I love the café/bakery eatery chain Panera Bread. Ever since I was introduced to them in 2003, my wife and I have frequented this establishment in many different cities of the US, finding with delight that our trust in their food quality and quantity has not been misplaced. We love their menu items, soups and sandwiches – even some of their seasonal salad offerings (and that’s saying something, because neither of us is a very salad-y person). My wife is particularly keen on their Chai Tea Latté. Their bakery is excellent, not to mention the delicious breads they make, which can be bought separately. So imagine my consternation, when on a recent visit, I discovered that they appear to be peddling some weapons-grade bullshit about chemicals and additives in food.

From their Fall 2016 brochure available in the stores:

Screenshot from Panera Breads Fall 2016 brochure

They proclaim that ingredients like sodium benzoate are on something they refer to as a “No-No List”. Why? Are these harmful? Are there serious safety issues around these ingredients concerning children? No, apparently, the reason is: these ingredients “aren’t so easy to picture”, and that “Kids shouldn’t have to imagine what’s in their food”. And of course, they provide irrefutable proof for that assertion: it is easy to draw a tomato, but I bet you can’t draw sodium benzoate, can you? Boom!

Well, Sodium Benzoate —a salt of benzoic acid (an aromatic carboxylic acid) and a strong base, sodium hydroxide— is actually pretty easy to draw, with the sodium cation (Na+) exchanging places with the hydrogen ion (H+) in the carboxyl group attached to a benzene ring… But I digress. In fact, scratch that. I don’t expect anyone, let alone a kid, who has no knowledge of basic organic/inorganic chemistry, to be able to draw the chemical structure of a food ingredient. Let’s simply see what happens if we apply broadly the general principle which Panera Bread seems to have embraced with gusto.

We must not eat what we cannot draw, eh?

We, especially kids, should never eat what we/they cannot draw, amirite?

Oh, I am sure that for Panera Bread, this is likely considered a ‘smart’ marketing decision, advertising thusly their street-cred as a ‘green’ eatery, thereby drawing in a specific niche demographic that subscribes to various New-Age-y, ignorant myths and pointless conspiracy theories about food safety so popularized by the likes of the execrable Food Babe, but jeez, I wish they had dialed down a notch this patent enablement of chemophobia, an irrational attitude described as a “reflexive rejection of modern synthetic chemicals”, often based on demonstrably false assumptions. To illustrate, let me take the case of Sodium Benzoate.

Why Sodium Benzoate?

I was curious – of myriads of available food-related chemical substances, why focus on Sodium Benzoate? After all, benzoic acid is a naturally occurring substance produced by plants, discovered first in the sixteenth century, and is a starting material for a host of useful primary and secondary metabolites. Benzoic acid, in free and various bound forms (such as esters), are widely present in the environment, occurring in fruits (prunes, berries of different types, et cetera), vegetables, honey, and various other natural food items. And because of its interesting ability to pass through cell membranes of yeasts and other fungi and disrupt cellular machinery by creating an acidic environment in the fungal cells (a mechanism that was elucidated by someone no less than Nobel Laureate Hans Krebs, of Kreb’s Cycle fame), it has been used as a food preservative since late 19th century for acidic foods and materials, such as fruit juices, pickles, wine, and pharmaceuticals.

In addition, Sodium Benzoate has an important therapeutic application. Our intestines metabolize nitrogen-containing substances (including proteins) to generate a gas, ammonia, which is ordinarily detoxified in the liver via the urea cycle. If for some reason (inherited or acquired), this process is deficient, ammonia can accumulate in the blood (a condition called hyperammonemia), reaching life-threatening neurotoxic levels. Administration of Sodium Benzoate is one of adjunct therapeutic approaches taken for preventing ammonia accumulation and removing excess ammonia. And the human body ordinarily appears to tolerate Sodium Benzoate rather well (within reason, unless there are additional risk factors, such as reduced renal function); excess Benzoate is conjugated with the amino acid glycine (to produce a metabolite called Hippuric acid) or with a sugar acid called Glucuronic acid, and excreted from the body. Therefore, at naturally occurring levels, as well as therapeutically administered levels, Sodium Benzoate is non-toxic and not deleterious to humans. No wonder then, that FDA accords it the GRAS (Generally Recognized As Safe) status for a maximum level of 0.1% in food. So, none of this answered my question: why Sodium Benzoate?

