(Graz, 04 January 2017) When women take the contraceptive pill, they are taking in various sex hormones in a combination and dosage that suppresses ovulation and therefore prevents them from becoming pregnant. The preparations have likewise been shown to affect memory performance, as well as verbal and sensory abilities. A study conducted by the Karl Franzens University in Graz and the Medical University of Vienna now shows: the pill also affects our sense of smell.
"The concentration of the sex hormone oestradiol and the duration of intake are important factors," stresses Veronika Schöpf from the Institute of Psychology at Graz University. "A higher oestradiol content diminishes olfactory performance. At lower concentrations, the women were much more sensitive to smells. This effect was primarily seen after a longer period of intake," explains Schöpf. The results of the study have been published in the international online specialist journal PLOS ONE.
Our sense of smell is not only important for personal well-being but also for quality of life in general, for example for experiencing sensory pleasure. At the same time, it is also a crucial warning mechanism, for example to alert us to spoiled foodstuffs or dangerous situations. Our sense of smell also plays an important role in choosing a partner, says Schöpf: "In the absence of any influence from hormonal contraceptives, we would usually seek out a partner with a complementary immune system, because, from a biological perspective, they are the perfect partner to supplement our immunity genes. And so we choose our other half with our noses."
What Schöpf and her colleagues, Kathrin Kollndorfer and Iris Ohrenberger from MedUni Vienna, have discovered is that the olfactory performance of women using a hormonal contraceptive is directly related to the oestradiol content of the product and how long they have been taking it. For their study, they tested 42 women who had been taking hormone preparations with different oestradiol concentrations for between one and 15 years. “Those who had opted to take a pill with a low oestradiol concentration over a longer period had a better sense of smell than the volunteers taking a pill with a higher oestradiol concentration," say the scientists. However, Schöpf reassures us that there are absolutely no health implications: "The women themselves cannot perceive the changes, which are not within a range that could affect sensory enjoyment." However, the researchers conclude: "If women who are taking the pill are included as test subjects in scientific studies, it is necessary to allow for this as a baseline factor."
Olfactics is a special area of interest for Veronika Schöpf, who has been working as Professor of Neuroimaging at the Institute of Psychology of Karl Franzens University in Graz for two years now, as part of the BioTechMed-Graz joint research programme.
Service: PLOS one
Kathrin Kollndorfer, Iris Ohrenberger, Veronika Schöpf (2016). Contraceptive use affects overall olfactory performance: Investigation of estradiol dosage and duration of intake. PLOS ONE. DOI: 10.1371/journal.pone.0167520