An Apple a Day
By Chris Atack
We’ve all heard the aphorisms, but what role does nutrition really play in keeping the doctor away? Researchers in the School of Dietetics and Human Nutrition are delving into communities across Quebec, from First Nations towns on the shore of James Bay to cancer patients in Montreal hospitals, to better understand how our eating choices can prevent disease.
In the general consciousness, there’s an inextricable, yet rather hazy, link between health and food. Starve a fever. Feed a cold. And lest we forget, the mythical apple and its physician-repelling properties.
But is there scientific truth underpinning these folksy maxims? Researchers from McGill’s School of Dietetics and Human Nutrition, founded in 1908, are taking a serious look at the relationship between our health and what we eat.
“Disease prevention requires good nutrition,” says Kristine Koski, Director of the SDHN. “Some foods may actually protect us from illness, while deficiencies or excesses of other nutrients underlie disease processes.” SDHN researchers are studying the effects of nutrition on a variety of populations in order to learn more about the complex relationship between diet, disease and good health—and they’re taking that knowledge back into the community to help people across Quebec and Nunavut understand and achieve the nutritional balance needed to maintain good health.
Obesity, lack of exercise and a high-fat diet are thought to be the major causes of type 2 diabetes, a disease reaching epidemic levels in the Cree communities of northern Quebec; in 2002, 15 per cent of the Cree population of James Bay had diabetes—three times higher than the incidence of occurrence in southern Quebec. Diabetes isn’t as prevalent in Nunavut, but Inuit communities want to engage in prevention efforts before it is too late.
These northern communities are isolated and small; the largest has about 4,000 residents and is linked to its nearest neighbour by 100 kilometres of partially paved road. High transportation costs and the short shelf life of fresh produce therefore make refined carbohydrates cheaper than vegetables and fruits. Inflated food costs are most pronounced in Nunavut, where it typically costs $300 to feed a family of four for a week—that’s double the cost of the same market food items in Montreal. Factor in a high rate of unemployment and poverty in the north, says Grace Egeland, Canada Research Chair in Environment, Nutrition and Health and researcher with the Centre for Indigenous Peoples’ Nutrition and Environment (CINE), “and it’s clear that you can afford the pasta but not the meatballs or the fresh salad greens.”
Since 2005, Egeland has been working with Inuit communities and the Cree Board of Health and Social Services of James Bay. “We’re looking at the extent of traditional and market food consumptions, and the per cent of energy people are deriving from nutrient-poor, energy-dense food,” says Egeland. “Earlier surveys showed traditional foods—moose, fish, fowl—are consumed more by individuals over 40. People under 40, especially children, eat far less traditional food and more junk food. Younger people are more likely to adopt a modern lifestyle and diet, and less apt to take part in activities such as hunting and fishing.”
To measure junk food intake, researchers measured blood levels of trans fats, usually associated with chips, fries and baked goods containing hydrogenated oils. “People consuming more junk food had more trans fats in their blood,” explains Egeland. “This is worrying, because trans fats are a risk factor for cardiovascular disease, and possibly for type 2 diabetes.”
Egeland’s research has led to interventions—actions to modify unhealthy habits—designed in consultation with local communities. One such intervention builds on native people’s strong oral tradition by using local radio to engage in health-promoting storytelling. “Community leaders see radio as a key medium for disseminating culturally appropriate messages about nutrition,” says Egeland. “So, for example, elders talk on radio about seaweed and plants and berries. Later in the broadcast, these traditional food items are discussed from a modern nutritional perspective that can guide healthy market food choices.”
Type 2 diabetes is also a worry closer to home. As Scientific Director of the Kahnawake Schools Diabetes Prevention Project, Katherine Gray-Donald is focusing on preventing the disease in children living in the Mohawk community, located 15 kilometres southwest of downtown Montreal. Adult residents of Kahnawake already have more than twice the incidence of type 2 diabetes found in the general population—and there’s a risk of even higher numbers for the next generation of adults.
“The KSDPP is a community-research partnership aimed at finding ways of improving diet and physical activity amongst youngsters,” says Gray-Donald. ”These children are getting heavier and this has serious potential health consequences, because obesity is strongly linked to type 2 diabetes. Some years ago, the community realized the threat and said, in essence, to health care professionals, ‘Help us protect our children.’ Our research is aimed at doing just that.” The KSDPP has implemented several interventions, such as a daily 20-minute walk, that have greatly increased physical activity in the schools, and has initiated a ban on serving unhealthy foods in cafeterias.
