CASE STUDY 27.9 SO YOU THOUGHT SPINACH WAS GOOD FOR YOU

Essay

CASE STUDY 27.9
SO YOU THOUGHT SPINACH WAS GOOD FOR YOU?
For Questions , use the following narrative
Narrative: Case study 27.9 summary
A study published in the New England Journal of Medicine shows that the antioxidant beta-carotene markedly increased the incidence of lung cancer among heavy smokers in Finland.Incidence of lung cancer was 18% higher among the 14,500 smokers who took beta-carotene than among the 14,500 who didn't.The probability that the observed increase was due to chance is less than one in one hundred.(A difference in such studies is taken seriously when the probability that it happened by chance is less than one in twenty.)This result was particularly worrying to researchers and the media, because it comes from a large, randomized clinical trial, yet it goes against all the previously available evidence.Over a hundred epidemiologic studies indicate that people who have high levels of beta-carotene in their diet and in their blood have lower risks of cancer, particularly lung cancer.

-{Case study 27.9 narrative} Explain why we should perhaps not be surprised by the results of this study, in light of all the studies that had been done before.(Assume that the quality of the studies is not an issue.)