Walnuts are Drugs: In Defense of the FDA

Back in 2010 the FDA sent a warning letter to Diamond Foods Inc. regarding their walnuts.  Here's the original copy.  Much of the internet, especially the 'healthy eating' community, proceeded to lose its collective mind with statements like:

FDA Ignores the Science
Walnuts are DRUGS! FDA Makes Bizarre Claim
FDA Says Walnuts are Illegal Drugs

You get the idea.  First of all, something the general public may not realize is that a warning letter from the FDA is nothing novel.  It happens all the time—Diamond Foods isn't special.  The FDA publishes all their warning letters on their website, and by the looks of it they issued approximately 600+ letters just in 2015.

Before we dive into the perfectly rational and justified reasoning by the FDA, let's explore a hypothetical:  Suppose you lived in the early 20th century and a reputable pharmaceutical company came to town selling a brand new elixir that would treat a strep throat infection.  There's only one problem—the elixir comprises an 'active ingredient' drug mixed and diluted with a solvent, which is poisonous.  By the time anyone realizes the true nature of this new drug, over 100 people are dead from ingesting it.  The sad reality is that this is no hypothetical—this is the true story of Harold Watkins and his deadly Sulfanilamide elixir of 1937.   Watkins used a substance proven to help treat a streptococcus infection, Sulfanilamide, diluted it with diethylene glycol, and topped it off with some raspberry flavor to create his new drug product.  Watkins, despite being the head pharmacist and chemist of then S.E. Massengill Company, was unaware that diethylene glycol is poisonous.  No animal or human testing was done with the new mixture before they set out marketing the new drug.  Tragedy ensued.  This event was a catalyst for the organization of the FDA as we know it today.

What does this have to do with walnuts?  A key role of the FDA is to prevent a person or company selling a drug (or device) from either A) making unsubstantiated marketing claims about the safety or efficacy of the drug (or device), or B) making unsubstantiated claims about the indications of use of the drug (or device) to treat one or more particular disease states.  On their website, Diamond Foods was in violation of both of these relating to the assertion that their walnuts contain Omega-3 fatty acids.  One example is the claim that Diamond foods made:
"Studies indicate that the omega-3 fatty acids found in walnuts may help lower cholesterol; protect against heart disease, stroke and some cancers; ease arthritis and other inflammatory diseases; and even fight depression and other mental illnesses."
Here Diamond Foods is making the claim that their walnuts can be used to help treat or prevent heart disease, stroke, cancer, arthritis, depression, and other mental illness—this is called an indication for use.  So let's be clear—if you are selling a substance which is ingested which you claim can be used to treat or prevent various diseases or illnesses, no matter what that substance may be (i.e. walnuts), you are making that substance a de facto drug.  In this case, it was not the FDA that made the claim that walnuts were drugs, it was Diamond Foods, Inc.

Diamond Foods also got dinged for making claims about the efficacy of their product by stating:
"[T]here's good evidence that omega-3s can increase HDL (good cholesterol), further reducing the risk of stroke and heart disease."
Here they are not only indicating that their product can treat a disease state, but specifically that their product would reduce the risk of stroke.  This is a description of the efficacy of their product to reduce the occurrence of a disease state.  Once again, Diamond Foods is de facto claiming that their walnuts are a drug.

Now, one primary complaint by the nay-sayers is this: "But lots of studies show that Omega-3s have been proven to help with those things!"  This is largely true.  But where are the studies that show that Diamond Food walnuts specifically contain those Omega-3's?  How do we know that there isn't another substance in walnuts that confound the positive effects of the Omega-3's?  Where are the randomized clinical trials showing that by ingesting more Diamond Food walnuts than a control population leads to lower occurrence rates or better outcomes of those disease states listed above?  For all we know, and for all the FDA knows, these studies don't exist.  This is why Diamond Foods got in trouble.

It is an unfair logical leap for Diamond Foods to assert that, since Omega-3's help treat those diseases and their walnuts presumably contain Omega-3's, therefore their walnuts must help treat those diseases.  Harold Watkins made a similar logical leap with disastrous consequences.  Obtaining approval from the FDA to market a new 'drug' or device doesn't always require a big randomized human trial, either.  If there exists a predicate approved product (i.e. one that basically already does the same thing) then all that remains is to provide sufficient bench testing data and written justification to show the equivalency of the two products in safety and efficacy, and the newer product may be approved.  This is accomplished through a 510(k) filing.  Diamond Foods may have been able to obtain approval for these types of claims through this relatively straight-forward avenue.

So what conclusions can we draw from all this?

1) The FDA doesn't decide what is and is not a drug—people and companies do by making "drug-like" claims about their products.  The FDA simply ensures that those claims are backed up by real science.

2) The FDA is not ignoring the science—if anything, Diamond Foods is ignoring the need for science.  The FDA is demanding an overwhelming burden of proof (how scientific of them!).  The FDA does this to keep us American's safe from all the snake oil salesman out there in the world.  In fact, the FDA is one of the most restrictive and conservative regulatory bodies in the world.  This is a key reason why most drug and medical-device makers do their clinical trials outside the US—it's typically easier and faster to obtain approval (and, therefore, less expensive).  As someone who works in an industry regulated by the FDA, this can be very frustrating.  As a consumer, I am grateful I can go to a local drug store and pick up some NyQuil for my colds, or Sudafed for my congestion, or Claritin for my allergies, and know that those products will be both safe and effective.


  1. I just randomly selected an FDA warning letter to read, and I chose "Vansridge Dairy Farm" RE: Illegal Drug Residue. Sounded like fun. There were phrases like, "insanitary conditions", and,"animals under conditions that are so inadequate that medicated animals bearing potentially harmful drug residues are likely to enter the food supply." Thank you FDA! Keep doing your job.