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Dr David Jenkins has been instrumental in the promotion of food as medicine for over 50 years. Educated at Oxford University, Dr Jenkins first developed the glycemic index and the Portfolio diet. His life work has been to provide proof that following a specific diet can replicate results offered by medication, often without the significant side effects.
We spoke to Dr Jenkins, Canada Research Chair in Nutrition and Metabolism at the University of Toronto, to share what experiences guided him to his seminal research and his impact on human health around the world.
Key Take-Aways
Early inspiration
Dr Jenkins began metabolic studies that related to diabetes as an undergraduate at Oxford. His findings were instrumental in opening minds to the concepts of Dr Denis Burkitt which evolved from his work in Africa. Dr Burkitt found that the consumption of unprocessed carbohydrate and dietary fiber meant that people living in Uganda did not suffer from many of the common western diseases. These were the underpinnings of Dr Jenkins' development of the glycemic index.
Early work
Dr Jenkins conducted seminal research in areas investigating metabolic actions of sticky fibers, oats, nuts, and barley. He was hoping that the cholesterol-lowering effects of these foods would multiply and not cancel each other out. This combinatorial action turned out to be the case for multiple ingredients, leading to the development of his Portfolio diet.
The Portfolio Diet
Developed by Dr Jenkins, the Portfolio Diet is recommended by the American Heart and Stroke Foundation and the Canadian Cardiovascular Association, as well as numerous other organizations in the EU and around the world.
Changing food attitudes
Diets have shifted enormously over the last 50 years. People are increasingly interested in plant-based diets. Looking back further, important contributors to understanding healthy diets were the Kellogg brothers and their sanitarium in Battle Creek as well as Sylvester Graham and his vegetarian crackers.
Environmental issues
Environmental awareness has coincided with the rise of a plant-based diet movement and with that, themes of animal welfare and species loss on the planet. All these factors have converged to make for a very strong case for moving in the direction of plant-based diets.
Example of Japan
The Japanese experience has revealed the effects of changing diet. As the Japanese gave up their tofu and vegetables for Kobe beef and fast food, they have experienced declines in their general health, which has deteriorated as they shift from plant-based to meat-based diets.
Historical reliance on plants
A great deal of our gastrointestinal physiology was developed one to two million years ago to process plant materials. This was the diet that the great apes consumed. The Paleolithic diet and our migration to meats was relatively recent. Cholesterol, found in meats but not plants, has thus been a growing problem for Homo Sapiens.
Role of fiber
Fiber is a type of carbohydrate that the body can’t digest. Though most carbohydrates are broken down into sugar molecules, fiber cannot be broken down into sugar molecules, and instead it passes through the body undigested. Fiber helps regulate the body’s use of sugars, helping to keep hunger and blood sugar in check.
Fire
Once humans had control over fire they could more easily eat meat which led to shifts away from an all-plant diet.
Key Quotes
“The planet is the sickest person in the room right now and we've really got to look after the planet. Our main concern should be how we can feed ourselves healthily while preserving and promoting the planet.”
Dr David Jenkins OC MD FRSC FRCP FRCPC PhD DSc
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The opinions expressed in this Nutramedica program are those of the guests and contributors. They do not necessarily reflect the opinions of Nutritional Fundamentals For Health Inc.
This video is intended for licensed or registered health professionals and students of health professions only. These statements have not been evaluated by the Food and Drug Administration. Information contained in these programs are not intended to diagnose, treat, cure or prevent any disease.
