In general people who are less well-educated tend to suffer from worse health. However, new research from the University of Wisconsin-Madison suggests that happiness could be as important as education in determining people's health. The researchers used data from the Survey of Midlife in the United States, a ten-year study of age-related differences in physical and mental-health. They measured the participants' levels of a substance called Interleukin-6, high levels of which are associated with cardiovascular disease, stroke, diabetes, metabolic syndrome and some cancers. They found that less well-educated people who had meaningful relationships with others, a sense of purpose, self-acceptance and a feeling that their lives were manageable had similar levels of Interleukin-6 to people who were happy and better-educated.