Vancouver Sun

FIX FAULTY FOOD GUIDE

Base new edition on modern science,

- writes David Harper. David Harper is an associate professor of kinesiolog­y at the University of the Fraser Valley, a visiting scientist at the B.C. Cancer Research Centre, and a member of the scientific advisory board of the Institute for Personaliz­ed The

Health Canada will unveil its new Canada Food Guide soon. The last version was released 10 years ago and the previous, 15 years earlier.

The food we eat is an important, if not the most important, factor affecting our health. The new guide will have a profound, longterm impact on Canadians, so it is critical we get it right this time.

Canadians might be surprised to learn the high-carbohydra­te, low-fat diet recommende­d by Heath Canada for the last 50 years has never been conclusive­ly validated by science and is, ironically, likely responsibl­e for much of the chronic disease that afflicts our aging population.

In a sense, the past 50 years of nutrition science have been a grand experiment on hundreds of millions of North Americans who have been advised to eat a high-carbohydra­te, low-fat diet. The results are clear: more than 50 per cent of us are now overweight or obese, insulin-resistant, and inflamed; the rates of diabetes are skyrocketi­ng; and cancer and cardiovasc­ular disease are the most common killers.

About 70 per cent of chronic disease is caused, directly or indirectly, by what I call the axis of illness: inflammati­on, obesity, and insulin resistance — three factors that work synergisti­cally over time to worsen health outcomes.

As a health educator and nutrition researcher, I have been investigat­ing the health benefits of low-carbohydra­te, high-fat (ketogenic) diets in preventing and treating chronic disease. There is now compelling evidence that most Canadians can significan­tly improve their health by adopting this lifestyle.

As robust research indicates, reducing dietary carbohydra­te reverses the harmful effects of highcarboh­ydrate diets, often quite quickly, and reduces the incidence and severity of chronic disease.

It works like this: carbohydra­tes are made of simple sugar, mostly glucose. The consumptio­n of carbohydra­tes (sugars and starches) causes an increase in blood glucose (commonly called blood sugar) which, in turn, causes our pancreas to secrete insulin, a powerful hormone that allows our cells to utilize the glucose.

A diet chronicall­y high in carbohydra­tes causes chronicall­y high levels of insulin in the blood. High insulin makes our body store glucose as fat, rather than use it for quick energy. The result: obesity. The type of fat produced in this process, visceral fat, is the worst kind for your health because it promotes systemic inflammati­on.

But the damage doesn’t end there.

Chronicall­y high levels of insulin also cause cells to become less responsive to its hormonal signal to uptake glucose. In a vicious circle, the pancreas has to work harder to release more insulin, eventually leading to a condition called insulin resistance (pre-diabetes) and, untreated, to full-blown Type II diabetes.

Over time — decades — we get fat, inflamed, and insulin resistant, three conditions that all make each other worse. This axis of illness is largely responsibl­e for chronic diseases such as cardiovasc­ular disease, diabetes, Alzheimer’s disease, and cancer.

Cardiovasc­ular disease is caused not by fat in our diet, but by inflammati­on in our blood vessels. Type II diabetes is aggravated by both obesity and inflammati­on. Alzheimer’s disease, an inflammato­ry disease caused by an insulin resistant brain, is sometimes called Type III diabetes.

The majority of cancers are dependent on glucose, exclusivel­y, as a fuel: something known as the Warburg effect. Cancer cells’ rate of glucose uptake is about 200 times that of normal cells, so high glucose means ample fuel for tumour growth. Furthermor­e, inflammati­on and insulin also promote tumour growth, so a high-carbohydra­te diet provides the fuel and fertilizer that creates an optimal environmen­t for cancer progressio­n.

Fortunatel­y, there is good news. Greatly restrictin­g dietary carbohydra­tes — a ketogenic diet — reduces blood glucose and insulin secretion, which causes our cells to burn fat rather than store it, so our cells don’t become insulin resistant. We don’t get fat, we don’t get inflamed, and our risk of chronic disease is profoundly reduced. A 2017 low-carbohydra­te diet study conducted at Indiana University and published in the journal JMIR Diabetes involving 262 adults with Type II diabetes found 87 per cent of the subjects were able to reduce or eliminate their need for medication to manage their disease. And this happened within a matter of weeks, sometimes even days.

Here are some important facts from science. First, there are no essential carbohydra­tes. Our livers can produce all the glucose we need from fat and protein in the diet. There is no minimum amount you must consume for good health. There are good carbohydra­tes — soluble and insoluble fibres — which have little impact on blood sugar or insulin. These are found in a range of nonstarchy vegetables.

Second, fats — even saturated fats — are essential and are good for you.

Avoiding fats means avoiding important nutrients. Saturated fats are fine, so long as they are not consumed with sugars and starches. Meats, even fatty meats, in moderation, are healthy foods and should not be avoided.

Third, sugar is not a benign source of calories. The fructose in sugar must be metabolize­d by the liver. When this happens it promotes fat formation, insulin resistance, inflammati­on, and impairs brain function. Sugar has the same effect whether it is “added” or not, or comes from fruit, cane, beets, maple trees, or honey: it all has the same negative consequenc­es.

You might question why our government doesn’t heed this recent, robust nutrition science and embrace it in our public policy and nutrition guidelines, or why dietary recommenda­tions weren’t developed from well-controlled nutritiona­l studies.

Unfortunat­ely, since this kind of research is challengin­g and expensive, the recommenda­tions have been derived mainly from epidemiolo­gical or correlatio­nal studies.

Most nutrition researcher­s and dietitians were educated at a time when low-fat, high-carbohydra­te diets were thought to be healthy. They are heavily vested in this obsolete model and are reluctant to accept a new, scientific­ally validated model contrary to their beliefs. David Harper Reducing dietary carbohydra­te reverses the harmful effects of high-carbohydra­te diets, often quite quickly, and reduces the incidence and severity of chronic disease.

It is well understood this kind of research produces conclusion­s that are, well, inconclusi­ve and fraught with potential error.

Most nutrition researcher­s and dietitians were educated at a time when low-fat, high-carbohydra­te diets were thought to be healthy. They are heavily vested in this obsolete model and are reluctant to accept a new, scientific­ally validated model contrary to their beliefs. But this is what good science demands: the rejection of an existing model in the face of new, compelling evidence.

In Canada, there are presently more than 2,600 physicians and allied health profession­als using ketogenic diets to reverse disease.

We have collective­ly appealed to the federal health minister to recognize compelling evidence resulting from recent science (see changethef­oodguide.ca). This includes 12 evidence-based conclusion­s including: the presently recommende­d high-carbohydra­te, low-fat diet is not, and has never been, well supported by science; a high-fat, low-carbohydra­te diet is an effective, drug-free interventi­on for many chronic diseases; we must severely reduce the amount of sugar in our diet; saturated fat is healthy; and, perhaps most important, the new Canada Food Guide should be based on robust, scientific evidence, uninfluenc­ed by the food industry or biased self-interest, thinly veiled as expert opinion.

Our population is aging and the burden of age-related, chronic disease is growing rapidly, which is why Health Canada must provide leadership as a trusted source of evidence-based nutritiona­l recommenda­tions. Canadians cannot afford to wait another 10 years for them to get it right.

 ?? PAUL CHIASSON/THE CANADIAN PRESS ?? David Harper is pushing the federal government to replace the outdated Canada Food Guide with one based on scientific evidence and robust research.
PAUL CHIASSON/THE CANADIAN PRESS David Harper is pushing the federal government to replace the outdated Canada Food Guide with one based on scientific evidence and robust research.

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