RELATED: Your Coronavirus Questions, Answered Many studies have found that the antioxidant extracellular superoxide dismutase (EcSOD) helps protect against ARDS and other heart and lung diseases, according to a review published in May 2020 in the journal Redox Biology. And that protective effect may include helping prevent the severe complications occurring as a result of COVID-19, the article notes. Zhen Yan, PhD, professor of cardiovascular medicine at the University of Virginia School of Medicine in Charlottesville and the lead author of the paper, says that while it’s important to point out that evidence has not yet included people with COVID-19 (because the disease is too new), the data has implications for people with it and those at risk. “If you exercise regularly, you will have more EcSOD and better ability to deal with any stressors,” Dr. Yan says. The research suggests that EcSOD is one of the ways exercise may protect people with COVID-19 against more severe complications, like ARDS. According to information from the Centers for Disease Control and Prevention (CDC), studies that included more than 40,000 people in China who had COVID-19 showed that overall 3 to 17 percent developed ARDS; between 20 and 42 percent of all hospitalized patients developed the complication; and 68 to 85 percent of all patients admitted to ICU developed it. (Deaths from patients admitted to the ICU ranged from 39 to 72 percent.) RELATED: Coronavirus Daily Update
Why Is EcSOD So Good for Us and How Does It Protect Heart and Lung Functioning?
Although our muscles naturally produce EcSOD, they produce it in higher quantities during vigorous exercise. After it is produced in the skeletal muscles, it then spreads through the blood to other organs, such as the lungs, heart, and kidneys. It’s a potent enzyme, Yan says. And it’s unique because, so far, it is the only known antioxidant enzyme that naturally works in the fluid, noncellular part of blood known as plasma, and it breaks down toxic free radicals produced during disease processes. (Free radicals are harmful molecules our bodies produce. Usually, our own antioxidants are able to neutralize them before they do damage, but when our bodies are burdened with disease or illness, we’re less able to fight them off. We experience what’s termed oxidative stress, leaving us more vulnerable to disease.) Research from Yan’s and other labs (conducted mostly in animals) has found that exercise indeed raises EcSOD levels, which was associated with better lung, heart, and kidney health. Yan’s team has used genetic engineering to get mouse skeletal muscle to produce more EcSOD to mimic the effects of aerobic exercise training. He found that the mice were protected from severe ARDS when injected with a bacterial toxin that would usually cause high death rates. More research is needed to determine if this protective effect against ARDS happens in people, too — and more specifically in people with infections, like the one caused by the new coronavirus, Yan says. RELATED: What Is a Coronavirus? Other findings about EcSOD reviewed in the article include that levels of the enzyme have been shown to be increased in mice, as well as in human plasma, after endurance exercise specifically. Endurance exercise is exercise that increases your breathing and heart rate, such as jogging, walking, swimming, or biking. RELATED: How to Start (or Restart) a Cardio Habit You Can Stick With Resistance training did not appear to increase EcSOD levels to the same extent, but because weight training increases your muscle mass, this may in fact also be beneficial, as the muscle will produce more of the enzyme, says Yan. Although research shows that a single stint of exercise will increase our production of the enzyme, we don’t have evidence that just one bout of exercise will increase EcSOD to the level that it will be protective, says Yan. It is more likely that the protective effect builds up over time with regular exercise. Yan says the evidence collectively suggests that increased production of the enzyme EcSOD with exercise explains some of the underlying reasons why exercise is connected to so many health benefits. “It offers some clues as to why exercise is good for our bodies,” Yan says. Yan also hopes to explore developing versions of EcSOD that could theoretically be used in gene or protein therapies. The idea is that the agents would deliver the same therapeutic benefit as exercise (in terms of protecting organ function). It will, however, take much more time and research to develop and validate these therapies.
There Is More Work to Be Done Before Connecting EcSOD to COVID-19 Outcomes
Brett Bade, MD, a pulmonologist and assistant professor at Yale School of Medicine in New Haven, Connecticut, says that while exercise is clearly beneficial for heart and lung health, it needs to be recognized that this research review from Yan’s group did not look at ARDS in people with COVID-19 specifically, so based on this evidence, it’s impossible to know whether EcSOD would be protective against ARDS in people with COVID-19. But, he adds, exercise has always been foundational to our health and continues to be now during this health crisis. “It is possible that boosting immune function and anti-inflammatory properties via exercise could reduce the chance of infection or the severity of disease,” Dr. Bade says. RELATED: 7 Ways to Keep Your Immune System Healthy And it is important for people to find ways to exercise while following social distancing guidelines. RELATED: Online Workouts You Can Do At Home Right Now “In contrast to regular exercise, physical inactivity is associated with multiple worsened health outcomes,” Bade explains. “While minimizing social interactions helps us prevent the spread of the coronavirus, it should not preclude regular physical activity already recommended by reputable health groups.” But without much more evidence and testing, it is too soon to know what role a history of regular exercise has played in COVID-19 outcomes, he notes, stating, “We need more data.”
How Much Exercise Should We Be Doing?
The CDC recommends 150 minutes a week of moderate-intensity aerobic exercise such as brisk walking or 75 minutes a week of vigorous-intensity aerobic exercise such as jogging or running (or an equivalent mix of these two), plus muscle strengthening activities that work all muscle groups two or more days a week. RELATED: How Much Exercise Do You Need? Yan says the research suggests that aerobic exercise is the type that best improves EcSOD levels over time, but combining it with strength workouts to maintain muscle mass contributes to this outcome, too. The bottom line: You need to be doing both aerobic and strength workouts to keep EcSOD levels up. Remember, your workout plan should be appropriate for your level of health and fitness. If you have an injury or illness that might limit your fitness, check with your doctor before starting a new exercise program. RELATED: How to Start Working Out
