Ah, food studies. The breeding ground of bad science.
I am not saying this is bad science, but a quick glance shows this to be survey data.
The problem with the data is that people who eat "healthy" probably care more about their health. Even if the food has a negative effect, they could have other tendencies (exercise) that outweigh any negatives.
Plus they probably eat more carefully, in general, drink less, etc.
So... correlation != causation yada yada
A better study would be to take unhealthy people and now introduce the fruits and veg and see what happens.
The problem with the data is that people who eat "healthy" probably care more about their health. Even if the food has a negative effect, they could have other tendencies (exercise) that outweigh any negatives.
Plus they probably eat more carefully, in general, drink less, etc. So... correlation != causation yada yada
A better study would be to take unhealthy people and now introduce the fruits and veg and see what happens.