Written by Dr. Olivia Rose, ND

In healthcare, women and men are often grouped together and treated similarly, however scientific studies are increasingly indicating that there are clear distinctions between the sexes. A combination of genetic, hormonal, environmental and behavioural differences separate the way men and women respond to illness. This is also true when it comes to immune system function. 

Immune System Function – Women vs Men

There is a difference in the way men and women react to viral and bacterial invasion and research shows that women react with a more robust response.¹ In a study which looked at women and men from 20 to 89 years of age, researchers injected a seasonal flu vaccine to test the immune response.¹ After the vaccine was administered, blood samples were taken from participants to measure the number of antibodies and cytokines (immune proteins) produced.¹

The women in the study had a greater immune response to the vaccine when compared to their male counterparts.¹ Researchers hypothesized that the differences between the sexes is mainly due to genetics.¹ A cluster of genes which are modulated by testosterone were found to play a role in the immune response. Males with the highest testosterone levels had the lowest antibody response to the influenza vaccine.¹

A 2020 study added to this research by looking at the impact of age.² Both the men’s and women’s immune responses declined with age, however this decline occurred at different times for the two sexes. Major changes to the immune response in men were found to happen between the age of 62 and 64, while women did not experience this change until the age of 66 and 71 years.²  However, the greatest sex difference was detected after the age of 65 where women had a stronger adaptive immune response (long term immunity) while men had a stronger innate (non-specific) immune response; possibly explaining the increased sensitivity to infectious disease in men.² Researchers suggested that the sex differences in males and females have important clinical implications and this valuable information should be used when deciding on treatments.²

The good news for women is that in general, women’s bodies can handle the threat of a virus or bacteria more efficiently than men. Due to a robust adaptive immune response, women also create a superior ‘memory’ of invading pathogens.² Meaning, if they get sick again, women have an improved immune response against the virus or bacteria because their body has created more antibodies against it.²

However, on the other hand, the heightened immune response generated by women is one of the reasons why women have an increased risk for autoimmune disease.³ Autoimmune disease occurs when the body over-reacts to a benign substance and starts attacking its own tissue. Some common autoimmune diseases include rheumatoid arthritis, Hashimoto’s autoimmune thyroiditis, celiac disease, Graves’ disease, and type 1 diabetes.

The Effect of Stress on Immune System Function

Women may innately have a superior immune response when compared to men, however that only explains part of the picture. Immune health is determined by a multitude of factors which means that there are ways to increase your immune system’s efficiency that are within your control.

One of the most powerful steps towards creating a healthy immune response is to lower your stress. High stress is also a risk factor for autoimmune disease, therefore lowering stress levels is especially beneficial for women.⁴ On average, women are more stressed than men. During the COVID-19 pandemic, stress has increased for everyone, however, there has been a disproportionate impact on women as women are more likely to work in the service industry and tend to take on more responsibility in the home than men.⁵

The Adrenal Glands, Cortisol & Age

When in a chronically stressful situation, the body produces high amounts of the hormone cortisol. Cortisol is a steroid hormone released by the adrenal glands which sit right on top of the kidneys. Cortisol has many impacts on the body, one of them includes a dampening effect on aspects of your immune system.⁶ If cortisol remains high, immune dysregulation occurs and there is a weaker immune response overall. A study which looked at the impact of stress on the immune response found that individuals who sustain long periods of stress were more likely to be infected with the common cold.⁶ 

Age also impacts the immune response. With age, older adults are also unable to terminate the cortisol response as efficiently as younger adults which can lead to an accumulation of this hormone; further compromising the immune response.⁷

Therefore, limiting and managing stress is important for building a resilient immune system.

Incorporate Strategies to Decrease Cortisol and Manage Stress

Some strategies to help decrease cortisol and manage stress include:

• Deep breathing and meditation.⁸
• Exercise – but don’t overdo it. Too much intense exercise can increase cortisol production.⁹
• Get adequate sleep – 8 hours a night.¹⁰
• Shift your focus once a day with a hobby or activity that brings you pleasure.¹¹
• Supplement with adaptogenic mushrooms and herbs such as like Ashwagandha, rhodiola, licorice root, cordyceps.¹²

Other Ways to Improve Your Immune Health  

Adopt a healthier lifestyle

Maintaining a diet rich in fruit and vegetables, lean proteins, whole grains and low in processed carbohydrates and meats can give your body the fuel it needs to fight infection.¹³ Colourful fruits and vegetables are full of vitamin C, antioxidants and phytonutrients which assist in immune function.¹³ Lowering the intake of sugar, inflammatory fats and processed foods help the immune system function optimally.

