A Facebook friend of mine recently posted an article on his wall titled “Why it’s time to give up low carb diets once and for all“. This article interviews T. Colin Campbell, PhD who is most famous for his work on and publishing of a book about the China Study. Apparently Campbell came out with a new book last fall called The Low Carb Fraud. These were some of the thoughts going through my head when I read this late last night.
Before we jump into anything, I think it’s important to know where everybody is coming from.
Campbell is the closest thing to a vegan-world rock star as I can imagine. He’s made it into every single vegan documentary (that I’ve ever seen, anyway) and he and his book are the references of choice for everything pro-vegan. His stance is that ANY ingestion of saturated fat, cholesterol or animal protein is bad for your health. Obviously this is going to be his stance no matter what- he’s far too embedded in this world to change his stance now.
Me: It’s not hard to browse my website and get a feeling for my stance on nutrition and food, but I will save you the trouble. I am proudly registered on both Primal Docs and the Paleo Physicians Network, although I am personally not 100% paleo. Through an on-going process of trail and error I have figured out what works for me, although I admit that this is a life-long learning process. I was a vegetarian for 12 years before I found out that I was gluten and casein intolerant in the fall of 2010. Since then I have made a gradual transition toward eating less gluten-free grains (maybe 1-2 servings per day at most), but always sticking with the ones that have shown to not be an immunological problem for me. However, I have personally noticed that I don’t feel as “balanced” when I go super-low carb, thus my 1-2 servings of tubers or grains per day. More relevant to the topic at hand, I live by Michael Pollan’s mantra of “eat food, not too much, mostly plants” and eat accordingly. I do believe that meat is “real food” and is perfectly healthy to consume, although I’m not quite as meat-happy as some in the paleo world.
Now to pick apart that article.
In the first paragraph, Campbell basically says that population studies (cough, the China Study, cough) consistently show that low carb diets increase rates of cancer, heart disease and degenerative disease. For the sake of simplicity I will use Campbell’s own work to point out that this is actually NOT the case. Campbell’s own study (which is the pinnacle of such studies) was debunked long ago and was shown to be the result of careful data cherry-picking and ignoring of numerous confounding variables.
Another stance Campbell takes in that paragraph is that low-carb diets can cause symptoms including bad breath (halitosis), skin rashes, headaches, muscle cramps, and constipation. Now, brace yourself for this one, folks. Perhaps we should think about what that says about the individual person if they get said symptoms? For example, I would bet money that both constipation and bad breath could be the result of the same issue: Improper digestion of meat because of low stomach acid. Think about it. If you don’t have the proper acid in your stomach to break apart the meat you eat it will basically fester and putrefy in your gullet, giving you halitosis. A lack of digestive enzymes and acid in the upper GI tract (stomach in this case) will surely affect the “down stream” digestive processes and alter transit time through the intestines and colon, making you constipated. Oh, and if you’re saying to yourself “how common could low stomach acid possibly be?” just start asking your co-workers and friends if they take a proton pump inhibitor..
In the second paragraph Campbell basically says that this whole low-carb thing isn’t because of any new research and that it’s just a fad. This one is easy for anybody to disprove- just go to www.pubmed.gov and go wild. This one is sort of infuriating, actually. Why would he say something that is so blatantly untrue and easy to dispute? I think this is a case of “hopefully people will just recognize my famous name and assume I’m legit”. Searching the words “low-carbohydrate and low-fat” comes up with 403 results, but you can likely search for other search terms and find even more. From the first page of search results alone I came across the following articles (I may have paraphrased the titles a little bit……)
Just kidding, it’s carbs not fat (2014)
Low carb not only helps you lose weight, it decreases cardio risk factors (2014)
Low carb lowers insulin, and btw fasting + the Mediterranean diet is good (2013)
And don’t forget about this oldie but goodie:
Comparison of Atkins, Zone, Ornish and LEARN diets (from Dr. Perlmutter’s site)
The third paragraph I don’t take much issue with. Realistically, there wasn’t always meat to eat in ancient times. If you couldn’t hunt down an animal for it’s meat you simply had to eat more plants. End of story. By a similar token, if you lived in polar regions back in the day you definitely had to eat a LOT of meat and animal products because good luck foriaging for berries in the Arctic. That’s why I don’t advocate THE paleo diet- I like the term “paleo template” like Chris Kresser.
