Are Chemicals Responsible for Obesity?
Readers of this blog are aware of my love/hate relationship with Men’s Health. Some months, they will publish a dazzling article such as “The Cure for Diabetes” or the “Thin Man’s Diabetes” which squarely put the blame on refined and easily digestible carbohydrates. But then, they will follow that up with months and months of repeating the conventional wisdom which claims we’re all fat because we eat too much and move too little. If it were that simple, why would anyone be fat? Surely a person would correct the situation and simply eat less and take the stairs more often. In fact, that’s what most of you do. However, you know far too well that this doesn’t work very well for you or too many people that you know. You try to mimic the behaviors of those who have lost and kept it that way, but it hasn’t really worked for you or anyone you know because no one seems to understand why people are successful when they are.
In Men’s Health, they suggest that perhaps an array of chemicals are to blame. The problem with these theories is that the obesity epidemic predates the widespread use of these substances and if one were to include all of the relevant observations over these years, one can easily rule out competing hypotheses. To quote Taubes, any hypothesis that purports to explain the emergence of obesity must so explain obesity in any population at any time, not just the increasing obesity of recent decades. These chemicals would not describe the Pima Indian whom I’ve written about in the past.
Since 1960, researchers have been trying to explain the obesity epidemic in the United States and elsewhere. To that end, they surveyed thousands of people as part of the National Health Examination Nutrition Surveys (NHANES). According to this and other surveys, throughout the 1960s and 70s, 12-14 percent of Americans were obese. This figure rose by 8 percent in the 1980s and early 1990s and another 10 percent by the turn of this century. Obesity remains more common among African Americans and Hispanics more than whites or any other ethnic groups and the most common among these are the poorly educated and lowest income.
So with this backdrop, we are to supposedly understand that these people eat more and move less than other groups, although the poor tend to work at more menial, physically demanding jobs, they walk more, they eat less, etc. Psychologist Kelly Brownell, director of the Yale Center for Eating and Weight Disorder coined the term “toxic environment” to describe an American culture that “encourages overeating an physical inactivity.” From this viewpoint, obesity is more the rule rather than the exception. It is nothing short of a miracle that anyone survives such a fate.
It is not difficult to believe this theory because people view modern conveniences such as video games, fast food and computer terminals as the reason people are not as physically active as they used to be. They don’t see children out playing in the streets as they once did so therefore this much be the reason.
However, obesity has always been most prevalent among the poor and thus presumably harder working members of society. In developed nations, the poorer, the less healthy they are likely to be. The NHANES study only confirmed this. In 1965, Albert Stunkard and his colleagues noted that over their New York Hospital survey of 1,660 people, obese women were found six times more often at the lowest socioeconomic level than at the highest. Some 36 percent of the poorest were obese as opposed to 16 percent of the middle-income followed by only 5 percent of the rich. Poor men were twice as likely to be obese as the rich. All of these facts are suitable to question the notion that people are fat because they are sedentary or that they eat too much. They do eat a higher amount of cheap carbohydrate foods however. When people have food drives to help the poor, the send them primarily carbohydrates and wonder why their health is so bad.
In 1997, we find that University of Alabama Nutritionist Roland Weinsier reviewed the obesity evidence in an article called “Divergent Trends in Obesity and Fat Intake Patterns: The American Paradox.” There, he wrote, “It appears that efforts to promote the use of low-calorie and low-fat food products have been highly successful.” However, the reduction in fat intake did “not appear to have prevented the progression of obesity in the population.”
The Center for Disease Control (the “CDC”) has evidence suggesting that Americans were no less active at the end of 1990 than they were at the beginning of the decade, despite the continued rise in weight and obesity during this period. In fact, this coincided with what may be described as the “exercise and sports epidemic” in America. There was an explosion of an entire industry dedicated to leisure-time pursuits. In the 1960s, Jack La Lanne was the nation’s only physical-fitness guru, Gatorade was only for University of Florida football players, and skateboarding, inline skateboarding, snowboarding, mountain biking, power yoga, spinning, aerobics, and a host of other now-common physical activities were yet to be invented. During this time, the revenues of health clubs was estimated to be about $200 million per year. In 2005, that figure was $16 billion and an estimated 40 million Americans were members.
So what was bad for us in the 1960s, became the new conventional wisdom and the New York Times described it this way in 1977. Even the Washington Post estimated in 1980 that a hundred million Americans were now partaking in the “new fitness revolution” whereas just a decade earlier, they would have been derided as “health nuts.”
