You may already be suffering from one of the most common – and often overlooked – diseases to strike Americans. It’s not a deadly new virus. Not cancer. Nor heart disease. It’s a disease, surprisingly enough, caused by your body’s inability to make the most of the food you eat. And as many as one in three people suffer from it.
Doctors call this peculiar condition insulin resistance or, with a bit more mystique, Syndrome X.
If the name doesn’t ring a bell, the symptoms might: Feeling tired after you eat, and at other times when you shouldn’t. Gaining a pound here and a pound there – and having difficulty losing them. Seeing your blood pressure creep up year and after year. And finding that your cholesterol does the same.
Insulin resistance is the chief characteristic of adult-onset diabetes, which affects an estimated 15 million Americans. It also sets the stage for obesity and coronary heart disease – even if you’re not diabetic.
What can you do about it? The simple prescription is to eat right, take your vitamins and minerals, and exercise, because each reduces insulin resistance.
But as you might imagine, there’s more to the story.
Sugar and Insulin : A Double Whammy
Doctors have known about insulin resistance for decades, but only in the 10 years have they gained a clearer idea of exactly how it derails your health.
Insulin resistance is caused in large part by the over-consumption of refined carbohydrates, such as breads, pastas, and sugary foods. Eating too much saturated fat (found in beef) and omega-6 fatty acids (found in vegetable oils) also seems to increase the risk of insulin resistance.
Normally, after you eat a meal, your body breaks down carbohydrates into glucose, or blood sugar. The presence of glucose prompts the release of insulin, a hormone produced in your pancreas. Insulin helps transport glucose from the blood to cells, where’s it’s burned for energy or stored.
When a person eats a lot of refined carbohydrates year after year, a dangerous cascade occurs. Insulin levels remain chronically high, and cells become less responsive – and resistant – to insulin. As a consequence, relatively little glucose gets burned and levels remain high. With chronically elevated glucose levels, insulin resistance evolves into diabetes.
At an American Diabetes Association (ADA) scientific symposium on antioxidants and diabetes, held last November in Orlando, Fla., numerous researchers implicated elevated glucose as a major source of dangerous free radicals. Glucose, a highly energetic compound (and the primary source of energy in the body), spontaneously oxidizes itself and spins off large numbers of free radicals, according to Lester Packer, Ph.D., a cell and molecular biologist at the University of California.
Free radicals, molecules with an unpaired electron, react with normal molecules in the body and oxidize them, much the way heat or oxygen turns butter rancid. When glucose is steadily higher than normal – well above 120 mg/dL – it auto-oxidizes even more readily and spins off still more free radicals. Some of these free radicals, according to Alan Chait, M.D., a professor at the University of Washington School of Medicine, Seattle, oxidize cholesterol and set the stage for coronary heart disease.
High levels of glucose cause other problems as well. At the ADA meeting, Richard Bucala, M.D., Ph.D., of the Picower Institute for Medical Research, Manhasset, N.Y., explained that glucose can bind to proteins and “crosslink” them. The process, called glycosylation, is akin to tying your body’s proteins, which include your genes, into knots. Like free radicals, protein glycosylation has also been linked to aging and disease.
High levels of insulin create still more free radicals, leading to what researchers describe as “oxidative stress.” Ele Ferrannini, M.D., of Italy’s National Research Council, Pisa, has reported that high insulin levels increases the demand for vitamin E, which quenches free radicals. That’s not all. Dean Ornish, M.D., of Sausalito, Calif., recently wrote in the Journal of the American Medical Association that insulin helps convert calories into triglycerides and cholesterol, increasing the risk of coronary heart disease.
Insulin Resistance and Heart Diseases
Until 1988, researchers studying insulin resistance focused on its role in diabetes. Then, Gerald M. Reaven, M.D., of the Stanford University Medical Center, built a strong case for insulin resistance as a cause of obesity, hypertension, and coronary heart disease.
“The fact that an insulin-resistance subject may not become diabetic does not mean that they suffer no untoward consequences,” Reaven wrote in the journal Diabetes. “Indeed, an argument can be made that the more insulin sensitive [in contrast to insulin resistant] an individual, the better off he or she is, and that the attempt to compensate for insulin resistance sets in motion of series of events that play an important role in the development of both hypertension and coronary heart disease.”
