I have a hypothesis (which might be false) that chemicals in a natural food developed through evolution to work together nicely when a fruit/vegetable is consumed raw.

In last 100 years we started adding lot of chemicals to our food without knowing what long term effects they produce. Thats why fortified bread is not same as whole wheat bread.

Maybe in future we will make the ideal food in a lab or our gut will get adapted to process highly processed food.