Debunking The Netflix Twin Study Documentary

The Study: Premise And Results

Researchers randomly assigned 22 sets of twins to either an omnivore or vegan diet. Initially, meals were provided to the subjects for four weeks, followed by four weeks of self-preparation. Blood work and weight measurements were taken before and after the 8-week period.

The study reported a statistically significant decrease in LDL cholesterol, and notable weight loss in the vegan group compared to the omnivore group. However, these results alone do not fully support the sweeping conclusions drawn in the film, which we’ll delve into point by point. I’d also like to point out that the idea of LDL cholesterol being high as negative is extremely oversimplifying what’s actually a bit more complicated than you think. If you want to read more on that, check out this article. 

To continue, LDL cholesterol decreased on the plant-based diet. But that was far from the only difference. Participants in this group experienced significant muscle mass loss, a seriously unfavorable outcome. Additionally, triglyceride levels were elevated in plant-based participants, posing a heightened risk for heart disease.

Moreover, the vegan cohort exhibited a substantial decrease in vitamin B12 levels by 25%, alongside reductions in HDL cholesterol—both recognized as risk factors for cardiovascular issues. Beyond LDL-C and weight, researchers also observed slight reductions in glucose and insulin levels in the vegan group, which are positive indicators. However, the vegan group exhibited decreases in Vitamin B12, which also warrants attention.

Finally, the vegan diet's lower calorie intake complicates the interpretation of results related to insulin, glucose, and weight changes. The small drop in LDL cholesterol, while notable, may not hold significant clinical relevance, especially considering the potential adverse effects on HDL and triglyceride levels.

In essence, the study's short duration and limited scope make it challenging to draw definitive conclusions about the long-term impact of a vegan diet on cardiometabolic health. Therefore, claims suggesting the superiority of a vegan diet over an omnivorous one are unsubstantiated and potentially misleading, particularly in a clinical context. 

Challenging Misleading Information

A particularly concerning aspect was the documentary's presentation of greenhouse gas emissions data. The filmmakers claimed that agriculture contributes 31% of emissions, compared to 14% from transportation. 

But upon investigation, I found these figures to be incorrect. Agriculture actually contributes 14% to total emissions, with livestock accounting for 31% of that 14%. This discrepancy cast doubt on the accuracy of the documentary's information.

While the documentary promotes the benefits of a plant-based diet, it tends to oversimplify the complexities of nutrition. For instance, the series suggests that cheese is "biologically addictive," a claim that lacks scientific evidence. Additionally, it glosses over the importance of Vitamin B12 supplementation for vegetarians and vegans, which is essential for nervous system function. 

Consider, too, that while twin studies are done because twins have identical genetics, this leaves out an important idea: that genetics aren’t solely responsible for your health. That much of whether we end up fighting disease and sickness is dependent on our lifestyle and individual choices, not our genetic makeup. 

Let’s Talk About Animal Agriculture

A lot of “You Are What You Eat” is about factory farming and the treatment of animals in these types of operations. Let’s get this out there: factory farming is abhorrent. Really, that’s the main reason I was a vegan for 10 years. I couldn’t stand the idea of CAFOs, or concentrated animal feeding operations, where animals live in deplorable conditions. 

But once again, this documentary takes things pretty far. We’re told that farm animals are fed more antibiotics than what is used in human medicine. While that may be true, consider that there are a lot more animals than humans, which would naturally account for that number. I’m not saying antibiotics aren’t significantly overused on factory farms. Again, though, leaving out the full picture makes the documentary lose credibility. 

And while seeing CAFO farms is enough to make anyone feel sick, it’s not binary, that you must either eat like this OR be a vegan. You can consume meat that is high-quality, locally raised, hormone-free, antibiotic-free, and not from animals who are packed full of grains. It’s not either you eat disgusting factory farm meat, or else you go vegan. There are choices in between those two polar opposites that you can make. 

And this brings up another important point about the study: if we want to consider the omnivore results, we need to know the type of meat and frequency it was eaten. Let’s say they were eating grass-fed, local beef, vs. the stuff you’ll find at a conventional store. That is a study whose results I’d love to see, because I think we can agree what they’d show! 

