A vegetarian since he was 12, David Jenkins turned vegan a dozen years ago. Today, he won’t even eat honey.
Jenkins, a renowned nutrition scientist, is the man behind the glycemic index, a measure of how fast and by how much foods raise blood sugar and insulin levels. It lies at the heart of a load of weight-loss diets, from Atkins to the Zone.
Unsurprisingly, Jenkins is pleased with drum beats coming from Health Canada that the next iteration of the food guide, due out in early 2018, will steer people to chickpeas over cheddar and encourage the consumption of plant, not animal-based proteins.
“I can understand — you have people saying, ‘What about the family farm?’ Well, to be honest, if somebody says that to you, have some sympathy also for the Maritimers,” said Jenkins, a professor in the departments of nutritional sciences and medicine at the University of Toronto. After the cod fisheries were decimated in the 1990s, “Newfoundlanders had to leave, or think of something else,” Jenkins said.
Seventy-five years after Canada’s first official “food rules” debuted in wartime ads, the food guide is undergoing its first major overhaul in a decade with every sign it’s going to emerge leaning more vegan than omnivore.
The Dairy Farmers of Canada fret the “milk and alternatives” category will be removed from the guide entirely and lumped with plant-based foods into a single, protein-rich foods category. Animal-rights activists, meanwhile, are hailing the proposed principles framing the rewrite a “huge win for the cows.” Others have accused the government of pushing an environmentalist agenda.
In its “guiding principles” for the food-rules rewrite, published earlier this year, Health Canada says it isn’t recommending people shun animal-based products and proteins altogether, but suggests it might be better for greenhouse-gas emissions and soil and water degradation if we did.
In an interview with the Post, Health Canada officials said they considered the “totality” of the evidence when they reviewed the scientific base for updated dietary guidance to Canadians.
In addition to urging a shift toward a “high proportion” of plant-based foods (“without necessarily excluding animal foods altogether”), the preliminary recommendations also encourage eating less red meat (beef, pork, lamb and goat) and replacing foods that contain mostly saturated fat (cream, high fat cheeses, butter and the like) with foods that contain mostly unsaturated fat, like nuts, seeds and avocados.
But, will it make Canadians healthier?
Some argue that even the current recommended caps on saturated fat intake (less than 10 per cent of daily energy, or calories) are no longer justified by the latest evidence, and that even a relatively moderate intake of fruits, vegetables and legumes — three to four servings a day, half the current recommendation and a target that’s likely more achievable and affordable for many — is sufficient to lower a person’s risk of cardiovascular disease and death.
“The evidence for saturated fat has been very weak,” said McMaster University’s Andrew Mente, co-author of a large study published in August involving more than 135,000 people across five continents. The so-called PURE (Prospective Urban Rural Epidemiology) trial found those with a high intake of fat (35 per cent of daily calories) were 23-per-cent less likely to die after an average seven years of follow-up than those with a low intake (less than 10 per cent of calories). Total fat and individual types of fat, including saturated fat, were not associated with risk of heart attacks or death due to cardiovascular disease.
It’s not quite the “Low-fat diet could kill you” story some British headlines claimed it was. However, “What we show is going to low levels (of saturated fat) can actually be harmful,” Mente said.
Dairy and red meat are the primary sources of saturated fat.
I think they really need to state the rational for the emphasis on plant-based sources of protein, and have us understand how they linked that to diet-related disease
The PURE study also found people who consumed three to four servings of fruits, vegetables and legumes per day had the lowest risk of death, with little added benefit from eating more.
The study doesn’t prove cause and effect, only an association. And Mente says no one is advocating a very high fat diet, either. He’s hoping to see moderation in the new food guide, “a little bit of all the food groups.”
However, he and others are questioning the “beans-over-beef” argument.
