Sugar and Coronary Health: Yesterday and Today

The news that sugar is bad for your cardiovascular health is more than eighty years old.

One of the first attempts to determine whether a high-sugar, high-starch diet might be harmful at least to rodents indicated that rats became fatter in response to the extra carbohydrates. In some cases, where it was the sugar that did the most harm, the fructose component of sucrose received most of the blame. Other studies since the turn of the century have corroborated these findings.

  • A drop in sugar availability, leading to a decline in consumption, is usually associated with a decline in heart and blood fat disorders especially when fat in the diet is also omitted or restricted. Wartime sugar and butter rationing in Great Britain was better for people than they realized at the time.
  • Large amounts of fat in the diet seem less productive of cardiovascular complications when sugar is absent. This has been observed in so-called “less advanced” societies following natural diets.
  • Over the last two “sugar centuries,” as sugar intake increased twenty times, both Americans and Europeans have suffered far greater levels of heart trouble than ever before.
  • Approximately one-half of our calories are derived from carbohydrates like sugar today. Authorities such as Dr. Yudkin note that diabetes, as well as heart disease, has been on the rise. Diseases that involve changes in glucose levels in the blood and major organ damage do not occur in a vacuum. And they do not occur without dietary provocation.
  • Researchers are now suggesting that “ the reason people develop adult-onset diabetes maybe because they eat the wrong kind of carbohydrates, meaning those that give rapid rises in blood sugar, rather than simply too many carbohydrates.” Ms. Kolata cites the work of Dr. Jerrold Olefsky, who points out that “ diabetics may want to know that some foods that they frequently avoid, such as ice cream, are fine as far as blood glucose is concerned.” It is suggested that diabetics may start to question the starch exchange lists of their diet.
  • Ms. Kolata and Toni Goldfarb give further information about “ slow-release” carbohydrates mentioned in Kolata’s other article above. Dr. David Jenkins of the University of Toronto has done tests to see how different foods affect blood sugar and has devised along with Dr. Thomas Wolever of Oxford a “glycemic index” This measures the intensity and duration of the glucose response in the blood.

Sucrose Elevates Blood Fats

blood lipid levels cholesterol and triglycerides are usually high in people with heart and circulatory problems. Scientists and researchers who have uncovered the relationship between sugar consumption and blood lipid (fat) levels have made an important contribution to our understanding of the current epidemic of heart disease.

They say that fructose in sugar is the main lipogenic (fat-causing) agent, whether it is fructose administered to test animals or fructose as found in refined sugar. (This is another reason not to hop on the fructose bandwagon.) Lipid levels seem to escalate sharply when sugar is ingested in large quantities and taken up rapidly by the bloodstream.

Sugar, either as fructose or sucrose, seems to cause a speed-up of the function of the liver, prompting it to make too many fats and pour them into the blood. Such overproduction is checked by other mechanisms in the body, which flush out excessive blood fats. The normal metabolism can adjust to such temporary ups and downs; if overburdened, however, the normal mechanisms may not be able to control blood lipid levels, and cardiovascular disease may result.

A single candy bar (or three big baked potatoes, which are the same thing in terms of carbohydrate totals) may cause too many blood fats to accumulate in your bloodstream. After eating large amounts even of natural foods such as potatoes or rice, your blood fats can rise, too, even if you are in good health.

Many other studies have produced similar results, using various starches and sugars. Sometimes different sugars are pitted against one another. For example, when starch and glucose were studied side by side with sugar and fructose, refined sugar was shown to raise serum triglyceride levels consistently. Lowering sugar also lowered lipid levels. Serum triglyceride levels stay lower when a low-sugar diet is followed so watch your intake.

Fatty acid production increases when a diet of 12 percent sugar is fed to rats, says S. Mukherjee et al. at the Laboratories of Lipid Research at the University of Calcutta. In this third study utilizing fructose and sucrose, both caused neutral fat levels to go up, but sugar caused the manufacture of more cholesterol in the liver. This means, undoubtedly, that cholesterol breakdown products are proliferating as well. Glucose and fructose intake also stimulated the production of triglycerides.

Fructose vs. Sugar

Even if your diet is adequate or better, adding fructose may add a greater risk factor for heart disease than sugar, since it can stimulate, even more rapidly than sugar, the production of undesirable glycerol and fatty acids. Glucose appears to be third in terms of provoking such chemical changes, according to a study by J. L. Kelsay, which reported results with a group of females consuming a high-sugar diet.

These results with sucrose may stem from the fact that this sugar is speedily absorbed because it stimulates the excess synthesis of sucrase enzymes. Its rapid absorption may encourage a buildup of lipids in the liver cells as well.

If you have high blood fat levels, it is a good idea to avoid sugar and fat to prevent the situation from getting worse. According to M. A.

