How Eating Too Well Hurts You or: Managing the Diseases of Superabundance
One hundred years ago, most deaths in the U.S. were caused by infections, and life expectancy was in the low to mid-fifties. Before immunizations, childhood infections like diptheria and whooping cough were real threats and workplaces were less safe. One might think a person who ran the gauntlet of childhood illnesses, occupational hazards, and sub-optimal nutrition to reach the seventh or eighth decade would have had a good chance of dying from a heart attack, the most common cause of death today. That was not the case.
Heart attacks were so rare at that time they weren’t even discussed in the 1921 edition of Sir William Osler’s classic textbook The Principles and Practice of Medicine. Dr. Osler, perhaps the greatest physician in history, did discuss angina pectoris, the chest pain caused by a partial blockage of one of the coronary arteries which supply the heart. He noted it was rare but becoming more common, with one case a year expected in large metropolitan hospitals. He described it as a disease of the “better” classes.
The difference between 1919 and 2019 is that more people enjoy a standard of living formerly limited to the “better” classes, particularly in regard to eating the “Western diet.” This diet supplies a larger percentage of calories from long-chain saturated fats. As chefs knew long before scientists, humans prefer a high-fat, meat-based meal to a plant-based one, if affordable. A meat-based diet is necessarily more expensive because an extra consumer is interposed between the human and the origin of the calories, a plant. Therefore, a rising standard of living is associated with a transition from a plant-based to a meat-based diet. Diseases which are more common after this transition can be called “diseases of superabundance”
In China, the percentage of the middle class which consumed a high-fat diet (>30% of calories from fat) increased from 19.1% to 51.0% between 1989 and 1993, which was associated with increased weight, blood pressure, and cholesterol levels. Thus, heart attacks, obesity, high blood pressure, and high cholesterol are diseases of superabundance. While a high standard of living can lead to an unhealthy diet, it also increases red blood cell counts, decreases the prevalence of deficiency diseases like anemia, and increases protein levels in the blood, a measure of nutritional adequacy used clinically.
The importance of superabundance is seen in the decrease in deaths due to heart disease during World War I and II (Figure 1).
Between 1918 and 1919, food consumption in the U.S. decreased by 15%. Deaths due to heart disease decreased from 171.6 per 100,000 in 1918 to 147.9 per 100,000 in 1919. During World War II, meat, lard, shortening, food oils, cheese, butter, margarine, canned fish, canned milk, processed foods, dried fruits, jams, jellies, and fruit butter were rationed by November 1943. The death rate from heart disease decreased from 317.6 per 100,000 in 1943 to 314.6 per 100,000 in 1944. In May 1944, the rationing of meat, except for steak and choice cuts of beef, was discontinued. The death rate from heart disease increased to 320.3 in 1945. Shortages then developed, and meat rationing was restarted on Dec. 31, 1944. Nevertheless, severe shortages developed in the spring and summer of 1945. Even chicken and eggs were in short supply. The death rate due to heart disease dropped to 306.5 per 100,000 in 1946.
The history of dietary recommendations to limit harm from the Western diet and superabundance exposes the lack of insight into how they cause harm. For decades, restriction of dietary cholesterol intake was recommended. Years of investigation eventually revealed that dietary cholesterol does not significantly affect blood cholesterol levels. When data showed that saturated fats are harmful, switching to trans fats was recommended. Years later, it was determined that trans fats are even worse, and laws limited their consumption. In the absence of insight into how the Western diet causes harm, the only possible recommendation is to replace fat-rich foods with grains, vegetables, and fruit. In other words, reverse the transition and return to a plant-based diet.
Studies suggest that trans fats caused 100,000 fatal heart attacks annually, but changes in cholesterol levels accounted for only 30,000. A close look at trans fats reveals how harmful dietary fats, including long-chain saturated fats, cause the diseases of superabundance.
Trans fats were introduced in the United States in June 1911. In 1912, a heart attack was diagnosed in a living patient in the U.S. for the first time. Heart attack deaths increased continuously from 1913 to 1918, when civilian food consumption decreased because of World War I (Figure 2).
Events followed a similar pattern after trans fats were introduced in the United Kingdom in 1909. In 1913, angina pectoris was discussed for the first time in the third edition of the book Diseases of the Heart by the father of British cardiology, Sir James Mackenzie. The continuous rise in heart attacks is estimated to have begun between 1922 and 1924. The delay compared to the U.S. reflects the greater deprivation imposed by WWI.
Despite the noticeable increase in deaths due to heart disease which began shortly after their introduction, suggesting cause and effect, the mechanism by which trans fats cause harm is so subtle that it took decades to recognize they are harmful. Trans fats are made by chemically modifying inexpensive vegetable oils to create a solid fat as a cheap alternative to lard. They are harmful because when they are incorporated into the red blood cells which carry oxygen, they also solidify or rigidify them, decreasing their ability to change shape.
The normal red blood cell (Figure 3) is the most deformable biomaterial known. They change shape to flow more easily like a swimming octopus darting for cover. Also like octopi, they routinely squeeze through small spaces, in this case, the tiniest blood vessels.
