Does eating right cancel out the damage of chemicals that are now banned in foods we have consumed in the 50s and 60s ?

After doing research, a lot of it, I can find no evidence that eating right now will do anything to help cancel out the the damage that was done. people born in the fifties and sixties consumed foods and used things that are now known to cause cancer, heart problems, liver damage, etc. Does”eating right” actually help negate the damage already done? Do the changes to our DNA mean that generations after will have those same problems we are dealing with now? Can we truly change the damage?