It’s more important than ever to take good care of your immune system, and while eating immune-boosting foods like oranges and broccoli can certainly help, avoiding other foods may be even more important. “With the coronavirus, there’s a lot of talk about important measures like hand-washing, social distancing, and not touching our faces or shaking hands,” says Dr. Anna Cabeca, author of Keto-Green 16. “Yes, we should be practicing all of these, for sure. But not many experts are talking about something I feel is just as vital: strengthening your immune system.”
1. White Bread
White bread is a prime culprit for suppressing the immune system, according to Dr. Josh Axe, D.N.M., C.N.S., D.C., founder of Ancient Nutrition and DrAxe.com. “White bread, cookies, cakes, rolls, etc. that are made with white flour tend to be high in calories and low in nutrients,” says Axe, “so they can contribute to weight gain and risks associated with obesity/insulin resistance.” White bread can also contribute to inflammation, according to CJ Hammond, an XPS, FMT, and NASM Certified Trainer, diminishing the body’s ability to protect or heal itself. “When the immune system is spread thin trying to regulate and prevent inflammation or fight off diseases it won’t allow the body to use the immune system at its full capabilities,” Hammond says.
2. Unripe Bananas
Even the natural sugars in fruits can have a negative impact on your immune system and gut health, and this is even more true when they are unripe. Bananas, but also other unripe fruits and vegetables, can contain high amounts of a protein called lectin, explains Vinay Amin, Health Expert & CEO at Eu Natural. “Studies show that lectin may disrupt the absorption of nutrients and inhibit the production of intestinal flora,” says Amin. “In turn, this weakens your gut barrier, the intestinal wall that defends the body from toxins and harmful bacteria.”
While all forms of sugar can pose a problem to the immune system, soda is perhaps the worst culprit. In addition to being loaded with sugar, it’s also filled with artificial colors that, according to Alicia Galvin, RD, a resident dietitian for Sovereign Laboratories, can “negatively affect the gastrointestinal lining.” Hammond adds that carbonated drinks often contain phosphorus, which “can lead to a depletion of calcium from the cells through the kidneys.” And since calcium plays an essential role in the activation of cells in the immune system, low calcium means lower immunity.
While many consider tofu a health food, it can be problematic for a number of reasons, not the least of which is a high concentration of omega-6 fatty acids. These fats have been linked to a heightened inflammatory response in the body, especially when out of balance with the omega-3 fatty acids found in fish and some nuts and seeds. “By no means do you need to eliminate tofu,” says Amin, “but you should think twice before making it a staple in every meal.” Soy is also a common allergen, notes Axe. While it “may not be a problem for everyone,” he says, it can be “especially taxing to people prone to gut and autoimmune issues.” “When someone eats an allergen, their immune system may overreact by producing antibodies that are intended to ‘attack’ the allergen,” he says. “However these antibodies can damage to the person’s own organs, leading to a variety of symptoms.”
Alcohol like beer and wine can increase susceptibility to infection, according to Dr. Ivy Branin. “Chronic alcohol use actually interferes with normal functioning of all aspects of the adaptive immune response,” she says. “Alcohol also increases the stress hormone cortisol, blood sugar, and insulin, and all three can negatively impact immune function when elevated.” Mary Shackelton, ND, cites a paper published in the journal Alcohol Research, in which study authors noted a “long-observed relationship” between excessive consumption of alcohol and impaired immune response.
6. Canned Pasta
Other processed foods, like canned pasta, can also have a negative effect on the body, according to Hammond. He says that the word “canned” should be considered “another term for processed.” Canned pastas, especially, are usually filled with salt, sugar, and other additives that “can reduce the body’s ability to recuperate from stress-induced activities.”
7. Breakfast Cereal
Most breakfast cereal is both high in sugar and low in fiber, a problematic combo for the immune system, according to Axelrod. “Soluble fiber boosts the production of the protein interleukin-4, which stimulates the body’s infection-fighting T-cells,” she says. “Fiber also provides the key food for beneficial bacteria in your gut to thrive.”
8. Hot Dogs
Not only are hot dogs high in both acid and salt, they are also processed, which is a big immune system no-no, according to Axe. “High consumption of cured and processed meats like bacon, salami, cold cuts, and hot dogs has been linked to negative health outcomes like higher risk for some types of cancer,” he says. “Processed meats can contain harmful chemicals (such as polycyclic aromatic hydrocarbon) that form during the cooking/manufacturing process and are also usually high in salt, nitrates and other additives that can lead to oxidative stress.”
9. Red Meat
High-acid foods like red meat can weaken your immune system, according to Dr. Cabeca. “When you consume too many acidic foods, your body’s overall pH load will become acidic,” she says. “When that acid load remains high, minerals like magnesium, calcium, potassium and bicarbonate become low, adversely impacting your health.” Red meat is also rich in omega-6 fatty acids and is, therefore, doubly inflammatory.
While honey might seem like a healthier alternative to refined sugar, this isn’t quite the case. According to Dr. Ivy Branin, “natural” sugars like honey, maple syrup, and molasses can be “similarly problematic” to sugar.
Much like honey, the natural sugars in raisins and other dried fruits can spike your sugar levels, Dr. Branin warns. “Even if you aren’t eating dessert or super sugary foods, it’s likely that you’re going above the suggested six teaspoons of added sugar per day for women and nine teaspoons for men,” echoes Samantha Cassetty, MS, RD, nutrition and wellness expert.