I am going to fact check the claims made in It Starts With Food by reviewing all 450+ citations provided by the authors. Got your attention? Good, keep reading.

That Was Then

I was introduced to the Whole30 by way of my CrossFit gym (yes, I’m a cult member. Leave me be!). Like many other CrossFit gyms, they offered a paleo-centric nutrition program. For the program, you had to read through the Whole30’s book, It Starts With Food (ISWF), as well as various other texts about the importance of sleep, nutrition, etc. The program lasted 60 days and was a stricter version of what is prescribed by ISWF. On the traditional program, they essentially get you down to eating meat, veggies, fruits, and nuts for 30 days. At my Crossfit gym, we got down to eating meat, veggies, and some nuts during weeks 6-8. It was tough. The purpose of the program was three-fold:

Have people foster a healthy relationship with food
Break bad food habits/cravings
Get participants to eat healthier

My friends that were on it lost a ton of weight. The average weight loss for men seemed to be about 30 lbs. (13.6 kg) over two months granted some of this would have been water weight loss due to the low carb nature of the diet. People felt great, they slept better and talked about how much more energy they had. I even saw improvements in some of my metabolic markers.

Chapter grade for scientific accuracy: F (32.14%)

This should actually be a fairly brief It Starts With Food review as the chapter only contains 5 citations. That’s totally fine by me! I could use a break after writing the lengthy essays that were Chapter 8 and Chapter 14. Let’s begin.

Whole30

“MSG…is known to have neurotoxic effects [1].”

“MSG..is also linked to obesity by promoting leptin resistance [1].”

“In fact, MSG is used to induce obesity in lab rats [1]!”

“Distorting” and “disingenuous” are all words that came to mind when I read the above statements. Why do they start with the letter ‘D’? I can’t talk about it. Fight Club.

I’ve discussed MSG before on other websites, so I’ll paraphrase myself here to get everyone up to speed.

Monosodium glutamate is what you get when you bind the amino acid glutamate to sodium. This is similar to the way sodium binds with chloride to form table salt. When added to a dish, MSG acts to enhance the flavor of umami, the savory taste we experience when eating protein.

Glutamate is a naturally occurring substance that is found in many of the foods you eat every day including tomatoes, parmesan cheese, and potatoes. Meat, dairy products, seaweed, and many vegetables have higher levels of glutamate than you would typically consume from a meal at a Chinese restaurant. Your body actually produces glutamate (glutamic acid if you want to be picky) where it can act as a neurotransmitter, helping to carry nerve impulses throughout the body. On average, you will consume about 13 grams of glutamate every day from food and an estimated 0.55 grams from added MSG [2].

tl;dr - none of the three claims made about MSG by ISWF are accurate. If you want to skip the nitty gritty dissection, you can watch this 3-minute video below and learn the basics about MSG.

Alright, let’s examine these claims one by one.

Whole30

“MSG…is known to have neurotoxic effects [1]”

A neurotoxin is a poisonous substance that can harm or destroy nerve tissue. The paper they cited says nothing about MSG being a neurotoxin and was not even designed to look at that question. MSG would not have a neurotoxic effect on humans unless you were receiving a MASSIVE dose in a very short period of time. I’m talking about hundreds of grams of the stuff. And even then, you may have to inject it to produce nerve damage. The idea that MSG is a neurotoxin comes from early trials performed on animals [3]. One particular study performed on a rhesus monkey injected a dose of MSG that ranged between 0.7g and 2.7g per kilogram of body weight [4]. If you take a 155 lb. (70 kg) person, we’re talking about 49g to 189g of MSG in one dose. Compare that to Asian countries who typically have the highest daily MSG intakes. They’re only averaging 1.2g to 1.7g per day [5].

The theory of ‘glutamate-induced nerve death’ in the brain has not been substantiated in the literature. It does not even appear that glutamate can cross the blood-brain barrier, a necessary step for this theory to be proven accurate [6].

Whole30

“MSG…is also linked to obesity by promoting leptin resistance [1]”

A person reading the above statement would probably assume the authors were referring to an MSG-Obesity link in humans.

Nope.

The paper cited here was performed on rats and did not show any direct link between MSG and leptin resistance [1]. It did show that rats fed large amounts of MSG (100g/kg of body weight) over 45 days gained the most weight compared to controls although the differences were not statistically significant [1]. Overall food consumption and energy intake were significantly higher in the MSG group and they did have significantly higher leptin levels, indicating leptin resistance. But not even the researchers of the paper thought that this was caused by MSG. They state:

“It is believed that increased food intake leads to increased insulin resistance or high leptin levels [1].”

MSG has not been shown to reliably increase or decrease food intake in humans. A while back I wrote up a literature review for Examine.com looking at this topic. After reviewing all available studies looking for a MSG-weight gain connection in humans, most studies found it had no effect while a small handful found it might have a small effect. I also reviewed the evidence in humans for the effects of MSG on headaches, allergies, asthma, and other general adverse symptoms associated with MSG intake. You can read the full article lined above for the full breakdown, but here are the three main takeaways.