Antar et al. in Atherosclerosis, saturated fats and sucrose are a dangerous combination. Elements contributing to the rise of blood lipid levels include:

  1. The percentage of total calories as sucrose and starch. (Do you eat too many sweet snacks?)
  2. The amount of saturated vs. polyunsaturated fat. (Salad oil is far preferable to the saturated fats used to make commercial French fries, buttered popcorn, etc.)
  3. The amount of cholesterol in the diet. (Have you cut down on red, “marbled” meat?)

Sugar may not alter your blood fat levels if your metabolism is relatively normal. Even when you eat a diet abnormally high in sugar, your lipid levels may or may not change dramatically, since other factors are involved.

  • If you follow a low-cholesterol diet rich in PUFA (polyunsaturated fatty acid) foods, then starch and sugar, even in sizable doses, may not change your fat serum levels. For example, according to Dr. I. MacDonald, as reported in the American Journal of Clinical Nutrition, although triglyceride levels rose when animal subjects ate a combination of cream and table sugar, this did not happen when they were fed either cream and glucose or sunflower seed oil and glucose. However, cholesterol and triglycerides do rise if sucrose is added to either of those combinations, according to Dr. Yudkin.
  • If your blood fat levels are already abnormally high, large amounts of carbohydrate foods may cause an elevation.

Based on these and other findings, many researchers have concluded that the riskiest path is to add large amounts of sugar to a diet when it is already unbalanced by such undesirable elements as saturated fats, salt, and overprocessed foods that contain these negative factors. Also, the risk is greater when, for whatever reason, the blood fat levels are already above normal.

A further fact to bear in mind is your own biochemical individuality, which will determine your degree of susceptibility. For example, a man beyond the middle years is at much greater risk, generally speaking, of worsening the health of his heart with a sugary diet than a teenage girl.

What We Know About Sugar and CH D from Animal Experiments

Sugar is the food most of us love the most and the ingredient we use the most. And heart disease is the most common of our killer diseases.

One way to explore the connection that may exist between these two facts is to study animals who have been experimentally fed sugar. Here are a few more findings that have resulted from such inquiries.

  • If you are a female, you may have a built-in ability to protect yourself from sugar diseases and their blood-fat-elevating effect. This “sexist” immunity, seen in both humans and animals, is no doubt due to hormone factors.
  • Animals react with major organ damage and with damage to veins and arteries as well, reports Dr. M. Murakami in the Japanese Circulation Journal, when sugar is fed at high dose levels. Their blood showed high glucose levels and high fat and serum cholesterol levels.
  • If you would do anything to protect yourself from a build-up of dangerous fatty plaques, the warning signal for coronary heart disease, then avoid sugar. Reports by K. R. Bruckdorfer, I. H. Khan, and John Yudkin at the Department of Nutrition of Queen Elizabeth College in London, tell us that both cholesterol and atheromas became more serious as more sugar was added to the diet.
  • Sugar is not kid stuff, according to two studies with rats, the first conducted by Phyllis H. Moser and Carolyn D. Berdanier of the College of Human Ecology, University of Maryland, and the second by Dr. Berdanier and two colleagues from the University of Nebraska College of Medicine. In one study, sugar in large amounts quickly clogged the blood with fats, and either caused rodent life expectancy to be greatly curtailed or resulted in out and out death.


You need carbohydrates for energy, especially to fuel your brain. But you don’t need sugar. Too much glucose in your bloodstream— an after-effect of a typical coffee-donut break, actually worsens fatigue and overburdens your vital organs rather than waking you up. If you are keeping your metabolism healthy with a well-balanced diet, your liver will send forth new energy from its reserves, if it is not already there as you need it in your working muscles. Remember, carbohydrates alone— in a candy bar, for example— do not provide healthy energy. Relying on sugar for energy and a lift has a particularly serious impact on cardiovascular well-being. For example:

  • The harm that fat intake does is worsened when you eat sugar, too.
  • As our sugar intake has risen dramatically, so has the incidence of heart disease.
  • Eating sugar probably causes your liver to produce excess fats which are sent into circulation in your blood.
  • Sugar may cause such disorders as ulcers or Type IV hyperlipidemia syndrome, which in turn may lead to diabetes and other serious problems.

Studies using animals have furthered our understanding of sugar’s effects on the body. Females seem to be less vulnerable than males to cardiovascular symptoms. But sugar especially sucrose has been shown to damage major organs, veins, and arteries; increase plaque buildups in the arteries; and to shorten rodents* lives, especially when fed to them when young.

For a healthy heart, it is a good idea to:

  • stick to a low-sugar diet that does not cause unhealthy blood fats to rise in your blood. Such a diet may even lower your blood fat levels.
  • Watch your carbohydrate intake. Remember, a small candy bar is the carbohydrate equivalent of three baked potatoes. O f course, there are nutrients and fiber in the potatoes which make them less stressful to assimilate.
  • Concentrate on a diet that eliminates sugar and refined foods as much as possible and you may never have to worry about your energy levels, your cholesterol, or an ailing heart.

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