“Eat food. Not too much. Mostly plants.”
– In Defense of Food: An Eater’s Manifesto, by Michael Pollen
Diet and Cancer: Is there a link?
Michael Pollen has written extensively about the kinds of food we eat. He targets junk food as a source of internal pollution. His manifesto challenges us to remake the way we eat: “real” i.e. unprocessed food; in moderation, in defense of ideal body weight and the healthy lifestyle that slim promotes; and a diet based on fruits and vegetables rather than meat. Pollen is a journalist, not a physician or scientist. What can the medical and scientific communities contribute to this discussion? How much if any of the discourse is based on evidence? A mantra of modern medicine is that medical decisions and therapeutics should be evidence-based, that is, based on published studies that prove that something works. Is there an evidence-based healthier way to eat, and what health benefits can be accrued? Can we prevent cancer and heart disease by eating differently?
A number of men in recent years have become wealthy and famous promulgating certain diets. Dr. Robert Atkins comes to mind for his low-carbohydrate approach. Barry Sears takes Atkins to task with his Zone Diet and has some data to suggest that athletic performance can be improved in you adhere to his tenets. Is there a diet more scientifically based than either of these approaches?
The entire question of the relationship of food to illness as been revisited by a remarkable scholarly publication entitled The China Study. In this monograph T. Colin Campbell, Ph.D. reviews his lifetime of nutrition research, culminating in a massive study done in China looking at the relationship of diet and illness. China is racially monolithic, with 95% of Chinese Han. Their genetic makeup is more nearly similar than any found in the rest of the world, except possibly in Iceland, where immigration is forbidden. Based on detailed observations and laboratory studies conducted by a large team of scientists throughout that country, he concludes that the tremendous variation in illness in China is a reflection of geographic differences in diet necessitated by the climactic and geographic extremes seen in that country. More to the point of this blog, based on his career-long observations he reviews the relation of diet and illness. Summarizing 400 pages of scholarship: the key poison we ingest is animal protein. The high fat diet, so maligned by nutrition experts for the last fifty years, is deleterious because it is also high in animal protein. What diseases in particular are caused by animal protein? Primarily heart disease and cancer but, according to Campbell, also autoimmune diseases such as lupus. Plant protein causes none of these.
As someone who has read the peer-reviewed medical and nutrition literature for the last forty years, I viewed this monograph with a high degree of skepticism before reading it. I have been converted by the data. The arguments are compelling. Many major academic groups have maligned Dr. Campbell’s work but none has been able to lay a glove on the science. He concludes that we are all too ingrained in our thinking to allow a revolution in nutrition to take hold. His work needs a long look from all of us, but especially from the medical establishment. Bill Clinton adopted the Campbell plant-based diet after his second heart surgery. The rest of us need to open our minds and think seriously about how we eat.