Healthy Living and Risk of Major Chronic Diseases in an Older Population FREE

A recent article in the Archives¹ examined the extent to which 4 healthy lifestyle factors and their combinations were associated with reduced risk of developing chronic diseases. In the European Prospective Investigation Into Cancer and Nutrition (EPIC)-Potsdam study, compared with participants with no healthy factors, those with all 4 healthy factors had reductions of 93% (95% confidence interval [CI], 88% to 95%) for diabetes (P value for linear trend, <.001); 81% (95% CI, 47% to 93%) for myocardial infarction (MI) (P value for linear trend, <.001); 50% (95% CI, −18% to 79%) for stroke (P value for linear trend, .054); and 36% (95% CI, 5% to 57%) for cancer (P value for linear trend, <.001). As suggested by Ford et al,¹ further studies in other populations are needed to evaluate the extent to which chronic disease may be potentially preventable. We investigated whether adhering to the 4 healthy lifestyle factors detailed in the EPIC-Potsdam study influenced the risk of developing incident diabetes, MI, and stroke in an older Australian population.

The Blue Mountains Eye Study (BMES-1) is a population-based cohort study of sensory loss and other health outcomes, with methods previously reported.² During 1992 to 1994, 3654 participants 49 years or older were examined (82.4% participation). At the 5-year follow-up examinations (BMES-2), 2335 surviving participants (75.1% of survivors; 543 had died) were examined. Of the 2335 survivors in the BMES-2, 1952 (75.6% of survivors; 1103 persons died) were re-examined at the 10-year follow-up examinations (BMES-3).

Incident disease outcomes were assessed using the same definitions as in the EPIC-Potsdam report.¹ Similarly, we used the same 4 healthy factors and methods to form an index ranging from 0 to 4, as detailed by Ford et al.¹ However, because our physical activity measures were not available in hours per week, we included a definition of engaging in physical activity as 3 times/wk or more. The covariates adjusted for in incidence analyses included age, sex, educational status (having/not having tertiary qualifications), and occupational status (employed or unemployed).

Of the 3654 participants at baseline, 2639 had information on all 4 healthy factors. As in EPIC-Potsdam, participants who had diabetes (n = 208 [7.9%]), MI (n = 219 [8.3%]), stroke (n = 84 [10.9%]), and cancer (n = 189 [7.2%]) at baseline were excluded from analyses. Of the remaining participants, 50.0% had a healthy diet score, 82.5% had a body mass index lower than 30 (calculated as weight in kilograms divided by height in meters squared), 48.2% had never smoked, and 44.1% had participated in physical activity at least 3 times/wk. After adjusting for age, sex, and educational and occupational status, the risk of developing incident diabetes (P value for linear trend, < .001) and MI (P value for linear trend, < .001) decreased as the number of healthy lifestyle factors increased (Table), but this was not observed for incident stroke. Having 1 or more healthful factors compared with 0 factors did not lower the risk of incident MI and stroke. However, having all 4 healthy lifestyle factors had the greatest impact on incident diabetes—an 83% risk reduction.

In our older population, a slightly higher proportion (11.4%) of participants than in the EPIC-Potsdam study (9.1%) adhered to all 4 healthful factors.¹ The BMES participants with all 4 healthy lifestyle factors had an 83% reduced risk of incident diabetes, and a significant linear trend was observed for incident MI, reinforcing the findings by Ford et al.¹ In contrast, having all 4 healthy lifestyle factors among the BMES participants did not significantly reduce the risk of incident stroke. As recommended by Katz et al,³ refinement of dietary quality (eg, including fish consumption, lean vs fattier meats) may have strengthened observed associations between lifestyle and health outcomes in our study. Nevertheless, our findings in a population older than those in the EPIC-Potsdam study¹ concur with its take-home message, and that from other prospective studies,^4- 6 that healthful dietary and lifestyle factors are beneficial in reducing the risk of developing chronic diseases, particularly diabetes.

Correspondence: Dr Mitchell, Centre for Vision Research, University of Sydney, Westmead Hospital, Hawkesbury Road, Westmead, New South Wales, Australia 2145 (paul_mitchell@wmi.usyd.edu.au).

Author Contributions:Study concept and design: Gopinath and Mitchell. Acquisition of data: Mitchell. Analysis and interpretation of data: Gopinath, Rochtchina, Flood, and Mitchell. Drafting of the manuscript: Gopinath. Critical revision of the manuscript for important intellectual content: Gopinath, Rochtchina, Flood, and Mitchell. Statistical analysis: Rochtchina. Obtained funding: Mitchell. Administrative, technical, and material support: Flood and Mitchell. Study supervision: Gopinath and Mitchell.

Financial Disclosure: None reported.