SECOND OPINION | The demise of a dietary dogma?

Hello and happy Saturday! Here's this week's round-up of eclectic and under-the-radar health and medical science news. If you haven't subscribed yet, you can do so here.

The buzz started even before the press releases went out. Something big is coming, our sources told us. Then on Tuesday, it happened.

A new study was released in The Lancet challenging the dogma of the diet-heart hypothesis. For decades, that dogma has stated that eating less saturated fat will lower the risk of heart disease and death.

Headlines quickly flashed the surprising findings: Thousands of people in the Prospective Urban Rural Epidemiology (PURE) study who ate more fat — even saturated fat found in meat and cheese — had a lower risk of death. And people who ate more carbohydrates had a higher death rate.

Immediately, the Twitterverse lit up with reasons why the new study is flawed:

• It spanned 18 countries with vast differences in health care and access to nutritious food, which meant differences in diet might have reflected differences in wealth and poverty

• It used a food questionnaire that depends on people accurately reporting what they ate, and they only filled it out once, at the beginning of the seven-year study

• The researchers didn't count calories, and they didn't report what types of food were consumed

"Does it have limitations? Of course, all studies do," said Richard Bazinet, associate professor at the University of Toronto. He wasn't involved in the research, but Bazinet said it's the latest in a series of studies that have complicated the dietary fat story.

"This is seven years of big studies coming in that don't fit," Bazinet said. "It's getting hard to say there's nothing to see here."

Bazinet is a nutrition scientist who studies the effect of dietary fat on the brain. He believes he's seeing a major shift in the dietary fat dogma that he was taught as a graduate student in the 1990s.

"I was trained in a field where this was taught to everybody. Saturated fats are bad. They raise your cholesterol. They raise your risk of heart disease. And now my honest opinion is that's at least oversimplified, if not wrong."

The dietary fat dogma started more than a century ago with some meat-eating rabbits.

Back in 1908, scientists noticed that rabbits who were fed high cholesterol diets (meat, eggs, milk) developed plaque in their arteries. It was the beginning of a diet-heart hypothesis that reached full flower in the 1950s, when researcher Ancel Keys convinced the world that diets high in saturated fat increased the risk of heart disease.

But gradually the scientific pendulum has started swinging in the other direction, as a series of studies and meta-analyses suggest the fat/carb diet/health equation is much more complicated.

In one dramatic twist to the whole fat story, two large randomized trials from the early '70s were never published. Later, when the data was recovered, it became clear why. Both studies failed to support the diet-heart hypothesis.

• The case of the missing data

• Benefits of switch from saturated fat to corn oil for longer life challenged

A few months ago, a group of British researchers dared to suggest that the dogma was dead. We reported on the dietary dust-up that followed in an April edition of Second Opinion.

"As nutritional scientists, we've been watching this develop for almost 10 years," Bazinet said. "Maybe we're reworking the diet-heart hypothesis, maybe we're tweaking it, but something is going on."

It will take a well-designed randomized controlled trial to ultimately resolve the uncertainty about diet and health. In an accompanying commentary in The Lancet, one researcher had this advice: "Until then, the best medicine for the nutrition field is a healthy dose of humility."

What about the rest of us, raised on the dogma that fats are bad? That story hasn't changed.

"The recommendation from our study is moderation in both carbohydrate and fat intake," said PURE study author Mahshid Dehghan, from the Population Health Research Institute at McMaster University.

The human body needs a balance of fats, protein and carbohydrates to fuel its complex metabolic processes. So the basic nutritional advice remains the same: control calories, eat both fats and carbohydrates in moderation and aim for as much fresh food as possible.

An affordable made-in-Canada CAR-T therapy

An important milestone in cancer treatment was reached this week, when the U.S. Food and Drug Administration (FDA) officially approved the first of a new type of cell-based immunotherapy for use in patients with a form of childhood leukemia who have not responded to standard chemotherapy.

It's a great step forward for cancer therapy.- John Bell, senior cancer researcher, Ottawa Hospital Research Institute

While the FDA approval was expected (see Second Opinion July 15), no one knew what it would cost. Before the announcement, analysts speculated about how high the price might go. Within hours, Novartis revealed the number: $475,000 US.

Right now, the therapy is only available in a few specially selected centres in the U.S. But a Canadian team is trying to come up with an affordable, made-in-Canada version that will be offered as part of the public health care system.

"It's really exciting that this has finally happened. It's a great step forward for cancer therapy," said John Bell, senior cancer researcher at the Ottawa Hospital Research Institute. "Part of what we're trying to do is explore the ways to provide this product to Canadians without having it commercially produced and see if that's a way to make it more affordable to Canadians."

The treatment is called chimeric antigen receptor T cell therapy (CAR-T), and it's complicated.

First, doctors extract a patient's white blood cells and infect the cells with a specially engineered virus that reprograms them to attack cancer. Then the cells are infused back into the patient's body. The therapy is risky because it can trigger a potentially fatal immune response. Patient deaths have interrupted clinical trials of competing therapies.

"This is a technology that in some patients appears to be curative even when they have advanced disease," Bell said. He is the scientific director of BioCanRX, a research network based at the Ottawa Hospital that is funding Canadian CAR-T projects."We hope to start a trial sometime in the next year or early the following year using this exact kind of strategy."

Canadian researchers are also studying CAR-T for use against solid cancer tumours. So far, the therapy has only been shown to work on acute lymphoblastic leukemia (ALL) and other blood cancers.

FDA cracks down on direct-to-consumer stem cell therapies

The U.S. FDA also made headlines this week after cracking down on clinics offering untested stem cell therapy.