I think it’s important that the documentary brings up the impact of conventional meat and fishing industries in our world. It’s vital to consider the impact of the choices we make in our food, and how they affect the world and people around us. 

Uncovering Conflicts Of Interest

I get it; people who are vegan would have the most interest in making a show whose results seem to show that more people should consider going vegan. 

But the funding sources behind the Stanford Twins Study raise concerns about potential biases. The involvement of individuals with ties to vegan advocacy and plant-based food companies adds another layer of complexity to the study's credibility. The study was partially funded by a tech entrepreneur who is a vegan, and the lead researcher in the study has received funding from the plant-based “meat” company, Beyond Meat. 

That’s not to say the study can’t be valid because of those factors, but those people would have made things much more credible by admitting their potential for bias. 

Study Shortcomings: Length, Gender, & Lack Of Control

The study's primary limitation lies in its short duration. Eight weeks hardly scratches the surface in the realm of nutrition science, where researchers typically prefer longer-term studies for more comprehensive insights. Additionally, nutrition science is notoriously intricate and multifaceted. The efficacy of eating any certain way ultimately hinges on its practicality and sustainability.

Furthermore, adherence to dietary interventions poses a significant challenge for many individuals. Only one participant from the vegan cohort maintained their dietary pattern post-study completion, so it leaves out the possibility of seeing whether any results would hold out over more significant time periods. 

Consider, too: there weren’t many participants to begin with in this study, but note that most are women. In addition, the second part of the diet, where participants made their own food, was not controlled. That means the participants could’ve vastly strayed from their diets for the last four of the eight weeks, which doesn’t exactly boost the reliability of the results.  

Correlation Vs. Causation

A look at this documentary wouldn’t be complete without a discussion about correlation vs. causation. 

In discussions about the benefits of a vegan diet, it's crucial to distinguish between correlation and causation. 

Correlation does not imply causation; just because vegans may exhibit certain health advantages does not necessarily mean that veganism itself directly causes these benefits. Other factors, such as increased consumption of fruits and vegetables, reduced intake of processed foods, or a generally healthier lifestyle among vegans, could contribute to these observed outcomes. A lot of vegans I know practice yoga and other forms of movement and strength training regularly. They’re aware of their stress levels and take steps to manage all forms of stress in their life. 

There is a lot more to health than what we put in our bodies, and so taking a look at the advantages (or disadvantages) of veganism over eating meat needs to be a lot more complex. It doesn’t help that the researchers in this study seem to be cherry-picking certain stats that match their desired outcomes, and minimizing the impact of others. 

There Is No One-Size-Fits-All Approach

No matter how each of us chooses to nourish ourselves, judgment and disdain for others' beliefs aren’t a good look. We're all navigating our unique paths, and it's vital to honor and respect each individual's journey. However, this doesn't preclude us from sharing our experiences and knowledge with kindness and empathy.

My journey as a vegan took a significant turn when I embarked on the study of functional medicine. It became evident early on that a singular, universal approach to wellness simply doesn't exist. I grappled with the realization that despite my efforts to eat healthfully, I wasn't experiencing optimal health. Something vital seemed amiss, leading me to recognize that my diet wasn't aligning with my body's needs.

After a decade of adhering to a vegan lifestyle, I made the difficult decision to transition away from it – and the results were transformative. While veganism had undoubtedly improved my well-being compared to the Standard American Diet, I came to understand that improvement alone doesn't equate to optimization. For me, personally, a vegan diet wasn't the optimal choice. However, this realization doesn't invalidate the merits of veganism for others; it's a deeply individual journey.

Make Your Own Decision

While documentaries like "You Are What You Eat" may spark plenty of conversation, it's essential to approach their findings with caution. Don’t be afraid to look behind the curtain and figure out who’s paying for the study, who might have an interest in it, and think critically about what gaps exist in their methodology. 

By promoting a nuanced understanding of nutrition and encouraging dialogue about the limitations of research studies and media representations, we can foster a more balanced approach to health and wellness.