The New York Times Magazine has an article blaming "inequality" for what it says is a lack of progress in improving life expectancy in America. As the article puts it, "But life expectancy measures only gains that refer to a whole population, and in the United States, rising inequality has become a drag on this most basic measure of human progress."
It's not clear what "rising inequality" the author of the article is talking about. Certainly women and racial minorities are more equal before the law in America today than they have been in most of the country's history. As usual, the Times doesn't bother to link to any academic research on the subject. It mentions one assistant professor, Justin Denney of Rice University, and says "he told me that other studies have shown that wealthy, well-educated smokers outlive poorer, less-educated smokers, even if you control for the amount of tobacco consumed."
I looked up one of Professor Denney's articles on "Socioeconomic Disparities in Health Behaviors." The link is here (the Times typically doesn't give such links, preferring to tell readers what to think instead of letting readers think for themselves). You'd be much better off reading the Denney article than reading the article in the Times, because the Denney article gets into all kinds of subtleties that the Times article ignores. For example, it explores the possibility that rather than the inequality causing the health disparities, the health disparities may cause the inequality, or some underlying problem may cause both the inequality and the health disparity. It observes that some unhealthy behaviors, like tobacco consumption, cost considerable money. And it reports that high-status groups once had higher rates of tobacco use, cocaine use, and cholesterol.