No Link Found Between PCOS, Personality Traits and Mediterranean Diet Adherence in Infertile Women

A case-control study of infertile women in Iran has found no statistically significant associations between polycystic ovary syndrome (PCOS), personality traits, and adherence to the Mediterranean dietary pattern, according to a peer-reviewed article published in BMC Nutrition on 23 October 2026.

The study, led by Maryam Hassanzadeh Bashtian and colleagues, set out to examine whether the hormonal disorder, which can disrupt ovulation and contribute to infertility, might be linked to psychological characteristics or dietary patterns among women already experiencing infertility. The researchers enrolled 180 non-pregnant women aged 18 to 45 years with a history of infertility, dividing them into two groups of 90: women with PCOS and infertile women without the syndrome.

Personality was assessed with the NEO-FFI questionnaire, an instrument that measures the five major dimensions of personality: conscientiousness, openness to new experiences, extraversion versus introversion, agreeableness, and neuroticism.

When the researchers compared the two groups, the personality dimensions showed no statistically significant differences. The reported p-values were 0.87 for conscientiousness, 0.26 for eagerness for new experiences, 0.14 for extraversion or introversion, 0.44 for agreeableness, and 0.81 for neuroticism, all well above the 0.05 significance threshold the study set in advance.

The dietary analysis was equally unremarkable. There was no statistically significant difference between the PCOS and non-PCOS groups in Mediterranean diet adherence scores, and no statistically significant relationship emerged between adherence to the Mediterranean dietary pattern and the presence of PCOS itself, with a p-value of 0.87 for that comparison.

The authors were careful to frame what this null result does and does not mean. In their conclusion, they state that the findings did not demonstrate statistically significant associations among polycystic ovary syndrome, personality traits, and adherence to the Mediterranean dietary pattern among the infertile women studied. Crucially, they note that because body mass index, physical activity, insulin resistance, and other major metabolic and lifestyle variables were not assessed, the absence of an observed association between Mediterranean diet adherence and PCOS should be interpreted with caution and should not be regarded as evidence of an association independent of these potential confounders.

That limitation matters for how the study is read. A case-control design that does not measure or adjust for these variables cannot separate the effect of diet from the effects of the metabolic and lifestyle factors that travel alongside it. The authors therefore call for future investigations employing longitudinal designs, mediation analysis, or structural equation modeling to better elucidate these complex interrelationships.

The study’s design also shapes what can be concluded. As a descriptive analytical case-control study of 180 women with a history of infertility, it examined associations at a single point in time rather than following participants over years, so it cannot establish whether any dietary or psychological pattern preceded the development of PCOS. The findings apply specifically to infertile women in this age range and should not be generalized to women with PCOS who are not experiencing infertility, nor to the general population.

PCOS remains a significant reproductive health concern. As the study’s background notes, hormonal disorders such as PCOS result from hormonal imbalances that may disrupt ovulation and lead to infertility, and various factors, including genetics, mental health, insulin resistance, and nutrition, are thought to contribute to the development of the syndrome. Understanding whether modifiable factors such as diet are linked to the syndrome is an active area of research, and the published literature includes related case-control studies examining Mediterranean diet adherence, dietary inflammatory indices, and other dietary patterns in women with PCOS.

For now, the message of this study is a measured one: among these 180 infertile women, personality profile and Mediterranean diet adherence did not differ between those with and without PCOS. The authors’ own caution about unmeasured confounders, and their call for longitudinal and modeling-based follow-up work, set the agenda for what would need to happen before any firmer conclusions could be drawn about diet, personality, and this common endocrine disorder.

Subject of Research: Associations between polycystic ovary syndrome, personality traits, and Mediterranean diet adherence in infertile women

Article Title: Investigating the relationship between polycystic ovary syndrome, personality type, and adherence to the Mediterranean dietary pattern in infertile women: a case-control study

Article References: Hassanzadeh Bashtian, M., Hasannezhad, N., Sangsefidi, Z. S., Lashkardoost, H., Niazi, A., Hamedi, A., & Farazmand, T. (2026). Investigating the relationship between polycystic ovary syndrome, personality type, and adherence to the Mediterranean dietary pattern in infertile women: a case-control study. BMC Nutrition. https://doi.org/10.1186/s40795-026-01528-5

Image Credits: AI Generated

DOI: 10.1186/s40795-026-01528-5

Keywords: polycystic ovary syndrome, PCOS, Mediterranean diet, personality traits, infertility, case-control study, NEO-FFI, diet adherence, women's health, BMC Nutrition, Investigating, relationship