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With a heavy heart, we share the news of Dr. John McDougall’s passing. A visionary physician and author, beloved husband, father, grandfather, brother, mentor and friend, Dr. McDougall died peacefully at his home on Saturday, June 22nd, at the age of 77.

Multiple Sclerosis: The Cause

The fundamentals of the McDougall Program are simple yet often difficult to implement. Learn about the 12-Day McDougall Program - a life-saving medical program that empowers participants with the knowledge and practical steps needed to live a vibrant, long life. For questions on whether a change in diet can help your ailment, learn more about our consultations.
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Also see Multiple Sclerosis in Hot Topics

When the subjects of multiple sclerosis and diet are mentioned in the same sentence, the reaction from most health professionals is to dismiss the connection as being absolutely ridiculous. How could something as simple as what we eat be involved with such a mysterious disease as multiple sclerosis? Most professionals are expecting that the answer will be found, someday, by some “high tech,” high profit, research in viral or immunological investigations.

However, when I have asked some doctors and dietitians, who are supposed experts in the field of multiple sclerosis, to support their contention that diet has nothing to do with the cause or cure of the disease, they have consistently been unable to give me a scientifically supported answer. In my research, I have yet to see a study which says that a sensible diet will not help victims of multiple sclerosis. In fact, the scientific evidence published to date provides evidence supporting the benefit of diet for victims of this debilitating disease. Is the evidence offered so far adequate for you to take action?

World-wide, the incidence of multiple sclerosis crosses all racial barriers and geographical boundaries. Multiple sclerosis is common in Canada, the United States, Northern Europe; it is rare in Japan, elsewhere in Asia, and in Africa. When people migrate from a country of low incidence of multiple sclerosis to a country of high incidence, their chance of getting this disease increases as they learn new ways to live and to eat. Many investigators have looked into the environmental factors that would account for the differences in disease incidence among different populations.

The culprit appears to be the strongest contacts we have with our environment–the foods we eat each day. Does this surprise you? After all, “we are what we eat.” One general observation that can be made is that countries with lots of cases of multiple sclerosis are also wealthy countries. An exception is the wealthy country of Japan. But there is an explanation for this: even though the Japanese have money, stress, pollution, and the smoking habits characteristic of people in other industrialized nations, their traditional rice-based diet is more characteristic of the foods consumed in poorer nations.

A diet filled with rich foods assails us with many different substances that may be related to diseases that trouble us, but the animal fats, especially those from dairy products, have been most closely linked to the development of multiple sclerosis. One important theory proposes that cow’s milk consumed in infancy lays the foundation for injuries to the nervous system that appear later in life. Cow’s milk contains one fifth as much of an essential fat, called linoleic acid, as does human mother’s milk. This essential dietary-derived substance helps to make up some of the chemical components in nervous tissues. Children raised on a linoleic acid-deficient, high-animal fat diet, as are most kids in our modern affluent society, quite possibly starting life with a damaged nervous system, susceptible to insults and injuries in later life. Analysis of brain tissues has shown that persons with multiple sclerosis have a higher content of saturated fats than do people who do not have this disease.

The factors that can precipitate the attacks of multiple sclerosis in mid-life are suspected to be viruses, or allergic reactions, and/or disturbances of the flow of blood to the brain. Most likely, whatever factor may be involved, there is a close tie to the circulatory system, because the areas of injury sustained by the nerve cells surround blood vessels.

One theory holds that the primary injury to a person with multiple sclerosis is caused by a decrease in the supply of blood to tissues in certain parts of the brain. Dietary fats in the amounts consumed by Americans can and do cause a decrease in flow of blood to many kinds of tissues, including those in the brain. Fats from the gut enter the blood stream, coat the red blood cells, and thereby inhibit the normal property of their membranes that keep the cells from sticking together. Therefore, blood cells coated with fats do stick together, forming clumps that slow the flow of blood to vital tissues. In many blood vessels the clumping and sludging become so severe that the flow of blood stops entirely, and the overall oxygen content of the blood falls. Tissues deprived of nutrients and oxygen for even short periods of time will die. Could something as basic as this be a factor in the attacks that destroy nerve cells in victims of multiple sclerosis?

A low fat diet reduces frequency of attacks. During World War II civilian people in Western Europe were under tremendous stress, as their countries were occupied by one enemy or another, yet doctors observed that patients with multiple sclerosis needed 2 to 2 1/2 times fewer hospitalizations during this war period. At that time all kinds of foods were scarce, and the civil populations could no longer afford to eat their meat-producing animals. Instead, they ate the grains and vegetables that earlier had nourished their cows, chickens, and pigs. The overall result was a significant reduction in the amounts of animal products they ate, and, therefore, in the amounts of animal fats they consumed.