Reaven coined the term “Syndrome X,” to describe how insulin resistance sets the stage for more serious disease. The syndrome is characterized by six traits: insulin resistance, glucose intolerance, abnormally high insulin levels, high triglycerides, low high-density lipoprotein (the “good” cholesterol), and hypertension. “The common feature of the proposed syndrome is insulin resistance,” he explained, “and all other changes are likely to be secondary to this basic abnormality.”
Alpha-Lipoic Acid Helps
Some of the best ideas for preventing and reversing insulin resistance come from emerging treatments for adult-onset diabetes, the condition in which insulin resistance is most severe. One approach aims at reducing glucose levels (and consequently insulin levels) and the other uses vitamins to counteract free radicals generated by glucose.
A number of micronutrients help insulin efficiently move glucose into cells for burning. If you think of your body’s cells as engines, refined carbohydrates provide plenty of high-grade fuel. But you also need spark plugs to efficiently ignite the fuel. One of the most promising of these biological spark plugs is alpha-lipoic acid.
A natural cell constituent, alpha-lipoic plays a fundamental role in converting glucose to energy. Researchers have known from animal experiments that it can lower and stabilize glucose levels and, in Germany, alpha-lipoic acid is sold as a “drug” for the treatment of diabetic polyneuropathy, a type of severe nerve pain.
At the ADA meeting, Stephan Jacob, M.D., of the University of Tübingen, Germany, described his recent study of 74 diabetes given at least 600 mg of alpha-lipoic acid supplements daily. The alpha-lipoic acid stimulated insulin activity, which safely lowered and stabilized glucose levels. It also made the patients more insulin sensitive and increased their glucose tolerance, both positive changes.
Other nutrients also help improve insulin sensitivity and, conversely, reduce insulin resistance. The mineral vanadium, found in vanadyl sulfate supplements, also improves insulin’s ability to transport glucose into cells. With insulin working efficiently, the body needs and produces less of it. According to Barbara F. Harland, Ph.D., of Howard University, Washington, D.C., vanadium has been researched for 40 years and is close to being recognized as an essential nutrient.
Chromium, which is recognized as an essential mineral, also helps lower glucose levels. It is a component of the “glucose tolerance factor,” a molecule essential for normal insulin function and glucose metabolism. Last year, Richard A. Anderson, Ph.D., a researcher at the U.S. Department of Agriculture, described a joint U.S./Chinese study in which diabetics received either daily supplements of chromium picolinate or dummy pills. He said that 200 mcg of chromium picolinate daily safely lowered and stabilized blood sugar levels in diabetics in just four months. People taking 1,000 mcg of chromium daily ended up with glucose and insulin levels comparable to those of normal people.
The omega-3 fatty acids, or fish oils, also improve insulin sensitivity and reduce insulin resistance, according to a recent animal study by Margaret T. Behme, M.D., of University Hospital, London, Ontario. The omega-3 fatty acids restore a balance disrupted by excessive consumption of omega-6 fatty acids and saturated fats.
Vitamin E Prevents Damage
Researchers at the ADA meeting came close to unanimously endorsing vitamin E to relieve some of the “oxidative stress” caused by excessive glucose and free radicals in diabetics. It’s likely that non-diabetics with insulin resistance also suffer from oxidative stress, though to a lesser degree.
Why the emphasis on vitamin E? Many studies have reported that 400 IU or more daily can dramatically reduce the risk of coronary heart disease, the cause of death among 80 percent of diabetics – and the leading cause of death overall in the United States. In fact, it appears that the same process that causes coronary heart disease in most people is accelerated in diabetics.
What happens is this: free radicals generated by glucose oxidize the low-density lipoprotein (LDL) form of cholesterol in the blood. White blood cells scavenge the oxidized LDL, then infiltrate heart tissue and get stuck. This causes the cholesterol deposits characteristic of heart disease.
Vitamin E can neutralizes many of these free radicals and retards the development of coronary heart disease, according to research by Ishwarlal Jialal, M.D., of the University of Texas Southwestern Medical Center. Jialal described a 14-week study in which he gave 21 healthy patients 1,200 IU of natural vitamin E daily. The vitamin significantly reduced LDL oxidation and prevented white blood cells from sticking to the heart. Jialal has seen similar reductions in oxidized LDL among diabetics. “In my own practice, I suggest to my coronary artery disease patients that they take 400 IU of vitamin E daily,” he said.