Injecting MSG is unsafe. Especially directly into the brain. Don’t do this.
Most studies that reported ill effects from MSG had administered large doses (≥3 g) without food over a short period of time, and even then, the ill effects were mild and temporary. Such doses would be hard to reach by eating foods with added MSG in a real-world setting (and it’s very unlikely you would swallow such high doses without food). Please note, however, that some studies were funded by the International Technical Glutamate Committee, whose aim is notably to “promote the uses of glutamates as food ingredients”.
There is a lack of trial evidence indicating a detrimental effect of MSG for the general population, and some evidence suggests potential benefits for elderly people with appetite issues.

Whole30

“In fact, MSG is used to induce obesity in lab rats!”

One might misread this as MSG is what caused these lab rats to become obese. Just to be clear, MSG makes things taste really good, to both humans and rats. When MSG is added to the rat’s foods, they overeat. Do this consistently and the rats become obese. The paper cited in ISWF to support their claim concludes the following:

“…addition of MSG to a standard diet enhanced food intake. Overfeeding induced metabolic disorders associated with oxidative stress in the absence of obesity [1].”

It is the overfeeding and excess calories that cause weight gain. Not the MSG. While this additive may be used as a way to achieve overconsumption in rats, we don't see these same effects in humans (as mentioned above).

Since you’ve just had to endure a fair amount of MSG fear-mongering, I’d like to point out that MSG does potentially have some benefits:

May be used to help reduce salt content of foods [7]
As a treatment to help older patients with taste disorders [8]
Provide flavor to low calorie foods [9]

Final MSG Flavored Thought – It's really easy to cherry-pick studies that reinforce your pre-held beliefs while ignoring the ones that challenge them (everyone is susceptible to this, myself included). For example, this study concluded that MSG “suppresses weight gain, fat deposition, and plasma leptin levels”. If I were a more unscrupulous fellow, I could write a diet book claiming that MSG is the miracle weight loss cure the world has been waiting for! However, that study was performed on rats and we already have many human trials showing that the effects of MSG on appetite are probably neutral(ish). When the totality of evidence on a given topic is not taken into account, you get diet books shouting about how “MSG is a neurotoxin”.

Oh, look! Everything we just talked about in an infographic.

The internet is wonderful.

Whole30

“Sulfites occur naturally in many foods and beverages and are a byproduct of fermentation, so they are found in most wines, as well as balsamic and red wine vinegar. They are also added to processed foods to increase shelf life, preserve color, and inhibit microbial growth. Sulfites can cause significant dermatological, pulmonary, gastrointestinal, and cardiovascular symptoms in sensitive people, so avoid added sulfites during your program [14,15].”

It is true that some people are sensitive to sulfites and need to watch their intake. Sulfites have been known to trigger asthma or even hives in these allergic populations. But the Whole30’s elimination of added sulfites from your diet brings up an interesting conundrum. Why aren’t the most common food allergens excluded from this diet?

Food allergies affect about 4–10% of the population [10,19]. There are 8 foods that account for ~90% of all food allergies in the United States [11]. They are:

Crustacean Shellfish
Eggs
Fish
Milk
Peanuts
Soy
Tree Nuts
Wheat

Tree nuts may be a new one for some of you. These are items like brazil nuts, chestnuts, hazelnuts, pine nuts, walnuts, almonds, pecan nuts, coconuts, and cashews. Sulfite sensitivity/allergen prevalence may be less than 0.05% of the population and disproportionately affects those with asthma [12-14]. I mention this to point out the logical inconsistencies of this program. Four of the 8 most common allergens are never eliminated from this 30-day diet: eggs, fish, crustacean shellfish, and tree nuts. ISWF even explicitly states elsewhere in the book that:

“You want to completely eliminate your exposure to any potentially inflammatory compound during your Whole30…”

We have evidence that these 4 items are more likely than most to cause food sensitivities or allergic reactions. The ISWF authors state that one of the main goals of the program is to remove all "potentially harmful" foods for 30 days so that you may identify previously unrecognized sensitivities or allergies upon reintroduction of said foods. Elimination of the 8 most common food allergens seems like an obvious place to start. ISWF has advocated that you eliminate other food groups using far weaker evidence than we have for these 8 foods, so why didn’t they eliminate them all in their program?

I can only speculate. My theory/opinion is that when Dallas and Melissa set out to write this book they had already had an opinion of what they assumed to be a “healthy diet” (from their viewpoint, a paleo-type diet). They possibly looked for scientific studies that supported their current beliefs, without carefully reading them, and did not seek out data that challenged these beliefs (i.e., cherry picking). Since eggs, fish, crustacean shellfish, and tree nuts are “paleo approved” and milk, peanuts, soy, and wheat are generally not, I suspect it didn't occur to them that these foods would need to be eliminated for their rules to remain logically coherent with what they claim the programs goals are.

This disconnect illustrates the issue of attempting to evaluate scientific evidence believing you already know the answer — it can blind you to the data that may challenge your conclusions.

Enough about allergies, let's talk about carrageenan [kar-uh-gee-nuhn].

