'Western' Diet Doesn't Make for Healthy Seniors

A diet high in fried, sweet, and processed foods is not associated with healthy aging, a large cohort study found.

Participants on a Western-style diet had lower odds of ideal aging, defined as the absence of chronic diseases and mental health problems, as well as good cardiometabolic, respiratory, musculoskeletal, and cognitive function, according to Tasnime Akbaraly, PhD, of INSERM in Montpellier, France, and colleagues.

The odds of participants in the Western diet group aging ideally were low (OR 0.58 for top tertile versus bottom tertile, 95% CI 0.36 to 0.94, P=0.02), researchers wrote in an early online release of a study in the May edition of the American Journal of Medicine.

Researchers characterized the Western diet as one consisting of fried food, processed food and red meat, pies, sweetened desserts, chocolates, refined grains, high-fat dairy products, and condiments.

Although the impact of diet on specific age-related diseases has been studied extensively, few investigations have adopted a more holistic approach to determine the association of diet with overall health at older ages, researchers said.

They therefore sought to identify dietary factors assessed in midlife that can not only prevent premature death, but also promote ideal aging.

"Identifying predictors of exceptional health in old age ... may provide new insights into optimal levels of established risk and protective factors," Akbaraly and colleagues wrote.

The investigators suggested that new thresholds and targets for intervention may surface when more research into ideal aging is commenced.

Akbaraly and colleagues used data from the Whitehall II cohort (phase III) and included 3,775 men and 1,575 women (mean age 51 at baseline) whose baseline assessment spanned 1991-1993. Diet was ascertained at baseline, and health status was ascertained every 5 years from various sources.

The research team created five potential phenotypes to characterize aging outcomes after 16 years of follow-up: ideal aging (comprising 4% of the cohort), nonfatal cardiovascular event (7.3%), cardiovascular death (2.8%), noncardiovascular death (12.7%), and normal aging (73.2%).

For a comparator, the investigators relied on dietary patterns and adherence to the Alternative Healthy Eating Index (AHEI).

The AHEI is a "validated index of diet quality, originally designed to provide dietary guidelines with the specific intention to combat major chronic conditions such as cardiovascular diseases," diabetes, and the metabolic syndrome, according to the study. High AHEI scores have correlated with reduced risk of these conditions.

"Analyses were adjusted successively for age, sex, total energy intake (model 1), and health behavior: smoking and physical activity (model 2)," the authors explained.

They found that a diet with high intake of vegetables, fruits, and fish (the "healthy-foods" diet) was significantly inversely associated with noncardiovascular mortality (model 1; OR per 1 standard deviation [SD] increment 0.76).

However, when researchers adjusted for smoking status and physical activity (model 2), the association was no longer significant (OR 0.90).

Participants in the highest tertile of Western diet were nearly 50% less likely to reach ideal aging compared with the bottom tertile (model 1), and 42% less likely using model 2.

The Western diet conferred a 53% greater chance of cardiovascular death and a 36% greater chance or noncardiovascular death in model 1 (per 1 SD increment on the OR), which lost significance after further adjustments.

Other disadvantages associated with the Western diet (top versus bottom tertile) included poorer musculoskeletal status, measured by walking speed (OR 1.45), and worse cognitive function (OR 1.58).

However, researchers did not find any significant association with the Western diet and indicators of cardiometabolic and respiratory functioning and mental health.

"While our results indicate that low adherence to healthy recommendations of the AHEI guidelines is associated with increased premature death, the 'Western-type' diet significantly reduced the likelihood of achieving ideal health at older ages ... independent of other health behaviors such as physical activity and smoking," they concluded.

Limitations of the study included a lack of generalizability of the results to a more ethnically diverse population; the exclusion of participants with missing values; questionnaires with only specific foods represented; and the possibility for unmeasured confounders, researchers said.

The Whitehall II study is supported by grants from the British Medical Research Council, the British Heart Foundation, the British Health and Safety Executive, the British Department of Health, the National Heart, Lung and Blood Institute, the National Institute on Aging, and the Agency for Health Care Policy and Research.