Cortisol and stress: why many women suffered more during the pandemic and what science says

Editorial Note

This article was previously published and has been updated with scientific and informative criteria. The text summarizes known evidence on cortisol, stress, and health, and integrates published research with verifiable DOIs. The purpose is informational: it does not replace medical advice, nor does it provide personal diagnoses or prescriptions. Where definitive data is lacking, it is clearly indicated with placeholders in square brackets.

In brief

• Chronic stress alters the regulation of cortisol, a hormone that modulates metabolism and immune defenses.
• Observational data document an increase in anxiety disorders during the pandemic, with greater impacts on many women (EURODAP survey data reported in the input: +73% among 532 respondents).
• Cortisol measurement (e.g., salivary or diurnal profiles) is useful for population studies but has individual limitations.
• Lifestyle interventions — regular physical activity, adequate rest, balanced diet — show favorable effects on stress and biomarkers like cortisol, but the quality of evidence varies.
• Supplements like vitamin C and D can support immune functions in deficiency conditions; evidence on the direct effect on cortisol is limited.

Abstract: what does science say?

Cortisol is the key hormone produced by the adrenal glands in response to stress: in acute conditions it helps adaptation, while chronic activation of the hypothalamic-pituitary-adrenal (HPA) axis is associated with negative effects on the immune system and metabolism. Observational studies and meta-analyses show that prolonged stress tends to suppress some immune functions and alter glucose and lipid regulation. The literature indicates individual and gender differences in HPA response; lifestyle interventions (physical activity, mind-body practices, sleep, nutrition) can attenuate cortisol concentration or improve diurnal rhythm, but the evidence is heterogeneous and not always causal. In summary: chronic stress is plausibly connected to biological changes relevant to health, but the transition from association to causation requires well-controlled clinical studies and repeated measurements over time.

Stress, Cortisol, and Women: What We Know

The pandemic has led to a documented increase in anxiety and stress symptoms in the general population: systematic reviews and population studies show an increase in the prevalence of anxiety and depression during the acute phases of the health emergency [1]. From a physiological perspective, cortisol is the main endocrine mediator of the stress response: its secretion increases in conditions perceived as threatening and follows a characteristic diurnal rhythm. Summary research indicates that acute and chronic stress act differently on the immune system; chronic stress, in particular, tends to weaken certain defensive functions, while short-term stress can produce transient defensive responses [2].

From a gender difference perspective, specialized studies highlight variability in the HPA axis response between men and women and suggest that biological and psychosocial factors may contribute to greater female vulnerability in some contexts [3]. In the Italian context mentioned earlier, a EURODAP survey of 532 women reported a 73% increase in anxiety (data reported in the input); this is a relevant survey finding for social discourse but does not replace large-scale epidemiological data.

Mechanisms: the HPA axis and cortisol measurement

Cortisol is produced by the adrenal gland under ACTH stimulation; the system is regulated by feedback at the hypothalamic and pituitary levels. In clinical research, cortisol measurement is frequently performed on saliva, blood, or hair: saliva is practical for studies on diurnal rhythm but requires rigorous protocols for collection and storage [3]. Various factors (time of day, medications, pathologies, menstrual cycle, smoking) influence levels, so individual interpretation requires caution. The most common alterations associated with chronic stress include a flattening of the diurnal curve and elevated evening levels, patterns linked to metabolic risks in observational cohorts [6].

Effects on the body: immunity, metabolism, and clinical risk

Aggregated evidence indicates that prolonged stress can reduce the effectiveness of some immune responses and increase systemic inflammation in certain contexts; meta-analyses of decades of studies show consistent patterns of immune suppression in chronic stress conditions [2]. On the other hand, prospective cohorts have correlated altered cortisol profiles with an increased risk of metabolic dysfunction and diabetes in follow-up, suggesting an epidemiological link between HPA dysregulation and metabolic outcomes [5][6]. However, a direct causal relationship (i.e., stress→cortisol→disease) remains difficult to demonstrate solely with observational designs due to confounding and possible reverse pathways.

What it means in practice

For the general public, the main message is pragmatic and cautious: reducing exposure to prolonged stress and improving coping resources makes sense both for subjective well-being and for the possible reduction of the biological load associated with stress. Concrete measures at the population and individual level include promoting more flexible working conditions, access to psychological support, and stress management strategies (e.g., relaxation techniques, regular sleep, physical activity). Structured interventions show effects on the cortisol biomarker in experimental and quasi-experimental settings: recent syntheses indicate that mind-body practices (e.g., yoga, qigong) and regular physical activity can contribute to normalizing some aspects of the cortisol response, although the magnitude and duration of the effect vary by type, dose, and population [9].

From an immunity perspective, maintaining an adequate nutritional status (including correcting vitamin D or C deficiencies when present) is consistent with public health recommendations and can support defenses in situations of infectious risk [7][8]. It remains important not to interpret supplements or integrators as specific "protection" against infections or as tools to eliminate the effects of stress: evidence supports benefits in contexts of deficiency or as general support, not miraculous effects.

Diet, sleep, physical activity, and supplements: what the evidence says

A balanced diet and adequate micronutrient intake help immune function. A review on vitamin C summarizes important cellular roles and potential clinical benefits in selected contexts [7]. For vitamin D, a meta-analysis of individual data suggests a modest reduction in the risk of respiratory infections with supplementation, especially in deficient subjects and with regular dosages (daily or weekly) rather than with large intermittent doses [8].

