Infant mortality and life expectancy are improving with modern medicine and diet. Most of our problems today stem from the over consumption of food and lack of physical activity. Cancer rates are at an all time low even though media makes it seem like everything(non caloric sweeteners, plastics, herbicides) around us causes cancer.
Except that the US, a major proponent of modern medicine, ranks very poorly compared to other nations in the infant mortality charts -- especially against countries that prefer natural non-western medicine, and life expectancy is clearly linked to financial status -- those that can afford health care. IE: where I used to live in Arkansas, the average life expectancy is 67, whereas in a rich state like Virginia, it's 87. What's the difference? Ability to afford health care.
Everything is correlated to obesity. Arkansas has the highest obesity rate in the nation. When you look into our infant mortality rate it is linked in preterm births. Preterm birth is highly linked to obesity and is trending up.
https://www.cdc.gov/cancer/dcpc/data/race.htm