I agree with @MikeInBatonRouge on this. Although I'm sure there have been increases in all these, a lot of them were not historically tracked or even diagnosed. One hundred years ago there were also much higher under-6 child mortality rates and some of these kids - if treated - could have been the ones with asthma, food allergies, or autism had they lived. I mean, the number of kids exposed to lead paint alone back then is probably awesome. So I'm going to err on the side of optomism on this one.

Great timing for this subject because for the past two days I have been reading about longevity on the island of Okinawa. Many people on this island live past the age of 100yrs and enjoy good health. They tend to eat a plant based diet with low amounts of animal protien, they enjoy a comfortable social life with friends and family, they get a lot of exercise in the form of walking, bike riding and gardening and tend to live a low stress life. On the other hand the young people have adopted a Western life style that includes Western foods and attitudes and are becoming obese and unhealthy. Every day I notice all the fat young men and women with their attention directed towards their smartphones or some other high tech device. They eat a diet of junk food, get very little exercise and probably watch television . For the past two days I have been working in a bank on their water system and could not help but notice the women that worked there, they were fat and not just a little bit. In their break room was a newly restocked supply of colas, corn chips, and other trash. Not smart. I think that all these health issues are caused by our very poor diets, lack of exercise,and vaccines.

There are lots of reasons from food, to chemicals, pollution, stress and on and on. There is no songle action and the more of us that demand more from our life support system the more stress is placed on it and the result is increasing problems for our species and many other ones as well.

Much of it is the sugar in our food system. Excessive sugar really screws your body up, but avoiding sugar means home cooking and not from boxes. Who has time for that? It means fresh foods, not highly processed. It means reading labels.

Could it be that GMO's have a lot to do with this, considering they are banned in other countries I'd like to see the statistics for those countries. Of course Fast Food has a lot to do with childhood and adult obesity everywhere.

Geeze... could it be steroids from the meats we eat?