10 Ways Sugar Can Suppress your Immune System

Research shows that optimal nutrition can help upregulate your immune function and support your body’s ability to fight off pathogens, but the reverse is also true. 

Eating a diet high in sugar and processed foods can actually weaken your immune system and increase risk of chronic diseases such as obesity, hypertension. and diabetes, which are associated with hospitalization of COVID-19. 

Excess sugar intake can also contribute to weight gain and an increased risk of diabetes and hypertension. A month ago I wrote about how COVID-19 is disproportionately hitting those who are less healthy at baseline. Researchers confirmed this again last week. 

A new study published in the Journal of the American Medical Association (JAMA) reported that 88% of patients who were admitted to the hospitals in New York City with COVID-19 had more than one comorbidity. The study also found:

  • Only 6% of those hospitalized were free of any comorbidities. 
  • Nearly 60% had hypertension.
  • 42% had a body mass index (BMI) greater than 30.
  • 34% had diabetes. 

COVID-19 and Metabolic Dysfunction

This “acute care illness” is clearly amplified by a chronic disease terrain that is driven by food, movement, stress, and sleep, in addition to age. It begs the question: how detrimental would this virus be if chronic disease did not exist? As a society, a natural response is to cover your faces in masks, keep six feet distance and wash hands but what would this disease look like if we actively pursued increasing phytonutrient density in meals, moving the body, sleeping eight hours a night and reducing stress? Why is it that as a society, people are willingly to stay home and shut down the economy but not willing to eat more vegetables in order to contribute to a healthier, more resilient foundation to health?   

Metabolic abnormalities that occur in individuals with diabetes and also obesity, especially excessive visceral adipose tissue (VAT), appear to play a role in inflammation and immune health. Another new study found that after age, carrying excess weight is the most significant risk factor for requiring hospitalization with Covid-19. I believe that weight is only one small measurement of a person’s health but there is a clear association with weight and risk of hospitalization from the virus. 

Prior studies have shown that having higher levels of VAT can lead to the secretion of several proinflammatory molecules such as adipokines and cytokines. These molecules can trigger an immune response that lowers T regulatory cells and increases neutrophils, dendritic cells, and more. 

And as people sit in their homes, feeling stressed from the news and economy, baking bread and cookies, and losing sleep from late night Netflix binging, you have to wonder why no attention is being drawn to the role that lifestyle choices play in the larger picture of COVID-19 and flattening the curve. 

Based on the latest evidence on COVID-19 published in April of 2020, most people who need to be hospitalized and require medical attention upon getting the virus have comorbidities. Based on this information, one of the most effective ways to flatten the curve and support the incredibly brave healthcare workers is to focus on building immunological resilience and improving metabolic function to lower risk of chronic disease. Beyond adding more nutrient dense foods to your diet, limiting added sugar intake is one of the best habits that can be adopted at this time.  

Added Sugar Intake

The average American consumes almost 152 pounds of sugar every year. Sugar comes in two forms: Those naturally occuring in whole foods and added sugars in processed foods. Eating too much of any type of sugar can become a problem, but added sugars can be far more detrimental.

About one-third of added sugar comes from soft drinks. Fruit juices and baked goods are other popular sugar sources. 

Twenty-five percent of that added sugar, though, comes from foods and drinks you might not suspect. These less-obvious foods and drinks include marinara sauce, packaged meats, and bottled green tea.

Put this into perspective: Three out of every four packaged food and drink products — 74 percent, to be exact — contain added sugar. 

Some, you might not recognize on the ingredients list. There are at least 61 different names for sugar, and they have one thing in common: All of them take their toll on your overall health when overconsumed. 

A High-Sugar Diet Contributes to Chronic Disease & Excess Weight

Foods high in added sugar provide immediate pleasure. They can make you feel better for a few minutes by increasing your dopamine levels. But whatever short-term bliss they might offer, a high intake of baked goods and sugary foods leads to metabolic dysfunction. 

Research shows that high sugar intake can be associated with chronic diseases including type 2 diabetes, non-alcoholic fatty liver disease (NAFLD), cognitive decline, some cancers, and heart disease. 

One study, for instance, found that people who consumed 17 – 21 percent of their calories from added sugar had a 38 percent higher risk of dying from heart disease compared with those who consumed eight percent of calories from added sugar.

Excessive sugar intake may also be associated with poor immunological resilience. As immune health takes a massive priority in the face of Covid-19, you may want to do more than wear a mask when you leave the house. Use this time at home to improve your metabolic function rather than go in the opposite direction! A simple way to make a big impact is by minimizing or eliminating added sugars!  

Excess Sugar Can Weaken Your Immune System

We’ve known that sugar can dampen immune health for decades. One study from 1973 — dinosaur years as far as science goes! — looked at how sugar impacted neutrophils, a type of white blood cells that protect you against infections. 

Researchers found that 100 grams of sugar significantly decreased the ability of neutrophils (white blood cells) to destroy harmful bacteria. To put that into perspective: That’s the amount of sugar in about two 16-ounce colas.

