 instead of 50.

The reaffirmation of the procedure comes as medical experts debate the quality of research used to support mammograms for breast cancer screening. Consumer health groups have also raised concerns about false positive cancer readings from the procedure, saying they often result in unnecessary fear, medical procedures and radiation treatments.

“Mammography is not a perfect tool,” Tommy Thompson, secretary of Health and Human Services, said Thursday. “But mammography is an important and effective early detection tool that does help save lives. We want women to understand this point very clearly.”

The recommendation follows three years of study by the U.S. Preventive Services Task Force, a panel of private health care experts that assesses scientific evidence behind a broad range of medical tests.

In 1996, the task force, which was established by the U.S. Public Health Service, reported that there was “insufficient evidence” to recommend for or against regular mammogram screenings for women in their 40s. But the panel recently determined that new data on the incidence and mortality rates for breast cancer provided “fair evidence” that regular mammograms could reduce the chances of dying from the cancer.

The benefits of regular mammograms are greatest among women age 50-69, the panel found. Although the panel determined that the benefits aren’t as great for women age 40-49, it still endorsed the procedure for those in that age group.

Breast cancer is the most common form of cancer among women in the United States. In 2001, an estimated 192,200 women were diagnosed with breast cancer and 40,600 women died from the disease.

The controversy surrounding mammograms surged recently after two Danish researchers reviewed seven studies on mammography and mortality and found “no reliable evidence” that screening for breast cancer reduced mortality. A similar review by a National Cancer Institute advisory panel also found insufficient evidence that mammograms reduce breast cancer fatalities.

The American Cancer Society also advises that regular mammograms begin at 40.