I want to get some Juno-inspired T-shirts printed up for researchers that say “What other kind of shenanigans can I get into?” Seriously. I cannot believe the stuff that gets published in medical journals these days. I don’t know which is the scarier possibility: that the researchers are really so poorly trained that they consistently violate the most basic principles of medical research (that you probably learned in your 8th grade science class), or that they are so dishonest that they intentionally and blatantly lie about their results.
A prime example of this is an article that came across my newsfeed a couple of days ago. The headline read “High fat diet during pregnancy leads to severe liver disease“. I’m always very, very suspicious when I see articles like this because of my previous experience evaluating such studies. All too often researchers make basic (and frankly, inexcusable) mistakes like lumping all fat types together (i.e. combining saturated fat with polyunsaturated fat, although the two fatty acids have completely different effects on human physiology).
I didn’t have time to review the study and write about it, so I emailed Chris Masterjohn, a researcher pursuing a PhD in Nutritional Sciences with a concentration in Biochemical and Molecular Nutrition at the University of Connecticut. Chris has a blog called The Daily Lipid where he writes about the benefits of saturated fat and the dangers of polyunsaturated fat. Turns out Chris had seen the article on ScienceDaily too and was planning to write a critique. Here’s what he wrote. I encourage you to check out his blog, and also his website, both of which have some great information about the health benefits of cholesterol and saturated fat.
According to a recent article on ScienceDaily, scientists have discovered that mothers who eat too much saturated fat during pregnancy will give their future child severe fatty liver disease once he or she becomes an adult.
The use of words in this article like “mother,” “child,” and “adulthood” suggests that the researchers performed some type of scientific research in humans. In fact, ScienceDaily goes so far as to claim that the researchers were studying the consumption of high-fat diets during “a woman’s pregnancy.”
Nowhere in the article do the authors inform the reader that the research was performed in mice. This is the first time I have ever read of a mouse referred to as a “woman.”
The most egregious distortion of the study, however, comes from one of the researchers himself:
Professor Christopher Byrne, with colleagues Dr Felino Cagampang and Dr Kim Bruce, of the University’s School of Medicine and researchers at King’s College London, conducted the study, funded by the BBSRC. Prof Byrne explained: “This research shows that too much saturated fat in a mother’s diet can affect the developing liver of a fetus, making it more susceptible to developing fatty liver disease later in life. An unhealthy saturated fat-enriched diet in the child and young adult compounds the problem further causing a severe form of the fatty liver disease later in adult life.”
Really, “saturated fat” causes liver disease? This stands in surprising contrast to other rodent studies showing that saturated fat prevents liver disease:
- A 1995 paper in the journal Gastroenterology lauded “dietary saturated fatty acids” as “a novel treatment for alcoholic liver disease” after showing that substitution of saturated palm oil for polyunsaturated fish oil reduced alcohol-induced liver damage.
- A more recent paper published in the Journal of Nutrition 2004 showed that saturated fat from MCT oil (medium-chain fats similar to those in coconut oil) and beef tallow reduced alcohol-induced liver damage when substituted for polyunsaturated corn oil. In fact, they replaced 20 percent, 45 percent, or two-thirds of the corn oil with saturated fat and found that the more saturated fat they used, the greater the protective effect.
- An even more recent paper published in the journal Hepatology in 2005 found that rats fed corn oil readily developed liver damage when fed over a quarter of their calories as alcohol, but rats fed saturated cocoa butter were virtually immune to liver damage when consuming the same amount of alcohol.
- A 2007 study published in the journal Nutrition and Metabolism found that although corn oil-based high-fat diets can induce non-alocholic fatty liver disease in rodents, long-term feeding of high-fat diets based on coconut oil or butter cannot.
So how is it that “saturated fat” wound up causing liver disease in the offspring of these mice?
If we look at “supplementary table 1,” we find that the “saturated fat” used in this study was mostly monounsaturated and polyunsaturated fat. In fact, 22 percent of the fat on the low-fat diet was saturated, while only 15 percent of the fat on the high-fat diet was saturated!
That means that less than seven percent of the calories from the “unhealthy saturated-fat-enriched diet” actually came from saturated fat.
The “unhealthy saturated fat-enriched diet” actually contained 44 percent of its fat as polyunsaturated fatty acids (PUFA) and almost twenty percent of its total calories as PUFA. This is in great excess of the PUFA consumption seen even in the Standard American Diet (SAD), loaded in processed PUFA-rich vegetable oils.
Apparently “saturated fat” consumed during a “woman’s pregnancy” leads to liver disease once the “child” reaches “adulthood” only when the “saturated fat” is the highly polyunsaturated kind one would find in corn oil and the “woman” is a light, fluffy critter no one would ever mistake for a human.
What can we learn from this study? Perhaps that we can never trust the news account of a research study. Unfortunately we cannot even trust the quotes in those news account taken from the researchers themselves.