Diet and Immunity for Life (and during COVID-19)

Posted on May 05, 2020

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One of many casualties of the COVID-19 pandemic and resulting stay-at-home orders was the ‘Food as Medicine’ Health Innovation Economic Forum. The event will recover (it has been rescheduled for October 29th). In the meantime, we asked two of the panelists to share evidence-based information about how nutrition affects our immune systems—and to specifically address whether there is any truth to the claims popping up on social media regarding ‘boosting immunity’ or fighting COVID-19 through supplements or nutrition.

Carrie Verishagen is a registered dietitian and coordinator of Eat Well Saskatchewan, a new service offered through the University of Saskatchewan that connects registered dietitians with people in Saskatchewan so they can receive current and evidence-based nutrition information during the COVID-19 outbreak. 

“The immune system is complex.” she says. “Diet definitely plays a part, but so does getting enough sleep, exercising regularly, limiting alcohol and not smoking. When you talk about diet specifically, optimal nutrition over time can prepare the body to fight off infection. But no diet or supplement is going to prevent or cure COVID-19, and unless a deficiency is present, there is no evidence taking vitamin supplements such as Vitamin C beyond what you get through a healthy diet will be of any benefit.”   

“What is most relevant to health is diet quality, not a number on a scale. Diets high in saturated fat, salt and sugar and low in fibre, vitamins and minerals are associated with chronic illness. A diet low in nutrients can lead to deficiencies, which could affect your ability to fight illness.”

Both Verishagen and Dr. Elizabeth Klodas, preventive cardiologist and founder and Chief Medical Officer of Step One Foods in Minneapolis agree on this fundamental statement: you can’t prevent getting COVID-19 through nutrition, but good nutrition can make you more resilient if you do get it.

Klodas reinforces Verishagen’s focus on diet quality, not just during the pandemic, but for overall health. “COVID-19 is not the only health issue right now. Other health conditions like heart disease, hypertension, diabetes and obesity are continuing their relentless march and killing thousands of people every day. These diseases are also big risk factors for increased complications if you contract COVID-19. If you’re eating for heart health, you’re also eating for immunity. A healthy, well-nourished body is better able to withstand any insult.”

To maintain a healthy immune system, it’s important to do your best to eat a variety of healthy foods every day. “Certain nutrients are associated with a healthy immune system: protein, zinc, Vitamin C and Vitamin D for example all play certain roles in immunity. With the exception of Vitamin D, which we may benefit from a  supplement in northern climates during the winter months, most can meet their needs by filling half their plate with fruits and vegetables, eating protein with every meal, and having healthy fats and whole grains every day,” says Verishagen.

Citing the most recent data coming out of New York City, Klodas says, “Healthy people do really well with this. Two per cent of COVID-19 patients end up needing hospitalization and 0.5 per cent die. Of the people who die, 1.8 per cent are under 65 with no underlying health conditions. The chances of a healthy young person dying is 0.009 per cent. That’s a tiny risk.”

While it’s important to eat for health, Verishagen says good nutrition is also important should you fall ill. “With illness, your body goes into stress which can increase your needs for nutrition and fluid. Trying to eat and drink small amounts every one to two hours, sipping broth, fluids, or using nutrition supplements can help you recover faster.”

So does nutrition make a difference to our immunity? Klodas sums it up: “Eating junk food can put you at increased risk of complications of COVID-19. In a setting where we have an unpredictable disease with no treatment and no vaccine, everything you can do to protect yourself by having a good defence matters. Why wouldn’t you eat well?”

 

Noelle Chorney