Dietary patterns and the risk of mortality: impact of cardiorespiratory fitness.
BACKGROUND
While dietary patterns that are both predictive of chronic disease and mortality have been identified, the confounding effects of cardiorespiratory fitness have not been properly addressed. The primary objective was to assess the relation between dietary patterns with all-cause mortality, while controlling for the potentially confounding effects of fitness.


METHODS
This was a prospective cohort study. Participants consisted of 13 621 men and women from the Aerobics Center Longitudinal Study (ACLS). Participants completed a clinical exam and 3-day diet record between 1987 and 1999. Participants were followed for mortality until 2003. Reduced rank regression (RRR) was used to identify dietary patterns that predicted unfavourable total and high-density lipoprotein-cholesterol, triglyceride, glucose, blood pressure, uric acid, white blood cell and body mass index values.


RESULTS
One primary dietary pattern emerged and was labelled the Unhealthy Eating Index. This pattern was characterized by elevated consumption of processed and red meat, white potato products, non-whole grains, added fat and reduced consumption of non-citrus fruits. The hazard ratio for all-cause mortality in the fifth vs the first quintile of the Unhealthy Eating Index was 1.40 (1.02-1.91). This risk estimate was reduced by 13.5 and 55.0% after controlling for self-reported physical activity and fitness, respectively.


CONCLUSIONS
In this study the association between diet and overall mortality was, in large part, confounded by fitness.
Héroux
Mariane
M
Department of Community Health and Epidemiology, Queen's University, Kingston, ON, Canada.
Janssen
Ian
I
Lam
Miu
M
Lee
Duck-Chul
DC
Hebert
James R
JR
Sui
Xuemei
X
Blair
Steven N
SN
D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking / Q000453:epidemiology; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D015992:Body Mass Index; D002318:Cardiovascular Diseases / Q000453:epidemiology* / Q000401:mortality; D015986:Confounding Factors, Epidemiologic; D004032:Diet / Q000706:statistics & numerical data*; D005080:Exercise Test; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D011446:Prospective Studies; D012737:Sex Factors; D012907:Smoking / Q000453:epidemiology; D014527:Uric Acid / Q000097:blood
D001786:Blood Glucose; D008055:Lipids; D014527:Uric Acid