"There are a small number of unscrupulous actors who have seized on the clinical promise of regenerative medicine," FDA Commissioner Scott Gottlieb said in a new release announcing measures to increase enforcement. "We have examples where some of these unproven treatments have clearly harmed patients."

The FDA sent a warning letter to one Florida clinic that removes stem cells from fat tissue and re-injects them into the spinal cords of patients suffering from Parkinson's disease, heart disease and other serious conditions.

In a second action, U.S. marshals seized vials of a live vaccinia virus vaccine from a California clinic. The vaccine is not commercially available and it is reserved for people at high risk of smallpox exposure. The clinic was using the vaccine as part of what the FDA called a "potentially dangerous" cancer treatment, mixing it with stem cells and injecting it directly into patients' cancer tumours.

What has emerged are a number of businesses in Canada marketing stem cell treatments for orthopedic indications.- Leigh Turner, bioethics researcher, University of Minnesota

Bioethics researcher Leigh Turner has studied the proliferation of direct-to-consumer stem cell clinics.

"It's an important message that the FDA plans to engage in increased enforcement activity in the direct-to-consumer stem cell space," said Turner, who is an associate professor at the University of Minnesota. But he is concerned that the FDA is understating the problem by saying that there are only a small number of "bad actors."

"That's a misrepresentation of the current state of the direct-to-consumer stem cell market in the United States."

Turner has analyzed the consumer stem cell market and established a database.

• Hundreds of companies sell unapproved stem cell therapies in U.S.

"We found 351 distinct businesses in the United States making marketing claims about stem cell treatments operating a total of 570 clinics. And I've been following the marketplace since then and I can say the numbers are climbing at a rapid rate."

Turner has also studied the Canadian stem cell marketplace.

"What has emerged are a number of businesses in Canada marketing stem cell treatments for orthopedic indications," he said.

In an email, Health Canada said it has only granted market authorization for one stem cell therapy to treat complications from bone marrow transplants in children.

Consumers told to watch for deceptive food labels

"Found a deceptive food label? We want to hear from you." The Canadian Food Inspection Agency sent that tweet in mid-August as a reminder to Canadians to be on the lookout out for food fraud. Is it really made in Canada? Are there hidden allergens? Those are a few violations that Canadians can report.

"It can be a wide range," said Aline Dimitri, the CFIA's deputy chief food safety officer. "In some cases they can say that weight that's on it, I don't think I'm getting as much as I thought I was getting because net weight is also part of the labelling-related issues we look for at CFIA."

Food labelling regulations are a shared jurisdiction between Health Canada and the Canadian Food Inspection Agency. "Health Canada sets the standards and requirements for health and safety when it comes to food," Dimitri said. "We are the enforcement and inspection arm."

Is there too much water, or added sugar in maple syrup or honey? "There are certain products for which we have a standard. We know what sugar has to be there, what's the water content," Dimitri said. "And we know in these cases it can be mislabelled."

But what about misleading nutritional claims? That's the question Dr. Yoni Freedhoff had after he saw the CFIA tweet.

Freedhoff is an Ottawa obesity expert who also writes a food watch blog. After he saw the CFIA tweet, he went shopping and posted a series of food labels that he described as deceptive. But if he had complained to the CFIA, nothing would have happened.

If you put vitamin D and whole grains on the front of your package, it's a health claim without being an explicit health claim.-Dr. Yoni Freedhoff 

"Nothing would have happened because they're not breaking any laws," he said. But he believes Health Canada should be concerned about some of the ways food processors imply their products are healthy.

Freedhoff says certain words have health inferences without making any overt claims.

"If you put vitamin D and whole grains on the front of your package, it's a health claim without being an explicit health claim."

"You see these health claims or health inferences on products that contain a large amount of sugar," he said. "The issue is that ultra-processed foods appear to be problematic to health."

"The harder a package tries to convince you that its contents are healthful, the more skeptical perhaps you should be."

New front-of-label packaging regulations are being considered for foods high in salt, sugar and saturated fat. A Health Canada spokesperson said more consultations on those label changes are planned for this fall.

A Canadian moment in medical history

As part of our summer Second Opinion series, we're featuring great Canadian moments in medical history. This week, meet Brenda Milner, one of the world's leading neuroscientists, who discovered how the brain remembers.

When Milner began her research in the 1950s, the human brain was mysterious, uncharted territory.

Working at the Montreal Neurological Institute with famous Canadian neurosurgeon Dr. Wilder Penfield, Milner studied patients after Penfield operated on their brains to remove lesions or treat epilepsy.

Through that work, Milner systematically established that particular regions of the brain are associated with specific functions. It was foundational research in the emerging field of cognitive neuroscience.

"She's probably most well known for essentially discovering that the hippocampus, a structure deep in the temporal lobe of the brain, is responsible for the formation of memories," said Robert Zatorre, a neuroscientist at the Montreal Neurological Institute who worked in Milner's lab in the '80s.

Her most famous work involved a patient known as H.M., who had his entire hippocampus removed, leaving him unable to form any memories. Milner discovered that even though H.M. failed to remember even meeting her, he was still able to improve his performance on specific tests, without recalling ever learning them. Those experiments proved that there are different memory systems in the brain.

"This is now in every psychology textbook," said Zatorre. "If you take an intro psych course anywhere in the world they will tell you the difference between episodic memory and procedural memory. That was a discovery she made back in the 1970s. She followed this up with lots of work in other domains."

Dr. Milner was born in 1918. At age 99, she is still on faculty at the Montreal Neurological Institute.

These fascinating stories of discovery were selected from the Canadian Medical Hall of Fame, a medical history organization that began in 1994. Every year, six Canadians are inducted. There is a small exhibit hall in London, Ont., but executive director Lissa Foster told us the real hall lives online, with video features for the 125 laureates.

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