The Truth About Ancel Keys: We’ve All Got It Wrong

22 12 2011

(Note: This post was inspired by the “Ancel Keys” section in a recent series of paleo-challenging YouTube videos, which I may critique in the future. The anonymous videomaker “Plant Positive” highlighted some important misconceptions about Keys and his research that I’d like to broadcast to a larger audience, but didn’t address some equally important points tangled in the Keys saga, and likewise made some arguments I believe are incomplete or misleading. This blog post is an attempt to address those misconceptions in a more balanced and thorough way, and provide a broader context for how we view the infamous Mr. Keys.)

This is one of those “gotta bust me some myths no matter where they come from” blog posts. And by that, I mean I’m about to challenge a story that’s been so well-circulated among paleo, low carb, and real-food communities that most of us have filed it away in a little brain-folder called “Things We Never Have to Question Because They’re So Ridiculously True.”

I’m talking about the late, great Ancel Keys, and his equally late (but maybe not as great) role in the history of heart disease research. The oft-repeated tale goes something like this:

Once upon a time, a scientist named Ancel Keys did an awful thing. He published a study about different countries that made it look like heart disease was associated with fat intake. But the truth was that he started out with 22 countries and just tossed out the ones that didn’t fit his hypothesis! When other researchers analyzed his data using all the original countries, the link between fat and heart disease totally vanished. Keys was a fraud, and he’s the reason my mom made me eat skim milk and Corn Chex for breakfast instead of delicious bacon and eggs. LET HIS SOUL BURN. BURN! BUUUUUURN! Read the rest of this entry »





The New USDA Dietary Guidelines: Total Hogwash, and Here’s Why

4 02 2011

A few days ago, the USDA finally unveiled their (fashionably late) 2010 dietary guidelines—the first update they’ve made since 2005. Are you as excited as I am? Can we live without bread yet? Leave the fat on our dairy? Ditch the rancid vegetable oils? Gobble down butter and coconut oil without fearing imminent death? By golly, has the USDA finally pulled its head out of the soybean fields and given us something useful, emerging as a reliable authority instead of a food industry puppet?

Nah.

Contrary to my title, though, the new guidelines aren’t total hogwash. Just mostly. A few of their recommendations are passable, like these:

  • Prevent and/or reduce overweight and obesity through improved eating and physical activity behaviors. (Duh.)
  • Increase physical activity and reduce time spent in sedentary behaviors. (Duh.)
  • Keep trans fatty acid consumption as low as possible by limiting foods that contain synthetic sources of trans fats, such as partially hydrogenated oils. (Duh.)
  • Limit the consumption of foods that contain refined grains, especially refined grain foods that contain solid fats, added sugars, and sodium. (Yes!)

Unfortunately, the rest of the guidelines are the regurgitated—and often unsubstantiated—snippets we’re already inundated with. Case in point:

  • Consume less than 10 percent of calories from saturated fatty acids by replacing them with monounsaturated and polyunsaturated fatty acids.
  • Consume less than 300 mg per day of dietary cholesterol.
  • Consume at least half of all grains as whole grains. Increase whole-grain intake by replacing refined grains with whole grains.
  • Increase intake of fat-free or low-fat milk and milk products, such as milk, yogurt, cheese, or fortified soy beverages.
  • Use oils to replace solid fats where possible.

According to the guideline packet, these recommendations provide “information and advice for choosing a healthy eating pattern” and are “based on the most recent scientific evidence review.” If you’ve read anything else on this blog, you probably know by now that I’m weary of trusting second-hand interpretations—the original data often tells a different story than the mouths claiming to interpret it. So instead of taking the USDA’s word as gospel, why not see what they’re basing their recommendations on?

Luckily, the USDA has a Nutrition Evidence Library, where they’ve compiled the studies they used to create their latest guidelines. Let’s dig in. Read the rest of this entry »





New Interview and More Sucky Science

1 11 2010

I’m back from a blogging hiatus that you probably didn’t know about because I never told anyone. Sorry! But what better time to return than on World Vegan Day?

