The amelioration of olfactory acuity upon sexual maturation might affect food preferences

Abstract

Upon sexual maturation, olfactory acuity in women ameliorates and starts oscillating across the cycle. During ovulation, mean olfactory threshold is 30 times lower than during bleeding. Interestingly, menstruated women undergo maleodorant trimethylaminuria. We argued that olfactory amelioration during ovulation might concur to a mating strategy, whereas olfactory impairment during bleeding might protect women against self-refusal. Testosterone and its 17β-estradiol derivative might be responsible for the synchronization of these menstrual events. Furthermore, we posed the question whether olfactory detection amelioration upon sexual maturation might provoke a change in food preferences, for instance a reduction in fish consumption. A preliminary survey in Italy provided encouraging results: 15-44 year-old women have lower fish consumption than 3-14 year-old girls. Surprisingly, men exhibited the same behaviour, so new olfactory tests as well as testosterone measurements are under way.

Keywords: fish consumption; food preferences; menstrual cycle; olfactory threshold; testosterone; trimethylamine.

Figure 1

Hypothetical view of the multiple physiological processes concurring to modulate olfaction and liver FMO3 enzyme activity in women during menses. (CYP19A1 = Aromatase enzyme; Estradiol = 17β-Estradiol; TMA = Trimethylamine; TMAO = Trimethylamine oxide; FMO3 = Flavin mono-oxygenase 3; DA interneurons = Dopaminergic neurons; hPR = Progesterone receptor).

Figure 2

Variation of the percent of Italian consumers who ate fish at least three times a week from 1993 to 2007 (included), for sex and age classes, 3-14 (A) and 15-44 (B) years old.