10 Foods That May Weaken Your Immune System

Your diet affects how you feel and how well your body functions.

While a nutrient-dense, well-rounded diet supports your immune system, a diet that’s low in nutrients and high in ultra-processed foods impairs immune function (1Trusted Source, 2Trusted Source).

This article lists 10 foods that may weaken your immune system.

1. Added sugar

There’s no doubt that limiting how much added sugar you consume promotes your overall health and immune function.

Foods that significantly raise blood sugar, such as those high in added sugars, increase the production of inflammatory proteins like tumor necrosis alpha (TNF-α), C-reactive protein (CRP), and interleukin-6 (IL-6), all of which negatively affect immune function (3Trusted Source).

This is especially pertinent in people with diabetes, as they can have elevated blood sugar levels for longer than people with well-regulated blood sugar levels.

What’s more, having high blood sugar levels may inhibit the response of neutrophils and phagocytes, two types of immune cells that help protect against infection (4Trusted Source).