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.”