The research study followed 20 people with diabetes, hypertension, and high cholesterol for a year, with some people tasked with watching 30 minutes of something humorous every day. Both groups took medications for their conditions. After just two months, the humor group had increased their HDL cholesterol levels (the “good” kind). At the four-month mark, the humor group also had lower levels of inflammatory markers that point to high blood pressure and cardiovascular disease.
Daily laughter might also be linked to a lower risk of heart disease, according to a 2016 article in the Journal of Epidemiology. The study asked more than 20,000 people in Japan how often they laughed and whether they were diagnosed with heart disease. People who never laughed had a higher prevalence of heart disease compared to people who found something to laugh about every day. Laughing was also associated with a lower risk of stroke. The researchers did point out that the results could indicate reverse causation, meaning that people with heart disease or stroke could have fewer reasons to laugh.