Following publication of these observations about improvement in the well-being of multiple sclerosis patients (as well as of patients suffering from other diseases; such as atherosclerosis), Dr. Roy Swank, former head of the University of Oregon’s Department of Neurology and presently a practicing physician at the Health Science Center of the University of Oregon, began treating his patients with a low-fat diet. Dr. Swank can draw now upon more than thirty-five years of experience in the use of a low fat diet for more than three thousand multiple sclerosis patients. His results are unchallenged by other studies, and unmatched in effectiveness by any other treatment for this crippling disease.

The course of this disease usually leads to a progressive decline in the patient, reducing him to existence in a wheelchair (or worse) likely by the end of 10 years. However, according to his landmark research published in the Archives of Neurology, Dr. Swank reports that if this disease is detected early, and if attacks have been few and the patient adopts a low-fat diet, then he has a 95% chance of remaining in the the same condition, or even for improvement over the next 20 years. Even people who have had multiple sclerosis for a long time, and have already suffered severe neural damage, will slow its progress with a change to the low-fat diet.

The healthiest diet is based on low-fat vegetable foods. In published research in the December 1988 issue of the American Journal of Clinical Nutrition, Dr. Swank presented data, from patients studied for more than 34 years, showing the importance of strict dietary practices for multiple sclerosis patients. First, he and his colleagues found that every incremental increase in intake of saturated fats (that is animal fat) is associated with a corresponding increase in frequency of attacks. Second, to arrest the disease the diet must contain as little fat as possible, or approximately 7% fat. Those on a low fat (17 g) diet lived almost 3 times as long and generally improved their level of function. On a high fat diet (42g) the average patient went from active to wheel chair and bed ridden (or dead) over the three and a half decades of study. Thus the threshold of safety can be reached with the diet taught by the McDougall Program. A diet consisting of starches, vegetables and fruits contains only 5 to 10% total fats, and less than half of this amount is represented by the saturated fats. Obviously, this is the ideal diet for patients suffering from multiple sclerosis. And it is a practicable diet, as well as a palatable one.

Dr. Swank has added a small amount of vegetable oil (polyunsaturated) to his diet, hoping that the poly-unsaturated fats may make the diet more palatable, if not more helpful. However, studies that simply added oils high in essential fats, such as linoleic acid, to the diet have shown conflicting results concerning any benefit. Therefore, I believe the low-fat content of his diet (not the added vegetable oil) is the explanation for his successful treatment of people with multiple sclerosis. Dr. Swank himself also inclines toward the view that the lowest level of saturated (animal) fats is the critical issue. Furthermore, other health reasons prevent me from adding vegetable oils to a person’s diet. At the very least, these oils contribute calories that may lead to obesity, and, at worst, they may promote cancer and gallbladder disease.

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    When a doctor recommends a therapy, he or she must weigh the benefits of it with the risks it entails. The dietary change I recommend, as far as I can tell, offers many benefits without any evident risk: it has no adverse consequences. In relatively well people, it promotes weight loss in the obese, and relieves constipation, and at the same time cuts the food bill by about 40%. Actually, these changes are in line with recommendations from national health organizations. The American Cancer Society, the American Heart Association, and the Surgeon General of the United States join in making these recommendations to the nation’s people to eat less fat, meat, and dairy products and more whole grains, vegetables, and fruits.

    The results of this sensible dietary treatment have been very gratifying for my patients (and for me), not only because the progress of the multiple sclerosis has been halted in most cases, but also because their health is unquestionably improved. And no one will deny that, these unfortunate people need every bit of help they can get.

  • References

    Agranoff, B. Diet and the geographical distribution of multiple sclerosis. Lancet 2:1061, 1974

    Alter, M. Multiple sclerosis and nutrition. Arch Neurol 31:267, 1974

    Swank, R. Multiple sclerosis: twenty years on low fat diet. Arch Neurol 23:460, 1970

    Swank, R. Multiple sclerosis: the lipid relationship. Am J Clin Nutr 48:1387, 1988

    Elian, M. Multiple sclerosis among the United Kingdom-born children of immigrants from the West Indies. J Neurol Neurosurg Psychiatry 50:327, 1987

    Swank, R. Multiple sclerosis: a correlation of its incidence with dietary fat. Am J Med Sci 220:421, 1950

    Bates, D. Polyunsaturated fatty acids in treatment of acute remitting multiple sclerosis. Br Med J 2:1390, 1978

    Millar, J. Double-blind trial of linoleate supplementation of the diet in multiple sclrosis. Br Med J 1:765, 1973

    Paty, D. Linoleic acid in multiple sclerosis: failure to show any therapeutic benefit. Acta Neurol Scandinav 58:53, 1978