For all the increased physical activity, the rise in obesity and overweight numbers has steadily increased. This coincides with none other than the rise in sugar consumption during this period. There is nothing ambiguous about this nor is it controversial. But people refuse to believe that sugar, which is only 4 grams of fat per serving could cause all of this. Yet, when we consume much less of it, we were much healthier. The math is rather simple.
The Concept of Gamma-Glucose
A few months back, I shared some of the 1950’s era work of Dr. Benjamin P. Sandler. He wrote a terrific work called, “How to Prevent Heart Attacks.” You’ll recall that he said, “I do not subscribe to the theory that the fat content of the diet is responsible for this difference in incidence of heart disease. I have evidence to implicate the carbohydrate content of the diet, especially the ingestion of refined sugar and starch. I have found that the most striking feature of the primitive peoples’ diet is the practically complete absence of refined foods, especially sugar. The consumption of refined sugar by the Western countries, by contrast, is appalling. Refined sugar and starch is a luxury in primitive countries and the general population is just too poor to buy them.”
He basically argued that the heart requires a constant supply of blood sugar and this particular level must be maintained throughout all conditions or it has the potential to “embarrass the heart muscle.” When a person consumes sugar and starch, it sends the blood sugar skyrocketing followed by a huge secretion of insulin which lowers blood sugar to a point lower than necessary. This hypoglycemia causes a person to experience hunger. This is the normal way in which a person gets hungry, but for a person ingesting large amounts of sugar and starch, this natural process is greatly exaggerated and puts great strain on the body.
Now comes Dr. Sandler again and this time he explains what he only hinted at in the article, “How to Prevent Heart Attacks.” There, he opined that there was a qualitative difference between dietary glucose from sugar and starch and the kind received from animal fats. It may be that those studies where people have shown no change in physical endurance when comparing cyclists on high carbohydrate and high-fat diets. Some claim that the longer one is on a high-fat diet, the worse their endurance becomes as compared to that of carbohydrate-based diets. But people with experience on diets high in animal fats would strongly object. History also paints a very different picture. When a human lives on meat and fish exclusively, as does the Eskimo or Arctic explorer, he is living on protein and fat. Yet glycogen is stored in the liver in normal amounts and there is a constant normal blood sugar level. Where do the glycogen and glucose come from on such a diet? They are derived from protein and fat. Fifty-eight percent of protein and 10% of fat can be converted by the body to glycogen and ultimately to glucose.
Before we discuss where the glucose comes from in such a diet, it’s important to understand that ordinary glucose is a mixture of two chemical forms called alpha-glucose and beta-glucose. Alpha-beta-glucose mixture is derived from the cane sugar we eat, and from the sugar present in fruit; and it is an end product of the digestion of starch. Gamma-glucose is so labile (unstable) that it has never been isolated in the test tube and identified as such. The evidence for its existence however, while indirect, is strong. Many authorities in chemistry and physiology believe it exists since it helps explain certain phenomena which otherwise would be obscure. (Just as in nuclear physics where faith in the existence of protons, electrons, and mesons, helps to explain many phenomena.)
Gamma-glucose is considered to be labile, highly reactive, and readily oxidized. It is very likely that the cells of the body prefer to oxidize gamma-glucose to the exclusion of alpha-beta-glucose. Dr. Shaffer, an authority on the subject, in a review of the literature on gamma-glucose, has stated that the hypothesis appears attractive that alpha-beta-glucose is converted under the influence of insulin into gamma-glucose. In this discussion, and in the present state of our knowledge, it is sufficient to believe that alpha-beta-glucose is synthesized to glycogen in the liver under the influence of insulin and that the glycogen is subsequently broken down into gamma-glucose which is then liberated into the blood. I want to point out that the blood sugar on such a diet may be said to exist exclusively in the gamma form.
On a high-fat diet the blood sugar is produced entirely within the body and so may be called endogenous glucose as opposed to the exogenous alpha-beta-glucose which is introduced from the outside in the foods we eat. Certainly it would appear plausible to regard the sugar derived from meat and fish (protein and fat) as being different chemically from the sugar derived from cane sugar, fruits, and starch. From my studies I have been forced to conclude that alpha-beta-g1ucose is so foreign to the cells of the body as to be harmful to the body’s economy.
