How Sugar May Be Linked to Autoimmune Diseases
Sugar

How Sugar May Be Linked to Autoimmune Diseases

Excessive sugar consumption is closely associated with low-grade chronic inflammation and the onset of autoimmune diseases.
(Kateryna Kon/Shutterstock)
November 24, 2023
Updated:
January 15, 2024
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This is part 12 in The Ultimate Guide to Kicking Sugar

In this series, we will explore the good and bad sweeteners, uncover the unexpected outcomes of cutting out sugar, and discover the ultimate way to achieve this.

The immune system is like an army, defending against threats, both domestic and foreign. However, when the immune system turns against the body itself, it can cause significant harm, which is what happens in individuals with autoimmune diseases. Many people may not be aware that such diseases could be associated with the added sugars in their diet.

The Wide Spectrum of Autoimmune Disease

Autoimmune disease is a single term but refers to many conditions. “Now we know about 100 different types of autoimmune diseases as the name,” Aristo Vojdani, clinical professor in the Department of Preventive Medicine at Loma Linda University in California and founder of Immunosciences Lab, told The Epoch Times.

Certain conditions, including Type 1 diabetes, rheumatoid arthritis, lupus, multiple sclerosis, and inflammatory bowel diseases, all fall under the category of autoimmune diseases. For example, in rheumatoid arthritis, the immune system attacks the joints, causing swelling, pain, and even disability. In Type 1 diabetes, the immune system targets the insulin-producing beta cells, resulting in insulin deficiency.

However, there are still many rare autoimmune diseases that prove challenging to diagnose, causing patients to endure years of suffering before receiving a proper diagnosis. Moreover, many of these conditions remain incurable, with some requiring lifelong treatment that offers only symptom relief.

When the Army Turns Its Weapons Inward

“The immune system is like your body’s army,” said Nicholas Norwitz, who has a doctorate in physiology, anatomy, and genetics from the University of Oxford and is a candidate for a medical doctorate at Harvard Medical School. It’s equipped with “powerful inflammatory weaponry of all sorts” to protect us from both internal and external threats, he said in an email to The Epoch Times.

However, long-term triggers for the immune system can also cause harm. “Imagine some trigger (let’s say sugar) is constantly provoking your immune army to stay active and tossing grenades left and right,” Mr. Norwitz said, describing the damage that an overactive immune system can inflict on the body.

In autoimmune diseases, the immune system either fails to differentiate between the body’s own tissues and foreign cells, leading to self-attack, or it can’t regulate the intensity of the immune response.

There are many factors influencing the development of autoimmune diseases, Epoch Times contributor Datis Kharrazian, a Harvard-trained clinical investigator, functional medicine practitioner, and associate clinical professor at Loma Linda University School of Medicine, told The Epoch Times. These factors include diet-induced inflammation, toxins, molds, viruses, parasites, chronic stress, and metabolic disorders, he said. The interplay between these environmental and genetic factors contributes to the development of autoimmune diseases.

However, according to a study published in International Immunology in 2020, twin studies from different countries indicated that genetics alone can predict only 22 percent of common autoimmune disease cases, leading to a growing recognition of the importance of environmental factors.
Additionally, epidemiological studies have found that in Western countries the shift away from traditional dietary patterns correlates with the incidence of autoimmune diseases being typically higher and steadily increasing.

“Most people in our culture eat more sugar than the body was designed to handle,” Mr. Kharrazian said. Excessive sugar intake can trigger inflammation through various pathways, and the enhanced immune activity resulting from chronic inflammation creates “an environment in the brain and body that raises the risk of developing autoimmunity.”

“In nearly a hundred autoimmune diseases, what we commonly see is a person who is in a chronic state of heightened inflammation.”

The Sugar–Autoimmune Disease Connection

In recent years, with an increasing number of researchers investigating the relationship between high-sugar diets and inflammation, it has become evident that excessive sugar consumption is closely associated with low-grade chronic inflammation and the onset of autoimmune diseases, such as rheumatoid arthritis.

