We passed through endless miles of pristine mountain forests, which were hugged at the rugged coastline by an almost cobalt blue Atlantic Ocean. The sky, only a shade lighter, was cloudless. My friend and cowriter, Judy Calmes, and I were driving up the coast to the little seaside village of Camden, Maine. There, Dr. Benjamin Spock and his wife, Mary Morgan, summer residents of Camden, had asked me to work with them as a consultant on revisions for an all new edition of Baby and Child Care.
As we drove along this beautiful coast, nothing as far as our eyes could
see, would intimate the concern of a newly organised group of Maine citizens,
The Dioxin Coalition. This band of environmentalists, public advocates, and
business leaders were concerned that dioxin, an industrial byproduct, was posing
a new and serious health risk to the citizens of their state.
The earliest work on dioxin, done by my friend and colleague, Dr. T. Colin Campbell, in 1963, identified it as one of the most powerful toxins on earth-an ingredient of Agent Orange, which was used in Vietnam to defolianate forests. It wasn't until 1994 that the Environmental Protection Agency (EPA) took a serious look at this chlorinated compound. In a 2,000 page document the EPA stated that this waste product of such industrial processes as paperbleaching and the burning of plastics, was not only a toxin, but also a probable carcinogen similar to formaldehyde and chloroform.
According to the report, it has almost certainly been accumulating for years in the tissues of fish and larger animals. Furthermore, it's present in the tissues of nearly every American who consumes animal based foods.
As expected, dioxin is concentrated most heavily in larger animals, and once there it's usually permanent, not readily detoxified or excreted by metabolic processes.
Moreover, continued exposures lead to more absorption. One of the few ways dioxin is released from the body - other than prolonged fasting - seems to be through lactation. Consequently, another source of this compound is the milk of cows, which eat dioxin contaminated grass, weeds, and grains.
And if a mother is breastfeeding, stored dioxins are to some degree released to her child. These amounts in breastmilk are most likely very small, probably with little risk, but that obtained by eating red meat, fish, and dairy products is significant and cumulative. Obviously, people eating fish from a river where a paper mill discharges water are probably at even greater risk. Maine, the Coalition says, is a good study model, since it is the second largest paper producing state and burns 30 percent more household trash than other states. Not unexpectedly, trash and medical incinerators have been shown to emit ash heavily laced with this chemical. Interestingly, dioxin, along with other manmade heavily chlorinated chemicals polychlorinated bifenals (PCB) and dichlorodiphenyl trichloroethane (DDT)-have an estrogenlike effect upon tissues. This may explain at least one of the mechanisms of the apparent relationship of animal based foods to the hormonedependent cancers of the breast, prostate, and testes in industrialised Western countries.
But just how important is dioxin as a carcinogen? Animal fat and animal protein, without industrial contaminants, apparently cause cancer. In the rural areas of China, sharp differences in cancer incidence are found between villagers consuming low and high animal fat and protein diets, where no known industrial pollutants exist. I suspect that natural animal protein and fat account for the greatest majority of foodrelated cancers. Dr. Campbell agrees. "In my view," he wrote in December '95 in his editorial for New Century Nutrition, "no chemical carcinogen is nearly so important in causing human cancer as animal protein."
But dioxin is everything we thought it was, and probably much more. As a toxin it may lead to neuropathies, muscle weakness, and even paralysis. As a carcinogen, it's much more subtle and poorly understood. With very few pathways of detoxification or excretion, it's effects are almost certainly cumulative and in many cases permanent. and while it's un certain how much dioxin one can tolerate without serious consequences, it's obvious that this compound should be avoided wherever possible. Many of my patients have become alarmed after reading newspaper accounts about dioxin. But escaping the slow and progressive absorption of this chemical, as it turns out, is far simpler than most would have expected. Dr. Beverly Pagan, senior staff scientist at Jackson Laboratories in Bar Harbor, Maine, reminds us that dioxin cannot be absorbed by inhalation from the air, and so can be avoided if people eat low on the food chain. "Those who follow a vegetarian diet," she says, "usually don't have to worry about dioxin." Vegetables, fruits, and grains do not contain concentrated amounts of this compound. This, along with the thousands of cancerinhibiting phytochemicals in these foods, all working in concert, once again reminds us that human nutrition is really not that complex. A plantbased diet of whole foods does it all for us. Calories, grams of fat, grams of protein, vitamins, minerals, phytochemicals, and antioxidants are all there in the right amounts.
The only things missing or deficient are animal fat and protein, and of course, dioxin.
Charles R. Attwood, M.D., F.A.A.P., a physician and writer, based in Crowley, Louisiana, is the author of Dr. Attwood's LowFat Prescription For Kids (Penguin 1-800-253-6476) and the audio series, The Gold Standard Diet: How to Live to be 100 (Knowledge Products 1-888-TOP-DIET).