The key finding
A 2025 review in Endocrinology proposes that polycystic ovary syndrome (PCOS)—affecting up to 10% of reproductive-aged women—may have evolutionary origins tied to ancient survival strategies. The review argues that PCOS characteristics like preferential abdominal fat storage, insulin resistance, and hyperandrogenism (elevated male hormones) could have provided survival advantages in three ancestral contexts: during periods of food scarcity, when fighting infectious diseases (aided by visceral fat stores), and through increased muscularity. However, these same traits come with reproductive costs, as women with PCOS often experience irregular ovulation, suggesting an evolutionary trade-off between survival and fertility.
What the study looked like
This is a comprehensive literature review that synthesizes recent physiological studies comparing subsistence-level populations with modern Westernized populations, analyses of survival-reproduction trade-offs in nonhuman mammals, and research using animal models of PCOS. The authors examined studies of women with normal body weight who have PCOS, focusing on their distinctive fat distribution patterns and metabolic characteristics. They also analyzed experiments with prenatally testosterone-treated animals and naturally hyperandrogenic animal models to understand how developmental programming might create PCOS-like traits. The review integrates findings from endocrinology, anthropology, and evolutionary biology to construct a framework explaining why PCOS traits persist despite reducing fertility.
Why researchers think this happened
The authors propose that PCOS represents an “environmental mismatch”—traits that were advantageous in ancestral environments but become problematic in modern settings characterized by abundant food and sedentary lifestyles. They suggest that preferential abdominal fat accumulation would have been beneficial during unpredictable food availability, allowing rapid energy storage and mobilization. Visceral and omental fat may have supported immune function during infectious disease challenges, which were major mortality risks in pre-modern populations. Increased androgens would have promoted greater muscle mass, enhancing physical strength for gathering resources. The review notes that these traits are linked through genetic inheritance and epigenetic programming that occurs before and after birth, suggesting they evolved as an integrated metabolic strategy rather than separate characteristics.
How to read this carefully
This is a theoretical framework rather than experimental evidence proving PCOS has evolutionary origins. The review synthesizes existing research but doesn’t provide direct genetic or archaeological evidence of PCOS in ancestral populations. The proposed survival advantages are plausible hypotheses based on what we know about metabolism and human evolution, but they’re difficult to test directly. Additionally, PCOS is heterogeneous—not all women with the condition have identical symptoms or metabolic profiles—which complicates any single evolutionary explanation. The trade-off between survival and reproduction is a well-established evolutionary principle, but applying it to a modern medical syndrome requires careful interpretation. This perspective is meant to generate new research questions, not to suggest that PCOS was somehow “beneficial” for women who have it today.
What this means for everyday life
Understanding PCOS through an evolutionary lens might help explain why standard diet and exercise recommendations often feel inadequate for managing the condition. If PCOS traits evolved for environments with food scarcity and high physical activity, the modern environment of abundant processed foods and sedentary work may be particularly challenging for women with these metabolic tendencies. This framework suggests that lifestyle interventions for PCOS might need to be more intensive or specifically tailored than for women without these traits. The review also highlights that PCOS isn’t simply a “disorder” but rather a collection of traits that made sense in different contexts—which may help reduce stigma while acknowledging real health challenges. For researchers, this evolutionary perspective could guide development of therapies that work with, rather than against, these deep-rooted metabolic patterns.