Bad Seed
When it comes to diet and health research, some of the weakest science comes in the form of epidemiological surveys. These studies rely on surveys of how people behave over periods of time, typically weeks or months. Needless to say, they aren’t particularly reliable—not because people are dishonest, but because people only vaguely recollect what they did. For instance, they probably don’t remember how often they eat green vegetables in a typical week or month, much less how many ounces or servings per day, or how many calories they consume in general. They may also incorrectly report that they spend more time exercising than in reality, believing what they say.
These surveys also ask respondents about their health, or about family histories with disease. If the surveys are done well by the statistical standards of public opinion research, they still aren’t particularly useful when it comes to medical science. Yet they are relied on as better than nothing, in many instances because superior methods are comparatively costly.
The better research comes from random-controlled trials (RCTs), in which test subjects are separated into at least two groups—one that undergoes the treatment, and another that undergoes no treatment or a fake one consisting of an innocuous, neutral input (the control). The two groups of subjects aren’t supposed to know who got the real treatment and who didn’t, and ideally, the researchers don’t know which subjects are which either, making for a double-blind RCT. The RCT is meant to isolate only one variable and test it on subjects to determine differences is in health outcomes over time—which is where the RCTs get very expensive quickly when it comes to testing diet and behavior. To achieve the most accurate results, the research project would have to pay for hundreds of subjects to eat all their meals as prepared for them over a long period of time. It would almost exclude any project short of a months’ long in-patient study, just to be sure no one could sneak off to enjoy a favored snack on the side.
Most studies such as this would be out of the question today also out of ethical concerns for the psychological effects on people of isolating them for any duration, even if within larger groups. But in decades past, just such RCTs were undertaken with patients in settings where they were incarcerated or housed at in-patient treatment facilities for other reasons. One in particular was the Minnesota Coronary Experiment, carried out from 1968 to 1973, on around 9,000 male and female patients at state mental wards.
In this study, patients were divided into two diet groups. One group was served a diet where most of its fats were polyunsaturated fatty acids (PUFAs)—think vegetable oil. The other group was served a diet whose fats were almost exclusively saturated fats from animals (butter, cheese, lard, beef tallow).
So-called vegetable oils in reality are made from seed plants like corn, soy beans, sunflower, safflower, rape seeds, peanuts, and so on. These seed oils only became possible as the industrial revolution swept food production in the 19th century. It takes a lot of seeds to produce each ounce of oil, but the fats from the process are flavor neutral and shelf-stable, and they don’t appear to go rancid like most other fats. Thanks to the reasonably strong agricultural yields of seed grains, the fats are comparatively inexpensive. Our forebears a century and a half ago thought of these seed oils as nearly miraculous—an inexpensive source of calories for a population that faced the occasional threat of malnutrition or starvation.
The medical, health, and agricultural experts at the time were confident that seed oils were not just safe, but beneficial. Eventually this became something of an unquestioned assumption, a bias that subsequent research was interpreted to support.
Meanwhile, the Minnesota researchers were finding something different than predicted. While the PUFAs lowered subjects’ blood serum cholesterol—an effect that was presumed to be healthy—this did not improve their health outcomes. Instead, those who were on the PUFA diet had higher incidents of heart disease and heart attacks than those fed saturated-fats. The researchers found the results so shocking and confounding to their firm beliefs that they hid the results away for nearly 20 years before publishing them in an obscure journal.
This preamble has gone on a bit long already now; the intention was to capture the gist of the video presentation below. The video covers more aspects of the problems with seed oils, and is one of the best video productions on this scientific topic I have seen. It has earned its two million views.
The only things I know of that delve deeper are several recorded speeches from different low-carb-diet conferences and, in particular, the book The Big Fat Surprise: Why Butter, Meat & Cheese Belong in a Healthy Diet by Nina Teicholz (2014).
The broader point is that seed oils are a key contributor to what makes processed foods unhealthy—and the oils by themselves may account for the exploding rates of obesity, diabetes, and metabolic syndrome in modern advanced societies. The oils are ubiquitous in processed foods because they are flavor neutral, inexpensive, and have long shelf lives. These are key factors along with taste and convenience that make processed foods so irresistible.
Thanks again for all the well wishes for the day. It turned out differently than expected - a most glorious afternoon on the beach, with dress shopping moved to the forecast rain drenched Friday.
Three children (two nearby, one two hours away), one parent, four takes on every situation. I am confused, but not as anxious as I was before I got down here. We'll see what tomorrow brings.
That's the plan. Fingers crossed for tomorrow - today turned out differently than expected.