The immune system response is a high-energy process, and the fuel for this comes from your diet. Knowing which foods provide nutrients to support immune health is essential, but knowing which foods are less than ideal is just as important. Making the right food choices and knowing which foods to limit will keep your immune system running efficiently and your defenses against seasonal threats strong. 

Foods To Avoid for Better Immune Function

1. Sugar

It is important to note that not all sugars are equal. Healthy fruits contain natural sugar, but this is markedly different from added sugars. The sugars added to foods can have a harmful impact on health by contributing to unhealthy blood sugar levels. This can affect the response of neutrophils and phagocytes, two types of immune cells that contribute to your body’s defenses.

Bacteria in the gut can become unbalanced with excess sugar consumption. This can alter the integrity of the gut wall, triggering an otherwise unnecessary immune response. With the gut microbiome being a large part of your immune system, changes to bacterial balance can really impact how you take on seasonal threats. 

What to eat instead: Reach for some fruit if you’re looking for something sweet to eat, and save the cookies, ice cream, candies, and cake for special occasions.

Senior woman about to enjoy an apple

2. Salt

Salt may also inhibit normal immune function by altering the bacterial balance in the gut. When the microbiome is out of balance, this can promote the generation of immune cells that are implicated in aberrant immune responses. Studies have found that exposure to high salt concentrations inhibits enzyme activity that supports immune cell development. Without the proper amount of energy, immune cell development is impacted in ways that reduce their ability to effectively defend the body. 

What to eat instead: Choose whole unprocessed and minimally processed foods in place of frozen and boxed meals, canned vegetables, choose nuts and seeds over snacks like chips, pretzels, and use herbs and spices to season foods.

3. Fried Foods

Fried foods are high in a group of molecules called AGEs (advanced glycation end-products). These are formed when sugars react with proteins or fats during high-temperature cooking. If levels become too high in your body, AGEs can contribute to occasional oxidative stress and unwelcome immune responses. Excessive consumption of fried foods and increased AGE levels can also have a negative impact on metabolic function, increasing common health concerns as you age. 

Roasted chicken with potatoes and green beans

What to eat instead: Bake, sautee, or broil your food and limit french fries, potato chips, fried chicken, pan-fried steak, fried bacon, and fried fish.

4. Processed Meat

Processed meats contain large amounts of saturated fats, and in high quantities, these fats have been linked to strained immune responses. Consumption of too many saturated fats can contribute to metabolic conditions that interfere with maintaining a healthy weight. This can contribute to long-term immune activity, which may leave you vulnerable to seasonal threats. Processed meats are also high in AGEs.

What to eat instead: Tuna, salmon, eggs, roast chicken or turkey, or alternative forms of protein such as beans, lentils, and tofu in place of meats that have been preserved such as deli meats, bacon, and hot dogs.

5. Refined Carbohydrates

Refined carbohydrates are defined as those that have been heavily processed, and a diet rich in these may alter gut microbiome composition. With 70% of your immune system living in your gut, a balanced microbiome is essential for healthy immune support. Many of these refined carbohydrates are high glycemic foods that can contribute to uneven blood sugar levels, typical oxidative stress, and unwanted immune responses. 

What to eat instead: Consider less processed forms of carbohydrates such as whole grain bread, whole grain cereals, brown rice, quinoa, amaranth, as well as fresh fruit and starchy vegetables. 

Tri-color quinoa in separate wood bowls

Something Extra For Immune System Health

Making some healthy changes to your diet can be critical to promoting your overall health. In addition to this, you can support immune health with doctor-recommended supplements like BreatheMD and ImmunityMD®.

BreatheMD is a comprehensive lung and immunity formulation containing supportive dosages of African geranium, elderberry, L-cysteine, vitamin D, and vitamin C to promote antioxidant activity, respiratory system performance, and immune system defenses. Recommended daily allowances of zinc and chromium are added to provide additional immune support and whole-body health. 

ImmunityMD® is a unique, probiotics-based supplement that helps ensure the growth of the beneficial gut bacteria at the root of healthy immune system function. The inclusion of zinc supports healthy immune cell function, while L-lysine helps promote everyday health by reducing everyday worry and stress.

Final Thoughts

Immune system function is influenced by several factors, including diet. Eating a balanced diet consisting of a range of vitamins and minerals, combined with healthy lifestyle factors like adequate sleep and exercise, most effectively supports proper immune responses. Choose to limit or avoid these five foods and instead grab fresh fruits and vegetables, whole grains, healthy proteins, and the targeted benefits of 1MD Nutrition’s immune health supplements for optimal immune system function and longevity.

Dr. Brian Greenberg

Dr. Brian Greenberg is an immunologist, allergist, and pediatrician who received his medical degree from the University of Florida, and completed his residency and fellowship at UCLA. He has practiced medicine in Southern California for almost 25 years.