Some people rarely get a cold or the flu, while others experience many episodes every year. Why is that?
First things first, let’s define the “average” number of cold and flu infections, to better understand what “frequent colds and flu” means.
According to the Centers for Disease Control and Prevention, the average American adult gets an average of 2-3 colds per year, and children have even more. The flu is less common- about 5-20% of adults experience flu yearly. Overall, the average person will experience about 200 episodes of common cold and 16 episodes of flu during their entire life.
Here are the top reasons why a person may experience more colds and flu more frequently than others.
Weakened immune system
One of the main roles of the immune system is to defend the body from microbes, from cold and flu viruses to other viruses, bacteria, and fungi.
In normal conditions, the immune system mounts a response against microbes that can infect the cells. The immune system includes an immediate or innate response and a slower or adaptive response. While the innate response can prevent and control some infections, it is the adaptive immune system that reacts more specifically to a microbe. This adaptive immune system includes B cells which produce antibodies to a variety of viruses and other microbes and T cells that are specifically targeting cells infected by viruses.
What happens if the immune system is weakened? The response to viruses and other microbes is less effective. The result: increased risk of colds, flu, and other infections.
Individuals who have weaker immune systems include the elderly, those with cancer, diabetes, chronic heart, liver, and kidney diseases, infections like HIV, and certain genetic conditions. Smoking and excess alcohol also have a negative impact on the immune system. Certain medications like steroids and cancer therapies suppress the immune system, and thus the ability to fight infections.
Based on research from the National Institutes of Health (NIH), scientists found that the cells lining the airway are working hard to defend against viruses that cause the common cold, but there is a trade-off. When the cells are exposed to other air pollutants, pollen, or cigarette smoke, they have a significantly decreased ability to fight viruses. This research explains why individuals who smoke, have allergies, or other lungs or chronic conditions are more likely to get colds and flu. These individuals also tend to have more severe symptoms as well.
Hundreds of viruses cause colds and flu, and new strains develop each and every year. Even if a person had colds or flu in the past the immune system is unlikely to build a defense against every viral strain to which that person is exposed. During cold seasons, it is easy to get exposed and get infected when spending time in crowded spaces, hospitals, and other workplaces, schools, on a plane, or using public transportation. Families with young children, teachers, healthcare workers are at higher risk to get colds and flu more often.
Scientific studies show that psychological stress increases the risk of common cold and other respiratory infections. While short bouts of stress or positive stress can be a good thing and help a person take action when needed, chronic stress suppresses the immune system, as well as affects the heart, hormones, and digestion. One study found that an individual who experiences chronic stress is two times more likely to catch a cold compared with someone who doesn’t have high levels of stress.
Staying active is very important to overall health. Regular exercise is associated with more energy, better mood, and helps prevent or better manage stroke, diabetes, hypertension, anxiety, depression, arthritis, and many types of cancer. Regular exercise also improves immune function and may help reduce the risk and severity of respiratory infections like colds and flu. However, moderation is the key, warn scientists. Not only lack of exercise, but also prolonged, intense exercise causes immunosuppression and thus increased risk of colds, flu, and other infections. The goal is to stay active and exercise most days of the week. The duration of the workout depends on the type of exercise: from 20-30 minutes for high-intensity interval training to 45 -60 minutes for aerobic or weight training.
In addition to stress management and regular exercise, there are other lifestyle changes that you can make to reduce the risk of colds and flu. Work on improving both the quality and quantity of sleep, because sleep supports a healthy immune system. Short sleep duration and sleep disturbances both had been linked with increased susceptibility to viral infections like colds and flu. Fast food diet promotes excess weight and inflammation, both being independent risk factors to immune system suppression. Read this article to learn more about foods that can help recover quickly from a cold and flu, because the same foods may help prevent infections as well. As you may notice, many of these risk factors for frequent colds and flu can be modified. Improving diet, sleep, fitness, and stress management are a good start. Limiting exposure to smoke and other pollutants is also important. If you have a chronic condition like asthma or heart disease, it is best to work with your doctor and have it well controlled.