Get your vitamin D tested and supplement if necessary

Vitamin D plays a crucial role in proper immune system function. A low vitamin D status is associated with a higher prevalence of bacterial and viral infections.¹⁴ Many Canadian’s have either sub-optimal or deficient vitamin D status. The lack of sun exposure in the winter months means that nearly all Canadian’s should be supplementing with vitamin D to achieve optimal levels.

There is a difference in the immune response of men and women, however, regardless of your sex, there are many ways to support a healthy immune response and it’s important to focus on the aspects of your health that are within your control.

References:

1. Furman D, Hejblum BP, Simon N, Jojic V, Dekker CL, Thiébaut R, Tibshirani RJ, Davis MM. Systems analysis of sex differences reveals an immunosuppressive role for testosterone in the response to influenza vaccination. Proceedings of the National Academy of Sciences. 2014 Jan 14;111(2):869-74.

2. Márquez EJ, Chung CH, Marches R, Rossi RJ, Nehar-Belaid D, Eroglu A, Mellert DJ, Kuchel GA, Banchereau J, Ucar D. Sexual-dimorphism in human immune system aging. Nature communications. 2020 Feb 6;11(1):1-7.

3. Moulton VR. Sex hormones in acquired immunity and autoimmune disease. Frontiers in immunology. 2018 Oct 4;9:2279.

4. Stojanovich L, Marisavljevich D. Stress as a trigger of autoimmune disease. Autoimmunity reviews. 2008 Jan 1;7(3):209-13.

5. Uncovering the hidden iceberg. Why the human impact of COVID-19 could be a third crisis. August 2020.

6. Cohen S, Janicki-Deverts D, Doyle WJ, Miller GE, Frank E, Rabin BS, Turner RB. Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk. Proceedings of the National Academy of Sciences. 2012 Apr 17;109(16):5995-9.

7. Morey JN, Boggero IA, Scott AB, Segerstrom SC. Current directions in stress and human immune function. Current opinion in psychology. 2015 Oct 1;5:13-7.

8. Kim SH, Schneider SM, Bevans M, Kravitz L, Mermier C, Qualls C, Burge MR. PTSD symptom reduction with mindfulness-based stretching and deep breathing exercise: randomized controlled clinical trial of efficacy. The Journal of Clinical Endocrinology & Metabolism. 2013 Jul 1;98(7):2984-92.

9. Beserra AH, Kameda P, Deslandes AC, Schuch FB, Laks J, Moraes HS. Can physical exercise modulate cortisol level in subjects with depression? A systematic review and meta-analysis. Trends in psychiatry and psychotherapy. 2018 Dec;40(4):360-8.

10. Morgan E, Schumm LP, McClintock M, Waite L, Lauderdale DS. Sleep characteristics and daytime cortisol levels in older adults. Sleep. 2017 May 1;40(5):zsx043.

11. Detweiler MB, Lane S, Spencer L, Lutgens B, Halling MH, Rudder TF, Lehmann L. Horticultural therapy: A pilot study on modulating cortisol levels and indices of substance craving, posttraumatic stress disorder, depression, and quality of life in veterans. Alternative Therapies in Health and Medicine. 2015 Jul 1;21(4):36.

12. Chandrasekhar K, Kapoor J, Anishetty S. A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults. Indian journal of psychological medicine. 2012 Jul;34(3):255.

13. Myles IA. Fast food fever: reviewing the impacts of the Western diet on immunity. Nutrition journal. 2014 Dec;13(1):1-7.

14. F Gunville C, M Mourani P, A Ginde A. The role of vitamin D in prevention and treatment of infection. Inflammation & Allergy-Drug Targets (Formerly Current Drug Targets-Inflammation & Allergy). 2013 Aug 1;12(4):239-45.