There is ample evidence for this statement from observations made by two of this country’s leading researchers in metabolism, Benedict and Carpenter. These workers determined the minimum (basal) oxygen requirements of normal human subjects and then measured the oxygen consumption of these subjects after various test meals of sugar, starch, protein, and fats, alone and in combination.
After a protein meal they always observed a marked rise in oxygen absorption (consumption), a phenomenon called “the specific dynamic action” of protein and which is regarded as highly beneficial to the body. After a fat meal there was a slight rise in oxygen absorption or none at all. After sugar and starch they found a slight initial rise followed by a fall in oxygen absorption in some experiments, and in other experiments they observed a consistent fall in oxygen absorption, with no initial rise. Benedict and Carpenter were unable to explain this fall in oxygen absorption after sugar and starch. They were much surprised to discover that the ingestion of sugar and starch actually could cause a depression of total bodily oxygen absorption below basal requirements.
Here are some of the actual experimental results reported by Benedict and Carpenter. They fed one subject 400 grams of bananas (413 calories) and observed an increase in oxygen absorption of 5.5 grams during the first hour, and a fall in oxygen absorption below basal requirement during the second, third, and fourth hours. Bananas contain chiefly sugar and starch. In the same subject, after 217 grams of beefsteak, (451 calories) which consists of protein and fat, there was an increase in oxygen absorption during each of four hours, with a total increase of 17.5 grams of oxygen against a net increase of only 1.5 grams of oxygen after the bananas.
With larger meals the results were even more striking. For example, after 1382 calories of a sugar mixture, there was a fall in oxygen absorption of 11 grams over an eight hour period with no initial increase; in other words the subject would have consumed 11 grams more oxygen if he had fasted for the eight hours. On the other hand, after 1305 calories of beefsteak there was an increase in oxygen absorption of 40 grams during an eight-hour period.
Now, how does the ingestion of sugar and starch depress oxygen absorption? There are two ways by which this can be brought about: first, by causing low blood sugar, and second, by depressing the liver output of gamma-glucose. As has, been previously explained, sugar and starch may cause low blood sugar about an hour after eating, and this period of low blood sugar may last from one to three hours. During the period of low blood sugar there will be a reduced delivery of glucose to all the cells of the body with a resultant reduced oxidation of glucose; as a result, less oxygen will be absorbed by the body since cells utilize oxygen in proportion as they utilize glucose. Also, during the period of reduced glucose-oxygen consumption, less heat will be generated and so the body temperature may fall. This reduced heat production during low blood sugar readily explains the presence of subnormal body temperature in certain individuals in the morning before breakfast, and even after meals. Such individuals tolerate cold weather very poorly.
The second mechanism whereby sugar and starch may cause a depressed oxygen consumption involves the concept of gamma-glucose. During fasting, the blood sugar is derived entirely from the breakdown of liver glycogen and may be regarded as existing in the readily oxidizable gamma form. Now Dr. Soskin and his co-workers have found that when ordinary alpha-beta-glucose is injected into the blood the greater the amount of alpha-beta-glucose injected the greater the depressant effect on the liver output This reduced output by the liver occurs because there is no apparent need for the liver to pour out endogenous glucose as long as exogenous alpha-beta-glucose is being introduced from the outside. The injection of exogenous glucose raises the blood sugar level and, to prevent too great a rise, the liver responds by lowering its output. The oxygen absorption of the body may fall, however, in spite of the rise in blood sugar level which followed the injection of glucose, because of the reduced output from the liver of the more readily oxidizable form which I believe to be the gamma form.
The influx of alpha-beta-glucose into the blood drives the gamma-glucose out of the circulation, just as bad money drives good money out of circulation. The oxygen absorption of the body falls in proportion as the output of gamma-glucose falls. This concept will explain why Benedict and Carpenter observed a moderate fall after small sugar meals and a greater fall after larger sugar meals. After a pure protein and fat meal (beefsteak) there is no introduction of alpha-beta-glucose and hence there will be no depressant effect on the liver output of gamma-glucose and there will be no fall in oxygen absorption. The marked increase in oxygen absorption after beefsteak may be readily explained by the oxidation of the products of digestion resulting from the digestion of the protein and fat.
Summarizing, the ingestion of sugar and starch may depress oxygen absorption by causing low blood sugar and/or depressing the output of gamma-glucose from the liver. In some instances only one of these mechanisms may be operating, and in other instances both mechanisms may be operating. In the latter, the fall in oxygen absorption will be greater than in the former, and the fall in oxygen absorption may be so great and so prolonged that susceptibility to infection will occur.
