Does healthy make you happy? Or does happy make you healthy? Forbes.com reports on a new study published in the Proceedings of the National Academy of Sciences, that suggests the latter. The research indicates that our degree of happiness is directly related to specific bodily functions that protect against cardiovascular disease, diabetes, autoimmune deficiencies and stress-related illnesses. Dr. Andrew Steptoe, the British Heart Foundation professor of psychology at University College London, administered laboratory stress tests and standardized mental health questionnaires to more than 200 white men and women aged 45 to 59. Blood samples taken before and after the stress tests indicated that happiest men and women had the lowest levels of the stress hormone cortisol, and that cortisol levels were, on average, more than 32 percent higher among the least happy individuals. The authors also found that the least happy men and women had up to 12 times higher levels of a liver-produced protein known as plasma fibrinogen, which has been associated with a higher risk for cardiovascular disease. Forbes reports that the researchers concluded that a having a strong sense of well-being and happiness may help boost biological systems, ultimately helping to lower the risk for developing a range of illnesses down the road. But before you start congratulating yourself on your healthful habits, note that the scientists emphasized that this happiness-healthiness pathway appears to be a direct mind-body link that is independent of lifestyle choices, such as exercise, smoking and drinking.