Mediterranean Diet Improves Survival in Elderly
Laurie Barclay, MD
Sept. 21, 2004 -- Among 70- to 90-year-olds, adherence to a
Mediterranean diet and healthful lifestyle is associated with a more
than 50% lower rate of all-cause and cause-specific mortality,
according to the results of a cohort study published in the Sept. 22
issue of JAMA.
"Dietary patterns and lifestyle factors are associated with mortality
from all causes, coronary heart disease [CHD], cardiovascular diseases
[CVD], and cancer, but few studies have investigated these factors in
combination," write Kim T. B. Knoops, MSc, from Wageningen University
in the Netherlands, and colleagues from the Healthy Ageing: a
Longitudinal study in Europe (HALE) Project. "Because of the
cumulative effect of adverse factors throughout life, it is
particularly important for older persons to adopt diet and lifestyle
practices that minimize their risk of death from morbidity and
maximize their prospects for healthful aging."
The HALE population cohort study was conducted in 11 European
countries between 1988 and 2000 and followed 1,507 apparently healthy
men and 832 women, aged 70 to 90 years, enrolled in the Survey in
Europe on Nutrition and the Elderly: a Concerned Action (SENECA) and
the Finland, Italy, the Netherlands, Elderly (FINE) studies. In this
cohort, the investigators studied the association of individual and
combined dietary patterns and lifestyle factors, including alcohol
use, smoking status, and physical activity, with 10-year mortality
from all causes, CHD, CVD, and cancer.
Of 935 participants who died during follow-up, 371 deaths were from
CVD, 233 from cancer, 145 from other causes, and 186 from unknown
causes. Factors associated with a lower risk of all-cause mortality,
after controlling for age, sex, years of education, body mass index,
study, and other pertinent factors, were adhering to a Mediterranean
diet (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.68 -
0.88), moderate alcohol use (HR, 0.78; 95% CI, 0.67 - 0.91), physical
activity (HR, 0.63; 95% CI, 0.55 - 0.72), and nonsmoking (HR, 0.65;
95% CI, 0.57 - 0.75).
Results were similar for mortality from CHD, CVD, and cancer. In
patients with all four low-risk factors, the all-cause mortality rate
was reduced to 0.35 (95% CI, 0.28 - 0.44). Lack of adherence to this
low-risk pattern was associated with a population-attributable risk of
60% of all deaths, 64% of deaths from CHD, 61% from CVD, and 60% from
cancer.
Study limitations include few cases with no healthful diet or
lifestyle factors, and low number of deaths due to cause-specific
mortality.
"Among individuals aged 70 to 90 years, adherence to a Mediterranean
diet and healthful lifestyle is associated with a more than 50% lower
rate of all-causes and cause-specific mortality," the authors write.
"Establishing a causal relationship would require an intervention
study, and the number of years an individual needs to maintain such a
lifestyle to realize a benefit is unknown. However, a Mediterranean
diet, rich in plant foods in combination with nonsmoking, moderate
alcohol consumption, and at least 30 minutes of physical activity per
day is associated with a significantly lower mortality rate, even in
old age."
The European Union supported this study, based on the HALE project.
In an accompanying editorial, Eric B. Rimm, ScD, and Meir J. Stampfer,
MD, DrPH, from the Harvard School of Public Health in Boston,
Massachusetts, note that to be protective, healthful behaviors need
not be extreme. For example, the physical activity criterion could be
met by half an hour of walking daily. They also discuss a research
article in the same issue showing that the Mediterranean diet is
superior to a reduced-fat diet in patients with metabolic syndrome.
"Although understanding of the relation of lifestyle and health
outcomes will continue to be refined, information available now is
sufficient to take action," the editorialists write. "As a society,
the United States spends billions on chronic disease treatments and
interventions for risk factors. Although these are useful and
important, a fraction of that investment to promote healthful
lifestyles for primary prevention among individuals at all ages would
yield greater benefit."
JAMA. 2004;292:1433-1439, 1490-1492