Don’t Try to Resist Cinnamon

Cinnamon Improves
Insulin Sensitivity

Strong link between insulin resistance and
polycystic ovary syndrome prompts new study
By Will Block

© iStockphoto.com/abackimages
n this politically correct age, it’s probably hard for the younger generations to imagine the time, half a century ago and more, when people could go to the circus or state fair and see the sideshow of freaks, as they were callously called. Drawn in by provocative posters and the barkers’ lurid pitches, people gladly parted with their money to be able to gawk at nature’s unfortunate oddities—some of them real, some fake.

Many of the people on display were the victims of birth defects that produced grotesque abnormalities. Others were afflicted with hormonal disorders that resulted in bizarre aberrations of size or shape, or in misplaced secondary sexual characteristics, such as men with sizable breasts or women with excessive facial hair and chest hair (hirsutism)—the notorious “bearded ladies.”

Some of those ladies may have been afflicted with advanced cases of polycystic ovary syndrome (PCOS), a condition commonly characterized by hirsutism, obesity, menstrual abnormalities, infertility, and enlarged ovaries. PCOS is one of the most common hormonal disorders in women, affecting (to some degree) about 7–10% of women. It usually begins at puberty, and obesity is a major risk factor—most women with PCOS are obese.

The condition gets its name from the many cysts (fluid-filled sacs) that develop from ovarian follicles that fail to rupture and release their eggs; these cysts can be seen with ultrasound imaging. Typically, the woman menstruates less frequently than normal (oligomenorrhea) or not at all (amenorrhea). As a result of all this, she is very likely to be infertile.

Masculinization—A Major Downside of PCOS

A common cause of this ovarian dysfunction is an overproduction of luteinizing hormone by the pituitary gland. That, in turn, causes an overproduction of androgens (male sex hormones, primarily testosterone) by the ovaries and adrenal glands. (All healthy women have some androgens, just as all healthy men have some estrogen.)

Although the ovaries continue to produce estrogen, which causes the endometrium (the uterine lining) to grow, the excessive androgen levels interfere with the process of ovulation and reduce the production of progesterone, a hormone that helps regulate the menstrual cycle. Because of this, the endometrium is not shed as it’s supposed to be in normal menstruation, and over time, it may become extremely thick (endometrial hyperplasia). This increases the risk of endometrial cancer. Women with PCOS are also at increased risk for breast cancer, hypertension, and cardiovascular disease.

The excessive androgen levels also cause many of the overt symptoms of PCOS, such as hirsutism, acne, a deepening of the voice, male-pattern baldness, decreased breast size, and increased muscle size. In other words, the woman is masculinized, which is understandably distressing.

Interestingly, many women with PCOS are the daughters of men who became bald early in life. It is believed that a defect in a single gene is responsible for both conditions.

PCOS Is Associated with Insulin Resistance and Diabetes

Our interest in PCOS stems from the fact that the disease is associated with an increased risk for type 2 diabetes, a metabolic disease characterized not just by abnormally high glucose levels in the blood but also, often, by abnormally high insulin levels as well.* This is because the pancreas produces more and more insulin in an attempt to overcome the effects of insulin resistance, a characteristic feature of type 2 diabetes. Insulin resistance, which typically precedes diabetes as a precursor condition, occurs when the body’s cells resist the action of insulin as it tries to regulate blood glucose levels. People with this dangerous condition will not necessarily progress to diabetes, but the risk is high.


*Don’t confuse type 2 diabetes, which afflicts primarily adults, with type 1 diabetes, which afflicts primarily juveniles. The latter is the kind in which the pancreas fails to produce insulin, so insulin must be injected daily to maintain control of blood sugar (glucose) levels.


The more the cells resist insulin’s action, the more insulin the pancreas produces, to compensate. This can lead to a state of chronic hyperinsulinemia (excessive insulin), which is harmful in many ways, one of which involves interference with the body’s delicate sex-hormone balance. And that brings us back to PCOS, in which there is an overproduction of androgens.

Weight Loss Is Important, but Difficult— Glycemic Control Could Help

It’s especially important, by the way, for PCOS patients to exercise regularly and to control their diet, both of which help to prevent obesity, the number one risk factor for insulin resistance and, therefore, diabetes. In some women, losing weight can lower insulin levels enough that ovulation can begin and fertility can be reestablished. Weight loss may also help reduce hair growth and endometrial hyperplasia.

Unfortunately, about 50 to 70% of all women with PCOS have insulin resistance and hyperinsulinemia, and the prevalence may be as high as 95% in the ones who are overweight.1 This insulin disorder makes it difficult for such women to lose weight. All the more reason for them to be very aggressive about exercise and diet—especially with regard to carbohydrates, whose release of glucose into the blood is the trigger for insulin release. Here the nutritional concept of glycemic control—selecting foods with low values of the glycemic index so as to slow the rate at which glucose enters the bloodstream—becomes exceptionally important.


