Yesterday Ace linked to an article reporting on a study that appears to be saying saturated fat is good for you. The subtitle at the report’s link indicates that the research “overturned previously accepted wisdom.”
Actually, not really.
First of all, one small study of this type doesn’t “overturn” much of anything. Secondly—as is almost always the case with mass media reports of studies on health, the linked article at the Express gets an awful lot about the research wrong.
Let’s look at the actual study, shall we? Unfortunately, the full text is unavailable unless you shell out a lot more money than I’m willing to pay. But the abstract is here, and the research findings appear quite mild. In fact, completely unremarkable.
First we have the number of participants, variously reported as 46 or 38 (eight apparently dropped out) overweight men between 30 and 50 and divided into two groups, each of which received a different diet. So half got the high-fat diet, which makes the number of subjects very small indeed. And we have no idea what the age distribution was, just the range. At any rate, we’re not talking about older people, the population most at risk for heart disease. Whatever findings there were, we have no idea whether they can extrapolated to a more general population.
Both groups got a diet. One was high fat (73% of calories from fat) and one low fat (30% of calories from fat). Both groups lost weight. We know that losing weight tends to improve blood pressure and cholesterol and other such markers, however it is lost, so if both groups lost weight one would expect things like blood pressure to go down. Both groups ate the same number of calories, the same amount of protein, and their diets “emphasiz[ed] low-processed, lower-glycemic foods.” In other words, they were very healthful, highly-controlled diets that differed only in the ratio of fat to carbs consumed.
The abstract is mum on what they actually ate. But none of the articles I read that reported on the research (and I read many) indicated that red meat was a big part of the diet of either group. Instead:
…[T]he food types were the same [in both groups] and varied mainly in quantity, and intake of added sugar was minimized.
“We here looked at effects of total and saturated fat in the context of a healthy diet rich in fresh, lowly processed and nutritious foods, including high amounts of vegetables and rice instead of flour-based products,” says PhD candidate Vivian Veum.
“The fat sources were also lowly processed, mainly butter, cream and cold-pressed oils.”
In the high-fat group, only half the fats were saturated, and the other half consisted of oils.
My sense is that for both groups the diet was mainly very low sugar and mostly vegetarian except for dairy products. This is a far cry from saying something like “red meat is good for you,” and it certainly doesn’t say “red meat is better for you than carbohydrates.”
And then there are the actual results. None of the MSM articles I read made it clear that the findings were essentially the same for both groups. Nor did they emphasize the fact that the diet was only followed for three months, and all the effects were small.
Back to the abstract:
The diets similarly reduced waist circumference (11–13 cm), abdominal subcutaneous fat mass (1650–1850 cm3), visceral fat mass (1350–1650 cm3), and total body weight (11–12 kg). Both groups improved dyslipidemia, with reduced circulating triglycerides, but showed differential responses in total and low-density lipoprotein cholesterol (decreased in LFHC group only), and high-density lipoprotein cholesterol (increased in VHFLC group only). The groups showed similar reductions in insulin, insulin C-peptide, glycated hemoglobin, and homeostasis model assessment of insulin resistance.
The best non-technical article I saw on the subject was this one at a British health website:
After various drop-outs, only 38 of the original 46 men were available for analysis – just 18 in the LFHC group and 20 in the VHFLC group.
Body weight dropped by about 11-12kg, or 3.6 BMI points in both groups over the 12-week period.
Total abdominal fat and fat around the organs decreased by roughly 20-30% in both groups. Waist circumference decreased by 11-13cm. There were no significant differences between the groups.
Fasting blood sugar only reduced in the LFHC group, but there were no other between-group differences for other measures of blood sugar control, such as insulin.
Levels of one type of fat (triglycerides) decreased in both groups. Low-density (“bad”) cholesterol decreased only in the LFHC group, but high-density (“good”) cholesterol increased only in the VHFLC group.
Improvements were noted to occur within the first eight weeks in the VHFLC group, but were more gradual in the LFHC group.
The men were all healthy to begin with, by the way, because anyone with pre-existing disease had been eliminated.
So that’s it, folks. Something of a nothingburger—perhaps literally (were they allowed burgers? Your guess is as good as mine—unless you want to pay for the article and see.)