As Dr. Sandler has written as far back as 1951, blood sugar must be maintained at regular levels at all times. When this is not the case due to physical exertion or bad diet, a person’s health can be compromised in a major way. This conventional advice to eat less of a bad diet and exercise more only leads to more unstable blood sugar and less oxygen absorption over time. This would explain why the physical exercise intervention doesn’t last very long before an individual gives it all up in exchange for the couch.
In: Diet, Exercise, Heart Disease, Hypoglycemia, Immune System
Being Fat Does Not Stop the Surgeon General
One in three U.S. children and 67 percent of adults are considered overweight or obese. Those sobering statistics have caused the most important people in the US to give the matter of obesity and overweight their full attention. Among them, is the US Surgeon General, Dr. Regina Benjamin. That wouldn’t be so controversial except for the fact that Dr. Benjamin is an overweight individual herself. Her opinions on this matter were very intriguing to read.
In response to a question regarding whether or not people are listening to the government’s message on obesity, she said “Weight loss programs and gym memberships are a cottage industry. There was an article last month, I believe in JAMA [Journal of the American Medical Association] that showed that the obesity rate seems to be slowing. It obviously hasn’t completely stopped, so we still have a lot of work to do. Some people are listening, but not enough.”
So the general consensus is that those who are obese and overweight just don’t listen and they disregard the advice to eat less and move more, in keeping with their physiology. Here at ZIOH, we believe that a person should always eat to hunger and never experience the clamor of hunger. What’s crucial is the type of food one consumes. Consuming the wrong fuel causes an engine to run in a faulty manner. By filling the engine with the right fuel, the engine runs as the manufacturer intended.
Dr. Benjamin continues, “People need to exercise and eat well because they enjoy it and they want to be fit. It could be taking a walk in a park. But we need nice parks. We need people to buy better foods. But a lot of communities don’t have access to fresh produce. Right now, it’s very difficult to find a meal that’s healthy and competes with a “dollar meal” like a burger and fries. We need to ask the communities and food manufacturers to offer more healthy choices not as alternatives, but as first choices.”
So from her perspective, the problem is that people don’t care enough about themselves to make the required changes. So I suppose that would explain why the diet industry is so poor and that there are myriad books and health sites all claiming to have the answer, if the person would just care enough about themselves to implement the advice, right? More nonsense. Never occurs to us that perhaps the advice just isn’t correct.
Next, she offers her input on personal responsibility: “I believe in personal responsibility, but as a government, a community and a society, we can help people. [For some people] food is love. In the African-American culture everything is about food, but not everyone is overweight. In my family, we had desserts on Sundays, not every day. It was part of our big Sunday dinner, and the rest of the week we never had as big a meal. Part of the conversation about health and fitness is about portion sizes and what we’re eating.”
It’s very true that not everyone gets fat in our toxic environment. The same is true with all the diseases of civilization. We seem to have missed what happened during the nutritional transformations of native populations that began eating carbohydrates. They all got sick. Everyone did not get fat. Some got heart disease, some diabetes, some stroke, some Alzheimer’s, some hypertension, etc but not everyone got the same thing. However, none of these diseases existed before the advent of carbohydrates being the center of our dietary scheme. If we’re eating correctly, the “how much” doesn’t come so much into play. We eat until we’re full and then we stop.
On using food as a “reward”, she says “Parents need to set examples. Kids usually want to eat what their parents eat. It’s like when a kid gets a shot, a parent would promise an ice cream when they got home. Well, we would put a sticker on their arms. Don’t reward with comfort food. Americans don’t deny kids anything. Kids ask for something and they get it. Sometimes you have to say no.”
I tend to agree with her on this one. However, it’s tough to say, “no” when you have created this environment by starting them out on addictive sugar since they were in the womb. Just like us, when children are fed a diet high in sugar, they have a pancreas which secretes huge loads of insulin trying to balance blood sugar. When the blood sugar goes low as a result of all the insulin, the cravings for sweets will be fierce. Few parents can stand the site of children going hungry, even if the majority of that hunger is fueled by cravings. This is the reason people feel the need to graze every two hours.
