What is the Immune System?

The immune system is the body’s defense against the invasion of microorganisms that can cause us to get sick. The immune system is located in different organs and cells throughout the body with 70% of our immune system being located in the gut (1). There are two divisions of the immune system: the innate immune system, which provides a barrier (such as skin, tears and saliva) against invading microorganisms, and the adaptive immune system, which elicits a targeted response to specific microorganisms (1).

How Does the Immune System Change During Pregnancy?

Pregnancy triggers a number of changes in our bodies, many of which are due to fluctuating hormone levels. One of these shifts is alterations in immune system function in order to help keep baby healthy. It has long been thought that the immune system weakens during pregnancy to prevent it from attacking the fetus; however, recent research suggests that the immune system follows a pattern of predictable changes that allow for the healthy development of the baby (2). With these changes to the immune system, pregnant women may be more vulnerable to sickness.

How Can You Support Your Immune System?

You may be wondering whether there is anything you can do to keep your immune system healthy and help prevent sickness during pregnancy. It should be noted that there is not one single food or supplement that will “boost” your immune system. In fact, an overactive immune system would not be a good thing. However, practicing daily habits can help to support your immune system and keep it functioning as it should. Try implementing the following practices into your daily routine to help support your immune system during pregnancy:

• Eat a balanced diet
  • Choose a variety of fruits and vegetables to provide antioxidants including vitamin C, selenium and carotenoids
  • Include whole grain foods in your diet including whole grain bread, pasta, brown rice, whole oats, barley and quinoa
  • Include protein rich foods such as legumes, nuts and seeds, eggs, dairy products and some dairy alternatives, fish, chicken and meat
• Engage in gentle movement
  • Aim for 150 minutes of moderate exercise per week; this includes aerobic and resistance training (3)
  • You can also include gentle stretching or yoga
• Get enough sleep
  • Aim for 7-8 hours per night
• Manage stress
  • Stress can weaken the immune system and make us more vulnerable to sickness
  • Strategies to help reduce stress can include practicing mindfulness, eating a balanced diet, getting enough sleep and exercising
• Wash your hands properly
  • Wash your hands for 20 seconds (or use hand sanitizer) before preparing or eating food and try not to touch your eyes or nose with unwashed hands (4)
• Take a prenatal multivitamin supplement daily
  • Certain nutrient needs increase during pregnancy so this is a general recommendation for all pregnant women, but prenatal supplements also contain vitamins and minerals that can offer immune support including zinc, vitamin C and vitamin D
• Utilize safe food handling practices
  • Fully cook meat, shellfish, fish and poultry and avoid consuming raw fish, unpasteurized dairy products, juice and cider, and raw or lightly cooked eggs

The Bottom Line

Pregnancy is a time where the immune system is temporarily weakened. Though there is no single food or supplement to boost the immune system, implementing daily habits can offer support to the immune system. If you have any concerns about your health during pregnancy, make an appointment with your doctor or Registered Dietitian to help keep you and your baby in the best possible health.

References

1. Dietitians of Canada. Immune System Background. In: Practice-based Evidence in Nutrition^® [PEN]. 2019 Oct 10 [cited 2020 Jul 1]. Available from https://www-pennutrition-com.proxy1.lib.uwo.ca/KnowledgePathway.aspx?kpid=16006&trid=18279&trcatid=38. Access by subscription only. Click sign up on PEN login page.
2. Digitale, E. (2017). Immune system changes during pregnancy are precisely timed. Stanford Medicine News Center. Retrieved July 1, 2020, from http://med.stanford.edu/news/all-news/2017/09/immune-system-changes-during-pregnancy-are-precisely-timed.html
3. Canadian Society for Exercise Physiology. 2019. 2019 Canadian Guideline for Physical Activity throughout Pregnancy. Canadian Society for Exercise Physiology. Retrieved July 1, 2020, from https://csepguidelines.ca/guidelines-for-pregnancy/#resources
4. Dietitians of Canada. Eating Habits for a Healthy Immune System. Practice-based Evidence in Nutrition^® [PEN] Knowledge Pathway Immune System. 2020 Apr 1 [cited 2020 Jul 1]. Available from: https://www-pennutrition-com.proxy1.lib.uwo.ca/KnowledgePathway.aspx?kpid=16006&trid=28211&trcatid=467. Access by subscription only. Click sign up on PEN login page.