Angelo Azzi, Ph.D., a professor at the Institute of Biochemistry and Molecular Biology in Bern, Switzerland, echoed Jialal and expressed a strong preference for natural vitamin E. “Natural vitamin E is two times more effective than the synthetic compound,” he said, adding that the body has prefers the structure of the natural molecule. “The important thing is to take it,” he said.
As antioxidants go, alpha-lipoic acid is also extremely important, according to the University of California’s Packer. In 1988, researchers discovered that it was one of the most potent and versatile antioxidants. It also helps recycle vitamin E and other antioxidants, such as vitamin C and CoQ10.
In sum, you have a one-in-three statistical risk of developing insulin resistance, but your real risk increases sharply if you consume a lot of refined carbohydrates, omega-6 fatty acids (found in fried foods and vegetable oils), and saturated fats. But you’re not going to wake up one morning to discover that you’re suddenly insulin resistance.
Insulin resistance takes years to become servere. If you pay attention to some of the early signs – higher blood pressure and elevated triglyceride and cholesterol – when you’re in your 30s or 40s, you can reverse insulin resistance and stand a good chance of preventing diabetes and coronary heart disease when you’re older.
A related article : Diet, Exercise, and Insulin Resistance
Being overweight increases your risk of developing insulin resistance. But being a thin couch potato is comparable – in terms of your body’s metabolic activity – to being fat.
Regular exercise, even a daily walk, primes your cells for activity. To get the energy you need for exercise, your body uses insulin to move sugar and fat into cells, where they’re burned as fuel. With the increase in insulin activity, sugar levels in the blood decrease. And with less sugar in your blood, your body produces less insulin and becomes more responsive to both sugar and insulin. Insulin sensitivity – the opposite of insulin resistance – goes up, and that’s good.
If you’re insulin resistant – high blood pressure and cholesterol are clues – the worst thing you could eat are highly refined carbohydrates, such as breads, pastas, cookies, donuts, and candies. Furthermore, Gerald M. Reaven, M.D., of Stanford University, points out that medications that lower blood pressure don’t alter insulin resistance, the underlying problem.
Experts, however, disagree on the best diet to follow. Robert Atkins, M.D., of New York City, recommends a high-protein, high-fat diet. He argues that low-fat diets really mean high-carbohydrate diets – which aggravate insulin resistance.
In contrast, Julian Whitaker, M.D., of Newport Beach, California, favors a high-protein diet, but one that relies mostly on fish and complex carbohydrates, such as legumes. Both diets may work, but for different people, so you may have to experiment to determine what works best for you. Also, both doctors recommend alpha-lipoic acid, vitamin E, and other nutritional supplements.
In addition to staying away from foods with a lot of refined carbohydrates and sugars, eat smaller and more frequent meals – not big, heavy meals that trigger the production of lots of insulin. – JC
- 1 Ornish D, “Very low-fat diets for coronary heart disease: perhaps, but which one?,” Journal of the American Medical Association, 1996;275:1403.
- 2 American Diabetes Association 32nd Research Symposium: The Role of Oxidants and Antioxidant Therapy in Diabetic Complications, Orlando, Florida, Nov. 15-17, 1996.
- 3 Ibid.
- 4 Ibid.
- 5 Galvan AQ, et al., “Insulin decreases circulating vitamin E levels in humans,” Metabolism, 1996;45:998-1003.
- 6 Ornish D, op. cit.
- 7 Reaven GM, “Role of insulin resistance in human disease,” Diabetes, 1988;37:1595-1607.
- 8 Challem J, “Antioxidants might ease diabetic complications, Medical Tribune (Family Physician Edition), Dec 12, 1996:18.
- 9 Harland BF and Harden-Williams BA, “Is vanadium of human nutritional importance yet?” Journal of the American Dietetic Association, 1994;94:891-894.
- 10 Pramik J-J, “Study says chromium supplement helps some diabetics,” Medical Tribune News Service, June 11, 1996.
- 11 Behme MT, “Dietary fish oil enhances insulin sensitivity in miniature pigs,” Journal of Nutrition, 1996;126:1549-1553.
- 12 Storlien LH, et al., “Dietary fats and insulin action,” Diabetologia,” 1996;39:621-631.
These articles originally appeared in Let’s Live magazine.