Sorry guys. I watched this movie (along with
Safety Not Guaranteed) way back when I was in North Carolina. I made a few notes while I was watching
Forks Over Knives, so this will probably be a bit disjointed as I try to weave those thoughts together. Having said that, here goes:
The basic proposal in this movie is that a whole-food, plant-based diet is the answer to our obesity epidemic, our worst diseases, our constant fatigue, and our skyrocketing healthcare costs.
For example, in the first half of the last century, it was thought that we needed a diet of protein, protein, protein. "Milk. It does a body good." Then a doctor involved in pushing this protein diet to his patients discovered that, compared to Asian and Indian diets, us Americans were way less healthy. Some additional research showed evidence that all this animal protein turned on the "cancer gene," causing increased rates of breast and prostate cancer.
Ditto for generational differences. A few generations ago, Hawaiians lived long, healthy lives on traditional, Asian-leaning diets. Now it's one of the most overweight states in the country.
To investigate further, some researchers did a study in rats. Rats were fed either a 5% (Asian) or a 20% (American) protein diet. Rats on the 20% diet rather quickly showed early cancer tumor growth. Rats on the 5% diet showed no such growth. What's more, when rats on the 20% diet were cut to 5%, they actually showed improvement - tumors got smaller. What? Can that happen? Apparently.
And here's another problem: dairy products cause acid buildup in body. When acid content is too high, your body draws on its most available source of neutralization, which is calcium in the bones. Over time, this constant depletion of calcium weakens the bones. Probably not coincidentally, rates of
osteoperosis are higher in countries where milk consumption is higher.
A little historical research turned up some evidence on cardiovascular disease in WWII. When the Germans invaded Poland, they needed food. The German army confiscated all the livestock from Polish farms to support their army. If they weren't killed by the soldiers, Polish life expectancy skyrocketed. Subsequent studies showed that the removal of animal proteins and dairy products from a diet allowed endothelial cells in the blood vessels to repair themselves. Those
endothelial cells release nitrous oxide into the blood stream, which in turn helps remove plaque and prevent clotting, which in turn prevents heart attacks.
P.S. Boys, pay special attention to this: ED is the canary in the coal mine for heart disease, which is so obvious if you think about it as a circulatory problem. (The magic of Viagra is that it adds extra nitric oxide to the blood stream, which your body needs in order to direct blood flow.) So eat healthy food and keep your endothelial cells healthy!
One of the two physicians who started this trend wrote a book called
The China Study (hence all this info about Asian diets). Another point he focuses on is that processed foods and sweeteners are more calorie-dense than the whole foods they're made from. As a consequence, we take in many more calories before the volume of food in our stomach causes the brain to realize that you're full.
Now, it's been shown time and again that statistics can be twisted to prove any point the user wishes. I decided to consult my expert to make sure I got all this stuff right and get her opinion:
Overall, I think that Campbell’s and Esselstyn’s research is sound. Although I haven’t read the original study manuscripts (the one that The China Study is based on is over 1,000 pages long!), I did read the book and got some idea of the quality of the research.
Now, as a nearly lifelong vegetarian, I am a little biased here. I tend to agree with the Academy of Nutrition and Dietetics when they say that a vegetarian or vegan diet can actually be healthier than an omnivorous one. I think that there is a lot of research to back this up (examples here, here, and here). In science, though, extrapolation can be dangerous, and this is where my biggest criticism of this particular research lies. The researcher uses one animal-based protein - casein, found in milk – to make statements about all other animal-based proteins. To say that a study of casein in mice proves that not just milk but also meat is bad is a sweeping overgeneralization. A good scientist should always limit his conclusions to what he has studied. If he suspects a connection with something else, he should pursue further study before making recommendations.
That being said, I would argue that Campbell and Esselstyn’s work did something absolutely crucial. While research on the healthfulness of vegetarian versus omnivorous diets abounds, there is substantially less research on the healthfulness of vegan diets. To me, these studies begin to fill that gap. Where the nutrition world had previously assumed that milk was vital to health because it was a source of protein and calcium, the opposite may actually be true. These early discoveries point to the need for further research and, maybe, a change in what we recommend that people consume for optimal health.