The five simple sugars here —  glucose, fructose, sucrose, honey, and orange juice — all had the same immune-impeding effect, which could last up to five hours after consuming that sugar. 

Your immune army, composed of white blood cells, destroys bacteria and viruses through a process called phagocytosis. High levels of sugar in your blood can lower how white blood cells function and weaken your immune system. 

Consuming 100 grams of sugar, in fact, can reduce the ability of your white blood cells to function by 40 percent. As a result, you’re more susceptible to illness. 

Focusing on a whole, unprocessed foods diet is the best way to crowd out added sugar. 

10 Ways Sugar Can Suppress your Immune System 

1. High-Sugar Foods Have Few If Any Nutrients

Added sugar can lead to deficiencies in the vitamins and minerals that your body requires to keep your immune system strong. Most people are overfed but undernourished and added sugars are a big driver of this paradigm. 

Consider vitamin C. Sugar may directly compete with this immune-supporting vitamin, so your white blood cells may have less vitamin C to use. Eating a processed food based diet that is high in sugar also makes it difficult to get adequate vitamin D. Vitamin D deficiencies can also impair your body’s ability to fight bacterial and viral infections, including respiratory infections. 

Foods high in added sugars contain few if any nutrients, but they can also deplete nutrients from other foods and from body stores. Also the biochemical pathway that allows for food to be converted into energy requires micronutrients that serve as cofactors for this process. Therefore consuming foods high in sugar with little to no nutrition leads to a deficit in vitamin and mineral cofactors used for the oxidation of the sugar itself, in addition to other whole foods.

By incorporating more whole food ingredients you not only curb your intake of added sugar but also provide your cells with targeted information through phytochemicals and nutrients that upregulate your immune function.

2. Excess Sugar Has Been Associated with Inflammation

A little bit of inflammation can benefit you when, say, you cut your finger. We call that inflammation acute, because it does its job and then chills out. 

Too much sugar, however, contributes to chronic inflammation. This low-grade, festering inflammation can lower how well your body fights infection, increase your risk for allergies, and much more. 

Chronic inflammation can come from many sources. Physical inactivity, nighttime blue light exposure, tobacco smoking, environmental toxins, and psychological stress can all keep you inflamed, as can a diet rich in inflammatory foods.

Chronic inflammation can keep your immune system fired up, potentially triggering your white blood cells to attack healthy tissues and organs. Left unchecked, chronic inflammation can contribute to rheumatoid arthritis, cancer, heart disease, diabetes, asthma, Alzheimer’s, and more. 

3. Excess Sugar May Contribute to Damaging Free Radicals

A certain amount of free radicals, the unstable atoms searching for an electron partner, can keep your immune system strong. When free radicals overtake your body’s antioxidant defense, though, a condition called oxidative stress results. 

Long-term oxidative stress can contribute to cancer, diabetes, heart disease, and more. In fact, researchers link oxidative stress with early aging and over 100 diseases, including immune diseases

Oxidative stress can also cause chronic inflammation, compromising your immune system further and increasing your risk of disease. 

Your body makes some antioxidants, including glutathione. Others, such as vitamin C, you need to get from food and supplements.  

A diet high in added sugar can deplete these antioxidants and increase your production of reactive oxygen species, producing an inflammatory milieu and an imbalance between anti-inflammatory and inflammatory cytokines. Eliminating added sugars and eating a diet rich in antioxidants, on the other hand, can help neutralize or remove these free radicals and protect against oxidative stress.

4. Excess Sugar is Associated with Glycation 

When sugar attaches to a protein molecule, it can become “sticky,” inhibiting that protein from doing its job. That can weaken antibodies, proteins that your immune system uses to fight infections, and impair your immune system

When sugar disrupts those hard working proteins, you can lose elasticity in your blood vessels, skin, and tendons. You’re also more prone to autoimmune disease. 

Glycation eventually leads to advanced glycation end products with the appropriate acronym AGEs. AGEs can lower your innate immune system involving NLRP3 inflammasome-mediated defenses, the exact pathway that is targeted with Coronavirus.  

5. Excess Sugar Can Increase Risk of Insulin Resistance

Insulin manages how your cells utilize sugar. Optimal amounts of this hormone can support and even strengthen your immune system to fight infection. Insulin helps deliver glucose to your cells, which can use it for energy, and normalize your blood sugar levels. 

But like inflammation, insulin should do its job and calm down. 

When you eat large amounts of sugar, your blood sugar increases. As a result, insulin levels stay high. Over time, your cells become overwhelmed and less responsive to the signals of this hormone. We call this condition insulin resistance, which puts you at risk of endothelial dysfunction and developing type 2 diabetes. Insulin resistance can also impair your immune system.

6. Excess Sugar is Associated with Poor Gut Health

About 70 percent of your immune system is housed in your gut microbiome. The microbiota or beneficial bacteria in your gut help manage inflammation, insulin resistance, the strength of your gut wall, and more. 

