Dietary composition and ovarian function among Lese horticulturalist women of the Ituri Forest, Democratic Republic of Congo

Abstract

Objective: To assess dietary composition in relation to energetic status and ovarian function.

Design: An eight-month prospective study undertaken in 1989.

Setting: Ituri Forest, northeast Democratic Republic of Congo.

Subjects: Sixty-four female volunteers of reproductive age (16–45), with a subsample of 30 for nutritional focal follows, 39 for analysis of salivary progesterone levels, and 18 for analysis of salivary oestradiol.

Interventions: Regular anthropometric measurements of heights, weights, and mid-triceps skinfolds, 204 h of nutritional focal follows when all foods prepared and consumed were recorded and weighed, analysis of dietary composition using African food tables, collection of saliva samples every-other day for radioimmunoassay of salivary oestradiol and progesterone.

Results: The primary staple in the Lese diet is manioc, consumed at nearly every meal, but the diet is subject to seasonal fluctuations. Important seasonal crops are groundnuts and rice. Carbohydrates comprise 64% of the diet, protein 14% and fat 22%, but seasonal fluctuations in food items create significant differences in protein content (P=0.007). Energy intake falls by 25% in the hunger season. Lese energy balance reflects this lack with women losing a mean 7% of total body weight. The mean BMI for Lese women at the beginning of the study was 22.8 but, during the hunger season, the BMI for 20% of women fell to <18.5, indicative of chronic energy shortage. Mean levels of Lese salivary oestradiol and progesterone are chronically and significantly lower than healthy, Western controls (P=0.0001 for progesterone; P=0.03 for follicular values of oestradiol, P=0.0001 for mid-cycle values, and P=0.0002 for luteal values). Mean salivary progesterone levels were significantly lower for those Lese women losing weight (P=0.03), and significantly lower for weight-loss women when comparing levels at the beginning and end of the hunger season (P=0.03).

Discussion: The relatively low-fat, high-fibre diet of the Lese appears healthy, but there are occasional seasonal deficiencies in protein-energy and micronutrient content, especially for pregnant and lactating women. Dietary composition may affect Lese levels of reproductive steroids, partly explaining the chronically low salivary oestradiol profile of this population.

Sponsorship: This work was supported by a National Science Foundation Grant (BNS-88-10931) to PT Ellison, and a Royal Society Research Fellowship to GR Bentley.