U.S. News & World Report that the popular vegan lifestyle is ranked as number 19 on their list of best diets overall. But what makes something a “best diet”? We are currently in a vegan craze, and I have met more Vegans in college than I ever have before; the lifestyle is curious to me. It takes insane discipline, dedication, and seems incredibly challenging to find suitable meal options- especially at Penn State! I have read the magazines praising the diet as the end all be all of health, and honestly, there seems to be no reason to disagree. What could be wrong with eating loads of veggies and no animal products? Apparently, while many are quick to praise the diet, there have actually been little to no research done on its long term health benefits compared to a typical diet, meaning that veganism can be no different than a normal diet from a health standpoint. So, is being a vegan really better for our health?
There have been no studies that can confidently conclude that the vegan diet outshines other diets from a health stand point because there have been no controlled trials that have been able to prove veganism superior. It is often claimed that a low-carb and high fat diet is unhealthy for our bodies, and to some point, we should disagree. This study, Efficacy and Safety of a High Protein, Low Carbohydrate Diet for Weight Loss in Severely Obese Adolescents, was the first of many studies that found that a low-carb high fat diet might be most beneficial for humans, contrary to what was originally thought. This experiment was randomized, but not blind; two randomized groups of individuals were placed on either a high protein diet, or a low carbohydrate diet and were monitored for 13 weeks. This is another example of how science “updates” itself. Physicians thought blood letting was healthy, and until there was a deeper understanding of how the body operated, blood letting was an extremely common practice throughout America. We once thought that a low carb diet was bad for our health, and are now in recent years realizing that a high-carb diet is the unhealthy life style that can lead to obesity and diabetes.
This is low-carb revelation led me to the A to Z Study, a study that compared the Atkins diet to what is known as the Ornish diet, a diet extremely similar to veganism. The Atkins diet preaches low carbs while the Ornish diet (veganism with occasional yogurt and cheese) preaches high carbs and low fat. The A to Z study was conducted with the objective of comparing diets with various levels of carbohydrates, and their effects on weight loss, cholesterol levels, and more. This idea to me was really interesting, and I was able to find a YouTube video of the research’s presentation that was much easier to digest than the research paper itself. The A to Z study was a randomized control trial that lasted about three years and was conducted in the United States. The 311 participants, all obese, post menopausal women, were randomly assigned diets (Atkins, vegan/ornish, control) and were expected to follow them for the entirety of the experiment. Although we can rule out reverse causation (due to the laws of time), we should realize that this experiment was not conducted on what would be considered the average person. Does this conclusion still apply to men? To women that are not obese? To women that are not post-menopausal?
In a nutshell, the individuals on the Atkins diet lost nearly double the amount of weight than the Ornish diet group, losing an average of 10.4 pounds. On top of that, the Atkins group experienced a decreased blood pressure, triglycerides levels, and an increase in “good” cholesterol, known as HDL. It was deemed that the Atkins diet was more successful than the ornish-vegan look a like. In this situation, the scientists were able to reject the null hypothesis; that a vegan-ornish diet was healthier for weight loss. The alternative hypothesis was that the atkins diet would help participants lose more weight, and this was proved with a high p-value. Although we can never be sure the probability of a false positive in science, we for now, we have convincing evidence that this experiment wasn’t just a fluke. The possibility of third variables could be at large, however. Perhaps some participants strayed from their diet, or others starved themselves or exercised more.
Now, one study can’t prove it all, and studies such as the Seventh-Day Adventist Studies have found that there are lower mortality rates correlated with people who are vegan, but studies like this one are observational and we learned in class that observational studies can only show correlation, NOT causation. It is important to think about how third variables could effect the conclusions on studies like this. In class we talked about what third variables could adversely be affecting the “wormy kids”, such as their intelligence or affluence. We could theorize that the children who were stupid were stupid because they didn’t go to class and would play in the dirt all day, increasing their exposure to worms, or that the children were stupid because their worms caused them to be uncomfortable and distracted during class. In this situation, we can hypothesize that maybe vegans have lower mortality rates because they are more health conscious. Perhaps they are more likely to exercise, and less likely to smoke or participate in unhealthy activities.
Fortunately, the vegan life style doesn’t seem to be going out of style, and we can be confident that more studies will be done in the future to really hammer out a conclusion. If I was to conduct my own experiment, I would shape it similarly to the Efficacy and Safety of a High Protein, Low Carbohydrate Diet for Weight Loss in Severely Obese Adolescents study, although I would use a randomized double blind experiment with a control group. This study did not utilize a control group, and I personally believe that results might have been different if the two test groups were compared to a group of unaffected participants. I would also use non-obese, healthy American Male and Females. These participants would be randomized to a control group, a group of Atkin’s dieting, and a group of vegan dieting. The A to Z study was not conducted with 100% vegans, and this could have made a compelling difference.
Ultimately, there is no increased health benefit to being vegan, at least as far as today’s research can show. There is a correlation between a lower mortality rate and the vegan diet, but to me, that isn’t persuasive enough to give up cheese and steak for a couple extra hypothetical years on my life. What I found most interesting while writing this blog was the scientific explanation for why there hasn’t been more conclusive evidence on the vegan diet. Apparently, the swift rise and fall of fad diets creates very little incentive to for scientists to study because it will quickly be replaced by another diet. By the time a study is completed and published, the findings are no longer relevant to the public. If veganism sticks around, then I’m sure there will be more research, and I’ll be waiting!