You will find all kinds of extreme dieters on the internet, and many of them will swear to you that their diet is the only healthy way for a human to eat. At one end of the spectrum is Jordan Peterson with his carnivore diet consisting of nothing but beef, salt and water. On the other hand, “frugivorous” diets promoted by YouTubers and their ilk are not only vegan and raw, but consist almost entirely of fresh fruit. And then, of course, we have the classic and unashamedly restrictive weight loss programs like the Cabbage Soup Diet, the Master Cleanse (aka the Lemonade Diet), and the currently trendy Mono Diet, where you eat only one food.
Proponents of highly restrictive diets such as this one tend to massively emphasize the benefits of their approved foods, while severely exaggerating the drawbacks of all the other foods. But these are just the most extreme examples of a supposed “wellness” culture that makes huge generalizations and routinely manipulates or outright ignores scientific evidence. Unfortunately, this approach pollutes even those conversations that do have a legitimate basis, such as veganism.
There are numerous health benefits to a plant-based diet, and unlike the examples above, it’s not even a particularly restrictive diet per se – even non-vegans and non-vegetarians who eat mostly plant-based can reap the benefits. But the unfortunate truth is that, like most things on the Internet, a kernel of truth is stretched far beyond what science can prove.
It’s not hard to imagine why some votes for veganism might exaggerate or even fabricate health claims. The ranching industry perpetrates horrific violence against animals, as well as many of its workers and, of course, the health of the planet. So if health is going to force people to change their diet in ways that are beneficial to animals and the environment, it’s easy to see why some activists and influencers would push nutrition facts as the most effective way to help end the industry.
But in the end, misinformation will only damage the credibility of the movement. Veganism is a more pervasive idea in our society now than ever before – we can’t afford to make people dismiss the whole thing as bunk beds. And all this misinformation, exaggeration, and cherry-picking is a disgrace, because it obscures the factual strong evidence of the benefits of eating less meat, eggs, or dairy: a lower risk of heart disease, stroke, and various cancers, to to name a few.
Unfortunately, conversations about veganism are often full of pseudoscience. It’s not hard to find vegan influencers who proclaim unproven theories as if they are facts, use confusing and misleading logic or say things that are clearly untrue, such as that a vegan diet can change your eye color. Even real doctors have been known to make dramatic and shaky claims, such as that a single meal high in animal fat can “paralyze a person’s blood vessels,” citing a single, decades-old study involving just 10 subjects and no control group.
You’ll hear people say that nothing less than a 100% plant-based diet can be considered optimally healthy, when the reality is, we just don’t have the data to back that up. Of course, there are plenty of studies that support the general idea that plant-based foods are somehow healthy, and many of them are recent and use reliable methods. But even good data can be misinterpreted miserably. Correlation is often confused with causation, and it is difficult—if not impossible—to isolate very specific inputs and outcomes (such as, does cheese cause cancer?) because human biology and lifestyle are complicated.
Here’s an example: James Beard Award-winning Washington Post columnist Tamar Haspel points to this Bloomberg article, the headline of which boldly states, “One avocado a week cuts heart disease risk by 20%.” Which sounds huge! But a closer look reveals that the study only shows a link between avocados and heart disease, no causation. Do avocados reduce the risk of heart disease, or do people who make overall heart-healthy lifestyle choices simply eat a lot of avocados? We cannot say that based on this research alone. Any conclusion is at best a loose interpretation of the facts.
And the problems with nutritional science as we know it today run even deeper. For starters, many of these studies (including the avocado study) rely on self-reported information from study participants. That’s putting a lot of trust in ordinary people to accurately and honestly measure their own eating habits, which people are so bad at. If the input data is already in question, it is difficult to trust conclusions drawn from it.
Even putting that aside, observational studies don’t allow scientists to randomize their subjects. If we only notice what real people actually do, we can’t separate the elements we want to examine, for example meat consumption, from other factors such as income, education, gender, smoking and drinking behavior and what else they do. to eat. As a result, the kind of information we get from these surveys is inaccurate; and unless the results contain very dramatic, statistically significant trends, it is risky to extrapolate much of it.
But getting the kind of data that we can work reliably with is more or less impossible. To really control a study, researchers would have to literally monitor everything eaten by hundreds of participants (or more) over a period of years, to eliminate all (or even most) potential confounding factors. Real human lives are just too complicated to regulate like a real lab study requires.
Plus, the biological world is just more complicated than we’d like to think. Different people have different nutritional needs. For people with certain gastrointestinal conditions, eating completely vegan is simply not feasible. But even if not, human bodies are unique and one person cannot process a particular food exactly as another person would. With that in mind, general health advice of any kind should probably be subject to some skepticism. Given all this, it’s no wonder that doctors, nutritionists, researchers, and other recognized experts — not to mention outside interpreters of research, such as journalists and other media figures — tend to offer diverse, often contradictory, advice.
Meanwhile, an alarming segment of the population, and even the scientific community, is apparently indifferent to nutritional science. Less than 20% of medical schools in the US have a single required course on nutrition, and most medical schools provide less than 25 hours of nutrition education in the four years it takes to complete an MD program. All this, despite the fact that diet-related diseases – such as heart disease and type 2 diabetes – are among the leading causes of death in the US today.
Our food-obsessed culture is constantly looking for a panacea to solve all food-related problems. We try complicated, often punitive, and sometimes even dangerous methods of apparently “getting healthy” (often a euphemism for “losing weight”), based on so-called empirical evidence that is shaky at best. The fact is, nutritional science just isn’t at a point where we can confidently issue sweeping guidelines about how people should eat. Of course, there are some points on which the medical community has reached some degree of consensus: The American Heart Association tells us that “eating a lot of meat is not a healthy way to lose weight,” especially for people at risk or at risk for heart disease. The Centers for Disease Control and Prevention (CDC) says avoiding processed foods and sugary drinks to lower our risk of heart disease and stroke. And the American Cancer Society tells us to eat a variety of fruits, vegetables, and whole grains.
“Eat your veggies” and “avoid soda” probably aren’t groundbreaking advice for most people, and they certainly won’t sell any flashy new diet books. Anyone giving detailed advice on what to eat and what not to eat is probably acting more on faith than fact. Maybe a 100% vegan diet is the healthiest way for people to eat after all, but we just don’t know for sure. Gone are the days of vegan influencers and activists embracing that scientific reality. The credibility of veganism and the future of a more sustainable and compassionate world depend on it.