Today’s modern human diet poses a stark contrast to that of just a few hundred years ago. Large scale factory food production and processing have permanently altered the way the world perceives food. Even health conscious consumers selecting items labeled “paleo” or “all natural” encounter baffling product ingredient lineups longer than a weekly grocery list. While consumers frequently eschew substances such as monosodium glutamate (MSG) and high fructose corn syrup, three equally common, foreign substances that pervade food labels include xanthan gum, guar gum, and sodium benzoate. So, what really are these additives, and do they pose health risks?
What Are Food Additives?
The Food and Drug Administration (FDA) defines food additives as any food component not attributed to the food itself, including indirect and direct additives. While packaging and processing procedures may produce the former in trace amounts, direct food additives include any substances introduced into comestibles for a specific purpose, such as improving production, processing, packaging, flavor, freshness, and more. Of note, the FDA acknowledges that only “most direct food additives are identified on food labels.”
The FDA does regulate food additive safety, but admits that it can “never be absolutely certain of the absence of any risk from the use of any substance.” Even the widely denounced flavor enhancer MSG, which the Mayo Clinic acknowledges at a minimum may cause headaches, nausea, chest pain, and other ills, holds FDA approval and GRAS (generally recognized as safe) status, eliciting concerns regarding the organization’s regulatory practices.
Xanthan gum, guar gum, and sodium benzoate all hold FDA GRAS status, but definitively ascertaining whether their consumption is prudent warrants a deeper investigation exploring today’s existing research.
The Gums: Xanthan and Guar
Xanthan and guar gum serve similar purposes: food emulsification (helping fats mix evenly), stabilization, and texture enhancement via their absorbent nature and food-thickening abilities. They also possess similar chemical compositions; both are polysaccharides (long chains of simple sugar molecules).
Foods most often containing these gums include sauces, plant-based milks, juices, and packaged baked goods (cookies, breads, etc.), especially gluten-free options.
While cooking and baking enthusiasts might use these gums interchangeably, their origins are distinct. The nonpathogenic bacterium Xanthomonas campestris produces xanthan gum when it ferments simple sugars or starches. Dissimilarly, manufacturers extract guar gum from Cyamopsis tetragonoloba (a legume) seeds.
To create the finalized products, xanthan and guar gum powders, from these living origins requires extensive processing. Do such manufacturing procedures render these additives unwholesome and mandate their avoidance? The science elucidates.
Examining the Science: Xanthan and Guar Gum
Government agencies do not provide a defined xanthan and guar gum ADI (acceptable daily intake). Multiple studies have involved human subjects consuming as much as fifteen grams per day without negative effects. This does not reflect “normal” intake, however, as common foods including gums, such as baked snacks or processed beverages, contain less than 0.35% to 1% gum by weight or approximately one gram. Unfortunately, no studies exist evaluating long-term, low dose gum intake that more accurately reflects typical consumer consumption.
Therapeutic Uses: Xanthan and Guar Gum
While xanthan and guar gum are more commonly considered food enhancers, these substances have also been investigated therapeutically regarding their ability to promote healthy cholesterol levels, bolster satiety, and help manage blood sugar. Although, achieving healing effects generally requires high dosages.
When a Food Additives and Contaminants study fed five men approximately ten grams of xanthan gum daily (a large quantity) for twenty-three days, their total blood cholesterol levels significantly reduced by 10%.
Further, Bioscience, Biotechnology, and Biochemistry published an article demonstrating that healthy rats fed xanthan and guar gum for two weeks exhibited significantly lowered total and LDL cholesterol levels. Additionally, diabetic rats fed the same mixture for four weeks showed substantially lowered triacylglycerol levels (another marker of unhealthy high cholesterol). Of note, these results may not apply to humans, as rat diets included more than ten times the upper limit of human gum consumption.
Regarding satiety, the research provides inconsistent results. A study published in the British Journal of Nutrition concluded that ingesting six grams per day of guar gum may aid satiety in both the immediate and long term, and also assist weight loss by preventing snacking. Still, Bioactive Carbohydrates and Dietary Fiber found opposing results. When twenty healthy men drank apple juice containing similar quantities of added guar and xanthan gum, their blood glucose, insulin levels, and satiety were no different than those of men imbibing normal juice.