Trying to figure out what in Sodium Benzoate attracted the ire of the above-mentioned demographic, I had to go down the rabbit hole of —shudder!— food-pseudoscience, and found that more or less four major concerns have been breathlessly raised in various ‘natural’ food-associated websites. From one such:

What They Say What Is Left Unsaid
Hypersensitivity to Sodium Benzoate, which is known to occur in a small percentage of people.
  • In large dermatology studies, only 2-7 out of every 1000 participants showed symptoms of hypersensitivity
  • Hypersensitivity has been reported after oral or inhalation exposure, but symptoms were acute and resolved within a few hours
Combination of Sodium Benzoate with citric acid or ascorbic acid (Vitamin C) creates benzene, which causes cancer.
  • Cancer! – that ultimate instrument of fear-mongering. While it is true that benzene is designated as a human carcinogen, all aromatic chemical substances, including biomolecules, contain the benzene ring structure – but very few have the potential to cause cancer. Interestingly, according to a 2002 draft environmental risk assessment report from the EU, highest contribution to Benzene exposure (96 to >99%) comes from the air we breathe in.
  • Benzoic acid may undergo decarboxylation (loss of the carboxylic acid group) to Benzene, but it is important to remember that this occurs via attack from free hydroxyl (OH-) radicals. The involvement of Ascorbic or Citric acid is predicated upon the presence of transition metals like Copper(II) or Iron(III) which facilitate the production of OH- radicals. However, various antioxidants in the body clean up these free radicals, and interestingly, Ascorbic acid is one such antioxidant.
  • In repeated Rat studies, no evidence of carcinogenicity of Sodium Benzoate or Benzoic acid was discovered.
  • In repeated Rat studies, no attributable reproductive toxicity or teratogenicity due to Sodium Benzoate was observed.
Hint at a possible link between Sodium Benzoate and Attention Deficit Hyperactivity Disorder (ADHD), in which the name of Mayo Clinic is liberally thrown as saying “… the preservative (as well as several food dyes) may enhance or trigger hyperactivity in children.”
  • The 2010 survey-based study, performed in a group of college students, hinted at an association of ADHD-related symptoms and the subjects’ intake of Sodium Benzoate-containing beverages. Needless to say, no causality was established.
  • But what does the Mayo Clinic website say? Nothing really. The section of food additives and hyperactivity doesn’t mention Sodium Benzoate by name at all, but does state: “Food and Drug Administration Food Advisory Committee determined that studies to date have not proved there’s a link between food colorings and hyperactivity.”
Scientists evaluated genotoxicity of sodium benzoate; in cultured human cells, it significantly increased damage to DNA (which triggers cell mutation and cancer) when it was added to the cells in various concentrations.
  • As always, it is important to note that dose maketh the poison. Also, isolated in vitro observations cannot adequately describe or explain what happens in a complex system in vivo.
  • That said, Sodium Benzoate tested up to 200 milligrams per milliliter did not induce any chromosomal aberration or cell division abnormality in human embryonic lung cells in culture.
  • Two studies (2011, 2015) using human lymphocyte cell lines did show genotoxicity using traditional markers, chromosomal aberrations, sister chromatid exchange and micronuclei formation, but some of the results between the two studies are inconsistent.Sodium Benzoate also did not produce a gene mutation in lymphocytes one study was investigating.
  • In an in vivo chromosome aberration test performed in rats, Sodium Benzoate did not produce appreciable aberrations in bone marrow metaphase chromosomes. In fact, all in vivo genotoxicity tests were negative at somatic or germ cell level.
Data Source: [International Programme on Chemical Safety’s Concise International Chemical Assessment Documents. Number 26: Benzoic Acid and Sodium Benzoate (2000). Available as of April 27, 2016], unless otherwise stated.

I think I do get my answer finally: ignorance, misinterpretation of science, misrepresentation of the observations, cherry-picking of results that appear to support some preconceived notions; these well-known hallmarks of pseudoscience are rife in the strange bias against Sodium Benzoate, and chemophobia in general. In respect of Panera Bread, I find it particularly galling that they should peddle this nonsense targeted at kids, because inculcation of chemophobia at childhood has the potential to hobble a child’s intellectual curiosity and scientific understanding of the natural world. Not only that, parental chemophobia can have serious consequences for the child, as illustrated by this old essay by scientist and science communicator, Prof. Michelle M. Francl. (You can follow her interesting blog, The Culture of Chemistry, too!)