Nothing has been more polarizing on the internet in recent weeks than the discussion that has followed the June release of What the Health on Netflix. Initially, I was content to sit-back and not get involved. However, as I started reading film reviews by physicians and dietitians, I was a little taken aback by their stance, which was to completely disregard the messages in this documentary. While I think many of my colleagues made valid points in their discussion, I feel it’s unfair to dissuade someone motivated to adopt a plant-based diet based on the premise of this film.

Which leads to me to today’s post. I’ll warn you ahead of time, it’s lengthy. My intention in this post is to separate the sensational messages from those that are backed by quality science and research. But first, a quick synopsis of the film:

Kip Andersen and Keegan Kuhn, the filmmakers behind Cowspiracy, set out to prove that a plant-based diet can prevent many of the diseases plaguing our society, including cardiovascular disease and type 2 diabetes. Andersen and Kuhn also attempt to expose the collusion between the food industry, the American government, and national health organizations, whose mandate is to prevent, manage, and cure chronic diseases.

What the Film Does Well

The Food Industry Shapes Nutrition Guidelines
This film does an excellent job of unveiling the corporate sponsorship that many health organizations accept. For the organization, the financial gain from sponsorship is used to fund research, run campaigns, pay their employees, as well as create resources and marketing materials. For the company, such a partnership protects their food products from being cast in an unfavourable light and conveys an image of a company that cares about the health of its consumers. It’s a pretty win-win situation for everyone involved, except for the consumers who may be unduly influenced by such partnerships.

What Goes into our Environment Goes into Our Food System
It’s no secret that animal agriculture has a significant impact on our environment. Thirty percent of greenhouse gas emissions are attributed to animal agriculture [1] and 55 trillion gallons of freshwater are used by the industry annually [2]. Overfishing, deforestation, and species extinction are also unfortunate side effects of our demand for meat and dairy [3].

But meat and dairy don’t just put out environmental toxins, they also take them in. Methylmercury, polychlorinated biphenyls (PCBs), and polybrominated diethyl ethers (PBDEs) are residual pollutants found in our environment that can bioaccumulate in the fat tissues of animals [4]. These toxins may cause neurological, endocrine, and developmental consequences with repeated, prolonged exposure and should be limited, especially during susceptible times, such as pregnancy [4].

Antibiotic Resistance is Scary
Antibiotic resistance increases health care costs, duration of hospital stays, and can lead to untreatable infections, such as pneumonia. Misuse and overuse of antibiotics, which occurs in both the health and animal agriculture industry, is the main contributor to antibiotic resistance. Presently, nearly half of the world’s antibiotics are used in animal agriculture, as crowding, stress, and unsanitary conditions significantly increase an animal’s risk for disease. By reducing our reliance on meat and dairy, we decrease the need for antibiotics, thus preserving their use for the healthcare industry where they are needed most [5].

Chronic Disease Is Preventable
This is by far the most important message presented in the film, and the one I fear may be sacrificed by other health professionals’ critique of the film. When it comes to our health and disease risk, genetics are important. However, there is an entire field of research showing that the way we eat in pregnancy can influence our genetic potential for disease. Furthermore, being at risk for a disease, such as diabetes or heart disease, isn’t a guarantee that you will succumb to that disease. If anything, being at risk is a call to action to take important lifestyle steps to reduce your disease risk.

When you collectively consider the most common chronic diseases of our time, and tease out the commonalities between the clinical practice nutrition guidelines for each of these disease states, a pattern begins to emerge. Eating a diet rich in fruits, vegetables, whole grains, and pulses, with a low intake of saturated fat, trans fat, and sodium is not only beneficial in managing diseases such as cancer, diabetes, and hypertension, but can significantly lower your chances of developing these diseases if you are at genetic risk [6].

Google trend for “vegan” following the release of “What the Health” on Netflix.


What the Film Doesn’t Do Well

Anecdotal Reports
The film follows the changes in the health and medication usage of several individuals who adopt a plant-based diet. All of them show physical improvements in their health and report being able to reduce or eliminate their medication.

While the inclusion of anecdotes in this type of film is common and is used to connect with the audience, it’s not good science, as potential lifestyle confounders may not be controlled for and could contribute to the individual’s improved health status.

Focus on Food vs. Dietary Patterns
Our overall dietary pattern is more important than the individual components making up our diet. At the end of the day, no one food has been conclusively shown to cause disease. Rather, specific dietary patterns (i.e. a typical Western diet, which tends to include large portions of meat and dairy with few servings of fruits and vegetables) has been correlated to an increased risk of developing chronic disease such as obesity, cancer, diabetes, and cardiovascular disease.

Studying nutrition in humans is incredibly challenging; deriving conclusive evidence from those studies is even more challenging. Why? Because there are so many variables that can influence the outcome of the study. Exercise, sleep, alcohol, smoking, and medication are potential confounders that can be easily controlled. However, unless participants’ diets are supervised in a lab setting (which is very costly and, as such, results in a small sample and short duration of time) a researcher is unable to control for all the dietary factors that could alter the results of the study.