The Downsides: Xanthan and Guar Gum
Although the aforementioned beneficial uses might paint the gums as healthful, arguably more substantial downsides exist, including gastrointestinal problems, microbiome disruption, and chemical cross-contamination.
At their essence, xanthan and guar gum are indigestible fibers. Thus, they may cause flatulence, bloating, and even diarrhea. Xanthan gum is even cited by researchers as “a highly efficient laxative.”
Turning attention to the microbiome and gut health, a study published in Research in Veterinary Science evokes concerns. Researchers fed young pigs infected with a pathogenic E. coli strain either plain rice or rice containing 10% guar gum by weight. The latter portion represents an extremely high gum content, but the study’s results are still noteworthy. Pathogenic E. coli proliferated far more abundantly within the pigs’ intestines among those that ate guar-gum-infused rice versus plain. Additionally, the guar-gum-fed pigs gained less weight overall (a negative effect since the pigs were still growing), but developed heavier, enlarged colons that suggested gastrointestinal dysfunction and dysbiosis (an intestinal imbalance between healthy and pathogenic bacteria).
Beyond these potential side effects, processing procedures may introduce chemical cross-contamination. As previously mentioned, a bacterium produces xanthan gum via fermenting carbohydrates. Often, wheat or corn acts as the chosen starch medium. Although most producers label their gums “gluten free,” individuals demonstrating gluten sensitivity, such as those with celiac disease (an autoimmune gluten allergy), should exercise caution. No existing studies have definitively exposed gluten-contaminated xanthan gum, but since its production could employ gluten-rich wheat, the possibility of contamination exists.
Legume-derived guar gum merits consideration too, since legumes contain lectins and phytates, both inflammatory molecules linked to gut issues, headaches, and more. Especially relevant, seeds contain high lectin concentrations, and guar gum is seed-derived. No research currently explores whether these lectins directly cause negative side effects, but the possibility seems probable.
Moreover, dioxins (chemicals defined by the World Health Organization as highly toxic and potentially linked to reproductive and developmental problems, damage to the immune system, hormone disruption, and some cancers) pollute some guar gum. In 2008, the European Union laboratory analyzed Indian guar gum (80% of the world’s guar gum) and found dioxin concentrations 1000 times greater than the acceptable levels.
The Bigger Question: Processing
The gums may hold some therapeutic value, but generally only via immense quantities that also pose potential health risks, such as bloating and dysbiosis. Most imperative, these food enhancers are highly processed and therefore unnatural.
Revisiting xanthan gum’s processing procedures, scientists induce a bacterium to ferment carbohydrates (usually corn or wheat) that then produces a slime-like gel product that manufacturers compress, sterilize, separate via mixing with isopropyl alcohol and finally grind and package. The result is a colorless, scentless additive.
Guar gum follows a similar process, but starts with highly processed guar splits, the remnants after manufacturers remove the endosperm, husk, and germ (major plant components) from the Cyamopsis tetragonoloba (guar) seed.
These additives do not fit optimal nutritional principles, including whole, unprocessed foods and diets most aligned with ancestral eating patterns, which included predominantly tubers, plants, and animals. These aliments have fit human biology for many millennia, while today’s recent farming and industrialized food processing practices pose stark contrasts. The result?—a disconnect between what the human body craves, and what the modern human consumes. As processed foods have become increasingly ubiquitous, disease and ill health have simultaneously followed suit. Even based upon concrete research, straying from ancestral dietary principles likely interferes with attaining abundant health. Thus, eating heavily processed gums and other additives can compromise well-being.
Existing research makes it even clearer. After reviewing numerous studies, researchers concluded that nearly all food processing reduces a food’s nutritional value and often oxidizes fat molecules (chemically changes the fat molecules resulting in different, unnatural structures). Food and Chemical Toxicology linked fat oxidation to cancer, brain-degenerative disorders, and overall inflammatory reactions.
Sodium benzoate represents an entirely different food additive category: preservatives. Despite its prevalence, it is unfamiliar to most consumers. Typical foods containing sodium benzoate include soft drinks, sauces, condiments, and bottled, non-100% juice concoctions.
