Study shows lifestyle changes can lengthen life

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SAN FRANCISCO -- A carefully limited pilot study of 30 prostate cancer patients by scientists and doctors at University of California San Francisco and a Sausalito, Calif. research institute indicates for the first time that major lifestyle changes may prevent early cell death and lengthen human life.The study was led by Dr. Elizabeth Blackburn, the UCSF biochemist famed for discovering the mysterious proteins called telomeres that cap the ends of chromosomes and control the longevity of dividing cells.Her principal colleague is Dr. Dean Ornish, the San Francisco cardiologist and widely publicized advocate of diet control, exercise and stress reduction to prevent heart disease deaths -- a doctrine that was controversial many years ago when Ornish first proposed it but is now widely accepted. In their report, published Tuesday in the British journal Lancet Oncology, the researchers caution that with such a limited number of patients their study is only preliminary, and they call for a much larger and strictly controlled research project.But if these early findings are confirmed, they say, "this might be a powerful motivator for many people to beneficially change their diet and lifestyle."The research team studied the levels of an enzyme called telomerase in the prostate tissue of the 30 cancer patients who had volunteered to follow a low-fat diet, exercise moderately and reduce their stress. After only three months, 24 patients showed a highly significant increase in their telomerase levels -- an indication that the cell-protecting telomeres in their cells were being restored.The telomerase enzyme was discovered by Blackburn and her colleagues in 1984, and is considered crucial because it repairs telomeres that are in the process of dying and thus prevents the death of many human cells. Telomerase has often been hailed as the "immortalizing enzyme." The long telomere proteins protect the ends of chromosomes in the body, but they shorten naturally and ultimately die unless the telomerase enzyme acts to repair them and increase their length.Shortened telomeres, in fact, are often an indicator of disease risk and premature death in many types of cancer.In June, Ornish, the director of the Preventive Medicine Research Institute in Sausalito, and Dr. Peter Carroll, a UCSF prostate cancer specialist, reported in the Proceedings of the National Academy of Sciences that after only three months of living by Ornish's strict diet and stress-control regimen, they observed significant changes in the cancer-causing genes within the prostate tissue of the same 30 cancer patients used in the Blackburn study.Blackburn's principal associate, Dr. Jue Lin, a molecular biologist in her lab, said that team had already been looking at the relationship between human stress and cellular aging as telomeres die. The volunteer patients in the separate prostate cancer study led by Ornish seemed appropriate for Blackburn's team to learn what was happening to the telomerase they were studying, Jue said.So even with only 30 patients, Jue said, the association between their extremely healthy habits and the increased amount of telomerase proved highly significant."But at this point one can only speculate that the change in lifestyle is a cause of the increase in telomerase levels," she said.The patients at Ornish's research institute spent three days in a residential retreat where they learned stress-reduction techniques and undertook to follow a diet that included only 10 percent caloric content from fat and was low in refined sugars and rich in fruits, vegetables and natural foods, plus vitamin supplements and fish oil. They also did moderate aerobic exercises and learned relaxation techniques.All these eating and exercising habits, plus yoga and meditation, have long been part of the programs Ornish prescribes as effective for preventing and even reversing heart disease. He is the author of several books and is a health consultant to Safeway and several food manufacturing companies. E-mail David Perlman at dperlman(at)sfchronicle.com.(Distributed by Scripps Howard News Service, www.scrippsnews.com.)