Don’t Trust Science Blindly

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The world of scientific articles is like shark infested waters; be constantly on the alert, that ANY article published in even the most reputable journals might bite you.

The Clinical Journal of the American Society of Nephrology published an article in their July issue (Vol. No.1 ) which caused me nothing short of a hypertensive crisis (sudden elevation of blood pressure to possibly harmful levels). Why? Because articles of this kind find their way very quickly into the mainstream media, and lead to harmful, even dangerous recommendations to the general public.

Needless to say, that, as the crusader that I am, I feel compelled to unravel this article for you, in case you come across its conclusions in some well meaning magazine that you purchase next time you’re at the air port’s news stand.

The title of the article is innocent enough: Comparative effects of low-carbohydrate high-protein versus low-fat diet on the kidney.

So far so good.

Given the concerns that exist about the deleterious effects on the kidneys when people go on low-carbohydrate / high-protein weight loss diets, the authors decided to perform a randomized, controlled long-term trial: between 2003 and 2007, 307 obese adults without serious medical illnesses at three US academic centers were randomly assigned to either a low-carb / high-protein or a low-fat weight loss diet for 24 months. The main outcomes the study addressed were kidney function criteria (I will spare you the technical details, but you can always look into the original article, which I will list at the bottom). From their results, the authors concluded, that in healthy, obese individuals, a low-carb / high-protein weight loss diet over 2 years was not associated with noticeably harmful effects on the kidneys, compared with a low-fat diet.

Sounds great, doesn’t it?

Well, let’s look closer – real close – at this article, shall we?

The participants were between 18-65 years old, 208 women and 99 men, with BMI’s between 30-40, categorizing them as obese individuals. No one was allowed into the study if they weighed more than 300 lb. These people were then randomly assigned to either one of the two diets.

153 participants ended up on the unlimited fat / limited carbs diet, based on Dr. Atkins’ New Diet Revolution.

The other 154 participants were placed on a low-fat, calorie restricted diet (1200-1500 cal for women, 1500-1800 cal for men).

Let’s see how they defined this “low-fat” diet:

  • 55% of calories from carbohydrates
  • 30% of calories from fat
  • 15% of calories from protein

In addition, all participants received comprehensive, face-to-face group behavioral treatment weekly, for 20 weeks, every other week for another 20 weeks, and then every other month for the remained of the 2-year study period. Pretty intense stuff. Certainly not the kind of support people usually get, when they go on a drastic diet.

So, what happened?

Since they pretty much excluded anyone with any kind of medical problem – even people who had blood pressures of 140/90 (whether they were treated or not) – at the end of the study, no one in the Atkins group had any apparent kidney problems, based on the parameters the authors set. Which led them to the victorious conclusion above.

Not so fast.

What really happened here?
For starters, let’s look at the two diets; one is well known, the Atkins diet, which by now has been reviewed more times than I can count, and the conclusions are always the same: yes, there is initial weight loss, but at the price of putting the body into the most unnatural and unhealthy state of ketosis (keto-acidosis), which is only encountered, when an individual is severely ill. Long term effects of the diet are multiform: higher rates of heart disease, high cholesterol, kidney damage and more. Besides: it’s a DIET, meaning, no one can stay on it for life, it is simply unsustainable. And so, people gain the weight back, in which case they go back on “the diet”, thus joining the roller-coaster of dieting Jo-jos. Those, too, have deleterious consequences on long term health. A vicious cycle. One can not live on a DIET, eating must be a life style.

Let’s see what the control group ate, those on the “low fat” diet: not only was their calorie intake restricted, but 30% of their calories came from fat. That is NOT a low-fat diet, not by any stretch of imagination. Based on recommendations from the NIH (National Institute of Health) and the IOM (Institute of Medicine), no more than 15-20% of calories should ever come from fat, out of which no more than 7% should be saturated. The average American diet is hardly worse at 35-40% fat from calories.The control group is just as miserable as the study group – plus, they are HUNGRY.

No wonder then, that the drop out rate in both groups was astronomical: 52% in the Atkins groups and 46% in the control group, so that data for each study parameter was quite limited.

For those, who decided to stick it out, the rewards were few and disappointing: according to the authors, “[…] weight loss was similar in both groups… at around 7%”

Wait a second: so, after eating one of the unhealthiest diets on the planet in the name of weight loss (Atkins), or going to work and to bed hungry every day (AND eating lots of fat), both groups had the SAME weight loss?

But it gets worse: let’s do a quick calculation to see what 7% weight loss really mean. For the sake of argument, someone weighing 250 lb at the beginning of the study lost a mere 17.5 lb over TWO years! You have got to be kidding.

But at least they all had happy kidneys – happy end!

The end points of this study are so irrelevant, that they might have been the occurrence of head aches or pimples, just as well. Taking otherwise (still) healthy adults, who happen to be obese and subjecting them to an unhealthful diet, just to show that the few remaining ones (those who didn’t drop out) didn’t have damaged kidneys, is not furthering the science of healthy weight management in any form or fashion. Had they included weight loss and successful adherence to the diet as study end points as well, their conclusions would have been much less triumphant, but a whole lot more relevant, don’t you think?

The fact, that both the study and and the control groups received intensive group support and still failed both diet protocols, are very important insights, which the authors prefer to drop completely in their discussion.

And what about those who did drop out? Was it because they FELT sick, or maybe BECAME sick? No information there.

Yes, esteemed readers of my blog, this is science. And the authors did not receive any funds from the Atkins people either. They did this study in full faith.

Wanna bet that these “great study results” will be cited pretty soon in a magazine or nutrition newsletter out there? I am certain of this, because it has happened so many times before – see my first blog post about CSPI. This is a sad and dangerous state of affairs, since the public must rely on rehashed and digested scientific information. My advice: choose your sources wisely. Websites like www.PCRM.org, www.drmcdougall.com, www.jeffnovick.com and www.nutritionfacts.org are some of the best sources of information out there. You can rely on their truthfulness and validity 100%+. And with time, who knows, maybe WE, the crusaders, will win the battle against misinformation and manipulation after all…

I shall remain optimistic.

Bibliography:

  1. Friedman AN,Ogden LG et al. Comparative effects of low-carbohydrate high protein versus low fat diets on the kidney. Clin J Am Soc Nephrol 7;2012:p.1-9
  2. Lagiou P, Sandin S, Lof M, Trichopoulos D, Adami HO, Weiderpass E. Low carbohydrate-high protein diet and incidence of cardiovascular diseases in Swedish women: prospective cohort study. BMJ. 2012;344:e4026
  3. Dansinger ML, Gleason JA, Griffith JL, Selker HP, Schaefer EJ. Comparison of the Atkins, Ornish, Weight Watchers, and Zone diets for weight loss and heart disease risk reduction. JAMA 2005;293:43-53.
  4. McDougall Newsletter. Atkins Was Grossly Overweight and Sick– But the Media Loves the Dead Guy. February 2004.