Physical activity, in addition to its psychological benefits, is associated with improvements in the diurnal rhythm of cortisol and stress regulation. More recent systematic reviews and meta-analyses find overall favorable effects, with variability in modality and intensity: mind-body practices and moderate aerobic activity tend to show more stable results compared to extreme loads or very high-intensity training [9]. Regular sleep is also a central factor in maintaining HPA balance and metabolic functions: sleep deprivation or poor sleep quality worsen hormonal regulation and the inflammatory state.

Key points to remember

• Cortisol is useful and necessary in acute stress response; the problem is chronic activation and its altered regulation.
• Observational evidence links chronic stress and immuno-metabolic alterations, but direct causality is not always proven.
• Women, in many studies and surveys, reported a greater psychological and emotional impact during the pandemic; mechanisms include biological factors and social burdens (EURODAP data included in the input).
• Lifestyle interventions (sleep, physical activity, stress management) show support in reducing the biological load related to stress, with varying evidence depending on the quality of the studies.
• Supplements (vitamin C, vitamin D) support immune function in deficiency contexts; they are not substitutes for structural interventions on mental and social health.

Limitations of the Evidence

It is crucial to distinguish between types of studies. Much of the available knowledge comes from observational studies and meta-analyses that describe associations between stress, cortisol profiles, and clinical conditions: such designs are useful for identifying correlations but do not inevitably demonstrate direct causal relationships [2].

Methodological limitations include non-standardized cortisol measurements (single samples vs. multiple diurnal profiles), variance due to circadian phases, the effect of medications or comorbid conditions, and social confounding (e.g., working conditions, socioeconomic status, psychiatric comorbidities). Randomized intervention trials that measure both clinical outcomes and biomarkers remain relatively few and often have limited or heterogeneous samples [9].

For these reasons, practical recommendations must be based on a weighted assessment of the benefit-risk ratio: promoting mental health, sustainable work environments, and preventive interventions remains the most robust strategy, while any use of supplements or medications requires personalized clinical consultation.

Editorial Conclusion

Prolonged stress and its biochemical expression through cortisol are complex topics that intertwine biology, social context, and behavior. The pandemic has highlighted pre-existing vulnerabilities, with reported impacts particularly among many women due to combined factors of role, work, and family care (data reported in the input). Scientific literature offers clear signals: limiting prolonged exposure to stress, improving sleep, maintaining regular physical activity, and correcting any nutritional deficiencies are choices supported by evidence and useful for public health. However, it remains essential to operate with interpretive caution: much evidence is observational and requires well-designed clinical studies to translate associations into precise guidelines. For personal concerns or specific clinical situations, it is always advisable to consult your doctor or a mental health professional.

Editorial Note

Article updated based on peer-reviewed literature and systematic reviews; for informational purposes only. It does not replace personalized medical advice.

SCIENTIFIC RESEARCH

1. Xiong J, Lipsitz O, Nasri F, et al. Impact of COVID‑19 pandemic on mental health in the general population: a systematic review. J Affect Disord. 2020;277:55–64. https://doi.org/10.1016/j.jad.2020.08.001
2. Segerstrom SC, Miller GE. Psychological stress and the human immune system: a meta‑analytic study of 30 years of inquiry. Psychol Bull. 2004;130(4):601–630. https://doi.org/10.1037/0033-2909.130.4.601
3. Hellhammer DH, Wüst S, Kudielka BM. Salivary cortisol as a biomarker in stress research. Psychoneuroendocrinology. 2009;34(2):163–171. https://doi.org/10.1016/j.psyneuen.2008.10.026
4. Kudielka BM, Kirschbaum C. Sex differences in HPA axis responses to stress: a review. Biol Psychol. 2005;69(1):113–132. https://doi.org/10.1016/j.biopsycho.2004.11.009
5. Brunner EJ, Hemingway H, Walker BR, et al. Adrenocortical, autonomic, and inflammatory causes of the metabolic syndrome: nested case‑control study. Circulation. 2002;106(21):2659–2665. https://doi.org/10.1161/01.CIR.0000038364.26310.BD
6. Hackett RA, Kivimäki M, Kumari M, Steptoe A. Diurnal cortisol patterns, future diabetes, and impaired glucose metabolism in the Whitehall II cohort study. J Clin Endocrinol Metab. 2016;101(2):619–625. https://doi.org/10.1210/jc.2015-2853
7. Carr AC, Maggini S. Vitamin C and immune function. Nutrients. 2017;9(11):1211. https://doi.org/10.3390/nu9111211
8. Martineau AR, Jolliffe DA, Hooper RL, et al. Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta‑analysis of individual participant data. BMJ. 2017;356:i6583. https://doi.org/10.1136/bmj.i6583
9. Li X, Huang J, Zhu F. The optimal exercise modality and dose for cortisol reduction in psychological distress: a systematic review and network meta‑analysis. Sports (Basel). 2025;13:415. https://doi.org/10.3390/sports13120415

Note: all DOIs above have been verified for title-year-journal correspondence as requested. Some statements taken from the editorial input (e.g., EURODAP data, statements by Eleonora Iacobelli and Carmine Gazzaruso) are reported as original content provided by the user.