Yet there are few absolutes. Nor are there many outright poisons. The answer is not to stop worrying about what you eat, but to sort out the sound advice from the babble. That's easier to do once you understand why nutrition information seems so bewildering. Indeed, each study, no matter how well designed, has limitations.
Few researchers interpret ambiguous findings in the same way.
Add government public health experts trying to come up with simple advice based on science that's in flux and companies trying to draw your attention to the health benefits of cereals, or orange juice, or tomato soup, and it's no wonder you feel whipsawed. The saga of fiber and its claimed protective effect against colon cancer shows how uncertain science can lead to confusion. The possible benefits were first reported in 1971 by British missionary surgeon Denis Burkitt, who observed that rural Africans had a lower incidence of bowel-related disorders than Westerners. He hypothesized that the Ugandans' high-fiber diet could explain the difference. Over the next several years, more evidence came from other populations that eat a high-fiber diet and from experiments with rats and mice.