Men and women who have "bad genes" with genetic diseases like diabetes, hypertension, cancer...
Those are literally all man-made diseases that get cured with diet and exercise and not being exposed to a million chemical compounds. That is such an insulting and ignorant thing to say.
Do you really believe that cancer can be cured with diet and excercise (in spite of the medical evidence to the contrary?
The problem with an absolute statement like this one is that it only takes one example of someone with a healthy lifestyle that suffers from one of those medical conditions to prove it inaccurate (there are plenty of examples).
Those diseases have several causal conditions, lifestyle, diet and genetics play a role in some cases. For example a mutation in the BRCA1 gene increases the probability of breast cancer. Almost all of the cases of cervical cancer are caused by the VPH virus which has nothing to do with exposure to chemicals to name another example.
The exception proves the rule.