About the disparities among the races, she says, “One prescription doesn’t always fit everyone. Oftentimes, it’s better for people within that culture to set the pace, such as parents and local leaders. As Surgeon General we have the Indian Health Service and are working very closely with many clinicians. About 70 percent of American Indians and native Alaskans (are overweight). We are trying to get local people, people who are respected in the community, to shepherd this. That’s one of the [elements] of the First Lady’s “Let’s Move” campaign.”
As I’ve written on this space many times, obesity is found most commonly among the poor and disadvantaged more often than not mostly due to the fact that their diets tend to contain more easily digestible and refined carbohydrates than that of the majority. This is the reason they tend to suffer more from chronic disease in general. When sugar was scarce and hard to come by, these diseases were only found among the nobility and the elite. But once sugar became cheap and plentiful, it quickly became added to all sorts of foods and medicines such that’s its difficult to find any foods that don’t contain it in abundance, except meat and water. I was in the store this evening and saw a woman buying a gallon of fat-free milk. I looked at the label and each serving contains 12 grams of sugar. And this is supposed to be healthy? There is less sugar per serving in full-fat ice cream by Breyers (7g).
What about her own weight? She says, “I’m very secure in my own self esteem, but yes, it was hurtful. There were some mean comments. But what about those kids who will be looking at me as a role model? They may be very discouraged by some of those comments. I exercise regularly, at least four days a week. If I didn’t I probably would be a big blimp. And I try to eat pretty healthy, as much as I can. I know the things that I’m doing. I tend to stay on the elliptical as long as other people. I’m not out of breath. You can be healthy and fit at different sizes. The real message is that you don’t want to limit yourself by your dress size. You need to be comfortable with yourself and have a good body image. Don’t have some dress manufacturer tell you what size to be. Be a size that makes you fit.”
This is pretty typical. When you follow the conventional wisdom to the letter and your weight doesn’t budge, then it’s time for acceptance and being comfortable in your own skin. I whole-heartedly agree with that, but my biggest problem is not enough people know exactly what they need to do in order to be successful. If I would have kept following the conventional wisdom, I would have been yo-yo dieting like so many others. Once I found the way to eat for the rest of my life, weight maintenance is little more than an afterthought for me.
It can be that way for you.
In: Diet, Disease, Exercise, Obesity
High-Fat Diet Increases Stroke Risk – Really?
For some reason, people still don’t get it. In the latest headline, the answer is found in the opening paragraph, yet for some reason, people still want to demonize fat. Look at this:
Eating a lot of fat, especially the kind that’s in cookies and pastries, can significantly raise the risk of stroke for women over 50, a large new study finds.
It’s obvious that there are populations that have consumed a high-fat diet yet experienced no chronic disease, yet people still would love to blame fat for the problem without any inkling that perhaps it’s the carbohydrates in those cookies and pastries. I consume a high-fat diet and my stroke risk is very low but I do not consume cookies and pastries.
There are no “damaging” trans-fats in meats. There are some in baked goods, especially donuts and the like that people love for breakfast. Perhaps it’s not the fat in these things? The researchers have tunnel vision. The new study is the largest to look at stroke risk in women and across all types of fat. It showed a clear trend: Those who ate the most fat had a 44 percent higher risk of the most common type of stroke compared to those who ate the least. The study involved 87,230 participants in the Women’s Health Initiative, a federally funded study best known for revealing health risks from taking hormone pills for menopause symptoms. Where is the comparison of their sugar consumption?
There were 288 strokes in the group of women who consumed the most fat each day (95 grams) versus 249 strokes in the group eating the least fat (25 grams).
After taking into account other factors that affect stroke risk — weight, race, smoking, exercise and use of alcohol, aspirin or hormone pills — researchers concluded that women who ate the most fat had a 44 percent greater risk of stroke.
They also found a 30 percent greater risk of stroke among women eating the most trans fat, which is common in stick margarine, fried foods, crackers and cookies.
Faced with this evidence, one of the researchers concluded that “We need to look at the labels on the foods we buy,” because many of these fats are hidden in baked goods and people are not aware of how much they’re consuming. “This is a simple way that any woman, especially postmenopausal women, can improve their health. Simply avoiding fried foods is a big one.”
Notice how the emphasis is on baked goods. Are these not carbohydrates? These are not meats such as porterhouse, ribeye or New York strip steaks which I eat on a regular basis. I have no expanded waistline or high stroke risk and no woman or man would have either if they simply avoided them.