†For more on this strategy for losing weight through enlightened nutrition, see “Glycemic Control—Best for Weight Loss” in the September 2007 issue. See also the article “Glycemic Control May Protect Your Vision” in this issue.


Various prescription drugs are used to treat different aspects of PCOS, but none are ideal for their purpose, and all have undesirable side effects. One of many approaches is to treat ovulatory dysfunction by means of drugs, such as metformin and rosiglitazone, that tend to improve glucose metabolism by increasing insulin sensitivity (i.e., reducing insulin resistance). The effectiveness of this therapy is controversial, however, because of somewhat conflicting results.1

Cinnamon—An Alternative to Drugs


Ultrasound image (artificially colored) of a portion of a human polycystic ovary.
An alternative approach was taken recently by a group of medical researchers at Columbia University and the University of Hawaii in collaboration with Dr. Richard A. Anderson, a chemist at the Beltsville Human Nutrition Research Center of the United States Department of Agriculture in Beltsville, Maryland.1 Dr. Anderson is the foremost authority on the use of cinnamon extract as an insulin mimetic, i.e., a substance that mimics the biological actions of insulin. Such a substance can, at least in principle, circumvent the problem of insulin resistance by causing insulin’s functions to be fulfilled via biochemical pathways—whether the same or different as those of insulin—that yield the same results.


‡Anderson and his colleagues discovered this valuable property of cinnamon in 1990 in the course of an extensive study of food items that might be of value in combating insulin resistance. They first identified apple pie, of all things, as having a favorable effect on glucose metabolism, subsequently tracing the effect to the spice mixture used in making the pie, and then to the cinnamon in the mixture.


With that in mind, the researchers undertook a small-scale pilot study testing the hypothesis that a water-soluble cinnamon extract, taken orally, would reduce insulin resistance (improve insulin sensitivity) in women with PCOS.1 The water-soluble portion of cinnamon is preferred because: (1) it contains the desired insulin-mimetic compounds, which are called procyanidins (type A), and (2) it does not contain certain fat-soluble compounds in cinnamon, such as coumarin and cinnamaldehyde, that are potentially harmful in large amounts.

Alpha-Lipoic Acid Fights
Diabetic Polyneuropathy

A common complication of long-term, poorly controlled diabetes is polyneuropathy, a type of nerve damage that usually afflicts the extremities (mostly the legs), starting at the farthest points and gradually working its way in toward the body. Its symptoms, paradoxically, can include either pain or numbness (fire or ice). The condition is caused by chronic hyperglycemia, which damages many parts of the body, including blood vessels and nerves. It affects up to 50% of diabetic patients at some point, and it has a significant impact on quality of life in about 10% of patients.1

In Europe, a commonly prescribed treatment for diabetic polyneuropathy is a sulfur-containing fatty acid called alpha-lipoic acid, which we in America know as a nutritional supplement with exceptionally strong and versatile antioxidant properties (in fact, it’s called “the antioxidant’s antioxidant”). It’s no accident that this compound is useful in the treatment of a complication of diabetes, because for over two decades, it has been widely prescribed (in Europe) for the prevention and treatment of diabetes itself. It cannot cure the disease, though—there is no cure.

Since much of the damage caused by diabetes is believed to be the result, either directly or indirectly, of oxidative stress—the cumulative impact of reactive oxygen species, including free radicals—it makes sense that an antioxidant would be beneficial in preventing or alleviating such damage. Clinical and laboratory studies have shown that alpha-lipoic acid can reduce the symptoms of advanced diabetes, such as cataract formation and vascular damage, in addition to polyneuropathy.2*


*For more on the varied health benefits of alpha-lipoic acid, see “Lipoic Acid Helps Quench the Fire of Burning Mouth Syndrome” (November 2002), “Lipoic Acid Helps Restore Smell and Taste” (May 2003), “Lipoic Acid Helps Fight Diabetes” (December 2003), “Lipoic Acid May Help You Lose Weight” (September 2004), “Can Lipoic Acid Fight Diabetes-Induced Impotence?” (April 2006), and “α-Lipoic Acid May Help Keep You Sharp” (December 2006).


Recently a group of physicians at the Mayo Clinic published a paper prompted by a question put to them by a patient, a 70-year-old man with a 15-year history of type 2 diabetes and, for the last 3 years, numbness and burning pain that began in his feet and then spread up to his ankles.1 He showed up with a bottle of alpha-lipoic acid and asked if it might be helpful for these symptoms.

The doctors decided to examine the scientific literature on this matter. Their search turned up ten studies, of which only one involved orally administered alpha-lipoic acid rather than intravenous.3 It was selected as the best available evidence to answer the man’s question.

The randomized, double-blind, placebo-controlled trial involved 181 patients, aged 18–74, in Russia and Israel, who had diabetic polyneuropathy. For 5 weeks, they received alpha-lipoic acid daily in one of three amounts: 600, 1200, or 1800 mg. They were evaluated using a rating system called the Total Symptom Score (TSS), a summation of the presence, severity, and duration of the four main neuropathic symptoms: lancinating pain (a sharp, cutting pain), burning, paresthesia (prickling or tingling sensations), and asleep numbness.