Whole30

“Carrageenan is a concentrated seaweed extract used to thicken processed foods and is found in everything from deli meat to yogurt to chocolate. Carrageenan is inflammatory if it gets into the body, which could happen if you have increased gut permeability. (Carrageenan is actually used to create inflammation in lab animals.) Furthermore, in the digestive process, carrageenan may be broken down into components that can cross even a healthy gut barrier [16,17].”

It’s time for a breakdown!

Whole30

“Carrageenan is inflammatory if it gets into the body, which could happen if you have increased gut permeability [16,17].”

They cite two sources here. A study done on human intestinal cells in vitro (they exposed intestinal cells in a petri dish to carrageenan) and the World Health Organizations (WHO) Food Additives Series #59 - Safety evaluation of certain food additives and contaminants [16,17]. Neither of them offers data that would support the conclusion that “carrageenan is inflammatory if it gets into the body”. The piece that is missing from ISWF is context about what dose would be needed to see these inflammatory effects. As I’ve stated before in previous posts, if you drink enough water in a short timeframe it will kill you dead. The dose makes the poison.

The WHO report states that the No Observable Effect Level (NOEL) (for non-newborns) of carrageenan is 750 mg/kg of bodyweight per day. NOEL is the greatest amount of a substance you can be exposed to without it causing harm. For a 155 lb. (70 kg) person, 750 mg/kg is the equivalent of consuming 52.5 grams a day [17]. Compare that to the average Joe/Jane's intake of 30 to 50 milligrams a day, roughly 0.1% of the NOEL level.

Whole30

“Carrageenan is actually used to create inflammation in lab animals [16,17].”

Not quite. As the WHO report states [17]:

“Poligeenan has been widely used as an inflammatory and adjuvant agent in experimental models for investigation of immune processes.”

Poligeenan is often referred to as “degraded carrageenan” and is not allowed in food production. The WHO report notes that high-quality food-grade carrageenan did not induce inflammation in animal testing [17].

Whole30

“In the digestive process, carrageenan may be broken down into components that can cross even a healthy gut barrier [16,17].”

The implications here are that intact carrageenan can be broken down into degraded carrageenan in the stomach which can then harm the gut/your health. This has not been substantiated by the current body of evidence. Referring back to the WHO report originally cited [17]:

“…the Committee concluded that such breakdowns [of carrageenan] is probably of limited toxicological significance since, if native carrageenan were sufficiently degraded to cause ulceration or tumor growth, this would be detected in feeding studies.”

The European Commission's Scientific Committee on Food also reviewed the use of carrageenan and concluded the following [18]:

“On the issue of degraded carrageenan, while there is no evidence of any adverse effects in humans from exposure to food-grade carrageenan, or that exposure to degraded carrageenan from use of food-grade carrageenan is occurring, the Committee nevertheless proposes the specification for food-grade carrageenan to be tightened in order to ensure that the presence of any degraded carrageenan is kept to a minimum.”

“On the issue of undegraded carrageenan, the Committee agreed with the conclusions of the recent JECFA review that intakes of carrageenan and processed Eucheuma seaweed from their use as food additives were of no concern (JECFA, 2002).”

Unnecessarily scaring people over harmless food additives like MSG is a tried and true tactic. It has worked wonders for charlatans like the Food Babe and made her a pretty penny. But whenever people start hollering about how this or that food additive will give you face cancer, I’m reminded of a joke I heard once (can’t remember where).

A patient walks into his doctor's office.

Patient: “Doctor, I’m worried that the polychlorinated biphenyls (PCBs) in my salmon are destroying my health!”

Doctor: “You should stop smoking.”

THE scienciness SCALE

Scienciness Categories

True (4 Points) – true statements
Mostly True (3 Points) – where the bulk of the claim is factually accurate
Misleading (2 Points) – where statements are presented out of context
Mostly False (1 Point) – where the bulk of the claim is factually inaccurate
False (0 Points) – false statements

Results

7 Statements Evaluated
9 Out of 28 Possible Points Earned
32.14% Overall Factual Accuracy

Chapter 18 Scienciness Scale

STATEMENT CATEGORIZATION

True

“Sulfites can cause significant dermatological, pulmonary, gastrointestinal, and cardiovascular symptoms in sensitive people, so avoid added sulfites during your program [14,15].”

Mostly True

N/A

Misleading

“In fact, MSG is used to induce obesity in lab rats [1]!”

Mostly False

“MSG … is known to have neurotoxic effects [1].”

“Carrageenan is inflammatory if it gets into the body, which could happen if you have increased gut permeability [16,17].”

“In the digestive process, carrageenan may be broken down into components that can cross even a healthy gut barrier [16,17].”

False

“MSG … is also linked to obesity by promoting leptin resistance [1].”

“Carrageenan is actually used to create inflammation in lab animals [16,17].”

It Starts With Food: A Critical Review Introduction

That Was Then

Authors’ Note

Chapter 1: Food Should Make You Healthy

Chapter 8: Sugar, Sweeteners, and Alcohol

Chapter 14: Vegetables and Fruit

Chapter 18: The Whole30 Process of Elimination

THE scienciness SCALE

Chapter 18 Scienciness Scale

STATEMENT CATEGORIZATION

SOURCES