SAN DIEGO, April 17 (UPI) -- Mirthful laughter was linked to lower cholesterol and less risk of cardiovascular disease in a study of high-risk diabetic patients, U.S. researchers said.
Lee Berk, a psychoneuroimmunologist, of Loma Linda University, and Dr. Stanley Tan, an endocrinologist and diabetes specialist at Oak Crest Health Research Institute in Loma Linda, examined the effects of mirthful laughter on 20 high-risk diabetic patients with hypertension and hyperlipidemia -- an elevation of lipids in the bloodstream.
Both groups were started on standard medications for diabetes -- glipizide, TZD, metformin, ACE inhibitors and statins. The researchers tracked both groups for 12 months, testing their blood for the stress hormones epinephrine and norepinephrine; HDL cholesterol; inflammatory cytokines, which contribute to the acceleration of atherosclerosis and C-reactive proteins, a marker of inflammation and cardiovascular disease.
One group viewed self-selected humor for 30 minutes in addition to the standard drug therapies.
At the end of one year, 26 percent of the laughter group had higher levels of high-density lipoprotein, the "good" cholesterol, compared to 3 percent in the control group. Harmful C-reactive proteins decreased 66 percent in the laughter group vs. 26 percent for the control group.
The findings were presented at the annual meeting of the American Physiological Society, part of the Experimental Biology 2009 gathering in New Orleans Convention.