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Aging, Nutrition, & the Immune System

Disclaimer: The following is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. You should refer to the Centers for Disease Control (CDC), the World Health Organization (WHO), or other credentialed public health authorities for up-to-date information for proper measures to reduce your risk of exposure to COVID-19.

With the spread of the coronavirus (COVID-19), we are all trying to determine how likely we are to come into contact with this virus, how likely we will become infected, and what we can do to protect ourselves.

This is especially important in individuals 65 years and older as they are more susceptible than younger people to a variety of viral infections, including those that contribute to respiratory diseases. Additionally, as we age we recover slower from getting sick. 

Aging impacts both our immediate immune response as well our “memory” immune cells which impairs the ability to fight off viral infections. Additionally, as we age respond differently to vaccinations as we need new T-cells in order for them to be effective which means they might not be as efficient in protecting us from infections. 

Aging is associated with declined immune function, particularly T cell-mediated activity, which is responsible for destroying the disease-causing pathogens. Studies have shown that a nutrition-based approach may help to reverse or improve some of the diminished immune function that is associated with aging.    

Vitamin E 

Vitamin E is an antioxidant that helps protect cells from damage and supports the immune system. While vitamin E deficiency is rare, intake above recommended levels can enhance T cell function as we get older as well as decrease the incidence of upper respiratory infection in the elderly. Sources of Vitamin E include fats and oils, nuts and seeds, seafoods, and leafy vegetables.  


Zinc is an important micronutrient that supports our immune system. It helps to activate enzymes needed to fight infection. Most older adults have zinc intakes below the recommended amounts which can lead to a zinc deficiency. Zinc deficiencies are linked to impaired immune function and increased risk for acquiring infection. Some of the signs of a zinc deficiency include delayed wound healing or loss of sense of smell and taste. Zinc can be found in red meat, poultry, shellfish, legumes, nuts, and seeds.   

Vitamin D  

Our kidneys normally can synthesize some Vitamin D from our skin into the active hormone form. As we age, this process becomes less efficient. While many people enjoy vigorous health and active lifestyles well past the age of 65, limited time spent outside may contribute to lower vitamin D levels. Since vitamin D plays a key role in not only a healthy immune system but also cardiovascular, bone, and muscle health, it is important to be aware of vitamin D intake and the importance of maintaining adequate intake. Sources of vitamin D include fatty fish, like tuna or salmon, organ meat such as beef liver, cheese, egg yolks. Additionally foods that are fortified with vitamin D, like some dairy products, orange juice, soy milk, and cereals can help you boost your intake.


Probiotics are increasingly being recognized as an effective, immune-enhancing tool. A large part of our immune system falls in our gut. Supporting a healthy microbiome with foods that contain probiotics such as yogurt and kefir. Fermented foods such as sauerkraut and kimchi are also great sources of probiotics. Additionally, eating foods that contain prebiotics (foods and fiber compounds that support the growth of healthy bacteria) such as garlic, onions, barley, apples, and oats. Talk with your health care provider before starting any probiotic supplements, as there may be considerations for those who are immunocompromised or have certain health conditions. 

Omega-3 fatty acids  

Immune function is significantly impacted by our omega-3 fatty acid status. Increased intake of fish or omega-3 fatty acids may be beneficial to inflammatory and autoimmune disorders as well as to several age-related diseases. Omega-3 fatty acids are a type of fat that the body cannot produce on its own, so it is important to get them in our diet to stay healthy. Food sources include fatty fish such as salmon or halibut, walnuts, flaxseeds, chia seeds, and canola oil.

What else can you do to stay healthy after 65?

Sleep Well 

We release healthy proteins and antioxidants during sleep, so getting enough sleep is important to keep our immune system healthy. Research links too little sleep, or poor-quality sleep, to lowered immunity, even in young healthy people.The optimal amount of sleep for most adults is between 7 and 8 hours per night.  

Reduce Stress  

Stress has been shown to negatively affect your immune system and decrease your immune response. The hormone, cortisol, is increased during times of stress and can lower the number of lymphocytes (white blood cells) that our body produces which limits the effectiveness of the immune response. Some coping mechanisms to consider when trying to manage stress include physical activity, communicating with loved ones, indulging in a favorite hobby, mindfulness exercises, and journaling.

Avoid Sick People  

Limit your time around people that show obvious signs or symptoms including a dry cough, runny nose, fever, or difficulty breathing. It is also a good idea to avoid individuals that knowingly may have been exposed, even if they are not showing symptoms. Additionally, it is important to stay on top of your own health, especially if you have chronic health conditions such as COPD, asthma, or cardiovascular disease. If you do start to develop any coronavirus-related symptoms make sure to give your health care provider a call before you go into the office. 

Stay Active  

Exercise can decrease our levels of stress hormones and give a boost of the “feel good” hormones. There are also theories that exercise can help circulate our white blood cells which fight infections, as well as improve the function of our lungs and airways. Aim for a variety of strength, flexibility, balance, and aerobic activity if possible. Even walking stairs or doing household chores can be a great way to keep moving. If you can, try to get some exercise outside so that you can enjoy the fresh air which can help to improve your mood and help you get a dose of vitamin D.

Maintain Social Connections 

You don’t need to be physically present in order to stay in touch with your social network and support system. Using FaceTime, video-conferencing or even simply picking up the phone and calling someone is a good way to stay in touch. Studies have shown that individuals who felt they had a strong social network, even if they did not talk to them daily, were more likely to have better health outcomes.   

Quit Smoking  

Smoking decreases our body’s immunity and success at fighting off disease, making you more susceptible to illness and infection. Avoid being near smokers or consider looking into ways to quit if you are currently an active smoker.

Practice Food Safety

Be sure to cook foods (especially meat and eggs) thoroughly to prevent the likelihood of food illness, which can suppress your overall immune system.

Yours in health, 

Sherry Zhang, Ph.D. 

Founder & CEO

Next Steps?

Now that you've learned a bit about how nutrition can impact your immune system, you can do a couple of different things:

1. Read the next installment of our Immunity Series: Nutrition, Immunity, & Young Children to continue learning. 

2. Discover the best foods for your genes and start Eating For Your Genes through our Nutrition DNA Test

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