SAN ANTONIO (March 7, 2013) — “Mediterranean diet shown to ward off heart attack and stroke,” a headline in The New York Times announced in February 2013. The Times reported that, in a large clinical trial, participants eating a balanced diet of fruits, vegetables and olive oil experienced 30 percent fewer heart attacks, strokes and deaths from heart disease.
Reto Asmis, Ph.D., a biochemist in the School of Medicine at The University of Texas Health Science Center San Antonio, believes his team has uncovered a mechanism of action that better explains the Mediterranean diet’s benefits than the presence of antioxidants or mono-unsaturated fatty acids in the diet. His studies target the development of new mechanism-based dietary supplements for the prevention and treatment of atherosclerosis — the hardening and thickening of the walls of arteries due to deposits of fatty substances.
Plentiful in food sources
Dr. Asmis this year received a $1.86 million grant from the National Institutes of Health to study ursolic acid and similar compounds. In his lab’s preliminary research, dietary ursolic acid protected diabetic mice against atherosclerosis. Ursolic acid is found in olive oil; fruits such as apples, cranberries and prunes; and herbs such as sage, oregano, lavender and peppermint.
“We predict that ursolic acid is a member of a new class of anti-atherosclerotic compounds with a mechanism of action distinct from drugs currently used for the prevention and treatment of cardiovascular disease,” Dr. Asmis said.
White blood cells recruited to injury sites
Obesity, diabetes and high blood cholesterol are metabolic disorders and are associated with increased risk of atherosclerosis and cardiovascular disease. In cell cultures, the Asmis team observed key events through which metabolic stress “primes,” or excessively sensitizes, white blood cells called monocytes to chemoattractants — signals that recruit these cells to sites of atherosclerotic injury within blood vessels, Dr. Asmis said.
This dysfunction is a critical step in the development and progression of atherosclerosis, he said. Ursolic acid seems to prevent the undesirable changes, and the team so far has identified several novel potential targets for this protective action. The group also seeks to classify other compounds that perhaps are more robust in activity than ursolic acid.
Heavy toll on the nation
Although death rates have declined over the past decade, cardiovascular disease still accounts for nearly one in three deaths in the U.S., and it is one of the major complications and causes of death associated with diabetes. “With more than 25 million people suffering from diabetes — more than 8 percent of the U.S. population — and an estimated total annual economic burden of $245 billion, new cost-effective prevention and treatment strategies are desperately needed,” Dr. Asmis said.
Potential of low-cost, available supplements
A new mechanism-based dietary supplement that is both relatively inexpensive and safe would greatly benefit populations at high risk for diabetes and diabetic complications such as Hispanic/Latino Americans, who are 1.7 times more likely to have diabetes than are non-Hispanic whites, Dr. Asmis said. “The availability of such low-cost dietary supplements for the prevention and treatment of diabetic complications therefore would have a very significant impact on our current disease prevention efforts,” he said.
Dr. Asmis also serves as professor of clinical laboratory sciences in the School of Health Professions and associate dean of the Graduate School of Biomedical Sciences at the Health Science Center. He is a member of the Barshop Institute for Longevity and Aging Studies.