This preservative does not occur naturally, and is instead highly processed and laboratory synthesized from two chemical compounds—benzoic acid and sodium hydroxide. While most benzoic acid used to create sodium benzoate is laboratory-derived, benzoic acid does occur naturally in berries, tomatoes, and certain spices. On the other hand, sodium hydroxide is strictly a laboratory-synthesized chemical. It is an ingredient in most drain cleaners and soaps and demonstrates highly caustic and flammable properties.
The FDA recognizes sodium benzoate as GRAS (at a maximum of 0.1% concentration in foods and an ADI of five milligrams per kilogram of bodyweight per day). Still, the science supports consumers exercising caution.
The Science: Sodium Benzoate
Sodium benzoate has been investigated therapeutically regarding urea cycle disorders and multiple sclerosis (MS). A few potential positive applications have been elucidated, though these required ingesting far greater quantities than the FDA specified ADI. Research suggesting this additive poses a health threat, however, is prevalent.
Therapeutic Uses: Sodium Benzoate
Sodium benzoate is commonly used to treat urea cycle disorders (problems excreting degraded products from protein consumption). A Gastroenterology and Hepatology review concluded that the additive represents a plausible adjunctive therapy for hepatic encephalopathy, a serious neurological disorder attributed to urea cycle dysfunction and other liver complications. Patients consumed more than ten times the ADI to achieve these results.
Clinically administered sodium benzoate may potentially help to treat MS as well. Neurochemistry Research found that in the laboratory setting, growing human brain cells in the preservative’s presence significantly augmented CNTF (a molecule important to prevent MS) production. Moreover, mouse brain cells incubated with sodium benzoate produced fewer inflammatory molecules, which may help thwart MS development. In both studies though, researchers noted a need for additional research and that downsides do exist, such as the requisite high doses to produce the observed outcomes.
The Downsides: Sodium Benzoate
First, consumers can easily overconsume sodium benzoate considering its pervasive use among food manufacturers. Additionally, multiple studies link the additive to neurological dysfunction, such as impaired memory and even attention deficit hyperactivity disorder (ADHD), negative DNA alterations, and microbiome disruptions.
Exceeding the sodium benzoate ADI occurs commonly, especially in children due to their lower bodyweight. For example, a child weighing less than 84 lbs. who consumes two soda bottles and a portion of jam and ketchup exceeds the ADI. Even the average adult ingests 1.4 times the recommended limit.
Beyond dosage, its neurological effects raise major issues. Biochemical and Molecular Toxicology published findings that even low sodium benzoate concentrations impaired mouse memory and motor coordination after only four weeks. Additionally, the preservative decreased brain glutathione levels (an important antioxidant that aids in preventing brain damage). An African Journal of Biotechnology review examined this idea further, scrutinizing several studies that evaluated ADHD and hyperactivity symptoms among children. The authors concluded that surpassing the five milligrams per kilogram ADI (considered a common occurrence) provoked said symptoms.
A cell-based study from BioMed Research International evinces that sodium benzoate affects more than the brain. The researchers discovered that human lymphocyte cells (a type of white blood cell) treated with small amounts of the preservative exhibited DNA mutations that fostered cell abnormalities, malfunction, and even death. A Food and Chemical Toxicology lymphocyte study revealed similar results. Low sodium benzoate doses stimulated DNA breakage and mutation. The researchers recognized that while further investigation is necessary, at least within an in vitro (laboratory cell-based) environment, this additive can cause significant DNA damage.
This preservative also appears to affect the gut. An in vitro study from Folia Microbiologica concluded that common food additives, including sodium benzoate, can greatly decrease the beneficial and anti-inflammatory microbiome bacterial species L. paracasei. Additionally, research in Molecular Genetics and Metabolism found that when obese humans ingested the additive, their anthranilic acid levels (a marker of liver failure) surged. Gut microbes normally break down and remove anthranilic acid, so researchers hypothesized that sodium benzoate may have altered the subjects’ intestinal bacteria, inducing impaired anthranilic acid metabolism and potential liver complications. Note that both studies employed sodium benzoate concentrations that modeled average adult consumption.
The Bottom Line
Additive-containing foods are ubiquitous in modern life and often highly palatable as well as convenient. Still, science indicates that ingesting xanthan and guar gum and sodium benzoate does not help to achieve optimal health. The bottom line?—avoid food additives.