Every month an onslaught of new nutrition news dominates the health blogosphere. Fish will kill you. Fish are heart-healthy. Coconut oil is like manna from heaven. Coconut oil will definitely give you a heart attack. Red meat is the devil, unless it’s raw, in which case you can survive solely from it. Kelp. And so on.
Part of the challenge of reading the studies this news is based on—and, often, not based on at all—is recognizing that small sample groups do not always make for solid science. This is especially true with our diets, as environment, activity level, and genetics all play a role in how we interact with our food choices. Some people simply process certain foods better than others. There is no singular ideal diet.
Michael Pollan’s famous advice—“Eat food. Not too much. Mostly plants.”—has become an oft-repeated mantra of the modern era. The first part is a reminder to eat actual food, not the processed chemistry dominating supermarket shelves. The second is personal responsibility: eat until you’re full, not until your plate is clean. Don't snack so much. Recognize the link between emotional problems and binge eating, and address them simultaneously.
Now what does “mostly plants” actually entail?
A team of Austrian researchers based at the Institute of Social Medicine and Epidemiology, Medical University Graz, wanted to find out. Their meta-analysis of over 15,000 Austrians, age 15 and older, revealed important insights into what all-plant, mostly plant, and occasional-plant diets mean for our health.
Of those 15,000+ Austrian citizens, the team analyzed the data of 1,320 individuals: 330 vegetarians, 330 carnivores who eat a lot of fruits and vegetables, 330 carnivores who do not eat much meat and an equal number who eat a lot of meat. They took age, sex, and socioeconomic factors into consideration when matching groups. In the end 76.4 percent of this group were female, with 40 percent being under age 30. Another 35 percent fell between the ages of 30 and 50.
Interestingly, while there were positive benefits associated with vegetarianism, the group concludes the following:
Overall, our findings reveal that vegetarians report poorer health, follow medical treatment more frequently, have worse preventive health care practices, and have a lower quality of life… Our results have shown that vegetarians report chronic conditions and poorer subjective health more frequently.
They also discovered “significantly higher” incidences of cancer in vegetarians, as well as increased rates of anxiety disorder and depression, although they note that this is inconsistent with other research. They did point out another study which shows an increased risk of mental disorders in vegetarians. In general, vegetarians suffer from more chronic conditions and take more medication than even occasional meat eaters.
It’s not all bad news. Vegetarians have a lower body-mass index and suffer less from cholesterol problems, hypertension, coronary artery disease, and type 2 diabetes. Vegetarians enjoy a higher socioeconomic status, though correlation might not equal causation: a lot of lower income workers might not be able to afford high-quality plant products. Vegetarians also treat their bodies better: they exercise more and smoke and drink alcohol less.
The correlation between BMI and meat is clear in this study. Carnivores who eat a lot of meat have the highest BMI while pure vegetarians have the lowest. Again, correlation and causation are not clear, as meat eaters also show a much higher rate of alcohol consumption, which is one of the quickest and surest ways to pack on pounds.
Interestingly, vegetarians are vaccinated and visit the doctor less often than the other groups, which could play into the chronic conditions data. Given the questionable marketing tactics by “health food” brands that claim that “food is medicine” and call their products “superfoods,” it’s no surprise that some vegetarians believe their diet to be a panacea. Factor in that this group vaccinates less often and it’s easy to understand how one conspiracy rolls into the next, a pattern that could prove detrimental to their health.
The team's conclusion is stark:
Our study has shown that Austrian adults who consume a vegetarian diet are less healthy (in terms of cancer, allergies, and mental health disorders), have a lower quality of life, and also require more medical treatment.
So the “mostly” part of Pollan’s creed appears valid. Diet is a balancing act only in an era of excess. Protein and fat was, for most of our evolutionary history, scarce and harder to secure. We had to eat "mostly" plants. Choosing to overload on meat today, while ignoring plant carbohydrates (and the fiber that goes along with it) appears to be just as dangerous as avoiding meat altogether. During a time when so much is available, the inherent—and necessary, given they didn't have a choice—wisdom of our ancestors stands up. We do have a choice today, and must always remember that when deciding what we put into our mouths.
Derek Beres is the author of Whole Motion: Training Your Brain and Body For Optimal Health. Based in Los Angeles, he is working on a new book about spiritual consumerism. Stay in touch on Facebook and Twitter.