First of all: I recently had the pleasure of doing an interview at “Let Them Eat Meat” about my experience with veganism, thoughts on its healthfulness, my overwhelming adoration for the American Dietetic Association, and—because I’m forever branded as That China Study Girl—some final thoughts on a certain book we all know and love.

In case you haven’t heard, Let Them Eat Meat is the brainchild of Rhys Southan, a non-disgruntled ex-vegan who applies his stellar writing skills to the subject of veganism. If you haven’t already stumbled across this site, please stumble there now—you’ll find some fantastic interviews with former (and current) vegans, discussions of related health and moral topics, and a critical look at the arguments for avoiding animal products—including a recent deconstruction of vegan ethical tenets. Even if you don’t have personal experience with an all-plant diet, you might find the material there fascinating from a psychological perspective. So go peruse.

In other news, it looks like bad science—or at least bad reporting—is still alive and well. Case in point:

Fellas: is saturated fat lowering your sperm count? If you believe the flurry of recent articles, it sure sounds like men who eat more saturated fat have fewer—and less virile—swimmers. A Harvard study presented at a reproductive conference last week spawned some gems like these:

High saturated fat intake ‘damages’ sperm

Diets High in Saturated Fats Can Lower Sperm Count, Researchers Say

Eating saturated fat can damage your sperm

Are the meat and dairy industries actually massive government-funded schemes for population control? Is humankind’s history of meat consumption the reason we’re verging on extinction?

Interestingly, when you actually read the articles above, you’ll see that saturated fat wasn’t the only type of fat the researchers linked with sperm problems. From here:

According to the study, an increased intake of saturated fats and monounsaturated fats—which are commonly found in meats, butter, and dairy products—may result in a lower sperm concentration.

(Isn’t it cute how they don’t list the common sources of monounsaturated fat? No one wants to diss olive oil. That’s what the Mediterraneans eat!)

And from here:

The researchers found that men with the highest intake of saturated fat had 41% fewer sperm than men who ate the lowest amount of saturated fat. And men with the highest intake of monounsaturated fat had 46% fewer sperm compared with men with the lowest intake of monounsaturated fat.

I’d give the ol’ “correlation isn’t causation” reminder, but in this case, it might not even be necessary. It looks like the figures cited are the unadjusted ones, because according to this Medscape article (which has more details about the study than the others):

The association between fat intake and semen quality parameters was made with linear regression while adjusting for total energy intake, age, abstinence time, body mass index, smoking status, and intakes of caffeine and alcohol. The results showed that saturated fatty acid levels in sperm were inversely related to sperm concentration (r = −0.53); however, saturated fat intake was unrelated to sperm levels.

D’oh.

So basically, men with higher levels of saturated fat in their sperm tended to have poorer semen quality—but actual dietary intake of saturated fat wasn’t implicated after adjusting for confounders. At least that’s what I’ve pieced together from the available articles, since a quest for the original study yielded nada. Regardless, this is a prime example of the media skewing headlines to fit conventional nutrition wisdom and assuming an association between variables proves cause-and-effect.

And in case anyone’s wondering what’s going on with “The China Study” Suckypedia Wikipedia article that’s now moderated by a vegan editor: Along with pruning out all mention of my critique, gone also are the criticisms from Science Based Medicine’s Dr. Harriet Hall (here and here) as well as the fabulous critiques from Chris Masterjohn (here and here). The only one still up is a brief mention of Loren Cordain. And in case that’s not enough, the “Criticism” section has now been changed to “Reception and criticism,” so half of it is dedicated to praise.

Go figure.

And at the risk of sounding like The Girl Who Cried Wheat Entry, the wheat entry really is coming next! I promise. In the meantime, here’s a new study that shows we have microorganisms in our mouth that can actually degrade gluten. Might this play a role in how folks at risk for celiac respond to wheat? Seems possible.

Lastly, I’d like to thank everyone who’s contributed to the (oft-informative) discussions unfurling on previous entries. I haven’t had time to jump in myself, but I’m grateful to all of you who’ve taken the time to share your thoughts here and engage in what has generally been civil discourse. You people are awesome.








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