Reliance on Physicians and Nutritionists as Nutrition Experts
As the film points out, medical doctors receive very little training in nutrition. Yet, they are often relied on as the experts on nutritional science. And, as I’ve mentioned in many posts, nutritionists are unregulated health professionals who often receive their certificate after only 1 year of education. In contrast, dietitians complete a minimum 4-year diploma program (which includes 1 year of supervised internship) from an accredited university program, must demonstrate competency by passing a credentialing exam, and are required to register with provincial regulatory bodies that monitor their practice to ensure ongoing competency and ethics.

Despite this, only one dietitian was interviewed in the film. Now, I’m not saying that the physicians interviewed weren’t knowledgeable (as Dr. Neal Barnard has published many articles in peer-reviewed journals, including JAMA, and Dr. Michael Gregor spends his days reviewing and reporting nutrition literature), rather, the film could have garnered more credibility by interviewing those whose careers are based on nutrition.

The Battle Between Carbs vs. Fat vs. Protein
No matter how hard I try, I can’t understand why being vegan or plant-based means shunning fat or protein in favour of carbs. All three nutrients are essential for maintaining optimal health and are easy to obtain on a plant-based diet. Yet, it feels as though this documentary points the finger at fat and protein as the culprits for the current disease epidemics of our time.

As mentioned above, studying nutrition is complex and many factors beyond diet have been linked to certain chronic diseases. Nonetheless, what seems to be emerging from the science is that the source of our macronutrients plays an important role. Refined carbohydrates, such as white rice, are less healthful than unprocessed whole grain carbohydrates such as sweet potato and barley; replacing saturated fat with unsaturated fat (which predominantly comes from plants) improves our lipid profiles; and replacing animal protein, specifically red meat, with plant-based protein can reduce our risk of certain diseases.

Additional Points of Contention

Calories cause Weight Gain
The film makes the statement that carbohydrates can’t make us gain weight in and of themselves. This is true if an individual is in calorie balance… BUT, protein and fat are not necessarily the culprits of weight gain either. Essentially, our body stores excess calories as fat, regardless of where they come from. So, provided you are in relative calorie balance, it doesn’t necessarily matter where your calories are coming from.

Uncomfortable Cold Calling
Andersen makes calls to various health organizations in an effort to point out the dietary discrepancies between emerging research and the food the organizations endorse on their websites. While I applaud his efforts, I don’t think it had the impact Andersen was going for. The individuals answering the phones at these organizations were not trained scientists. And I understand why many of them refused to be filmed. All in all, this is a part of a film that really didn’t need to be included.

The “C” Word
Processed meat is considered a Group 1 Carcinogen by the International Agency for Research on Cancer (IARC) of the World Health Organization [7]. To understand what this means, it is important to review the various categories of carcinogens developed by IARC. Group 1 Carcinogens are those with sufficient evidence of carcinogenicity in humans (i.e. x leads to z). What the categorization doesn’t tell us is how strongly the link is between x and z [8].

In this film, smoking is viewed as being equivalent to processed meat as a risk factor for cancer. This is an unfair comparison, as smoking has an unequal contribution to different types of cancer. When it comes to colon cancer, a causal link with smoking cannot be drawn due to the quality of evidence at this time [9]. In contrast, the link between smoking and lung cancer is profound with some cases being 90% due to smoking [9].

Regarding processed meat, the committee concluded that each 50g eaten daily increases the risk of colorectal cancer by 18%. This doesn’t mean that someone eating processed meat has an 18% risk of developing colorectal cancer. Rather, the baseline risk (which is relatively small at 5%) increases by 18% (to around a 6% risk).

So, while processed meat is definitely and causally linked to colorectal cancer (and red meat is deemed as probably carcinogenic to humans) it’s not accurate to equate their risk to that of smoking, based on the available evidence.

Bottom line

What the Health employs a degree of sensationalism and fear-mongering to convey their message to eat plant-based. Given the body of research that exists on the benefits of adopting a whole-foods plant-based diet for disease management and prevention, this wasn’t necessary; science should always be used before sensationalism. Nonetheless, I encourage my dietitian colleagues, along with health organizations, to discuss plant-based eating as an approach to disease management, allowing their clients, rather than their own biases, to decide if they are interested in eating this way or not.


1. United States Department of Agriculture (USDA). (2010). USDA Climate Change Science Plan 4. Article available at:
2. Pimental, D., Berger, B., Filiberto, D., Newton, M., Wolfe, B., et al. (2004). Water resources, agriculture, and the environment. Biosciences, 54(10): 909-911. Abstract available from:
3. Bowling, A.G. (2015). A leading cause of everything: one industry that is destroying our planet and our ability to thrive on it. Stanford Environmental Law Journal. Article available from:
4. Environmental Protection Agency (EPA). (2013). Environment and contaminants: chemicals in food. America’s Children and the Environment, 3, pg 1. Article available from:
5. Food And Agriculture Organization (FAO). (2011). Antibiotics in farm animal production: public health and animal welfare. Article available from:
6. Macfarlane, S. (2017). Why plant-based? Available from:
7. International Agency for Research on Cancer (IARC) of the World Health Organization. (2015). IARC monographs evaluate consumption of red meat and processed meat. Article available from:
8. International Agency for Research on Cancer (IARC) of the World Health Organization. (2006). IARC monographs on the evaluation of carcinogenic risks to humans. Article available from:
9. International Agency for Research on Cancer (IARC) of the World Health Organization. (n.d.). Smoking: Summary of data reported and evaluation. IARC Monographs, 83. Article available from: