Scientific Tips on Preventing Cold, Flu, and COVID-19
A recent paper, published in Perspectives on Psychological Science, reviews predictors of upper respiratory viral infections, the common cold and the flu (influenza), as guidance for preventing COVID-19 infection after exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19 (Coronavirus Disease 2019).
A summary of the study’s findings follows (See Table 1).
Smoking
Compared to nonsmokers, smokers are at a greater risk of developing cold symptoms after exposure to the cold virus. A recent review study also found smoking increases the risk for the flu, noting that current smokers are “over 5 times more likely to develop...influenza than non-smokers.”
Smoking increases the risk for respiratory infections in a variety of ways—e.g., by inducing inflammation, altering the immune response, or causing structural changes in the airways.
Drinking alcohol
Drinking too much alcohol (e.g., binge drinking) inhibits the immune response and raises the risk for viral and bacterial infections. However, those who drink alcohol in moderation have a low likelihood of developing colds after infection. In one investigation, individuals who drank less than one alcoholic beverage a day were two times more likely to develop colds, when compared with moderate drinkers (three or four drinks a day).
Exercise
The benefits of exercise are many and include protection against infections. In the investigation cited above, people who exercised less than twice a week were more likely to develop symptoms of cold. Prolonged, intense exercise training, however, suppresses immune functioning. Therefore, moderation is key. American Heart Association’s recommendations may be a good place to start.
Vitamin C
In the 1997 study noted earlier, those who consumed less than 85 mg of Vitamin C per day (roughly equivalent to the recommended Vitamin C dietary allowance) were twice as likely to develop cold symptoms.
Vitamin C has potent antioxidant properties and is essential to the healthy functioning of the immune system. Some natural sources of vitamin C are citrus fruits (e.g., lemon, orange), cruciferous vegetables (Brussels sprouts, broccoli), bell peppers, and strawberries.
Sleep
Chances of becoming sick with the common cold or the flu increase in individuals with insufficient or inefficient sleep. Sleep efficiency refers to the percentage of time in bed spent actually sleeping.
In one study, participants with less than seven hours of sleep, compared to those with at least eight, were nearly three times more likely to develop symptoms of cold. And compared to participants with 98% or higher sleep efficiency, those with less than 92% sleep efficiency were five-and-a-half times more likely to get sick.
People with severe sleeping problems may benefit from any of several effective self-help solutions and research-based treatments for insomnia.
Psychological stress
Using an aggregate measure of stress, the author and collaborators found participants with the highest levels of stress were over twice more likely to get ill than participants with the lowest levels of stress. The measure was made of three stress indicators: Negative emotions (e.g., depression, anxiety), perceived stress (feeling unable to cope), and recent major stressful life events (e.g., job loss, death of a loved one).
Respiratory illnesses are more likely with long-lasting stressful events—e.g., recurring interpersonal problems or financial hardship due to unemployment/underemployment.
Chronic stress contributes to inflammatory diseases, and, in the case of the common cold or the flu, may either trigger symptoms of the disease (e.g., congestion, runny nose) or result in more severe symptoms.
Stress management and relaxation techniques (e.g., deep breathing, self-hypnosis, meditation, autogenic training) can be protective. Those interested may find Davis’s The Relaxation and Stress Reduction Workbook helpful.
Social support
Social support refers to resources (often emotional) accessible through one’s social network. The importance of social support becomes clearer during times of stress, such as during interpersonal conflict.
In one investigation, perceived support protected against infection (with the cold virus and the flu virus) associated with interpersonal conflict.
The American Psychological Association provides some suggestions on how to grow your social support network.
Social integration
Social integration refers to “active engagement in a variety of social activities or relationships, and a sense of communality and identification with one’s social roles.” Generally, a person who has more social roles (e.g., as a parent, spouse, church member, coworker) is more socially integrated.
Social integration has been shown to protect against mortality, perhaps because it promotes a sense of identity and self-worth, not to mention positive social pressure and motivation for self-care. In contrast, social isolation and loneliness are usually experienced as stressful.
In one study, compared to those with at least six social roles, individuals with three or fewer social roles were over four times more likely to develop a cold.
Lack of social integration is often a problem for immigrants and minorities, but any person or group (e.g., women, LGBTQ+, the disabled, older folks, people with mental health issues) might feel excluded or marginalized.
Socially inclusive policies, community activities, and social programs can help empower excluded individuals, promote a sense of belonging, and encourage social participation.
Takeaway and preventing COVID-19 infection
Many of us have been experiencing fear, anxiety, depression, and other mental health problems in response to the direct and indirect effects of the COVID-19 pandemic and related public health measures (e.g., lockdowns, quarantines, social distancing).
There have been economic difficulties (e.g., unemployment), increase in domestic violence, rise in unhealthy ways of coping (e.g., drug and alcohol abuse), reduced structure and daily routine, decline in healthy habits (e.g., exercise), reduced access to health resources, weakened social support structures, and others. These, considered in light of the risk factors for respiratory infection, suggest many of us are at a high risk of contracting COVID-19.
So, an awareness of these risk factors and doing whatever we can to address them can make a big difference not only for preventing COVID-19 infection but also for preventing respiratory illnesses like the common cold or the flu.