One of the clearest patterns in public health research is the correlation between income and health. The richer you are, the more likely you are to have good health, and live a long life. The poorer you are, the more likely you are to be sicker, and die younger.
That data could be an argument for just giving poor people money to improve their health. But in general, the way states and the federal government try to make poor people healthier is by giving them health insurance instead.