Exploring the effect of a lifestyle intervention on cancer risk: 43-year follow-up of the randomized Oslo diet and antismoking study.
BACKGROUND/OBJECTIVES
The Oslo diet and antismoking study showed that counselling for a healthy lifestyle reduced lifelong coronary mortality in high-risk men. We explored whether the same counselling reduced also cancer risk.


METHODS
The study randomly allocated males at high coronary risk to either a 5-year intervention for lifestyle changes (cholesterol-lowering dietary changes, weight loss and stopping smoking) or a control group (1 : 1) in 1972/73. We explored the incidence and mortality of all cancers and cancer forms related to smoking, BMI or diet up to 43 years after randomization.


RESULTS
A total of 595 men in the intervention and 621 in the control group were included. At inclusion median age was 45 years, 588 (48.4%) subjects were overweight (BMI > 25 kg m-2 ) and 925 (76.1%) current smokers. The intervention did not reduce the risk of cancer after 43 years (adjusted hazard ratio (HR) 0.96, 95% confidence interval (CI) 0.80-1.15). In the first 25 years of follow-up, among the 1088 (89.5%) men who were overweight/obese and/or smokers, the intervention reduced the incidence of those cancer forms related to smoking, BMI or diet (including carcinoma of the respiratory, digestive and urinary tracts; adjusted HR 0.69; 95% CI 0.49-0.99). The intervention had no significant effect on incidence beyond 25 years, or on mortality.


CONCLUSIONS
The 5-year counselling for a healthy lifestyle did not reduce the overall cancer risk in the very long term. However, in the first 25 years, the counselling reduced the risk of relevant cancer types in overweight/obese subjects and smokers.
['Botteri|E|E|', 'de Lange|T|T|', 'Tonstad|S|S|', 'Berstad|P|P|0000-0002-9025-4455']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D015992:Body Mass Index D002423:Cause of Death D002784:Cholesterol D003327:Coronary Disease D000078331:Correlation of Data D018752:Diet, Fat-Restricted D015444:Exercise D005500:Follow-Up Studies D006801:Humans D015994:Incidence D008019:Life Style D008137:Longitudinal Studies D008297:Male D008875:Middle Aged D009369:Neoplasms D009664:Norway D009765:Obesity D012307:Risk Factors D012907:Smoking D016540:Smoking Cessation
intervention cancer diet smoking cancer mortality prevention