“People who consume a lot of sugar or sugary soft drinks have a higher risk of rheumatoid arthritis,” Ranjeny Thomas, professor of rheumatology at the University of Queensland’s Frazer Institute, told The Epoch Times. Numerous studies have confirmed this.

A large-scale prospective cohort study analyzed more than 20 years of follow-up data from nearly 200,000 young and middle-aged women. The study found that women who consumed one or more servings of sugar-sweetened soda per day had a 63 percent increased risk of rheumatoid arthritis compared with those who consumed less than one serving per month. This association was even stronger in those who developed the condition later in life (after the age of 55), with a risk increase of up to 164 percent. Notably, this effect was independent of other dietary and lifestyle factors.
A 17-year study tracking more than 200 rheumatoid arthritis patients revealed that approximately one-quarter reported that food could impact their symptoms. Among the mentioned foods, sugar-sweetened soda and desserts were most often reported to worsen symptoms.
In 2020, the journal Nutrients published a cross-sectional study that examined the diets of 193 patients with systemic lupus erythematosus. The researchers found that higher consumption of free sugars had adverse effects on the activity and complications of this disease.
A tracking study involving nearly 2,000 children at high genetic risk for Type 1 diabetes revealed that among children with autoantibodies to insulin, those with higher sugar intake had a significantly increased risk of developing Type 1 diabetes, elevated by 75 percent, when compared with children with low sugar intake. Among children with risk genes, the risk was elevated by 84 percent.
Neuromyelitis optica spectrum disorder is a rare inflammatory autoimmune disease that affects the central nervous system. A case-control study published in 2019 compared 70 patients with this condition to 164 control subjects. It was discovered that for every 10 gram increase in total sugar intake, the likelihood of developing this disease increased significantly, by 72 percent.
Mr. Norwitz stated that he has acquired “limited strong human data” in the research, which, to some extent, support the claim that sugar can cause or exacerbate autoimmune diseases. Additionally, there’s a valid biological rationale for restricting carbohydrates in treating autoimmune diseases. However, he also pointed out that high-quality trials in this area are still relatively scarce, partly because of significantly lower research funding for dietary interventions than for drug testing.

Autoimmune Diseases Are Closely Linked to the Gut

“Many autoimmune diseases start in the gut,” Mr. Vojdani said.

Many harmful bacteria, such as Escherichia coli (E. coli) and Salmonella, are particularly fond of sugar. “They grow like crazy” while feasting on sugar, he said. Eating added sugar disrupts the balance of the gut microbiome, causing a reduction in beneficial bacteria and an increase in harmful ones. This imbalance can lead to gut inflammation and ultimately result in the “breakdown of the gut barrier,” Mr. Vojdani said.

Harmful bacteria can also directly feed on the mucus layer, which serves as a barrier between bacteria and the gut. The mucus layer is typically thick and healthy, making it challenging for bacteria to breach. However, when there is an imbalance in our gut microbiome—which scientists call “dysbiosis”—the mucus layer thins.

The toxin produced by sugar-feeding harmful bacteria, in addition to sugar itself, also disrupts the distribution of tight junction proteins in the epithelial cells of the gut. This disruption leads to increased intestinal permeability, often referred to as “leaky gut.” These alterations in the gut are linked to the development of autoimmune diseases.

“Now that the door is open,” as Mr. Vojdani put it, undigested food debris, toxic chemicals, and other substances can infiltrate the bloodstream and spread in the body. When these substances reach the joints, they can induce inflammation there, he noted as an example. Over time, this joint inflammation can progress into autoimmune diseases such as rheumatoid arthritis.

“Inflammation (in the gut) can go all the way to the brain as well,” contributing to the development of widespread immune diseases such as multiple sclerosis. Mr. Vojdani said that the toxins entering the bloodstream also disrupt the blood-brain barrier, similarly to how they affect the gut barrier.

