Familial correlation of dietary intakes among postmenopausal women.
A positive family history is a risk factor for many chronic diseases, including most cancers, coronary heart disease, and diabetes. Since diet is also associated with most chronic diseases, one possible explanation for non-Mendelian familial clustering is shared eating habits. Food frequency data were obtained on 3,515 sisters in the Iowa Women's Health Study, a prospective cohort of postmenopausal women. Intraclass correlations between sisters were computed on a range of energy-adjusted nutrients to determine whether dietary intakes were more similar among siblings than among unrelated individuals. Two methods were used to calculate correlations: analysis of variance modeling and weighted sibling correlations. F-tests and randomization tests were used to determine statistical significance. The intraclass correlations for all of the nutrients examined were statistically significantly greater than the hypothesized value of zero (P < 0.05). Representative correlations include dietary fiber (0.15), animal fat (0.12), vegetable fat (0.13), calcium (0.14), iron (0.04), cholesterol (0.08), sodium (0.10), vitamin D (0.16), and total energy intake (0.11). When corrected for measurement error, the magnitude of these correlations increased, on average 62%. Although modest in magnitude, these correlations may be high enough to influence familial clustering of complex diseases that are attributed, in part, to diet.
Vachon
C M
CM
Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis 55454-1015, USA.
Sellers
T A
TA
Kushi
L H
LH
Folsom
A R
AR
D000368:Aged; D000704:Analysis of Variance; D015982:Bias; D002908:Chronic Disease; D004034:Diet Surveys; D002149:Energy Intake; D005247:Feeding Behavior / Q000523:psychology*; D005260:Female; D006801:Humans; D007484:Iowa; D008875:Middle Aged; D009679:Nuclear Family / Q000523:psychology*; D017698:Postmenopause / Q000523:psychology*; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014930:Women / Q000523:psychology*