Your Immune System and Eating Habits

A well-functioning immune system is essential for good health and survival. To perform at their best, the body’s cells require proper nutrition — and that includes the cells in the immune system. 

A healthy diet helps immune cells guard against harmful pathogens and resolve any immune response quickly. Although no one single food ensures good immunity, including certain nutrients in your diet can help strengthen your body’s natural defenses — as can avoiding certain foods that impair immune system function. 

If you’re interested in strengthening your immune system, you may need to change your eating habits. Eating lots of fruits and vegetables is essential, and most Americans don’t get enough. According to the Centers for Disease Control, only 10 percent of Americans are meeting the daily recommendations for fruit and vegetable consumption. 

How does diet affect the immune system?

Certain nutrients play very specific roles in immune system function. For example, vitamin A and zinc help control cellular division and are essential for rapid immune system response. 

Some nutrient deficiencies have been shown to suppress immune system function. Other foods, such as sugar, impair immune system cells that fight bacteria. Building a healthy immune system, then, may require adding certain foods to your diet and minimizing your intake of others. 

Moreover, when it comes to the effects of diet on the immune system, the importance of healthy digestion can’t be overlooked. Most of the immune system cells in the human body are found in the gut. That means if you have a condition related to digestive health, your immune system may not be functioning as well as it could be. Even common digestive issues such as constipation could be affecting the health of your immune system. 

Which vitamins and minerals are best for the immune system?

Some of the most essential vitamins and minerals for the immune system include vitamin D, vitamin A, vitamin C, vitamin E, zinc, and selenium. Certain amino acids, such as glutamine and arginine, also play an important role in immune system function. 

What foods are bad for the immune system?

Chronic inflammation is an underlying factor in many diseases, and the standard Western diet is a known risk factor for inflammation. The Western diet is typically high in inflammatory foods such as sugar, trans fats, processed foods, simple carbohydrates, chemical additives, vegetable oils, and omega-6 fats. 

Make an effort to reduce your consumption of foods such as white flour, soft drinks and sports drinks, baked goods, and fast food. 

Which foods boost the immune system?

Some of the best foods to eat for a healthy immune system are fruits and vegetables, which are naturally high in vitamins and antioxidants that help strengthen the immune system. The more colorful fruits and vegetables you add to your diet, the better. Fruits and vegetables get their color from phytonutrients, which are compounds that also provide different health benefits. 

• Vitamin A can be found in orange foods, such as carrots, sweet potatoes, cantaloupe, apricots, mango, and pumpkin, as well in green foods, such as broccoli, asparagus, kale, bell peppers, and spinach. 
• Vitamin C is found in orange, lemons, acerola cherries, strawberries, yellow peppers, spinach, kale, kiwi, and broccoli. 
• Vitamin D is produced when the skin is exposed to sunlight. If you spend a lot of time indoors or live in an area without a lot of sun, you may need to take a vitamin D supplement. Vitamin D deficiencies are common in the United States. Some foods, such as milk and orange juice, are often fortified with vitamin D. It can also be found in some foods, such as fresh fish and mushrooms. 
• Vitamin E is found in nuts and seeds, such as almonds, peanuts, sunflower seeds, as well as in avocados and salmon. 
• Good sources of zinc include oysters, crab, beef, pork, chicken, pumpkin seeds, oatmeal, cashews, and almonds. Some foods, such as breakfast cereal, are often fortified with zinc. 
• Selenium is found in nuts and seeds, fish, beef, pork, chicken, eggs, and mushrooms. 
• Probiotics and prebiotics are also important to help maintain healthy levels of gut bacteria that help digest food and fight pathogens. Probiotics are foods or supplements that contain beneficial bacteria, while prebiotics are foods that feed gut bacteria. 
• Probiotics are found in some foods, such as yogurt, kombucha, and kefir. They can also be taken as a supplement. Healthy prebiotic foods include garlic, onions, carrots, asparagus, and bananas. 

Making healthier food choices

It can be difficult to overhaul your diet all at once. If you’re used to eating a standard Western diet—and if you’re among the 90 percent of Americans who don’t eat enough fruits and vegetables—start by making small changes. 

Make sure that every meal includes a source of phytonutrients. Instead of sugary cereal or a bagel for breakfast, try a bowl of oatmeal with fresh fruit. Add more salads to your lunches and dinners, but watch out for bottled salad dressings, which can be high in sugar. 

Get into the habit of reading ingredients labels and choose foods that are low in sugar and additives. It may feel overwhelming at first, but in time you’ll learn which brands use the best ingredients—and which ones to avoid. Try the ScriptSave WellRx Grocery Guidance app, which can help you find healthier alternatives to the foods you buy most often. Simply scan the barcode on your food package to reveal its WellRx Health Index and discover “better for you” alternatives. Download it on the App Store or Google Play today.

Karen Eisenbraun is a Certified Holistic Nutrition Consultant. She holds an English degree from Knox College and has written extensively about topics related to holistic health, clinical nutrition, and weight management.

Resources: 

https://www.cdc.gov/mmwr/volumes/66/wr/mm6645a1.htm

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723551/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6723

https://consultqd.clevelandclinic.org/the-role-of-the-western-diet-in-inflammation/

https://pubmed.ncbi.nlm.nih.gov/31747581/

https://pubmed.ncbi.nlm.nih.gov/8227682/

https://pubmed.ncbi.nlm.nih.gov/21310306/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5052746/