Strengthening immune health can help protect against COVID-19

March 13 (UPI) -- Research shows people with underlying health conditions or compromised immune systems are at greater risk as the novel coronavirus, COVID-19, spreads -- but experts say taking steps to improve health could make a big difference.

"I tell all of my patients with chronic health conditions like diabetes, high blood pressure and heart disease to do what they can to maximize their health right now," Kathryn A. Boling, a family physician at Mercy Medical Center, told UPI. "That means taking your medications as directed, exercising and eating well. If you have high blood pressure, for example, now is not the time to slacking off on your diet and eating a lot of salty foods."

A study published Wednesday in The Lancet, which reviewed the cases of 191 people with COVID-19, found that those with high blood pressure, diabetes and heart disease were more likely to have severe disease, require hospitalization for care or die than people who were otherwise healthy when they became infected.

In all, 54 of the 191 patients in the study -- all of whom were from Wuhan, China, epicenter of the outbreak -- died, and two thirds had at least one other health condition before getting sick. According to the authors, 26 had high blood pressure, 17 had diabetes, 13 had heart disease and four had chronic obstructive pulmonary disease, or COPD.

"All of these conditions, and other chronic disease, can suppress your immune system's ability to mount a defense against a virus like COVID-19," Boling said. "When people say those who are immune suppressed are at greater risk, they mean somebody who is undergoing chemotherapy, or has HIV or people who have rheumatoid arthritis who are taking immuno-suppressor medications. Pregnant women are also a little immune suppressed."

People who are 65 and older also don't have the same immune defenses they once did, which is why seniors get a high-dose flu vaccine every year, she added.

Still, those who fall into one or more high risk groups -- more than 30 million Americans have diabetes, while more than 100 million have high blood pressure -- can help minimize their risk by living a healthy lifestyle.

A balanced, nutritious diet, regular exercise and getting enough sleep can go a long way to optimizing the immune system to fight off infection, whether it's the flu or something more serious.

People can also make changes that enhance immune system function. For example, eating a low-carbohydrate diet with plenty of different-colored fruits and vegetables helps supply the immune system with the antioxidants and anti-inflammatory phytonutrients it needs to fight infection.

A high-fiber diet, including grains and yogurt, can strengthen the gut microbiome -- or so-called "good bacteria" in the digestive tract -- and bolster immune defenses.

Boling recommends that all her patients take up to 2000 IUs of vitamin D daily. Vitamin D has been shown to play a role in immune health, she said, and many people don't get adequate amounts of it in their diets.

The potential benefits of supplements like echinacea and vitamin C for immune health haven't proved in existing studies, she added, and those considering supplements should talk to their doctor before taking them.

Another study published Wednesday in The Lancet linked smoking with more severe disease in COVID-19. Boling said she has advised her patients who smoke to quit even more emphatically since the start of the outbreak.

"People need to make sure their immune systems are at peak functioning ability, so when or if they do get sick they do better," she noted. "Most people have a pretty good idea of how strong their immune system is based on how they do every year with cold and flu. I have people come in that say, 'I never get sick.' Well then, their immune system is probably pretty robust. But if people find that they get sick multiple times every winter, then it's probably something they need to work on, now more than ever."