Quantity and variety in fruit and vegetable intake and risk of coronary heart disease
Quantity and variety in fruit and vegetable intake and risk of coronary heart disease1-3
Shilpa N Bhupathiraju
Nicole M Wedick
An Pan
JoAnn E Manson
Kathyrn M Rexrode
Walter C Willett
Eric B Rimm
Frank B Hu
0 Supported by grants from the NIH ( P01 CA87969, P01 CA055075, R01 HL034594 , and HL60712). SNB is a recipient of a postdoctoral fellowship grant from the American Heart Association (13POST14370012). School of Public Health , 655 Huntington Avenue, Boston, MA 02115 , USA
1 From the Department of Nutrition, Harvard School of Public Health , Boston, MA (SNB, NMW, WCW , and FBH); Saw Swee Hock School of Public Health and Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (AP); the Division of Preventive Medicine, Brigham and Women's Hospital and Harvard Medical School , Boston , MA (JEM and KMR); the Department of Epidemiology, Harvard School of Public Health , Boston, MA (JEM, WCW, EBR , and FBH); and the Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School , Boston, MA, WCW, EBR, and FBH
2 Abbreviations used: CHD, coronary heart disease; FFQ, food-frequency questionnaire; HPFS, Health Professionals Follow-Up Study; NHS, Nurses' Health Study. First published online
Background: Dietary guidelines recommend increasing fruit and vegetable intake and, most recently, have also suggested increasing variety. Objective: We prospectively examined the independent roles of quantity and variety in fruit and vegetable intake in relation to incident coronary heart disease (CHD). Design: We prospectively followed 71,141 women from the Nurses' Health Study (1984-2008) and 42,135 men from the Health Professionals Follow-Up Study (1986-2008) who were free of diabetes, cardiovascular diseases, and cancer at baseline. Diet was assessed by using a validated questionnaire and updated every 4 y. Variety was defined as the number of unique fruit and vegetables consumed at least once per week. Potatoes, legumes, and fruit juices were not included in our definition of fruit and vegetables. Results: During follow-up, we documented 2582 CHD cases in women and 3607 cases in men. In multivariable analyses, after adjustment for dietary and nondietary covariates, those in the highest quintile of fruit and vegetable intake had a 17% lower risk (95% CI: 9%, 24%) of CHD. A higher consumption of citrus fruit, green leafy vegetables, and b-carotene- and vitamin C-rich fruit and vegetables was associated with a lower CHD risk. Conversely, quantity-adjusted variety was not associated with CHD. Conclusions: Our data suggest that absolute quantity, rather than variety, in fruit and vegetable intake is associated with a significantly lower risk of CHD. Nevertheless, consumption of specific fruit and vegetable subgroups was associated with a lower CHD risk. Am J Clin Nutr 2013;98:1514-23.
INTRODUCTION
Of the several dietary factors implicated in coronary heart
disease (CHD)4 prevention, the evidence is most consistent for
fruit and vegetables (
1, 2
). Dietary recommendations have
repeatedly underscored the value of increasing intakes of fruit and
vegetables in the diet, and, most recently, have also highlighted
the importance of greater variety. For example, the most recent
American Heart Association diet and lifestyle guidelines for
cardiovascular disease risk reduction have issued a
recommendation to consume a variety of fruit and vegetables (3).
Likewise, the 2010 Dietary Guidelines for Americans emphasize the
importance of increased fruit and vegetable intake and greater
variety (
4
).
In a few cross-sectional studies, higher variety scores for fruit
and vegetable intake were associated with lower odds of the
metabolic syndrome, obesity, hypercholesterolemia, and
hypertension (
5, 6
). However, these studies did not entirely separate the
concept of variety from quantity, because those with greater
variety also had greater intakes of fruit and vegetables. Therefore,
it is not clear whether the observed associations for variety were
independent of quantity of consumption. We previously reported
on the association of fruit and vegetable intake with risk of CHD
over 8–14 y of follow-up and observed that for every one serving
greater intake of fruit and vegetables per day, risk of CHD was
lower by 4% (7). The primary objective of this study was to
examine the independent associations of quantity and variety in
fruit and vegetable intake in relation to incident CHD over
a longer period of time in the Nurses’ Health Study (NHS) and
the Health Professionals Follow-Up Study (HPFS).
SUBJECTS AND METHODS
Study population
The NHS was initiated in 1976 as a prospective cohort study of
121,701 female registered nurses, 30–55 y of age, from 11 US
states. The HPFS is a prospective cohort study of 51, 529 male
health professionals, 40–75 y of age, from all 50 states that
began in 1986. In both cohorts, information on medical history,
lifestyle, potential (...truncated)