On average, American women in their 50s and 60s eat 63 to 68 grams of fat a day, federal health statistics show. A little context: A 2-ounce Snickers bar contains 14 grams of fat; a 2-ounce bag of Crunchy Cheetos has 20 grams, as does a Haagen-Dazs ice creambar.
The American Heart Association recommends limiting fat to less than 25 to 35 percent of total calories, and trans fat to less than 1 percent. The so-called healthiest fats come from nuts, seeds, fish and vegetable oils. I found this statement interesting especially when they just identified margarine as having dangerous fats. Yet, they would say that healthy fats are found in vegetable oils? Is not margarine composed of vegetable oils as well?
Again, there is no acknowledgement that these foods are all carbohydrates. I exceed these levels of fat on a daily basis yet I have no heart disease or stroke risk. So it’s hard to argue that it’s the fat. However, if you say that it’s carbohydrates mixed with fat, then we might be on to something. So why use the “industry-speak” and say “high-fat diet increases stroke risk” when it would be more accurate to say, a diet of junk food, suck as Snicker’s Bars, Cheetos, Ice Cream bars, cookies and pastries, radically increases stroke risk. I would have no problem agreeing to such a title and it might actually be accurate and actually useful to someone attempting to improve their health.
In: Diet, Disease, Heart Disease, Stroke
High Blood Pressure: A Neglected Disease in U.S.
The prestigious Institute of Medicine said that even though nearly one in three adults has hypertension, and it’s on the rise, fighting it apparently has fallen out of fashion: Doctors too often don’t treat it aggressively, and the government hasn’t made it enough of a priority, either. As the article declares, hypertension is a well-known plague of modern civilizations. This observation dates back to the 1920s. The disease was confined to only Western civilizations and the more affluent societies elsewhere. Blood pressure dropped lower with age in isolated populations but climbed in the civilized nations. With exposure to Western lifestyles and diets, blood pressure among the native populations also began to rise with age and the incidence of hypertension increased as well. For readers of my blog, this news should not surprise us. I call hypertension a symptom of the metabolic disorder of high insulin, not a disease. I think the same of diabetes, heart disease and even gout and cancer. Their genesis all stems from the same place. The overconsumption of refined and easily digestible carbohydrates.
The problem with hypertension is that people believe that it’s easy to treat. Indeed, the conventional wisdom says cut the salt, eat more potassium, get some exercise, and drop 10 pounds. Those steps could make a big difference in how many people suffer high blood pressure — 73 million at last count. Another 59 million are on the brink, with blood pressure hovering at levels officially deemed pre-hypertension.
A reduced-salt diet doesn’t lower everyone’s blood pressure. Some individuals’ blood pressure can actually rise in response to less salt, and most people aren’t affected much either way. The more notable drop in blood pressure tends to occur in some — but by no means all — people with hypertension, a condition that affects more than a quarter of American adults.
Even though lower blood pressure correlates with less heart disease, scientists haven’t demonstrated that eating less salt leads to better health and longer life. The results from observational studies have too often been inconclusive and contradictory. After reviewing the literature for the Cochrane Collaboration in 2003, researchers from Copenhagen University concluded that “there is little evidence for long-term benefit from reducing salt intake.”
So it comes down to the fact that we put the public under a huge, unproven experiment based on the idea that any benefit to the individual, no matter how slight (read: clinically insignificant) will have a significant impact on public health when magnified across a large number of people.
Blood pressure does indeed seem to fall with weight loss, but even that is a moving target. How many people would love to drop 10 pounds. They join gyms every year in January and by March, the intervention is over. Weight is lost initially but regain seems to be the bane of every dieters existence.
The salt hypothesis says that when we consume sodium chloride our bodies maintain the concentration of sodium in our blood by retaining more water along with it. The kidneys then respond to the excess by excreting salt into the urine, thus relieving both excess salt and water by excreting salt into the urine, thus relieving both excess salt and water simultaneously. Still, in most individuals, a salt binge will result in a slight increase in blood pressure from the swelling of this water retention, and so it has always been easy to imagine that this rise could become chronic over time with continued consumption of a salt-rich diet.
The problem is that it has been remarkably difficult to generate any unambiguous evidence to support this hypothesis. From 1967 to 1983, Jeremiah Stamler of the National Institutes of Health (NIH) described the evidence as “inconclusive and contradictory” when he described his inability to confirm the hypothesis in a clinical trial of school-age children. The NIH has funded other studies but little progress has been made. That has not stopped lobbyists such as Michael Jacobson of the Center for Science in the Public Interest from calling salt “evil” and the “deadly white powder.”