“So far, Health Canada hasn’t revealed what evidence they used to make that statement, so I think we’re all wondering,” said Stephanie Atkinson, a professor in the department of paediatrics at McMaster University who, like Jenkins, helped oversee the development of Canadian and U.S. dietary reference intakes.
“I think they really need to state the rational for the emphasis on plant-based sources of protein, and have us understand how they linked that to diet-related disease.”
It’s also not clear how much plant-based versus animal. “It’s kind of wide open,” Atkinson said: 50 per cent? More?
Under Health Canada’s 2015 “evidence review,” there’s a brief reference to soy and lowered cholesterol. It also summarizes “convincing evidence” from systematic reviews linking red and processed meat with increased risks of colorectal cancer, and increased risks of heart attack and stroke with saturated fat. Fibre-rich foods, it notes, have been shown to decrease colorectal cancer risk.
We have for a long time been talking about very quite small amounts of animal food in the diet to start with
Health Canada says it excluded studies produced by industry. “Let’s just say there is potential for either real or perceived conflict of interest for those sorts of reports,” said Hasan Hutchinson, director general of the office of nutrition policy and promotion.
Hutchinson says a persuasive body of evidence shows dietary patterns like Mediterranean-style diets that emphasize vegetables, fruits, whole gains, legumes, nuts and fish and decreased red meat, refined grains and sugar sweetened foods are associated with lower risks of cardiovascular disease.
“In reality, in my mind this is not very different than what our existing guidance is,” he says. For example, the current food guide recommends seven to 10 servings of fruits and vegetables daily for adults age 19 to 50, depending on gender, and only two to three servings of meat and alternatives, “and even there we’re recommending people go with meat alternatives,” Hutchinson said.
“We have for a long time been talking about very quite small amounts of animal food in the diet to start with.”
The government hasn’t yet decided what will be removed, renamed or regrouped, he added.
But people would be wrong to assume “that we are saying, ‘Have no dairy, have no meat,’” he said, noting the public consultation documents mention animal-based foods as well, such as eggs, fish, poultry, lean red meats and lower fat milk and yogurt.
Jenkins, a scientist at Li Ka Shing Knowledge Institute at St. Michael’s Hospital, says few studies have been done to support moving to a more plant-based diet. “And anybody who says they’ve got the answer is, I think, deceiving himself or herself.”
The best-controlled research on the subject, he said, is the PREDIMED study, which, in 2013, reported that a Mediterranean diet supplemented with either extra-virgin olive oil or nuts resulted in a 30 per cent risk reduction in cardiovascular disease, compared with a low-fat diet.
He also believes the new food guide may better reflect the nation’s cultural diversity and the growing numbers of people migrating from non-milk drinking, non-beef eating parts of the world. “Are these people any worse for it in their native situation? No, but when they come to us, they get sick.”
Canadians are also already drinking less milk and consuming less red meat. And while animal proteins are more complete proteins than plant based proteins, providing 100 per cent of the essential amino acids needed for skeletal muscle growth, Jenkins said that only becomes an issue if overall protein intakes are low. For the majority of Canadians, protein intakes are high.
There’s also nothing wrong with linking human health with environmental and humanitarian concerns, said British-born Jenkins, who turned vegetarian the year his aunt sent a Christmas hamper to his family. Inside were two bantam chickens, plucked and decapitated, that used to run wild on her English country estate. They had been Jenkins’s pets, won at a summer church fair. Jenkins used to take play with them on his holidays.
“The question you should ask is, ‘is the diet they’re recommending going to be dangerous?’ No, I think it’s going to have great benefits,” he said, including potentially improved health, lower insulin resistance and reduced body weight.
Still, there’s little doubt any dumping of milk or other radical change would meet “tremendous resistance,” he said. (The guiding principles emphasize only “regular intake of water.” Milk is included in an asterisk). In today’s food guide, “milk is a big thing — adults should be drinking two or three glasses of milk per day. Should they? Should adults be having two glasses of an infant food a day, or three?
“You have to ask yourself, is this important?”