In the fourth paragraph Campbell basically says “well, any of the good stuff paleo does is super short term”, and then he basically parrots back the old stance from the China Study of “high protein, high fat diets cause an increase in cholesterol which is a big ol’ risk factor for heart disease and cancer”. The thing that’s interesting to me is that in the aforementioned debunking article, the author pointed out that the reasoning to get to this point was extremely flawed (at least in the China Study data, anyway).
Campbell basically says this:
Higher cholesterol is associated with cancer. Everybody knows that high cholesterol comes from higher consumption of animal products. Therefore,
more animal product consumption = more cancer.
However, when you crunch the numbers to look at the association between increased animal product intake and cancer the association is simply not there. I won’t try to sum up Denise’s beautiful article, so just go read “Campbell claim number 1” for more.
Here’s some more articles that discuss changes in cholesterol and cardiovascular markers in high-carbohydrate and high-fat diets:
Hm.. Maybe high fat lower-carb is ok after all?
Ugh. This is more complicated than we thought. (2013)
Statins are good*, statins plus restricting carbs is better (2013)
**Dr. DiNezza’s note: No, they’re not!
And here’s where we blend our knowledge of math and physiology and it gets even juicier: Low-fat and low-carb diets both have the potential to favorably influence cardiovascular risk factors, but in different ways. There are four big blood markers that make up about 90% of the media press about heart disease: Total cholesterol, LDL (“bad”) cholesterol, HDL (“good”) cholesterol, and triglycerides. The funny thing is that low-fat diets are pretty good at lowering total cholesterol and LDL cholesterol. However, low-carb diets are better at raising HDL (“good”) cholesterol as well as lowering triglycerides. So if we’re keeping count we might say that they’re tied (they both have two points). But here’s the tricky thing: Total cholesterol is made up of both LDL and HDL combined. Maybe a part of the reason why total cholesterol isn’t affected as much in low-carb diets is because it actually raises one of those two types that make up the total count! Just a thought.
The two last bits I’d like to point out about paragraph four are thus: it would be nice to see his references on the whole “all the good stuff about paleo are only temporary” thing, and I kind of agree with the last point he makes. If you eat too much grains OR meat you will be eating less veggies, which is bad because veggies have all sorts of good stuff in them. Can’t we just come to an agreement that more vegetables is always best?
The fifth paragraph is barely worth addressing, but I don’t want to stress out my OCD readers by skipping a number here. He basically says that the only good thing about paleo is that it cuts out junk food like cookies. Really? Sir, if you’re SO narrow minded that you can’t even admit that “the enemy” diet has at least a few redeeming qualities other than the elimination of cookies, then maybe your PhD should be revoked.
Paragraphs six and seven basically reads “so what should we eat, then?” “Why, low fat and vegan, or course!”
So after all that, what can we say? I think that this article clearly shows that:
1. Campbell is still piggy-backing off of his fame from The China Study, and bases much of his current opinion off of a study who’s data was collected in the 1970s and early 1980s.
2. Campbell doesn’t log onto pubmed (or ignores the studies that conflict with his beliefs)
3. Maybe, just maybe, he’s really narrow minded (and I personally don’t place a lot of confidence in narrow-minded people’s opinions) OR he is not telling one side of the story because he knows that there’s more to it than he’s let on….
And finally, and perhaps most importantly, “what do we do now, doc??”
1. Be skeptical of everything and everyone. Don’t believe everything you read and don’t assume somebody knows what they’re talking about because they seem like an authority figure. This goes for what you’re reading right now, too. Don’t take my word for anything- always try to figure things out for yourself.
2. Be aware of people’s motives, conflicts of interest, and stances on what they are talking about. Also, be aware of what would happen if they were ever disproven or changed stances. Holy cow (hah, meat pun), can you imagine what would happen to Campbell’s life if he came out one day and said “just kidding guys, meat’s not that bad”?
3. Eat healthy stuff. Really guys, it’s not that hard when you think about it. Fruits and veggies, meat (gasp!), and grains (double gasp!) are all food. Just start eating real food that is not processed and you’ll be off to a good start. If you start from a vegan template that’s fine, just read this and supplement accordingly. If you start from a paleo template that’s fine too, just know that there are better and worse ways to do it and that paleo is really just a starting point from which you can grow. Also, it is worth mentioning that just because something is vegan, fat-free, paleo, low-carb or whatever doesn’t mean that it’s healthy.
Skeptically yours,