When these microbiota become out of balance, a condition called dysbiosis results. 

One particular sugar, fructose, can especially disrupt that gut balance. Too much fructose can increase the number of inflammatory microbiota, suppress anti-inflammatory microbiota, and lower overall gut-flora diversity

Fructose can also damage the gut’s tight junctions that keeps large proteins and other things not intended to slip through the gut wall intact. 

When these things slip through — appropriately called gut permeability — bacteria and other invaders can slip into the bloodstream. Your immune system goes on hyperalert, which makes it less able to manage viruses and other pathogens you’re exposed to. 

Along with increased permeability, too much fructose can create liver inflammation and increase your risk of insulin resistance.

7. Excess Sugar May Negatively Impact Mental Health 

A high-sugar diet can increase risk of depressive symptoms. For one, sugar creates imbalances in neurotransmitters such as dopamine, your brain’s reward chemical, and serotonin, your feel-good hormone.

One large study found that men who ate 67 grams or more of sugar daily were 23 percent more likely to suffer from depression compared with men who ate 40 grams or less of sugar daily after five years. 

What impacts your brain also impacts your immune system. Some immune cells can access the brain and potentially influence your neuronal networks, increasing inflammation. In fact, inflammation could be a key driver to the development of depression

8. Excess Sugar Can Be Addictive

Ever sat down with ice cream telling yourself you would eat just one serving, yet suddenly the whole pint disappears? Eating a little bit of highly processed sugar can make you crave more. 

At least in animal studies, there is a clear overlap between sugar consumption and drug-like effects. One animal study even demonstrated that added sugar can be more addictive than cocaine. A diet high in added sugar can send reward signals to your brain, triggering the release of your reward neurotransmitter dopamine

Not only does eating this food increase dopamine, but it also produces favorable biological changes in the moment, reducing pain, symptoms of depression, and stress soon after consumption. 

The concern is not eating a square of dark chocolate, but rather the sources of sugar that add up throughout the day and have a compounding effect. Your body becomes less sensitive to the dopamine produced from eating sugar and you need to consume more to have the same pleasurable experience.

As you reach for more and more to get that dopamine hit, sugar can adversely impact your brain but also your immune system.

9. Excess Sugar Is Associated with Poor Liver Health

Your liver plays a critical role in the immune response: This organ detects, captures, and clears bacteria, viruses, and other pathogens. To keep your immune system strong, your liver needs to be working well, too.

Fructose especially can lead to non-alcoholic fatty liver disease (NAFLD), where too much fat gets stored in your liver.  NAFLD impacts about 25 percent of Americans and is the most common form of chronic liver disease. 

10. Excess Sugar May Increase Your Body’s Stress Response

A diet high in added sugar can create physiological stress, impacting your liver and other organs. But too much sugar can also impact your stress hormones, increasing psychological stress.

When you get stressed out, your adrenal glands release hormones including cortisol to help you manage the situation. But these hormones should do their job and then calm down. 

Too much sugar can keep cortisol elevated when this hormone should simmer down. High fructose consumption especially can keep cortisol elevated and might be associated with increase inflammation

Psychological stress has other consequences: You’re more likely to reach for sugary comfort foods, which may further damage your immune system.

Two Simple Ways to Lower Added Sugar

Curbing added sugar is not easy, especially when it hides in sneaky or unsuspecting places! Identifying hidden sugars in your favorite foods and drinks is a great place to start eliminating them. 

Don’t be fooled by labels, which often make misleading or distracting health claims such as “high in fiber.” Manufacturers know those claims encourage you to buy products and even eat more of them. Instead, turn that product around and:

  1. Read the ingredients list. Anything with -ose is a sugar, but sugar can go by a lot of different names. (At least 61, in fact!) To get a list of the most common sources of added sugar ingredients, download the free BeingBrigid Blueprint here
  2. Look at the Nutrition Facts list. Specifically, look at the amount of added sugars in each serving. Ideally, this number should be zero, but lower is better. Be aware that manufacturers make serving sizes small sometimes to create lower numbers. 

The idea is not to set unrealistic expectations of yourself to never consume sugar. But at least start by identifying the foods that weren’t evolutionarily created to be sweet but have become that way as a result of food manufacturers. 

The second phase is to reduce sugar in baked goods that you are making at home. Here are some suggestions: 

  • Limit baking cookies and treats to 1-2 times per month. Experiment more in your kitchen with cooking new meals! 
  • After you bake treats, store in your freezer so that they aren’t in plain sight and need to be thawed before consumption. 
  • Follow low sugar recipes. 
  • Cut the sugar in your recipe in half. 
  • Substitute organic stevia or monk fruit if you are looking for some sweetness. 

Along with a ramping up on your nutrient-dense whole foods, minimizing added sugars can keep your immune army more resilient, no matter what virus or other pathogen is going around your office or home. 

If you found this article helpful, please pass it onto a friend or family member who could benefit from taking a proactive approach to support their immunological health.