Gray-Donald’s other major research project looks at the other end of the age spectrum. The five-year NuAge study is Canada’s first longitudinal, in-depth investigation into how eating habits impact aging. The research team hopes to learn how improved nutrition supports “successful” aging. Three years ago, the research team enrolled nearly 1,800 independent-living Quebecers (ages 68 to 82) from Montreal and Sherbrooke. At the outset, the participants underwent extensive nutritional evaluations, including dietary intake, body fat measurements and blood samples. Over the course of five years, they’ll participate in an annual, extensive half-day battery of tests, plus regular phone surveys, designed to measure changes in strength, weight loss, cognitive abilities and autonomy.
For the elderly, losing weight tends to equate to losing muscle—making them weaker, more liable to fall, and less able to participate in physical activities (which contributes to further decline)—which is why Gray-Donald is particularly interested in causes of unexplained weight loss. “In the first year, 9 per cent of our group lost more than 5 per cent of their body weight,” she says. “Some were sick, but others weren’t. We’re looking at what changed in their diets, what happened in their lives during the period of weight loss, and trying to understand why weight loss occurred.”
Hope Weiler, Canada Research Chair in Nutrition, Development and Aging, is working with NuAge to establish the role of vitamin D in healthy aging. The project is just one part of Weiler’s series of pan-generational vitamin D studies, and indicative of a larger trend toward studying this long-ignored vitamin. (Vitamin D is traditionally associated with childhood rickets, and little else, but recent research suggests that deficiencies may significantly contribute to cancer, multiple sclerosis, juvenile diabetes, influenza and
osteoporosis.) In August 2007, Weiler will join Grace Egeland for a CINE study called Qanuipitali (“How about us, how are we?”). Travelling on the Canadian Coast Guard ship Amundsen, researchers will conduct an unprecedented survey of health in remote Inuit villages; Weiler’s research will focus on the vitamin D status of children and women. Working with Dr. Celia Rodd, Director of Pediatric Endocrinology at the Montreal Children’s Hospital, Weiler is also conducting a pivotal study in infants to see how much vitamin D is needed for optimal health outcomes (such as bone mineralization). Over a period of 11 months, growth measurements, X-rays and blood samples are used to measure how the infants’ bones are progressing. The researchers hope the study, which began in March 2007, will offer the first clear definition of vitamin D requirements; the results may be used to revise Health Canada’s policy for vitamin supplementation in healthy infants.
In October, Weiler will begin a six-month pilot study with Ste. Anne’s Hospital for Veterans (in Sainte-Anne-de-Bellevue, in Montreal’s West Island) to determine the correlation between patients’ levels of vitamin D and the risk of mortality and functionality. During the summer months, vitamin D is predominantly derived from sun exposure but, she explains, “as people age, they may not be outside as much. And anybody who must stay inside—such as people who are hospitalized—rely heavily on diet to get vitamin D.” During the Ste. Anne’s study, researchers will monitor levels of 25-hydroxy vitamin D in the blood of patients (most of whom are in their 80s) hospitalized for various chronic health conditions. “We’ll be studying the relationship between nutrition, seasonal factors and vitamin D,” Weiler explains. “We hope to correlate vitamin D levels with functioning and strength. Some research suggests there is a relationship between vitamin D levels and patients’ ability to carry out daily activities, and also their muscle strength—but we’re not sure why, or how strong the link is. Based on what we learn, we’ll design an intervention to improve vitamin D status and health.”
Another SDHN researcher, Linda Wykes, is conducting her own hospital study, with an eye toward using nutrition to help speed recovery from surgery. The William Dawson Scholar is exploring innovative interventions which incorporate both anesthesia and intravenous feeding. “We call ourselves the NASTY team, which is short for nutrition, anesthesia and surgery,” says Wykes. “Our team has done multiple studies in cancer patients at McGill University Health Centre hospitals, and our results have helped us design a two-pronged intervention for this group.”
The body responds to the stress of surgery by secreting stress hormones and breaking down proteins, which can lead to muscle loss and impaired functions of the immune system—which, in turn, delays recovery. To prevent this response, Wykes and her colleagues give patients a little something extra. Two things, actually: epidural anesthetic (during and after surgery), and an intravenous meal of glucose and amino acids. The drugs ensure pain signals never reach the brain, stemming the flow of stress hormones and allowing the body to make better use of the nutrients. Patients receiving this intensive approach actually have a net gain of body protein after surgery, and meet discharge criteria sooner than those treated using standard protocols.
“Nutrition is a key concern, at any age and in every population, as more and more research shows,” Koski says. “It’s a topic the medical community is now taking very seriously indeed. As our school approaches its centenary in 2008, you might say nutrition is a science whose time has come.”
Funding for these research projects includes the Canadian Institutes for Health Research, the Cree Board of Health and Social Services of James Bay, the Niskamoon Corporation, the Social Sciences and Humanities Research Council, the Government of Canada’s International Polar Year Program and Dairy Farmers of Canada.