Updated: Jun 15
You are vaccinated and maybe even boosted, but you still wonder if there is anything else you can do to prevent severe COVID—19 in case of exposure or infection. Are there any natural ways to strengthen your immunity so that it can fight the virus better? With Omicron making its waves across the world, there are a lot of questions about how infectious, deadly, and vaccine—resistant the new strain is. Many of us are asking: if it is true that vaccines are not as effective in preventing infection as they were for previous strains, how can we continue to live our life (semi) normally while staying safe? What can you personally do to decrease your risk of severe disease, hospitalization, and death? Well science says: quite a lot!
To be clear, covid vaccines are still the single, most effective prevention measure against severe illness, hospitalization, and death, even for Omicron. Abundance of studies, clinical trials, and real—life data we have so far all serve as proof of excellent vaccine efficacy and admirable safety profile.
In addition, wearing a well—fitting mask independantly tested for high filtration efficacy has been proven many times over to offer excellent protection from virus exposure. After all, masks and personal protective equipment are what kept our doctors, nurses, essential workers, and the rest of us safe before vaccines became available. This article gives in depth info on mask efficacy, proper wear, and top recommended masks (aside from N95).
At the same time, like with any viral infection, the role of immunity in protecting us against severe disease and the ways we can strengthen it through beneficial behaviors within our control, should not be neglected or downplayed. It turns out (and hopefully to nobody’s surprise) that how we treat our body does make a difference. Aside from certain preexisting and genetic conditions, and some medications (like immunosuppressants), which can put people at increased risk of severe COVID—19, there are a lot of things that we can do by ourselves and naturally to reduce our risks from the worst outcomes.
This article is meant to be a summary of reputable, scientific studies and data we have so far, on factors, aside from age and comorbidities, that increase or decrease risk of severe covid, hospitalization, and death. Other things that you might have heard of being helpful in COVID—19 prevention, are likely not included here because their effect is either disproven by now or there is not enough evidence yet that benefits outweigh the risks. Lastly, information given here is not meant to treat or prevent any diseases or illnesses, and you should always consult your doctor for any medical questions.
People who exercise (even as little as 10 minutes per week) have lower chances of being hospitalized for COVID—19 or dying from it compared to people who are consistently inactive. Inactivity was found to be the third most important risk factor for COVID—19 death, only after age and previous organ transplant.
Many health benefits of exercise are widely known and acknowledged for heart disease, high blood pressure, obesity, cancer, mental health, and overall living longer (for more on the general health benefits of exercise check out my previous blog post).
So it should come as no surprise that a new study in British Journal of Sports Medicine, done on over 48,000 people of different racial backgrounds, confirmed a huge role of exercise in mitigating COVID-19 risks. When compared to people who were the most active (those who exercised 150 minutes per week), people who were consistently inactive were 226% more likely to be hospitalized, 173% more likely to be admitted to intensive care, and 149% more likely to die from COVID—19. This is huge!
Any Exercise is Better Than None
What’s even more striking is that people who were active for just over 10 minutes per week still had some protection against severe illness and death, compared to those who were consistently inactive. Of course, the protective effect was not as big as for those who got the full 150 minutes of exercise a week.
Still, this proves that any amount of exercise is beneficial for our health and for prevention of severe COVID—19 outcomes. In fact, as concluded in the study: consistent inactivity was the third most important risk factor for COVID-19 death, behind only age over 60 years and previous organ transplant. Most strikingly, researchers found that inactivity was more important than even smoking, obesity, diabetes, high blood pressure, cardiovascular disease, and cancer. This is absolutely mindblowing and encouraging at the same time, as it is something that we can definitely accomplish on our own.
What Can You Do?
For people who suffer from mobility issues or a specific condition or injury that makes exercising risky or a challenge, it is best to consult your doctor and physical therapist to find the best and safest ways to achieve realistic exercise goals.
For the rest of us, I advise getting up right now and doing 10 jumping jacks to start! Then check my previous blog post about easy and effective exercises that can be done at home, no equipment needed. Fun story: after reading this new study about exercise and covid I started a new routine — before each meal I do 15 jumping jacks, it takes literally a minute. And first thing in the morning, my husband and I do just 15 minutes of yoga. With these two quick routines, at the end of the work day I only need to do 10—15 minutes of cardio to meet recommended daily exercise goals!
Obesity and Being Overweight
Being obese or even overweight dramatically increases chances of testing positive, having a severe disease, being hospitalized, or dying from COVID—19. This applies to adults and children, and it is true across the world.
Obesity is defined as having BMI >30, while being overweight includes BMI between 25 and 30. In US today, 42% of adults are obese and additional 30% of adults are overweight. Roughly one in five US children now have obesity.
Talking about other people’s bodies and physical appearance is often criticized and frowned upon in the US and in addition, I am a supporter of everyBODY is beautiful. However, the extensive research data we have so far makes this topic impossible to ignore in the context of factors that increase risk of severe COVID—19.
