David Agus, professor of medicine and engineering at the Keck School of Medicine of USC and the USC Viterbi School of Engineering, acknowledged during a lecture earlier this month that his views on the practice of medicine have, at least on occasion, made him a lightning rod for criticism.

“I get hate mail all the time because I am always taking away people’s crutches,” he said to Keck School Dean Carmen A. Puliafito, who joined Agus in conversation, in a departure from the traditional Visions and Voices lecture.

Vitamins was one of the crutches Agus snatched away from audience members who attended the lecture at Mayer Auditorium.

He scoffed at the notion that vitamins in some way promote health, adding that there was no scientific research to support the intake of multivitamins and that in women they are associated with higher death rates.

Agus later declared drinking juice to be “one of the worst things you can do for your body,” noting that squeezing the fruits starts the process of degrading the nutrients.

And he said that New York City Mayor Michael Bloomberg is a “health hero” for his positions on trans fat and for banning the sale of oversized sodas in the nation’s largest city, a policy that has drawn criticism.

Agus also defended his recommendation of a heart scan earlier this year for ABC News correspondent Bill Weir, which was done while the reporter was taping a segment on Agus’ book, The End of Illness. The scan revealed that Weir had heart disease and was on course for a possible heart attack.

The USC professor said the scan landed him in hot water with the American Heart Association, which stated that scans are expensive procedures that expose patients to radiation and should not be encouraged for the general public.

“That scan saved his life,” Agus said. “The arguments that were made against this are completely messed up. Instead, groups like the American Heart Association should be lobbying for more dollars to create better screening technologies.”

Agus, an unabashed promoter of the use of technology in medicine, said that genetics should be part of modern medicine’s toolbox, in spite of ongoing ethical concerns.

“It can help you target exactly what you are up against,” he said.

And knowing what we are up against, turning medicine around to focus on preventing patients from getting sick in the first place, has to be pursued more aggressively, he added.

Agus noted that “there have not been major inroads in treating the big cancers — lung, breast and prostate — in recent years,” which is why he said there needs to be more focus on prevention and better methods of screening, some of which he called “barbaric.”

He noted that a blood test will soon be used to determine whether a patient has polyps and is at risk for colon cancer.

“We need to make all screenings for cancer better so people will actually do them,” he said.