Why do you think that cardiovascular and degenerative disease is so much higher in developed nations?

In developed nations people have more fast food options which lead to cardiovascular disease. As well as screen time all day since this is one of the factors of cardiovascular disease. Undeveloped nations don't have fast-food or television to watch all day, since they play outside.

In developed nations, people tend to live longer and healthier lives. There is so much less war/violent act related deaths in developed nations than in other areas of the world. Also, quality pre-natal care and standardized childhood vaccinations prevent many diseases and early deaths. On that same note, relatively accessible healthcare and medications prevent early deaths as well. Lastly, endemic areas tend to have very high rates of infectious diseases (think malaria, HIV, shigellosis) due to lack of clean running water, proper hygiene, proper education, accessible medications/vaccinations, etc. So, why then, do developed nations have more cardiovascular and degenerative diseases? Well, the point I am approaching is that these kind of illnesses are diseases of old age-in third world countries there are much fewer people that ever live to see the age where they may develop heart disease, diabetes, arthritis, cancer, etc.

they had the law tat factories that produces smoke cannot be built near residential buildings.

building of proper sewage system was done to ensure that the waste is carried away from the humans so that they do not get diseases from it.

also they built water systems to provide water in those areas which are drought prone.