Previous observational studies have suggested that β-cryptoxanthin, a micronutrient present in yellow and orange fruit and vegetables, may help delay the onset of menopause. Given the widespread social trend of delaying pregnancy, the possibility that β-cryptoxanthin supplementation may delay age-related loss of fertility and onset of menopause is of significant interest. In a parallel study, either saline or β-cryptoxanthin (5 µg/kg rat/day) was delivered to Wistar albino rats via an osmotic pump from 4 to 7 months of age. All control and β-cryptoxanthin-treated dams were fertile at 7 months of age, with no differences in litter size, sex ratio, or pup viability at the time of mating at 7, 9, 11, and 15 months of age (p ≥ .05 for all). As expected, over time there was a pronounced decrease in litter size and serum anti-Müllerian hormone (AMH), but with no significant differences between the two groups at any time point. Overall, there was a positive correlation between litter size and AMH (r = 0.324, p = .012), confirming a link between this serum marker of ovarian reserve status and fertility potential. At 16 months, bilateral oophorectomies were performed at necropsy, before conducting follicle density assessments of ovarian reserve. The total number and stage of follicle development were similar between the β-cryptoxanthin and control groups (13.8 ± 3.2 cf 10.2 ± 4.8, respectively, p > .05). β-cryptoxanthin supplementation for 3 months early in reproductive life was not effective in delaying ovarian senescence or enhancing fertility in rats later in life, contrary to the association suggested by observational studies in humans.
Keywords: AMH & litter size; diet; exercise; fruit; menopause; ovarian reserve; β-cryptoxanthin.