Along with other lifestyle factors like adequate sleep, exercise, and managing stress, nutrition plays an important role in maintaining a strong immune system. Priming our bodies to most effectively fight infection and disease is pivotal as we live with the threat of the current pandemic. Although there is no evidence on specific dietary factors that can reduce the risk of COVID-19, here are five ways help to ensure that you are optimally nourishing your body:

1. Eat a healthful and balanced diet as portrayed by the Healthy Eating Plate.  

Focus on fruits, vegetables, whole grains, legumes and nuts, moderate consumption of fish, dairy foods, and poultry. 

Eat mindfully.  Limit the intake of red and processed meat, highly refined carbohydrates (like white bread, white rice), and sugar (from sugar-sweetened drinks and desserts). Also limit butter and use healthy plant oils such as olive oil. 

A dietary pattern like the Mediterranean diet would meet these recommendations.

2. If you find yourself not being able to eat a balanced diet, consider taking a multivitamin containing the standard RDA for various vitamins and minerals as a safety net. Zinc, vitamin C, and vitamin D are examples of key nutrients that affect immunity

Older adults are most often deficient in certain vitamins and minerals, and would likely benefit from daily supplementation with a multivitamin.

3. Maintaining adequate levels of vitamin D may be particularly important. Vitamin D is normally produced in our skin when exposed to sunlight. However, exposure to sunlight may vary tremendously according to season and weather. Many of the commonly available multivitamin/multimineral supplements do contain 1000 or 2000 IU of vitamin D, which is a good target.

Those with darker skin (who tend to have lower blood levels because melanin in the skin blocks some ultraviolet light) may need more vitamin D; up to 4000 IU per day is considered safe.

4. Do not begin a restrictive, crash diet for weight loss during the pandemic as it may hinder your ability to eat healthfully. To help prevent weight gain during stay-at-home orders, aim to eat meals on a regular schedule, snack on fruits and veggies, and limit liquid calories, including alcoholic beverages.

 Many people are craving comfort foods at this time, especially sweet and high-fat foods, which are of course allowed, but be careful that they are not eaten so often that they crowd out the nutritious foods that support a healthy immune system. 

When you have a craving for comfort foods, pause and take a few in breaths and out breaths to be fully present with your craving.  Take the comfort food you really want and put it on a plate.  Eat mindfully, savoring each bite.  

5. Scientists are finding that the microbiome plays a key role in immune function, and our gut is a major site of immune activity. This means our diet plays a role in determining what kind of microbes reside there. To help support the growth and maintenance of beneficial microbes, eat a high-fiber, plant-rich diet with plenty of fruits, vegetables, whole grains, and legumes. Probiotic foods such as fermented or cultured foods (e.g., kefir, yogurt with live cultures, sauerkraut, tempeh, kimchi, and miso) may also be beneficial.

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  • Lilian Cheung, DSc, RD, is lecturer and  director of health promotion and communication in the Department of Nutrition at the Harvard T.H. Chan School of Public Health. Her work focuses on translating and communicating science-based recommendations to the general public to promote healthy lifestyles. She is editorial director of the School’s Nutrition Source website, which provides research-based guidance for healthy living. She also serves as co-editorial director of the Obesity Prevention Source, a website providing science-based information to support policy changes at the community level, and the Asian Diabetes Prevention Initiative, a website offering research-based public health messages for policymakers and the public to help counter the rising rates of type 2 diabetes in Asia. She has co-authored several books designed to foster healthy lifestyle development in young people, including the school-based nutrition and physical activity curriculum Eat Well & Keep Moving. As a student and practitioner of mindfulness, she actively promotes mindful living as a path toward well-being, and is co-author, with Zen master Thich Nhat Hanh, of Savor: Mindful Eating, Mindful Life that is in 17 languages.