4 Ways That Sugar Suppresses Immune Function

health care May 01, 2017

We know that sugar can be as addictive as any drug, and that it’s pretty much devoid of nutrients. But did you know how bad sugar is for your immune system? Anyone wanting to keep their body in tip-top shape and optimize their health should be aware of the 4 ways that sugar suppresses immune function. Armed with this knowledge, it might just be easier to say no to the next candy bar that looks your way.


1. Sugar reduces your white blood cells’ ability to kill pathogens in the body. In fact, 100 grams of sugar – about the equivalent found in 1 medium-sized soda bottle – can reduce the ability of white blood cells to kill microorganisms by 40%. Studies have found that the impact on immune function occurs within 30 minutes of ingestion, and lasts up to 10 hours (Sanchez, 1973).

2. Sugar competes with vitamin C for absorption into white blood cells. We need vitamin C for healthy immune responses – if glucose is competing for absorption, and less vitamin C gets to the cell, that will definitely compromise immune health.

3. Sugar intake increases pancreatic secretion of insulin, the hormone that is required to help shuttle glucose from our blood stream into our cells. Insulin suppresses growth hormone release from the pituitary gland. Growth hormone is one of the regulators of immune function. So more glucose => more insulin => less growth hormone => weakened immune response.

4. Foods high in sugar tend to be devoid of nutrients, further hampering immune function which depends on vitamins, minerals and enzymes to function. Those foods also tend to be high in saturated fats which a pro-inflammatory. One study found that sugar consumption decreases overall micronutrient intake by an average of almost 20% (Sanchez et al. 1973; Ringsdorf, Cheraskin & Ramsay 1976).

I get it, sugar can be a hard habit to break. I talk more about that here. But for vitality and immune strength, it is crucial to kick that habit. Naturally occurring sugars such as honey, maple syrup and fruit do not have same immune-suppressive effects as refined sugar. However, they can still contribute to yeast overgrowth and need to be used with caution in people with Candida issues.

Sugar may be a short-term crux for an energy boost, but will actually lead to energy crashes later, so ultimately is counter-productive in many different ways.

It’s just the beginning phases of coming off sugar that are hard, I promise you it gets easier with time, and after a while, your body simply will not crave sweet foods any more.