Note that not all food additives necessarily have a net negative impact on health. For example, I remember in the 1990's Ingster & Feinleib hypothesized that artificial flavours might be the reason for a decrease in cardiovascular disease mortality that was observed in the mid 1960's. The suggestion in their paper is that salycilates present in foods might have similar effects to supplementation by acetyl-salicylic acid (Aspirin).

I'm not sure if their work was ever followed up on by others, but you can read their original paper here.