Nutr Cancer. 1986 ; 8(4): 239-45.

Diurnal variations in prolactin and growth hormone levels in normal premenopausal vegetarian and omnivorous women.

Fentiman IS, Caleffi M, Wang DY, Hampson SJ, Hoare SA, Kwa HG.

Diurnal levels of plasma prolactin and growth hormone were measured in 47 normal premenopausal women, 26 of whom were established vegetarians and 21 of whom were omnivorous controls. There were no differences between the median prolactin levels of the two groups during a 24-hour period of investigation. When the groups were further subdivided into ovolactovegetarians and vegans, still no differences were found in prolactin secretion. In contrast, the vegetarian women exhibited elevation of growth hormone levels during the period of study, which was particularly marked at midnight and 10 A.M.