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Nutrition, Aging, and the Immune System

Disclaimer: The following is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. 

For the past nine months many of us have been very aware of the risk and severity of viral infections, especially the risks and outcomes related to COVID-19. Early on it became clear that COVID-19 affected individuals who were over the age of 65 or those who had underlying health conditions at a greater rate and increased severity. Not only are we still in the middle of a pandemic but we must also start to prepare for the upcoming flu season, which like COVID-19, tends to affect older individuals at a higher rate and with more serious side effects including pneumonia. This may, in part, be attributed to the fact that individuals 65 years and older 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 nutrient. 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.

How else can you stay healthy as you age?

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, lowers 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, corticosteroid, 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 be 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-bourne illness, which can suppress your overall immune system.

While changing your diet may be more challenging during stressful times, focusing on small changes, such as incorporating one or two additional servings of nutrient-rich immune-boosting foods can feel much more manageable. Taking the time to assess your current diet and needs or scheduling a telehealth appointment with a registered dietitian or other healthcare professional to help build a solid dietary foundation and plan can result in significant benefits. Even small, incremental tweaks to your diet and lifestyle can reap big rewards in the long run. 

Check out our previous blog on personalized nutrition here if you would like to learn more about how personalized nutrition can be utilized in your everyday life to help you optimize your diet and support your overall health. 


1. Wu, D., Lewis, E. D., Pae, M., & Meydani, S. N. (2019). Nutritional modulation of immune function: analysis of evidence, mechanisms, and clinical relevance. Frontiers in immunology, 9, 3160.

2. Lee, G. Y., & Han, S. N. (2018). The role of vitamin E in immunity. Nutrients, 10(11), 1614.

3. Gammoh, N. Z., & Rink, L. (2017). Zinc in infection and inflammation. Nutrients, 9(6), 624.

4. Cantorna, M. T., Snyder, L., Lin, Y. D., & Yang, L. (2015). Vitamin D and 1, 25 (OH) 2D regulation of T cells. Nutrients, 7(4), 3011-3021.

5. Lanske, B., & Razzaque, M. S. (2007). Vitamin D and aging: old concepts and new insights. The Journal of nutritional biochemistry, 18(12), 771-777.

6. Yan, F., & Polk, D. B. (2011). Probiotics and immune health. Current opinion in gastroenterology, 27(6), 496.

7. Gutiérrez, S., Svahn, S. L., & Johansson, M. E. (2019). Effects of omega-3 fatty acids on immune cells. International journal of molecular sciences, 20(20), 5028.


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