Furthermore, toxins produced by harmful bacteria can travel through the bloodstream, potentially triggering autoimmune diseases in different parts of the body. This can include conditions such as psoriasis, an autoimmune skin disease.

Toxins in the Mouth Travel to the Brain

Dentists often remind people to consume less sugar to prevent tooth decay and gum disease. However, most people are unaware that sugar intake can also harm the brain and nervous system when it enters the oral cavity, as sugar can disrupt the oral microbiome.

In other words, the risk of autoimmune diseases begins as soon as sugar enters your mouth.

There are both good and bad bacteria in our mouths. Excessive sugar intake can increase the number of harmful bacteria in the mouth, and the toxins released by these harmful bacteria may travel directly through the tonsils and into the brain, Mr. Vojdani said. Animal experiments have confirmed that harmful bacteria in the oral cavity can enter the bloodstream, Ms. Thomas said.

Furthermore, certain highly potent toxins produced by bacteria in the mouth can enter the gut along with ingested food, resulting in gut inflammation, Mr. Vojdani said.

Sugar Destabilizes the Immune System

T cells are widely recognized as having an impact on the autoimmune process. There are different types of T cells, and both excessive activation and underactivation of these immune cells can lead to the development of autoimmune diseases.

Specifically, some T cells can regulate the immune system, maintaining balance among its various components, while others can induce inflammation.

The toxins produced by harmful bacteria in the body can polarize the immune function: The T cells responsible for maintaining immune system stability are downregulated, while the T cells associated with inflammation are upregulated, disrupting the immune balance.

We can regulate our immune system by making dietary adjustments. A healthy diet not only helps to control the population of harmful bacteria and reduce their toxin production, but it also preserves the beneficial bacteria in the gut. These beneficial bacteria can produce a range of short-chain fatty acids, which, in turn, enhance the function of regulatory T cells.

In addition to these T cell mechanisms, Mr. Kharrazian and Mr. Norwitz highlighted that excessive sugar consumption can lead to insulin resistance, further contributing to autoimmune diseases. Individuals with insulin resistance often experience chronic inflammation. Additionally, high sugar intake can lead to obesity, which is inherently pro-inflammatory.

Reducing Sugar Intake for Health

“I think diet is one of the most powerful things you can control,” Ms. Thomas said. When people seek help for new-onset diseases, she and her colleagues always discuss diet with patients because “we can only do so much with drugs.” However, she also emphasized the preventive role of a healthy diet, saying, “It will be much better [to adjust the diet] in people before they get disease.”

When asked, if he would recommend his patients reduce their sugar intake to alleviate autoimmune diseases, Mr. Kharrazian’s response was, “Yes, always.”

“Regardless of how many carbs are appropriate for a person, there is no reason to eat more than about 25 grams max of sugar a day,” he said.

Mr. Norwitz echoed that advice.

“If you remove the trigger (sugar, in this example), the immune army has a chance to calm down, and symptoms may resolve,” Mr. Norwitz said. In clinical practice, he has observed severe autoimmune diseases and inflammatory conditions (including ulcerative colitis, Crohn’s disease, lupus, rheumatoid arthritis, and others) enter remission when the patient adopted a sugar-free and/or ketogenic diet.

“For those patients suffering from inflammatory or autoimmune diseases, what is lost by trying eight weeks without any sugar or processed food,” Mr. Norwitz said.

“Worst-case scenario, no benefit. In the best-case scenario, you change your life. That’s what happened to me.”

While he does recommend people eat less sugar, that doesn’t mean replacing  natural sugar with artificial sweeteners, he emphasized. Artificial sweeteners aren’t healthy; they can harm gut and oral microbiomes, and research suggests that they have carcinogenic properties, Mr. Norwitz said.

“So I absolutely do not recommend artificial sweeteners,” he said.

How can we curb sugar cravings and manage sugar intake without artificial sweeteners? Stay tuned for the final article of this series, “How to Quit Sugar the Right Way.”

Truly and completely quitting sugar takes more than just following a method; you must first delve into the underlying cause of your cravings.