c Department of Obstetrics and Gynaecology, Notre Dame Medical School, Fremantle, Western Australia 6160
Corresponding author:
Jack Lowe-Zinola
Email: jack.lowe-zinola@nhs.net
Professional address: Good Hope Hospital, Rectory Road, Sutton Coldfield B75 7RR
Telephone: 0121 424 2000
Dear Sirs,
We found the above recent article produced a most diverse and engaging discussion based within the present day pandemic of mental health issues.
The aforementioned Swedish population based study was at odds with its Nordic neighbour Denmark where the opposite effect of oral hormonal contraceptives upon depression was found [1]. As intimated by the authors, the confounders are endless, but what sprung to our minds was that Nordic countries are famous for two specific cultural items, diet and sauna bathing.
To illustrate the first of these two potential confounders, the Norwegian (MoBa) study in pregnancy, examining the dietary intake of over 50000 mother baby pairs linked to pregnancy outcomes, demonstrated a significant decrease in pre-eclampsia and preterm birth in women who consumed greater amounts of both pre and pro biotics [2]. Furthermore, recent data shows a potential reduction in the gut microbiome diversity amongst some hormonal contraception users that may be explain the heterogeneity in psychiatry and increased anxiety scores [3].
The second potential confounder is Sauna bathing or hyperthermic exposure. Sauna bathing has also been linked to an improvement in both physical and mental welling status across all genders and ages [4]. Anecdotally, there appears to be an increased incidence and use of saunas in Sweden in comparison to Denmark.
Perhaps these two common unique Nordic cultural factors are contributory confounders for the result of the findings. If so, should we be counselling our patients to examine lifestyle issues to avoid any potentially negative impact of hormonal contraceptives upon their wellbeing?
We would be most interested to hear the view of the authors but congratulate the group upon their work and perseverance to publish.