Nutrient intake by duration of ex-smoking in the Scottish Heart Health Study

Information on current-, never- and ex-smokers (including duration of cessation) was obtained in a cross-sectional survey of risk factors for coronary heart disease (CHD), the Scottish Heart Health Study. Diet was also assessed by food frequency questionnaire in a total of 4265 men and 4770 women. Nutrient intakes were computed by sex and smoking group and, according to their diet, the ex-smokers were categorized as current- or never-smokers using discriminant analysis techniques. The current- and five ex-smoking groups differed negligibly in past smoking characteristics. Energy-adjusted intake of polyunsaturated fat, fibre and the antioxidant vitamins were lowest in current-smokers, and for men, intakes increased progressively with duration of ex-smoking to reach the level of never-smokers. In a similar manner, energy, sugar and alcohol decreased with duration of ex-smoking. Fewer trends were observable for women, and the diets of ex-smokers more immediately resembled that of never-smokers. Discriminant analysis for the combined nutrients correctly categorized 72 and 69% of male, and 66 and 65% of female current- and never-smokers respectively. By 4 years of smoking cessation the general dietary pattern of ex-smokers was similar to never-smokers for both sexes. Whether this represents a change in diet over time or a cohort effect is unclear, but the results do suggest that the apparent healthier diet of ex-smokers may contribute to their reduction in CHD risk compared with life-long current-smokers.