You Are What You Eat: A Twin Experiment: Two truths about nutrition amid plenty of half-truths

You Are What You Eat was guilty of cherry-picking statistics that project vegan diets to be the healthier alternative for people of all age groups and physiological make-up

By Preetha Banerjee
Published: Saturday 13 January 2024
Photo for representation: iStock

Half the world is worried that artificial intelligence will take over the world, and the other half is certain vegans will. At least the makers of the Netflix docu-series ‘You Are What You Eat: A Twin Experiment’ have tried their best to establish that veganism is the Captain America shield against every kind of chronic illness and planetary destruction. Without it, neither will the human race survive, nor will the planet.

The Netflix synopsis for the show was convincing and sincere: A set of twins from different demographics are put on different diets – one vegan and the other omnivore for eight weeks, and a before-after comparison is done of their body composition, epigenome or “biological clock”, the gut microbiome and the brain.

But the execution was frustratingly over-literal, lacking nuance and unbiased science to the extent that barely 15 minutes into the pilot, it flew dangerously close to the mockumentary zone. Or, as a dismayed reviewer on Google wrote: “It felt like a four-episode vegan commercial”.

It was based on an actual study done by Stanford University on 22 twins, of which the filmmakers of the Netflix docu-series followed four throughout the duration. In the first four weeks, the subjects were provided packaged meals tailored for their diet and in the latter leg, they had to make their own food sticking to their respective regime.

The camera followed each of the twins grocery shopping at different aisles of the supermarket, preparing their food, working out and taking various kinds of tests. But apart from the home-video style camera movements, nothing felt like the fimmakers were honestly trying to give us an inside view of the lives of each sibling. 

Every interaction, even the inside jokes, seemed forced. So, apart from blatantly trying to sway the opinion of the viewers towards vegan or “plant-based” diets, it also has low entertainment value, unless one loves to binge on heavily-scripted reality television.

The research led by Christopher D Gardner was funded by Vogt Foundation, which also funds the Oceanic Preservation Society, which was founded by Louie Psihoyos, who incidentally directed the docu-series. The foundation also produced some other documentaries by Psihoyos – Academy 2009 favourite The Cove, a documentary on dolphin hunting in Japan, 2015 Racing Extinction on human-caused biodiversity loss and 2019 Game Changers, which is basically a tutorial on how to get jacked up without animal protein. Some news reports had established that mock-meat industry leaders financially backed the film.

Both Gardner and Psihoyos are celebrity vegans. Gardner is also the director of Stanford's Plant-Based Diet Initiative, a programme financially supported by Beyond Meat, one of America’s top plant-based meat substitute makers.

Like was the biggest complaint about Game Changers, You Are What You Eat also was guilty of cherry-picking statistics that project vegan diets to be the healthier alternative for people of all age groups and physiological make-up.

In fact, vegan diets have limitations and without supplementation can be inadequate to meet the body’s nutritional needs. Vegan diets are “technically feasible, (but) the successful provision of a nutritionally complete vegan diet for a child requires substantial commitment, expert guidance, planning, resources, supervision and supplementation”.

Moreover, some micronutrients have lower bioavailability from plant sources than animal sources. Besides proper fortification and supplementation, “vegan children are at a risk of insufficient supply and deficiency of some critical nutrients such as protein, long chain fatty acids, cholesterol, iron, zinc, iodine, calcium, and vitamin A, B12 and D. Deficiency of these nutrients could lead to various developmental and sometimes irreversible disorders,” according to a study in the journal Bioactive Compounds in Health and Disease 2022.

For adults, too, an unscientifically planned vegan diet can put endanger one’s nutritional security. For instance, “Plant-based iron (non-heme iron) is less bioavailable than the heme iron found in animal products, potentially leading to iron-deficiency anemia,” according to Iron and Vegetarian Diets in the Medical Journal of Australia.

Although it lacks scientific rigour, the documentary brings attention to two important issues that can be relevant for everyone, whether they eat steak or just salad.

One, is the focus on epigentics. It is the branch of science concerned with the chemicals that tag genomes to tell it how to act, governing how the body reads our DNA sequences. Our environment, diet and lifestyle can cause epigenetic changes, which are reversible, thus changing the way our genes express themselves, without changing the DNA sequence.

“Unlike the genome, the epigenome is variable by cell, tissue type, and developmental stage. These mechanisms also represent an adaptive intermediary that interprets and responds to environmental stimuli, resulting in alterations in gene expression,” the authors of a review article published in the journal Environmental Health Perspectives noted. 

While the docu-series oversimplifies the correlations, a gamut of studies have explored the link between epigenetics and disease predisposition.

Recent research in epigenomics has revealed that diet plays a crucial role in influencing these epigenetic markers, according to a review article in International Journal of Molecular Sciences. 

“For instance, foods rich in folate, such as leafy greens, nuts, and seeds, can promote DNA-methylation, a process vital for normal development and associated with reduced risk of cancer,” the authors of the piece added. 

Nutrients and bioactive food components can therefore reversibly alter the DNA methylation status, histone modifications, and chromatin remodeling, subsequently altering gene expression and having an impact on overall health, the article noted, adding:

Moreover, For instance, at its extreme, the Dutch Famine Birth Cohort resulting from the Dutch Famine of 1944–1945 has been used to study the effects of starvation during pregnancy and subsequent health and developmental outcomes including, but not limited to, increased risk of type II diabetes mellitus, cardiovascular disease, metabolic disorders, and decreased cognitive function in later life.

Several studies on epigenetics highlighted the harmful effects of high-fat western diets. One illustrated how such a poor diet can lead to obesity and stress, subsequently affecting gastrointestinal physiology and potentially leading to chronic diseases through epigenetic changes.

Epigenetics can also influence the severity of diseases like COVID-19 in patients with chronic lung diseases, which are associated with gene expression programs favoring SARS-CoV-2 entry and severity, according to a 2021 research paper in Nature Communications.

The documentary also highlights the negative aspects of modern food production, such as the farming of salmon. Farmed salmon, often raised in crowded conditions, are prone to diseases and parasites, which can spread to wild salmon populations, posing ecological and health risks.

In India, the farming of prawns and fish faces similar issues. Intensive aquaculture practices have led to environmental degradation and disease spread to wild populations. The use of antibiotics and chemicals in these farms raises significant health concerns.

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