New Review Investigates the Role of Diet, Lifestyle, and Nutritional Status in Severe Infections

We are currently seeing a worldwide pandemic from a novel virus that has impacted public health as well as the economy. Most of the attention has been focused on social distancing guidelines, wearing masks, proper hygiene, laboratory testing, and contact tracing. These are all important; however, public health discussions have not been focused around lifestyle and nutritional strategies to support optimal immune function. This is essential as significant risk factors for poorer outcomes are associated with chronic inflammatory diseases such as type II diabetes, obesity, chronic lung and cardiovascular diseases, as well as the elderly population. The link between infection severity and comorbidities has been seen in other viral infections as well.

In a review published three days ago in Nutrients, researchers investigated the role of diet, lifestyle, and nutritional status in severe infections. 

Chronic inflammation has been involved in the onset and development of most if not all chronic diseases and it exacerbates viral infections. Current treatments to address inflammation in this novel virus have included first line antiviral medications, and specific anti-inflammatory and antimalarial medications; however, long term use of some of these medications has been associated with cardiovascular side effects.

Numerous studies have demonstrated the role of nutrition in supporting the immune system. 

Poor diet and lifestyle choices are associated with low grade inflammation and increased oxidative stress, leading to the development of chronic disease and comorbidities. For example, a higher body mass index (BMI) has led to complications from this novel viral infection. Individuals with obesity have a higher risk of pulmonary issues and comorbidities which compromise heart and lung function and increase the risk of developing severe diseases from the virus.

Although there are no known single foods, supplements, or protocols to prevent the infection, it is clear that nutritional status plays a significant role in patient outcomes. The research team notes at a minimum, individuals should be obtaining the recommended daily allowances for nutrients that play a role in supporting immune function. This virus will likely be around for some time, so maintaining an optimal nutritional status is essential and something that each individual can control. The elderly population is at greatest risk and common deficiencies among them include vitamins C and D, folate, and zinc.

A Mediterranean diet is an ideal diet as it includes foods that have both immunomodulatory and anti-inflammatory compounds. These foods are rich in essential vitamins and minerals as well as polyphenolic compounds.

Omega-3 fatty acids are also essential for supporting the immune system as they help resolve the inflammatory response and have potential antithrombotic effects. EPA and DHA act as substrates for the production of specialized pro-resolving mediators (SPMs) which may help reduce viral replication. 

Vitamin C has been used for decades for colds and influenza. Regular vitamin C supplementation has been shown to help reduce the symptoms and duration of a cold. Dosing at 1 to 2 grams per day is recommended as it has been effective in helping prevent upper respiratory tract infections. 

The research on vitamin D has continued to emerge, as it has anti-inflammatory and immunomodulatory properties. Individuals that are deficient will experience the most benefits and increasing vitamin D levels may reduce the risk of infection. The recommended daily allowance for vitamin D is only 800 IU. The research team recommends supplementing with 10,000 IU of vitamin D daily for several weeks to increase vitamin D levels and then decrease to 5,000 IU per day. The target vitamin D concentration should be between 40 ng/mL to 60 ng/mL. It is also important to optimize both vitamins A and K along with vitamin D as these fat soluble vitamins have intricate interrelationships with each other.

Zinc is essential for the development of immune cells and a cofactor for many enzymes. Zinc may help reduce the viral replication as well as the effects of the gastrointestinal and lower respiratory symptoms of this novel virus. It is suggested to have a zinc intake between 30 mg to 50 mg/day to help with influenza and coronaviruses.

These results demonstrate the importance of diet, lifestyle, and nutritional status and their role in immune function. It is difficult for most individuals to obtain an optimal intake of all these nutrients in the diet, and therefore, supplementation should be considered. Other nutrients to consider include tocotrienols, geranylgeraniol, resveratrol, quercetin, and melatonin. 

By Michael Jurgelewicz, DC, DACBN, DCBCN, CNS

Source: Zabetakis I, Lordan R, et al. COVID-19: The Inflammation Link and the Role of Nutrition in Potential Mitigation. Nutrients. 2020 May 19;12(5), 1466.