The immune system is extremely complex and relies on the interplay of many factors to keep us healthy. It consists of a vast network of organs, white blood cells, proteins, and chemicals that work in sync to fight off unwelcome pathogens, such as bacteria, viruses, parasites, etc. Despite the strength and sophistication of our immune systems, there are a number of lifestyle habits that can disrupt or hinder its function, such as poor stress management, isolation, compromised diet quality, and level of exercise. These, among many other lifestyle habits that can weaken your immune system, are discussed in more detail below.

10 Lifestyle Habits That May Be Weakening Your Immune System.

1. Poor Stress Management

Everyone experiences stress; it’s a normal part of life and can have its benefits. However, if stress sticks around for an extended period of time and becomes chronic, it can create a hormonal imbalance in our body, weakening the immune system and making us more susceptible to illness¹. We may not be able to eliminate our stress entirely, but we can get better at managing it. To de-stress and stay healthy, try exercising to blow off steam, pausing to be mindful, or connecting with others. 

2. Loneline

Speaking of connecting with others, isolation can have a negative impact on immune health. Studies have shown that those who are socially isolated tend to have white blood cells that are highly active and increase inflammation. In addition, lonely individuals also appear to have lower levels of antiviral compounds known as interferons². Having strong relationships and a good social network is good for your immunity³.

3. Over or Under Exercising

Regular exercise can stimulate your immune system by enhancing its ability to make white blood c

ells that help the body fight disease. However, both over and under-exercising can counteract this effect and suppress the body’s ability to fight infection. For example, one study found that the risk of illness increased in athletes during periods of intensified training and competition⁴. Conversely, another study concluded that sedentary, or inactive, behavior weakens the immune response to pathogens⁵. Exercise can include anything from jogging and biking to gardening and walking; in fact, as little as 30 minutes of walking five days a week can help your immune system perform at its best⁶.

4. Smoking

Whether you’re partaking in traditional cigarettes, e-cigarettes, or regularly exposed to second-hand smoke, the substances found in cigarette smoke can weaken your body’s ability to resist infections⁷. In addition, exposure to the chemical compounds in e-cigarettes can damage the first lines of immunity defense: the linings of your mouth, and nose⁸. As such, quitting smoking is the best option for protecting and improving the strength of the immune system.

5. Excessive Alcohol Intake

Overindulging in alcoholic beverages can have a negative effect on your immune system. Studies have shown that frequent consumption and alcohol binges can impair the body’s ability to defend against infection, contribute to organ damage, and hinder recovery from tissue injury⁹. If you think you may be drinking too much, try limiting your intake. Canada’s low-risk guidelines recommend no more than two drinks per day for women or three for men, and to plan non-drinking days every week to avoid developing a habit¹⁰.

6. Chronic Exposure to UV Radiation: 

Ultraviolet (UV) radiation from the sun is on the rise, due to increasing air pollutants depleting the ozone layer. The increased UV radiation can not only lead to higher rates of skin cancer and cataracts but can also weaken our immune systems¹¹. Wearing sunglasses, protective clothing, and sunscreen of SPF 30 or higher can help.

7. Poor Diet Quality

The chances are that, if you are consuming ultra-processed foods high in salt, refined sugars, and saturated fat, you are not getting enough of the nutrients that are imperative for immune health. This dietary pattern is often referred to as the Westernized Diet and has been known to trigger inflammation and disrupt immune system functions¹². Conversely, dietary patterns made up of whole and nutrient-dense foods, such as the Mediterranean diet, are beneficial for immune function¹³. To optimize your immune system with food, choose vegetables, legumes, nuts, fruits, whole grains, and plant oils more often.

8. Inadequate Fluid Consumption

Water is the elixir of life and plays many important roles in your body, immune support. The fluid in your circulatory system, called lymph, is predominantly water and carries important immune cells around your body. Being dehydrated slows down the movement of lymph, and can blunt immune system functions¹⁴. Increasing your water intake can help flush out harmful substances and ward off illness. Adults should aim for 8-12 glasses of water daily – and remember, water-rich fruits and vegetables, soups, and herbal teas count too¹⁵!

9. Overdoing it on Caffeine

Coffee and tea are touted for their health-protective properties, due to their antioxidant content. However, too much caffeine can disrupt sleep, and result in increased inflammation, thus compromising immunity¹⁶. To best support, your immune system, try gradually decreasing your intake of caffeine and establishing a cut-off time for consumption, at least six hours before bedtime to prevent sleep interference.

10. Sleep Deprivation: 

Adequate sleep helps the body rest and prepare to fight foreign intruders, such as infections, bacteria, and viruses. When we sleep, our bodies release small proteins called cytokines, which are essential for the regulation of the immune system. The level of cytokines increase during sleep, therefore lack of sleep hinders the body’s ability to fight infections¹⁷.  Adults aged 18 or older should aim for 7-9 hours of sleep daily to keep the immune system working optimally¹⁸.