The viscosity of a fluid describes how easily it flows. Honey is more viscous than water and flows more slowly. Rigid red cells increase the viscosity of blood. Viscous blood requires more energy to pump and increases wear and tear on arteries. This accelerates the loss of arterial elasticity, a fundamental process in aging.
Arterial elasticity slows blood flow, thereby preventing the biological equivalent of Class 3 whitewater rapids from developing in blood vessels. Disturbed blood flow allows the development of the obstructions which cause heart attacks. Viscous blood is prone to clot when its flow is disturbed, causing these obstructions. Long-chain saturated fats also rigidify red cells and increase blood viscosity. MCT oil or medium-chain triglycerides, a dietary supplement, are liquid at body temperature and do not rigidify red blood cells or increase the risk of heart attacks.
LDL, the bad cholesterol, increases blood viscosity, while HDL, the good cholesterol, decreases blood viscosity. Trans and some long-chain saturated fats also increase blood viscosity by increasing LDL levels, although this has a smaller effect than increasing red cell rigidity. Trans fats also lower HDL levels. Therefore, increased blood viscosity is another disease of superabundance.
In addition to heart attacks, increased blood viscosity plays a role in three other diseases of superabundance: high blood pressure, type 2 diabetes, and metabolic syndrome. Viscous blood requires more pressure to pump, making increased blood viscosity a cause of high blood pressure. After eating, muscles take up and store glucose from the blood, normalizing blood levels. Viscous blood does not circulate as well as normal blood, prolonging the time that blood glucose levels are elevated after eating.
All of the changes brought by the Western diet, including stiff red cells, increased blood counts, decreased prevalence of anemia, and increased blood protein levels, increase blood viscosity. For this reason, and because it causes several diseases of superabundance, elevated blood viscosity is the fundamental disease of superabundance.
The trans fat content of food was limited to 2% of total fat in Denmark in 2003. In the next three years, deaths due to cardiovascular disease dropped by an average of 14.2 per 100,000 people per year. That finding and the effect of rationing show that variations in diet alter the death rate due to heart disease after a surprisingly short time, belying received wisdom that heart disease begins in infancy. In reality, the risk of a heart attack primarily reflects a person’s current blood viscosity. As Dr. Wiliam Dock wrote in his commentary to Dr. Osler’s textbook, “What had concerned Osler about diet was the precipitation of attacks [of angina pectoris] or of sudden death, by large meals of rich food.”
A physiologist named Ancel Keys was one of the first scientists (after Dr. Osler) to realize that superabundance could cause disease when he noticed that heart attacks were more common in middle-aged businessmen in Minnesota than the malnourished population of post-WWII Europe. He popularized the idea that cholesterol causes heart disease in the early 1960s, another example of a mistaken mainstream notion. Later work showed that diabetes, high blood pressure, smoking, and physical inactivity are stronger risk factors than cholesterol. Cholesterol also plays a smaller role in determining blood viscosity than the stiffness and number of red blood cells and the amount of protein in the blood.
Short of eating a plant-based diet, which many find unappetizing, the most effective intervention for the diseases of superabundance is donating blood. This makes perfect sense: the Western diet elevates blood viscosity, and blood donation reduces it. In the short run, blood viscosity decreases because the volume of donated blood is replaced by plasma, which is much thinner. Because new red cells are more pliable than the older cells they replace, blood donation also produces a more sustained decrease in viscosity relative to baseline. Red blood cells become progressively stiffer throughout their lifetime, which is 100 to 120 days, so repeat donation is necessary to achieve a sustained reduction in blood viscosity. The American Red Cross permits the donation of one unit every 56 days.
In a Finnish study, blood donors had an 88% decrease in the risk of a heart attack. This result has not been reproduced because studies of blood donation to date have assessed the effect of decreased iron stores on heart attacks, and the frequency of donation was too low to produce a sustained reduction in blood viscosity. If the Finnish result is not a fluke, blood donation is more effective in preventing heart attacks than statins, which have inconsistent effects on blood viscosity. Statin therapy prolongs life by an average of only 3.2 days.
Therapeutic phlebotomy, the removal of blood for health reasons, and blood donation are very safe if the subjects meet the general requirements to donate safely. The downsides are minor. Some donors will eventually require supplemental iron, which can be supplied in a multivitamin. Finding an adequate vein could be a problem in some potential donors.
In light of the Finnish results, one might wonder why the American Red Cross doesn’t publicize the health benefits of blood donation to recruit donors, given the constant need for blood for transfusion. It doesn’t because the Red Cross maintains that the safest blood is from an altruistic donor, and donors might be tempted to overlook conditions or behaviors which might make their blood less safe in order to benefit. Other collection agencies and organizations do publicize the benefits.
Therapeutic phlebotomy has been criticized for being barbaric or archaic, and best suited for restoring the balance between blood, black bile, yellow bile, and phlegm. Unfortunately, mainstream medicine has a history of being slow to accept new ideas and breakthroughs, as shown by the tragic story of John Lykoudis, M.D. This Greek physician cured approximately 30,000 patients of peptic ulcer disease with antibiotics decades before that therapy became mainstream. For non-medical reasons, the medical establishment rejected his ideas. The suffering of millions increased because of this closed-mindedness. The lesson from this episode is not to wait for the endorsement of the medical establishment to try a very low-risk intervention such as blood donation.