The reverse explanation (bowel cancer recurrence -> decreased coffee consumption) should be kept in mind.<p>There have been similar findings about caffeine and miscarriage, for instance, with higher caffeine intake associated with greater miscarriage risk. Then it was found that women who eventually miscarried are less likely to get morning sickness, and therefore less likely to feel nauseous from drinking coffee, and therefore drink more of it.<p>A similar causal path might be going on.
Is it the coffee, or is it that heavy coffee drinkers are employed white collar professionals with good genes who do better on just about every measure?