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The China Study 7 – Diabetes

Posted by tinako on December 16, 2009

This posting continues my discussion of Dr. Campbell’s book, The China Study.  I am just a reader, not a doctor.  If you find this interesting or want more of his sources (23 in this chapter), get the book!

Dr. Campbell gives a great explanation of diabetes: “Almost all cases of diabetes are either Type 1 or Type 2.  Type 1 develops in children and adolescents, and thus is sometimes referred to as juvenile-onset diabetes,” accounting for 5-10% of all diabetes.  “Type 2, which accounts for 90-95% of all cases, used to occur primarily in adults age 40 and up, and thus was called adult-onset diabetes.  But because up to 45% of new diabetes cases in children are Type 2 diabetes, the age-specific names are being dropped, and the two forms of diabetes are simply referred to as Type 1 and Type 2” [p.145].

Both types have a problem with glucose.  Normally, we eat food, it’s digested, and glucose is released.  It enters the blood, and insulin is produced in the pancreas to deliver it around the body.  This process breaks down in diabetes.  Type 1 diabetics cannot produce enough insulin because their pancreas is not functioning due to autoimmune disease (autoimmune diseases are discussed elsewhere in the book).  Type 2 diabetics can make insulin but it doesn’t work – the body doesn’t pay attention to it.  In both types the result is that the glucose is not distributed and rises to dangerous levels in the blood.  Diabetes is diagnosed when the glucose “spills over” into the urine.  All this sugar in the blood leads to many serious complications.

There is no cure for diabetes.  Diabetics can maintain a reasonably functional lifestyle, but the current drugs do not treat the cause of the disease, so diabetics are in for a lifetime of costly treatment.  The U.S. total is $174 billion per year.

It has been known for hundreds of years that diabetes is not evenly distributed throughout the world, and that populations with low rates eat a different diet than populations with high rates.  There is an incredibly counterintuitive chart on p. 148 showing diets and diabetes rates, 1925, with these studies [*, endnote 1] as sources.  It shows 6 countries, their percent of calories from carbohydrates going from about 50% in the U.S to about 85% in Japan, fat going from almost 40% in the U.S. to about 5% in Japan, and diabetes death rates going from .02% in the U.S. down to about .0025% in Japan.  These are smooth data lines running though all six countries, showing the diabetes rate falling as fat goes down and carbohydrates go up.  The reason I found this surprising is because I thought carbohydrates were the bad guys for diabetics.

So what’s going on?  We get our calories from protein, fat, carbohydrates and alcohol.  Looking only at the fat and carbs, in the U.S we were getting a lot more of our calories from fat, and a lot fewer from carbohydrates, than other countries.  These patterns represent the difference between a plant-based diet and an animal-based diet.

Another study verified this, bringing animal protein into the data set.  High carb countries had much lower diabetes rates, and Urguay, the country with the highest diabetes rate, had a typical western diet, high in calories, animal protein, total fat and animal fat.  The countries with lower diabetes rates particularly ate a lot of rice.  They enlarged their study and found that diabetes was most strongly correlated with excess weight and cholesterol.  Remember what was discovered about cholesterol, that it is more strongly correlated with animal protein than with dietary cholesterol and saturated fat.

Of course, these cultural studies can be chalked up to genetics or physical activity.  So researchers studied Seventh Day Adventists.  Due to religion, about half of them are vegetarian.  Very few are vegan, and so they still get many of their calories from animal products.  But even the meatiest among them eat much less meat than the average American, about five servings per week.  So this group is interesting to study because researchers can compare moderate vegetarians to moderate meat eaters.  This isn’t a big difference, but even so the vegetarians are much healthier than the non-vegetarians, with half the rate of diabetes and obesity.

In another study, researchers looked at U.S. sons of Japanese immigrants, who had 4 times the diabetes rate as similar-aged men who stayed in Japan.  The ones who developed diabetes also ate the most animal protein, animal fat, cholesterol, and total fat, and had excess weight.

Dr. Campbell lists the results of four other studies, showing variously that increased fat increases Type 2 diabetes; the Type 2 diabetes rate in Japanese children has tripled in 25 years, along with increased consumption of animal protein and animal fat; diabetes rates dropped during WWII rationing in England and Wales, when fiber and grain intake went up and fat intake went down.  Rates went back up in 1950 when people returned to eating more fat and sugar and less fiber; of 36,000 non-diabetic women in Iowa followed for 7 years, those less likely to get diabetes were those eating more whole grains and fiber.  These studies show that “both across and within populations, high-fiber, whole, plant-based foods protect against diabetes, and high-fat, high-protein, animal based foods promote diabetes.

These are all observational studies.    How about some controlled studies, where researchers change the diets of diabetics or pre-diabetics?  Dr. James Anderson put 25 Type 1 diabetics and 25 Type 2 diabetics through a diet change.  None of them were overweight and all were taking insulin shots.  First he put them on the American Diabetes Association diet for one week, then switched them over to his experimental “veggie diet.”  This was a moderate diet of whole plant foods but allowing the equivalent of a cold cut or two of meat per day.  After three weeks, the Type 1 diabetics, who you will remember cannot produce insulin, reduced their insulin medication by 40%, lowered their cholesterol by 30%, and improved their blood sugar dramatically.  All but one of the Type 2 diabetics was able to discontinue their insulin medication within a matter of weeks. One man, a 21-year diabetic, had been taking 35 units per day, and was able to discontinue his medication after eight weeks.

In another Anderson study of 14 diabetics, patients lowered their cholesterol by 32% in under three weeks by diet alone.  It remained low for 4 years while on the diet.

Another study, at the Pritkin Center, prescribed exercise and a low-fat plant-based diet to 40 diabetic patients.  34 were able to discontinue all medication after 26 days.  Benefits continued for years as the diet was adhered to.  Remember, this is an “incurable” disease.

Want some more?  Here is a meta-review of 11 diabetic-diet studies, all of which resulted in improved blood sugar and cholesterol.  Another study placed 3,234 non-diabetics with elevated blood sugar into three different groups.  Group one received standard dietary information and a placebo.   Group two received the same dietary information and the drug metformin, and the third group received lifestyle intervention, with a moderately low-fat diet and exercise plan to lose at least 7% of their weight.  After three years, group three had 58% fewer diabetics than group 1; group 2 had reduced the number of cases by only 31%.  Both treatments worked, but clearly the diet was more effective.  Dr. Campbell also points out that the diet would solve a lot of other health problems as well, whereas the drug would not.

Dr. Campbell ends this section by saying it is too bad that Dr. Anderson says his low-meat diet, while effective, is “impractical for home use for many individuals.”  So it is more practical to have a lifelong condition that can’t be cured by drugs or surgery, and which often leads to heart disease, stroke, blindness, or amputation, and which might require you to inject insulin into your body every day for the rest of your life… than to change your diet.

Next – Studies I’m not interested in.

Endnotes:

1. Himsworth, HP, “Diet and the Incidence of Diabetes Mellitus,” Clinical Science 1935

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