Protein intake and ovulatory infertility.
OBJECTIVE
The objective of the study was to evaluate whether intake of protein from animal and vegetable origin is associated with ovulatory infertility.


METHODS
A total of 18,555 married women without a history of infertility were followed up as they attempted a pregnancy or became pregnant during an 8 year period. Dietary assessments were related to the incidence of ovulatory infertility.


RESULTS
During follow-up, 438 women reported ovulatory infertility. The multivariate-adjusted relative risk (RR) (95% confidence interval [CI]; P for trend) of ovulatory infertility comparing the highest to the lowest quintile of animal protein intake was 1.39 (1.01 to 1.90; 0.03). The corresponding RR (95% CI; P for trend) for vegetable protein intake was 0.78 (0.54 to 1.12; 0.07). Furthermore, consuming 5% of total energy intake as vegetable protein rather than as animal protein was associated with a more than 50% lower risk of ovulatory infertility (P =.007).


CONCLUSIONS
Replacing animal sources of protein with vegetable sources of protein may reduce ovulatory infertility risk.
Chavarro
Jorge E
JE
Department of Nutrition, Harvard School of Public Health, Boston, MA 02115, USA. jchavarr@hsph.harvard.edu
Rich-Edwards
Janet W
JW
Rosner
Bernard A
BA
Willett
Walter C
WC
D000328:Adult; D004034:Diet Surveys; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D006801:Humans; D007247:Infertility, Female / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control*; D008460:Meat; D010060:Ovulation / Q000187:drug effects*; D014674:Plant Proteins, Dietary / Q000008:administration & dosage* / Q000494:pharmacology; D011247:Pregnancy; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014481:United States
D004044:Dietary Proteins; D014674:Plant Proteins, Dietary