James Smith, a health economist at the RAND Corporation, has heard a variety of hypotheses about what it takes to live a long life — money, lack of stress, a loving family, lots of friends....But what, he asks, is cause and what is effect? And how can they be disentangled? He is venturing, of course, into one of the prevailing mysteries of aging, the persistent differences seen in the life spans of large groups....But the questions for researchers like Dr. Smith are why? And what really matters? The answers, he and others say, have been a surprise. The one social factor that researchers agree is consistently linked to longer lives in every country where it has been studied is education. It is more important than race; it obliterates any effects of income.
Results from a large European study suggest that poorly educated people are more likely to be admitted to hospital with chronic heart failure than the better educated, even after differences in lifestyle have been taken into account....[The study authors] found that the most educated men and women had approximately half the risk of heart failure compared with the least educated. After they had adjusted for various cardiovascular risk factors, they found that people who had been educated for more than 10 years had a 39% lower risk of being admitted to hospital for heart failure compared with people who had been educated for less than eight years, and those who had been educated for between 8-10 years had a 25% lower risk.... [There is a] clear socioeconomic gradient in [the] risk of developing heart failure...in this and in other studies [that] is not explained by differences in lifestyle.....[One of the authors stated that] the study does not show what could be the mechanism by which social deprivation is associated with an increased risk of heart failure. "We need more studies on this, but possible explanations could include differences in heart failure treatment as already mentioned, but we must also look for explanations at the pre-clinical stages. One point to be mentioned is the role of psychosocial stress on development of heart failure -- this has received very little scientific attention so far."
There are a number of possible factors that might explain why education correlates with good health. Relating to hearth failure, there are differences that seem to transcend lifestyle. I take this to mean factors such as diet, exercise, smoking, and drinking. The authors of the study cited above, in attempting to understand the effects of the social gradient, arrived at what may be an important factor -- psychosocial stress in the home environment, even in the pre-clinical stage.