In their paper, the Mayo Clinic doctors gave a critical analysis of the study, examining its weaknesses. They concluded that: (1) all three oral doses of alpha-lipoic acid were effective in reducing the patients’ neuropathic symptoms (by at least 50%, as assessed by the TSS), and (2) all three doses were effective in providing good to very good self-reported patient satisfaction. Adverse events, such as nausea, vomiting, and vertigo, occurred mainly with the two higher doses, not with 600 mg, which was well tolerated.

One hopes that the man was satisfied with their conclusions (they didn’t say).

References

  1. Tang J, Wingerchuk DM, Crum BA, Rubin DI, Demaerschalk BM. Alpha-lipoic acid may improve symptomatic diabetic polyneuropathy. Neurologist 2007;13(3):164-7.
  2. Packer L, Kraemer K, Rimbach G. Molecular aspects of lipoic acid in the prevention of diabetes complications. Nutrition 2001;17(10): 888-95.
  3. Ziegler D, Ametov A, Barinov A, Dyck PJ, Gurieva I, Low PA, Munzel U, Yakhno N, Raz I, Novosadova M, Maus J, Samigullin R. Oral treatment with α-lipoic acid improves symptomatic diabetic polyneuropathy: the SYDNEY 2 trial. Diabet Care 2006;29:2365-70.

The study involved 13 women, average age 31, with an average body mass index (BMI) of 29, i.e., they were considerably overweight but not quite obese. All of them had polycystic ovaries as well as oligomenorrhea or amenorrhea; four of them showed abnormally elevated testosterone levels. They did not have diabetes, but their average level of insulin resistance (a calculated value) was greater than that of a group of 12 normally ovulating, nonobese women who had been studied previously and whose calculated values of insulin resistance were presumably not clinically significant.

Cinnamon Reduces Fasting Glucose and Increases Insulin Sensitivity

Of the 13 women in the new study, 6 were randomly allocated to the cinnamon test group, and 7 served as controls. For 8 weeks, they received either 333 mg of the water-soluble cinnamon extract 3 times daily, or placebo. At the end of that period, there had been no changes in BMI or testosterone or estradiol levels in either group. In the control group, the fasting glucose levels decreased significantly, by 8% (presumably owing to the placebo effect). In the cinnamon group, however, they decreased more than twice as much, by 17%; it’s the difference between these values that matters.

In the cinnamon group, three different measures of insulin resistance showed significant improvement, indicating increased insulin sensitivity, and for two of them, the post-treatment values were not statistically different from those of the normal women mentioned above. In the control group, by contrast, none of these measures of insulin resistance was changed. There were no reported side effects from the cinnamon.

Cinnamon Increases Glucose Uptake and Glycogen Synthesis

These results were in accord with those of previous studies by Anderson and his colleagues. In laboratory experiments, they had discovered that the powdered extract of bark from the cinnamon tree (Cinnamomum cassia) showed a strong ability to increase both the uptake of glucose by mouse adipocytes (fat cells) and the synthesis of glycogen, a polymeric form of glucose that the body stores, primarily in muscle and liver tissue, as a reserve source of energy for use on demand. These actions very effectively mimicked those of insulin. The scientists also found that cinnamon mitigated experimentally induced insulin resistance in rats.

And in a 40-day study of middle-aged patients with type 2 diabetes, they found that 1000 mg of oral cinnamon extract daily reduced fasting glucose levels (by 16%), as well as triglycerides, LDL-cholesterol (the “bad cholesterol”), and total cholesterol. German researchers subsequently confirmed cinnamon’s reduction of fasting glucose levels in diabetic patients in that country.§


§For discussions of these studies, see “Revitalize Yourself: Cinnamon Extract for Healthy Blood Sugar” (March 2002), “Cinnamon Reduces Blood Sugar and Cholesterol Levels” (February 2004), “For Good Health, Resist Insulin Resistance!” (June 2004), “Controlling Blood Sugar with Cinnamon” (December 2005), and “Cinnamon Reduces Blood Sugar in Diabetic Patients” (July 2006).


Steer a Healthy Course with Cinnamon

For those who are concerned with PCOS, the small study described above is suggestive but far from definitive. As the authors stated, “Clearly, a large, prospective, randomized, placebo-controlled trial involving a greater number of patients and a longer treatment duration would be needed to validate the findings of this pilot study.”

True, but this study does provide yet one more piece of evidence “piloting” us in the direction of understanding that cinnamon could be a most valuable asset in our lifelong quest to stay healthy, and to make our life long. It’s never too late—and perhaps none too soon—to spice up your life with cinnamon.

Reference

  1. Wang JG, Anderson RA, Graham GM III, Chu MC, Sauer MV, Guarnaccia MM, Lobo RA. The effect of cinnamon extract on insulin resistance parameters in polycystic ovary syndrome: a pilot study. Fertil Steril 2007;88(1): 240-3.


Will Block is the publisher and editorial director of Life Enhancement magazine.

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