Unnatural approach to diabetes

Mulberry leafThis post is almost six years old, but still attracting about 10,000 readers annually. There is so much interest in herbal remedies and alternative medicine, but I remain highly skeptical of many of the claims.

As regular readers will be aware, I’m very skeptical of unwarranted health claims for herbal and other remedies. Usually, these will claim to cure everything from premenstrual cramps to cancer by way of motor neurone disease and ingrowing toenails, all of them, with one pill. Forgive my flippancy, but the claims of many of those touting such panaceas usually beggars belief.

But some offer quite convincing claims for treating, but not necessarily curing, a specific illness with something novel. One such email arrived recently from a public relations company representing a company selling a herbal supplement. The release discusses the potential of an extract of mulberry leaf to prevent concentration spikes in the blood sugar of patients with Type 2 diabetes mellitus.

This disorder, which is on the increase in the developed world as obesity incidence rises, is characterised by insulin resistance, relative insulin deficiency and hyperglycemia (raised blood sugar levels). Changes in diet and more exercise can often ameliorate the effects in the early stages, but medication and insulin are usually needed in the long term. The main problem is the sharp rises and falls in the concentration of glucose in the blood, which puts a severe strain on the organs, in particular the heart.

The email I received, had the subject line “Type 2 diabetes: a look at natural alternatives to prescription drugs” and seemed innocuous enough. It mentioned the FDA’s pronouncements on diabetes drugs and the need to tighten up on their safety and then went on to highlight mulberry, a natural product that is now being marketed as Glucocil, which can purportedly help prevent those hazardous blood sugar spikes.

According to the press release, mulberry has been used for generations in Chinese medicine and some Indian foods, is showing great promise for Type 2 diabetes sufferers. After seven years of research and development, a medical researcher and scientist from China, Lee Zhong, has discovered a proprietary mulberry leaf extract that has been shown in numerous clinical trials to markedly lower blood sugar levels in Type 2 diabetics, helping them achieve a healthier diet and lifestyle. I asked Zhong for a few details about his work, the efficacy of this food supplement and possible medical issues associated with its use. You can read more about the study in the latest issue of Reactive Reports.

Zhong explains that, “Mulberry leaf is a natural α-glucosidase inhibitor. α-glucosidase
inhibitors do not lower blood sugar levels, they reduce and delay the abrupt elevation of blood sugars after a meal, therefore stabilize blood sugar levels. π-glucosidase inhibitor drugs, such as Acarbose, are found to 1) reduce diabetic cardiovascular risks 2) be good for weight management 3)
prevent pre-diabetics to become type 2 diabetics.” Zhong and colleagues have published positive results on pure mulberry extract in the journal Diabetes Care, see reference.

It all sounds reasonable so far. But, what is not clearly mentioned in the press release is that Glucocil is not simply mulberry extract. Rather it is a blend of different ingredients:

  • Mulberry leaf extract
  • Cissus sicyoides (Insulina) leaf extract
  • α-lipoic acid
  • C. quadrangularis extract
  • Banaba leaf extract
  • Chromium polynicotinate
  • vitamin B1, B6, B9 (folic acid), and B12

I asked Zhong about the presence of that chromium salt, as chromium deficiency has long been suggested to be a factor in the development of diabetes. “Chromium was not included in the extracts that used in our published clinical studies (or the efficacy tests),” he told me, “The ingredients used in the final Glucocil formula have records of many years’ safe human usage.” He adds that, “Glucocil was not developed overnight. We had thousands of tests and have plenty scientific evidence to support the product.”

That’s as maybe, but, I think he missed my point, it’s not the safety of the formulation that concerns me, although chromium picolinate has been linked to liver toxicity (Eur J Intern Med. 2002, 13, 518-520), it’s how it can be marketed as a natural product when it so obviously contains a rather non-natural ingredient in the form of that chromium salt. It seems especially odd given that chromium itself is thought to have an effect on diabetes, although that’s as yet unproven.

Aside from the clinical trials and tests carried out with mulberry in isolation, as far as I know, no double-blind placebo-controlled trials have been carried out on the mixed formulation that includes the chromium salt, which has variously been used as a “natural” slimming aid without serious proof of efficacy. Chris Leonard, Director, Translational Research and Technology at Memory Pharmaceuticals, points Sciencebase readers to what he describes as a “thoughtful and well-referenced discussion on chromium and diabetes.

Pharmacologist and toxicologist Sanjeev Thohan, Research Director at drug discovery company Exelixis, adds that chromium picolinate is quite distinct from the hexavalent form of chromium made infamous by the Erin Brokovich issue. He points out that there have been some clinical trials conducted within the last year that use different derivatives of chromium picolinate and that these are close to finishing and will make their data available in the next year or two. He adds that one must, “Remember that the bioavailability of the picolinate derivative and its action on the beta cells is what will determine if there is a positive effect on insulin. Insulin sensitizer drugs, I believe in some of the clinical trials, are being used with the chromium compounds to see the possibility of synergy.” Thohan highlights an additional UK government PDF resource on chromium. The US government’s PDF document on dietary recommendations for vitamins and trace elements also includes a section on chromium.

Zhong adds that, “This product is being marketed as a dietary supplement (not a food or drug) and is designed to assist those who are trying to manage their condition primarily through changes in lifestyle, primarily diet and exercise.” But, to my mind, something with proven activity in such a potentially debilitating disease should not be marketed as a supplement. Consumers should be made aware of the dangers of diabetes and consult their doctor over possible treatments and outcomes.

Zhong tells me that the marketing does stress that potential users talk to their healthcare workers and that they should monitor their blood sugar carefully. However, one in ten, he concedes, don’t necessarily do so. With diabetes on the rise, one in ten could turn out to be quite large numbers of people using an apparently potent supplement without any clear knowledge of what it might be doing to their bodies and without strictly monitoring the progression of their disease.

“Generally speaking, those who are most interested in this product are those who are newly diagnosed and are not on multiple meds as is the case with those who are more seriously ill,” adds Zhong, “The typical Glucocil consumer is someone who is looking for more natural nutritional support.”

Yes, there are problems with pharmaceutical products. But, maybe its time physiologically active herbal remedies were brought under the pharma umbrella rather than being sold disguised as food supplements. Indeed, there are calls for this to happen in Europe and elsewhere. This way, not only would they gain acceptance or rejection quickly, but those that are truly effective and worthy, and safe, would reach the patients who really need them and lose the downy feathers of alleged quackery.

UPDATE: There’ll be a post on the regulations debate on Sciencebase, July 23, so grab the site newsfeed to keep up to date or sign up here to get the item delivered by email.

Mudra, M., Ercan-Fang, N., Zhong, L., Furne, J., Levitt, M. (2007). Influence of Mulberry Leaf Extract on the Blood Glucose and Breath Hydrogen Response to Ingestion of 75 g Sucrose by Type 2 Diabetic and Control Subjects. Diabetes Care, 30(5), 1272-1274. DOI: 10.2337/dc06-2120