Eating a diet heavy in raw fruits and vegetables appears to help people lose weight and lower blood pressure, a group of Los Angeles doctors reports.

But they warn that an unsupervised diet of predominantly raw foods can cause infection, loss of teeth and even death.

In their study of 32 patients, a team headed by Dr. John M. Douglass of the University of Southern California found that the average obese person lost about eight pounds after almost seven months on the diet. Meals consisted of at least 40 percent uncooked vegetables, seeds, nuts, berries and fruits. Raw meat and fish were not included.

Douglass, writing in the Southern Medical Journal, says the reason for the weight loss may be that raw food makes people feel full sooner. "Two patients who were massively obese claimed high-percentage raw diets gave them long-term appetite control not obtained with cooked foods," he writes.

Diastolic blood pressure in the group dropped an average of 17.8 points. The researchers attributes this to the high fiber content of raw foods, but says fiber "is only part of the answer."

Drawbacks to the diet, they say, also may include mild weakness at first, "reduced gastrointestinal transit time" and difficulty finding raw foods in restaurants.

"One should not be blind to the hazards," they write. "Inadequate . . . raw diets can be devastating. Although our test patients did well, persons on long-term, self-choice raw-food diets, especially fruitarian, have died of myocarditis [inflammation of the heart wall], inanition [weakness and weight loss], and anasarca [fluid accumulation.]"