COVID—19 Stats on Obesity
Meta—analysis and systematic literature review, done by CDC, shows that risk of severe COVID—19 increases sharply with elevated BMI. This is why obesity is included in the CDC list of COVID-19 risk factors. Many studies came to essentially the same conclusion about the high negative effect of obesity, and even of being overweight, on poor covid outcomes. Summary of some of the study conclusions include the following:
Individuals with obesity were 46% more likely to test positive for COVID—19, 113% more likely to be hospitalized, 74% more likely to be admitted in ICU, and 48% more likely to die
COVID—19 patients with obesity were 131% more likely to have severe illness and outcomes vs. those without obesity.
Obesity may triple the risk of COVID—19 hospitalization. The increased risk for hospitalization or death was particularly pronounced in those under age 65.
77% of patients hospitalized with COVID-19 were overweight (29%) or obese (48%).
The same risk unfortunately also applies to children, as children with obesity have 2.87 times higher risk of mortality vs. non-obese children.
This negative effect of obesity and being overweight on COVID—19 outcomes applies across the world. As reported by one global study, COVID—19 fatality rates are 10 times higher in nations where at least 50% of adults are overweight.
What Can You Do?
If you are overweight or obese, it goes without saying that shedding some weight would be in the best interest of health. Some of the simplest ways proven to make an impact are:
Quit fast food — it is the single most unhealthy, overly processed source of (mal)nutrition regardless of weight.
Try to cook more at home — food you make at home from fresh ingredients will by default be healthier than prepackaged, processed, fast food.
Quit sugary drinks (more on negative effects of sugary drinks below). Besides the obvious soda, this also includes some seemingly “healthy” drinks, like over the top sugary herbal teas, or some coffees and smoothies sold at chain coffee shops like Starbucks etc.
Try to move more whether by walking, taking stairs instead of an elevator, and if possible starting a light exercise program, even if for just 10—15 minutes a day.
Even if you start small, you will be making long term progress for your health. If you have a condition that is making losing weight difficult or dangerous, please consult your doctor and nutritionist who can help you create a plan that suits your health goals and your lifestyle best.
Vitamin D Deficiency
Low levels of vitamin D have been associated with increased chances of testing positive for COVID—19, more severe disease, and even higher rate of hospitalization and death. The effect seems to be more pronounced in African Americans. Over 40% of Americans are vitamin D deficient.
Vitamin D has long been known for its effects on boosting the immune system and easing inflammation. Consequently, low vitamin D levels have been associated with an increase in inflammatory cytokines, risk of pneumonia and viral upper respiratory tract infections. Vitamin D deficiency is also associated with an increase in thrombotic episodes, which are frequently observed in severe COVID—19 patients.
According to the National Health and Nutrition Examination Survey 41.6% of adults in the US are vitamin D deficient. This number goes up to 69.2% in Hispanics and 82.1% in African Americans. In addition, 57% hospitalized patients and 60% of nursing home residents are vitamin D deficient. Another location—specific study showed that almost two thirds of healthy, young adults in Boston are vitamin D deficient by the end of the winter.
Causes of Vitamin D Deficiency
According to WebMD the most frequent causes of vitamin D deficiency are:
Vegan diet — since most sources of vitamin D are of animal-origin, like fish & fish oils, eggs, fortified milk, etc.
Not enough sun exposure — Today this presents a real issue, due to widespread use of sunscreen, staying out of the sun, or covering up with clothing. This issue is also more prominent in areas where it is difficult to get enough sun during long winters, like in Chicago. According to research, for most people 15—20 minutes of sun exposure three times a week is usually all that is needed to get enough vitamin D.
Obesity and weight loss surgery
Darker skin — Skin pigment, melanin, reduces skin’s ability to produce vitamin D. This is one of the reasons why African Americans are more prone to vitamin D deficiency.
Some conditions that disturb effective absorption of vitamin D: celiac disease, Chron’s disease, cystic fibrosis, some kidney and liver diseases, etc.
Some medications — steroids, laxatives, cholesterol and weight loss drugs, etc.
If you are in any of the above mentioned groups, ask your doctor to check your vitamin D levels at the next physical.
Impact of Vitamin D on COVID—19
When it comes to COVID—19, several new studies have shown that people with low vitamin D levels might be more likely to test positive for COVID—19, have more severe symptoms, or even be hospitalized and die:
According to a study published in The Journal of Clinical Endocrinology & Metabolism vitamin D deficiency was found in 82.2% of hospitalized COVID-19 patients and in only 47.2% of the general population control group. Vitamin D deficient patients also had a longer hospital stay vs. those with sufficient vitamin D levels.
In another study published by Jama Network Open, vitamin D deficient patients were 77% more likely to test positive for COVID-19 when compared to those with sufficient vitamin D levels. The difference was statistically significant.
A new study from Israel published in Plos One hospitalized patients with vitamin D deficiency prior to COVID—19 infection (vitamin D < 20 ng/ml) were 14 times more likely to have severe or critical disease than patients with high vitamin D levels (≥40 ng/mL).
This effect is even more pronounced in African Americans, for whom higher levels of vitamin D in blood were associated with significantly lower chance of getting infected, and more importantly lower chances of severe COVID-19, according to a study from University of Chicago, published in JAMA Open Network.
