An article in New Scientist ("The Best Medicine", Nov. 17, 2001 pgs. 40-43 by Colin Tudge) advocates going back to a more ancestral diet. A quote:

 

"Modern diets are based on just a few domesticated plants which in general have been bred not for their biochemical variety but for yield and succulence. Biochemically speaking, modern crops tend to be far blander than their wild counterparts. In general, then, I suggest that modern, agricultural human beings are "pharmacologically impoverished": deprived of that host of quasi-vitamins that our physiology has evolved to make use of.

 

"The real message, perhaps, is that we should revert to a more "primitive", botanically far more varied, diet much closer to the diets not simply of our hunting-gathering ancestors, but of our pre-human ancestors."