Unusual Sex Hormone Patterns among Desert-Dwelling Hunter-Gatherers*

Abstract

Endocrine parameters were assayed in a San ("Bushman") population of Botswana in an attempt to correlate hormonal secretion and body morphology. Serum levels of gonadotrophins and gonadal steroids were measured by employing radioimmune methods. No evidence for elevated estrogens could be found and males showed endocrine levels comparable with European and South African Negro values. Females have suppressed circulating levels of gonadal steroids and little corpus luteum function. A mechanism by which the ovaries may be suppressed, thereby limiting conception to times of high nutrition, may exist in the San. This hypothesis may have a bearing on the observation that births reach peak levels during March and April.

Serum and saliva sex hormone levels in !Kung San men

“…Moreover, the comparison of the !Kung Tser concentrations with the Tser levels of Kavango men from Namibia shows that the latter have a significantly higher mean Tser value (x = 6.26 ng/ml; ttest: P < .0001). Thus, our results together with previous findings (van der Walt et al, 1977(van der Walt et al, , 1978Worthman and Konner, 1987) suggest that San men have, on the average, a comparatively low level of total testosterone.…”

Adverse Effects of Dietary Habits on Menstrual Disorders in Young Women

“…Montero et al reported that among 1147 urban Spanish adolescents, aged between 14 and 20 years, nearly 40% of the adolescents tried to lose weight and that attempting to lose weight is significantly associated with an increase in irregular menstruation and dysmenorrhea without a significant relation with body mass index [54]. The epidemiological study showed that circulating level of gonadal steroids is suppressed in Bushwomen except when food is plentiful and hunting activities restricted, suggesting close relationship between nutritional deficiency and hypothalamic-pituitary-ovarian suppression [55]. It has been also reported that vegetarians frequently have menstrual disturbances [56][57][58][59].…”

Malnutrition and Fertility

“…One explanation for shorter amenorrhea among mothers with better diets is that they have more food available to supplement their infants, who are then satisfied with shorter and less intense periods of breast-feeding. This is apparently the reason for the shorter amenorrhea intervals among supplemented mothers in a Mexican study (10)(11)(12)). An alternative explanation, suggested by Gray (13) is that more vigorous suckling is required by infants of poorly nourished mothers, whose ability to produce milk is reduced by their low nutritional status.…”