Diet & Dogma

Much of what we thought we knew about the role of saturated fats in our diet comes from a series of research studies, recently debunked, sponsored by the sugar industry and conducted at Harvard University in the 1960s. The sugar industry was interested in diverting attention away from the harmful effects of sugar by pointing out the possible health risks of consuming too much saturated fat.

The researchers agreed to focus their lens on fat, resulting in data that promoted sugar and vilified saturated fat. At the same time, the edible oil industry – producers of canola, sunflower, corn and other polyunsaturated vegetable oils – was able to convince consumers and national health departments that these oils were far better for human health than saturated fats like butter, animal fat and other dairy products.

Unfortunately, no credible science exists to support those claims, and new research is showing them to be false. These findings, which ultimately show that saturated fats do not, in fact, have an effect on heart disease*, follow a huge study conducted, ironically, by the Harvard School of Public Health. That study looked at 72 published papers on heart disease involving more than 600,000 subjects worldwide that exonerated saturated fats.

*(editor’s note) Despite the findings of recent research, the question of whether or not there is a link between saturated fat and heart disease remains a controversial one. Although our knowledge about fat in the diet is evolving, many health organizations and governments still advise people that saturated fat is a risk factor for cardiovascular disease and to minimize their intake.

Gibson’s initial research focused on examining fecal matter from human infants. She and her team collected diaper samples from babies all over Kelowna (thus the “Poop Lady” appellation. “Even my kids call me the Poop Lady,” she says with a laugh), to find out what species of microbes exist in a person’s gut (there are hundreds), with a goal to learning what impact these microbes have on digestion, the development of gastrointestinal (GI) diseases, and the overall health of the individual.

One of the first successes of her research came with development of a standardized procedure for storing stool samples. She found that simply storing samples in the freezer resulted in inconsistent results – the process itself affected the microbes – and that the microbes appearing in one part of a sample may be different from those that appear in another. Her team developed a process she calls “homogenization,” where each sample is mixed and suspended in liquid nitrogen, ensuring no microbial changes can take place between diaper and microscope.

The primary goal of her research was to show how the diet of the mother had an impact not only on the fetus, but on the long-term health of the child. In experiments with rodents, Gibson learned that a “bad” diet in the mother resulted in the later development of GI diseases such as colitis and diabetes in the offspring, while mothers with a “good” diet tended to produce offspring with better health outcomes later in life.

Trans fat is produced by adding hydrogen to liquid vegetable oils to make them solid. The resulting product, usually referred to as “partially hydrogenated oils” on product packaging, has a long shelf life, works well in cooking and is cheap to produce. Margarine, shortening, snack items, deep fried foods and bakery products benefit most from the use of trans fats, but research in the 1990s showed that consumption of trans fat had a detrimental effect on human health. It tends to increase the production of lipoprotein LDL (bad cholesterol), while decreasing the production of lipoprotein HDL, the good one. Also, it promotes a dangerous level of inflammation in human cells and has been shown to increase the risk of heart disease.

Some trans fats occur naturally in meat and dairy products, including beef, lamb and butter fat, but in very small quantities. However, research has shown that naturally occurring trans fats may have a beneficial effect as it promotes an increase in both LDL and HDL lipoproteins.

Recognizing that trans fats aren’t good for human health, their use has been severely reduced, by legislation, in the US, with an outright ban scheduled for 2018. The Canadian government, while monitoring the use of trans fats in industry, has yet to introduce a plan to eliminate them from the Canadian diet. The use of trans fats in commercial food production has, however, decreased considerably over the past decade due largely to consumer demand. For this reason, trans fats are not being investigated at the Gibson lab.

Fat has been the bad guy in dietary circles for decades, particularly saturated fat, such as that found in meat, butter and tropical oils. “We tend to vilify all fats,” Gibson says, “especially saturated fats. But our research shows that some of these fats are protective in some serious GI diseases.”

Our modern nutritional best-thinking says saturated fat is just this side of poison. Many studies dispute this claim, but whole industries have grown up that cash in on this idea. Sanjoy Ghosh, assistant professor in the Irving K. Barber School of Arts and Sciences at UBCO, is poster boy for how long it can take to refute bad science. In 2004 as a PhD student at UBC, he undertook research to prove how saturated fats contribute to some of the more devastating aspects of diabetes. But his research proved the opposite: saturated fats actually provided some protection against these developments.

In his attempts to get his research published he was ridiculed and his work considered suspect, but he persevered. Ultimately, his work won him an international research award, and started him on his path to wider research into fat and how it metabolizes in the body. Now, working with Gibson, he and the team have made some ground-breaking discoveries about how the gut interacts with the fats we consume.

Their study, which examined how the type of fat consumed had a direct impact on infections in mice, was published by the Journal of Infectious Diseases in the UK. The study showed how mice fed fatty acids found in olive oil and milk fat, which is rich in saturated fat, were better able to fight diseases than mice fed fats rich in polyunsaturated fats such as those found in corn oil.

But fats are extremely complicated. They are essential for good health – many vitamins and minerals are unavailable to the body without fats to metabolize them – and vital in maintaining a healthy gut microbiome. But their function in the gut goes beyond nutrient metabolism. They are responsible for maintaining microbial balance, regulating inflammation and discouraging bad bacteria. The roles of the various kinds of fat are only now being understood.

Fats found in vegetative matter (called Omega 6 fats which also occur in poultry, eggs and grains) have, historically, made up a relatively small part of the human diet. However, fats processed from vegetative sources and made into edible oils have been a part of the human diet for less than one hundred years. These oils, including corn, canola, and sunflower, make up the vast majority of oils used in processed food and in cooking oils at home. Researchers are only now understanding their negative effects.

Recent data about the positive effects of saturated fat have people looking twice at the old standbys, like butter. Up against trans fat and vegetable-based fats, butter seems to be climbing back on top of the good-for-you food mountain.

But is it true? A study of Canadian dairy products by Sanjoy Ghosh and lead author Amy Botta, a PhD student at UBCO, might put a serious drag on butter’s ascent.

Canadian butter, along with that made in the US and China, has an extremely high Omega 6 to Omega 3 fat ratio as compared to butter produced in countries like France and Germany. Why? Because our dairy cows are fed a diet almost exclusively made of grain, while those in France and Germany are grass fed. The fat produced in grain fed animals reflects the high Omega 6 fat content of their feed. Grass fed animals produce fat much lower in Omega 6 fats. An overabundance of Omega 6 fats in the diet of humans is implicated in the development of various health problems.

This difference may explain why conflicting research data exists about the perils or benefits of butter and, Ghosh suggests, may illuminate the secret of the French paradox, where the high-fat French diet doesn’t seem to cause obesity or an increased incidence of heart disease.

The study was published in the Journal of Agricultural and Food Chemistry.

The problem is, according to Gibson, inflammation in the gut. While some inflammation is essential for good health – to kill bad bacteria and counter some infections – too much inflammation has been associated with a host of diseases such as diabetes, GI disease and even cancer. Omega 6 fats encourage inflammation of gut bacteria, while Omega 3 fats discourage it. Our North American diet loads up on Omega 6 fats, with a much smaller portion of Omega 3, while saturated fats are discouraged. This combination is a recipe for dietary disaster because the presence of all that Omega 6 fat in the gut produces a constant state of inflammation.

Ironically, supplementing one’s diet with Omega 3 fats, such as with fish oil pills or in baby formula, just causes more problems. Too little inflammation in the gut encourages the development of bad bacteria and infection in other parts of the body.

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