Regardless, systematic reviews have inevitably concluded that reducing salt to half of our current consumption level (which is difficult to accomplish in the real world) will drop blood pressure by perhaps 4 to 5 mm Hg in hypertensives and 2 mm Hg in the rest of us. If we have hypertension, even the lesser form of it, it means our systolic blood pressure is already elevated at least 20 mm Hg over normal. The next stage of hypertension is 40 mm Hg. Cutting our salt intake by half and decreasing our systolic blood pressure by 4 to 5 mm Hg makes little difference.
These observations were later confirmed in isolated populations all over the world. With exposure to Western diets the blood pressure in these isolated populations rose with age as it did in Europe and America. The incidence of hypertension rose right along with it. By the 1950s more than 10 percent of native Africans were diagnosed with clinical hypertension. The number rose to over 30 percent by the mid-1960s. By the 1970s, hypertension was considered as frequent in the native African as it was in Europe or America. In some urban populations, hypertension rates were as high as 60 percent.
The experts didn’t initially focus on the disparate rates between isolated and civilized populations. They debated whether it was the stress and tension of the civilized life. Once the salt hypothesis raised the possibility that diet may be involved, researchers focused on the disparity as a test of the salt hypothesis only. The Western diets contained a good deal of salt whereas the isolated populations didn’t typically consume salt so this epidemiological evidence was used to support the salt hypothesis.
The same societies that did not eat salt also did not eat sugar and refined carbohydrates so the evidence supported both hypotheses. Gerald Sharper studied Kenya and Uganda and Ian Prior studied the South Pacific Islanders of Tokelau and initially they blamed refined and easily digestible carbohydrates. Once they became aware that investigators in the United States embraced the salt hypothesis, they followed suit.
The evidence that carbohydrate-rich diets cause the body to retain water and raise blood pressure dated back over a century. The German chemist Carl von Voit was credited in 1960. In 1919, Francis Benedict, of the Carnegie Institute in Washington, and the one who performed a very important fasting study in 1915, described the situation as follows:
“With diets predominantly carbohydrate there is a strong tendency for the body to retain water while with high-fat diets there is a distinct tendency for the body to lose water.”
Benedict was referring to the voracity of the high-fat diet to induce weight loss. These observations were used against carbohydrate-restricted diets to explain the weight loss that occurred in the first few weeks. University of Wisconsin endocrinologist Edward Gordon and Walter Bloom in the 1960s reported in the Archives of Internal Medicine and The American Journal of Clinical Nutrition that water lost on carbohydrate-restricted diets is a reversal of the sodium retention that takes place routinely when we eat carbohydrates. Eating them causes the kidneys to retain salt rather than excrete it. The body retains extra water to keep the sodium concentration of the blood constant.
Taking in sodium does not cause us to retain water. Carbohydrates cause us to retain water due to the non-secretion of sodium already present in the kidneys. Removing carbohydrates from the diet works just like the antihypertensive drugs known as diuretics that cause the kidneys to secrete sodium and water.
The water loss causes a considerable drop in blood pressure. Some feared it might drop too low and suggest that we keep some carbohydrates in the diet to keep the blood pressure from dropping too low. Of course, these experts never tried it and would not have known that it doesn’t just drop forever.
By the early 1970s, the researchers demonstrated that insulin induces the kidneys to reabsorb sodium rather than excrete it and of course, hypertensives have higher levels of circulating insulin than normal individuals. Since then, investigators have demonstrated other hormonal mechanisms by which insulin raises blood pressure. Insulin stimulates the nervous system and the same flight or fight response incited by adrenaline. Lewis Landsberg, an endocrinologist of Harvard Medical School, showed that by stimulating the activity of the nervous system, insulin increases heart rate and constricts blood vessels, thereby raising blood pressure. He discovered that the higher the insulin level, the greater the stimulation of the nervous system.
So it may be that the reason hypertension is “neglected” in the U.S. is usually because people mistakenly believe that it’s easy to treat and that it is a part of a much bigger disorder that not enough people understand. When you consume a diet restricted in carbohydrate as I do, hypertension is not one of your worries.
In: Diet, Hypertension, Insulin, Obesity, Populations