What can you do?
First, ask your doctor to check your vitamin D level by a simple blood test. If your levels are sufficient, there is likely no need to add a supplement, as too high levels of vitamin D can be harmful.
If your levels are low or borderline, talk to your doctor about a supplement or how you can increase your intake of vitamin D rich foods in your diet.
Chronic Lack of Sleep and Burnout
People who sleep less than 7 hours per night, have several sleep problems, or report regular burnout have higher chances of getting COVID—19, having severe disease, and even being hospitalized for it.
International study done on health care workers published in BMJ Journals showed that 1-hour longer sleep at night resulted in 12% lower odds of getting COVID-19. People with several sleep problems were 88% more likely to get infected with COVID—19. Self—reported regular burnout was associated with 2.6 times higher chance of getting COVID—19, 2.98 times longer duration of illness and 3.3 times worse severity, compared with people who reported no burnout. These associations remained significant after adjusting for frequency of COVID—19 exposures.
Another well—controlled study recently published on CDC website and done with military personnel, showed that lack of sleep was associated with more severe COVID-19 cases that lead to hospitalization more often than people who slept 7 or more hours a night, even after adjusting for all other health behaviors. Hospitalized patients were 1.8 times more likely to report sleeping less than 7 hours a night, compared to their peers who had covid but did not require hospitalization.
What Can You Do?
This one is straightforward — hit the sack earlier every night and make sure you get at least 7 hours of sleep per night. Easier said than done? What I find helpful is to not have any caffeine after 5pm (for some this may need to be even earlier) and to set my alarm half an hour before my ideal bedtime. This reminds me to start winding down and get ready for bed. Otherwise, there is always something else that needs to be finished and before you know it it’s 1am and I am exhausted the next day. We are all busy and often overworked and overstressed. But it is crucial to prioritize your sleep for many reasons, covid now being just one of them. And only by taking care of yourself will you be able to offer your best to the world.
Consumption of Sugary Drinks
People who drink three or more sugary drinks per week are more likely to be hospitalized for COVID—19 compared to those who drink less than three.
This one caught me by surprise. Of course, we all know drinking overly sweetened beverages is not good for you. But who would have known that there is a direct, dose—dependent correlation between the amount of sugary drinks consumed and COVID—19 risks? This is exactly what the above-mentioned study confirmed: patients hospitalized for COVID-19 were 1.74 times more likely to consume 3 or more sugar-sweetened beverages per week, compared to non—hospitalized people with COVID—19, even after adjusting for other health—related behaviors. Even more so, the more sugar-sweetened beverages they consumed, the higher their odds of hospitalization. The most striking finding in my opinion is that just 3 overly sugary beverages per week was enough to see statistical difference in hospitalization, which is pretty mind blowing.
What Can You Do?
Drop that Coke / Pepsi / Starbucks Frappuccino and all similar, sugar—loaded drinks right now. Replace them with water, obviously, or with some other good—for—you swaps:
All natural fruit juices, ideally diluted with water. In our family, we drink water with a splash of fresh—squeezed apple or orange juice (with pulp, to keep all the good fiber in)
Sparkling drinks sweetened with stevia —My personal favorite is Zevia Cola flavor
Water flavoring drinks with good—for—your ingredients and vitamins. My newly discovered favorite is Water Drop.
Vitamin C and Zinc
Vitamin C has long been known to be vital for overall immune system health and zinc has antiviral properties and has been shown in vitro to inhibit replication of coronavirus in cells. A recent study found that having very low blood levels of zinc is associated with more severe COVID-19 and higher mortality rates. However, giving high dose zinc to hospitalized patients didn’t improve their outcomes. This indicates that people with low levels of zinc could benefit from supplementation in order to prevent more severe outcomes in case of COVID—19 infection.
While there is currently no conclusive proof that supplementation with vitamin C and zinc in people who are not deficient has any COVID—19 related benefits, it is clear that eating a well—balanced diet high in all necessary nutrients is very important for overall health and a strong immune system.
Green Tea EGCG
While this one is not yet proven in vivo, several in vitro and in silico studies showed that EGCG, a component of green tea, has antiviral properties based on inhibiting or weakening COVID-19 spike proteins that enable the virus to attach to the host cell. Through this action, EGCG is shown to potentially help impede COVID-19 infection, suppress its replication, and even decrease COVID—19 caused cytokine storm, thrombosis, lung fibrosis, and sepsis. As mentioned, this beneficial effect is yet to be confirmed in vivo and through controlled, double blind, randomized studies, which are important to have in order to make any definite conclusions.
In the meantime, I continue to sip my daily matcha latte (made with non—dairy milk for best absorption) while writing this. If for nothing else matcha has many health benefits (read more about that here), it gives me a subtle yet much needed caffeine boost, and it tastes delicious.
I invite you to try it and while you are at it, don't forget to get your 7 hours of sleep, do those jumping jacks, take it easy with added sugar, check your vitamin levels, and stay well!