I don't buy any conspiracy stuff, or anything about artificial chemicals or pharmaceuticals or food additives or whatever. Some people just don't live very long, that's all, it's just the luck of the draw. My mother's father smoked a pack a day from the time he was 11 years old until he died in his 90s of multiple organ failure, i.e. old age. At that age you can't blame it on cigarettes. And he was gassed in the trenches of WW1 and suffered severe lung damage from chlorine. He didn't get cancer, or emphysema, or cardiovascular disease, he just wore out. There have always been apparently healthy and clean-living people who die young, and people who pay no attention to all the rules of good health and nutrition and exercise and live for a very long time. Winston Churchill comes to mind. Every day he got through a ration of brandy and cigars, in fact there was probably no time in his adult life when his blood alcohol level was zero, he took no exercise anybody ever heard of, and he lived well into his 80s. Jim Fixx also comes to mind, a marathon runner, author, and Mensa member, didn't smoke or drink, was in tremendous physical condition, and died of a heart attack before he was 60. I had a severely alcoholic uncle who also smoked heavily and should have died in his 50s at the latest according to the actuaries, but he made it to 88. I've also known children who died of cancer at 7 years old.
Average life expectancy is over 80 years in this country. Most people live a long time, some people don't. It's pretty saddening sometimes, but that's just the way it is. There are no promises in this life.