BOSTON -- A new study is calling into question the effectiveness of the PSA blood test, the most commonly used diagnostic tool for prostate cancer.

The American Cancer Society currently recommends that men over 50 get a manual rectal exam, followed by a blood test to screen for prostate cancer.

Researchers at New York Presbyterian Hospital found that back in the mid-1990s, PSA levels were a good indication of the presence or absence of cancer. However changes in medical routines and treatment in the late 1990s and early 21st century have led to more doctors performing biopsies on men, even when PSA levels are not out of the normal range.

Doctors associated with this study said they urgently need a more effective test than PSA. However they, and critics, are quick to add that for the time being, PSA is the best cancer-diagnosing tool available.

Gulf War Syndrome Cause

It has been estimated that up to 30 percent of servicemen and women who served in the first Gulf War came home with chronic pain, fatigue, and mood problems, a group of symptoms commonly called Gulf War Syndrome.

Now, a review of 115 studies, which is published in Proceedings of the National Academy of Sciences, points to acetylcholinesterase inhibitors as the likely cause. The class of chemicals is found in heavy duty bug sprays, pesticides, and pills given to soldiers to protect them from nerve agents.

Gulf War syndrome remains controversial. A 2006 government study determined it didn't exist.

Low-Fat Diet Better For Heart Health

Next time you diet, keep this in mind. Doctors at the Medical College of Wisconsin found that though both low-fat and low-carbohydrate diets will help you lose weight, low-fat diets are better for your heart.

David Gutterman, M.D., and his colleagues found low-carb diets, like the Atkins, can clog a person’s arteries, increasing cholesterol levels in the short-term.

A low-fat diet, on the other hand, does not have that same effect.

A low-fat diet is defined as getting no more than 30 percent of calories from fat.

Researchers also found that in their small study, patients found the low-fat diet more tolerable. The study did not take into account age, gender or racial considerations.