Sample Dissertation (shortened) : YERBA MATE AND INSULIN RESPONSE


I Introduction

This study intends to obtain information and evidence on yerba mateine tea and its capability as a treatment approach to diabetes Type 2, a better understanding of the aging process, AGEs, diabetes as a disease, the current therapies and the effects of herbs on disease. The purpose is to test or determine the efficacy of yerba mate in reducing blood sugar levels. The results of the study will add to the current options to the treatment or treatment adjuncts to diabetes. The study is limited to the sample of volunteers to the experiment on the efficacy of the tea on their symptoms.


Diabetes is a chronic metabolic disorder, which affects the body’s ability to use blood sugar for energy.

Insulin is an important hormone produced by the pancreas. It is also a medication used to treat diabetes.

Yerba Mate is a commercial product derived after drying and shredding of the leaves and young twigs of the holly tree, Ilex Paraguayensis.

Mateine is the methylxanthine compound content of yerba mate, which is very similar to caffeine but lacks many of the negative side effects of caffeine.


II Review of Literature



Diabetes is a chronic disorder of carbohydrate, fat and protein metabolism, characterized by abnormally high sugar levels, especially after meals (Modak et al 2007). Global prevalence and incidence are expected to increase from 4% in 1995 to 5.4% by 2025, mostly in developing countries, according to the World Health Organization. In India alone, approximately 33 million adults are already afflicted and the incidence is predicted to increase to 57.3 million by 2025. Diabetes mellitus is due to either insulin insufficiency or insulin dysfunction. It is classified into Type I and Type II. Type I is caused by insulin insufficiency in turn because of the lack of functional beta cells. There is complete dependence on external sources of insulin. Type II, the more common type at 90%, is caused by the body’s inability to respond to insulin. It is manageable with dietary adjustments, exercise and medication. Symptoms of both types include high blood sugar levels, extreme thirst, frequent urination, extreme hunger and weight loss, blurred vision, nausea and vomiting, extreme weakness and tiredness, irritability and moodiness. The true and ultimate cause of diabetes remains unknown, but current evidence links free radicals to the disorder and its complications. Free radicals are believed to damage cellular molecules, DNA, proteins, proteins and lipids. These, in turn, affect and change cellular functions. A multi-factorial disease, diabetes leads to several complications which, in turn, require a range of therapeutic approach. Type I patients are given insulin injections. But Type II patients are prescribed different drugs to address disturbed carbohydrate metabolism. However, high cost and side effects limit the action of these therapies. Side effects include hypoglycemia, weight gain, gastrointestinal disorders, and liver toxicity. Recent discoveries have demonstrated the capability of antioxidants in neutralizing free radicals, preventing diabetes in animals, and reducing its complications (Modak et al).

Medicinal plants are considered to fill the gap and limits of treatment. Conventional drugs have been developed from the prototypic molecules of medicinal plants that can lower blood sugar level (Modak et al 2007). There are now more than 400 traditional plant treatments for diabetes, some of which have been confirmed effective in animal and human models for Type II. The World Health Organization Expert Committee on Diabetes encouraged further studies on medicinal herbs for the purpose. The main obstacle, however, is the lack of scientific and clinical data on their efficacy and safety. There is also a need to develop simple bioassays for biological standardization, pharmacological and toxicological evaluation and different animal models as regards their toxicity and safety. The active components of these plant extracts must also be identified (Modak et al).


The Aging Process and Diabetes

A number of theories have been proposed on how people age, among them the Neuro-endocrine Theory of Aging (Parrish 2009). This theory of aging was first suggested by Russian gerontologist Vladimir Dilman. It states that aging occurs and begins when receptors and secretory cells in the limbic system, hypothalamus and the pituitary lose their sensitiveness to hormones controlling them. The limbic-hypothalamic-pituitary axis and the end organ receptor sites in the thymus, adrenals, thyroid, ovaries and testes slow down. When the neuro-endocrine axis becomes less efficient and functional, the body goes out of balance. This increases the risk for major diseases, such as atherosclerosis, hypertension, diabetes, cancer and autoimmune disorders. Dr.Dillman’s associate, Dr. Ward Dean proposed a related theory, the Cross-linking Theory of Aging. Neuro-endocrine imbalance can lead to cross-linking, a destructive process. Cross-linked proteins have been associated with diabetic complications. Recent findings, however, showed that cross-linking proteins relate to other diseases, such as Alzheimer’s Disease, osteoporosis, arthritis, kidney disease, cataracts and aging skin. Cross-linking has also been observed to increase LDL or bad cholesterol (Parrish).

A Theory of Aging

This theory states that cross-linking occurs when a sugar links with a protein molecule (Parrish 2009). Cross-linking starts with the Maillard reaction, wherein the protein and the carbohydrates undergo chemical changes. Advanced glycation end products or AGEs are among these changes. Skin damage is one of the most visible effects of AGEs. Glycation products are produced in slowly renewing tissues, including the skin, during aging. These products increase the volume of cell death in the skin, destroy collagen, and reduce skin elasticity. Slowly metabolizing collagen proteins become more susceptible to these changes. Accumulated AGEs in skin collagen and the resulting structural changes impair skin tissue properties. This explains increased stiffness and decreased skin elasticity (Parrish).

Studies on the Theory

One study investigated the effects of AGE in rats by feeding them with high-fructose diet for three weeks to induce hyperglycemia (Parrish 2009). Results showed a substantial increase in AGEs in the aortas and in the skin of three of the mice. One vitro study revealed high AGE production, causing the rapid aging of young skin after glucose exposure. Another in vitro study showed increased cell death of human skin fibroblasts when exposed to AGEs. Antioxidant N-acetyl-cysteine and carnosine reduced skin cell death. Another recent study demonstrated the action of antioxidant lipoic acid in protecting AGE-exposed skin. Rats fed with high fructose diet were later fed with lipoic acid for 45 days. High-fructose feeding caused substantial cross-linking a shown by enhanced glycation and AGEs. But these changes were alleviated by lipoic acid, which had positive effect on collagen integrity (Parrish).

Similarly, the Maillard reaction produces a Schiff base when sugars combine with proteins (Parrish 2009). Schiff base is converted into a harmful product called Amadori. Amadori products become destructive substances when changed into AGEs. AGE molecules soon react and form unbreakable cross-links with fats, proteins and nucleic acids. These AGEs accumulate through aging. This condition occurs especially when the limbic-hypothalamic-pituitary axis is poorly regulated. Normal blood glucose concentrations become poorly regulated and block intracellular uptake of insulin and glucose. These lead to increased glycation and AGE production (Parrish).

AGEs and Disease

AGEs tend to intensify diabetic complications, such as diabetic retinopathy, neuropathy and cardiovascular diseases (Parrish 2009). Researchers now recognize the role of AGE production in the onset of diabetic atherosclerosis. They also recognize the close link between AGE and insulin sensitivity in fat cells. Specifically, they found that AGE inhibited glucose uptake and increased the production of free radicals, reactive oxygen species or ROS in fat cells. Researchers also saw the connection between AGEs and obesity-associated glucose intolerance, Alzheimer’s Disease, and osteoporosis. AGEs are known to accumulate beta-amyloid plaques. AGEs trigger chronic oxidative stress in Alzheimer’s Disease to which these plaques are, in turn, linked. Pentosidine, a type of AGE, increases substantially during aging and associated with bone mass density at this stage (Parrish).

The Diet and AGEs

AGEs are produced in the body not only because of imbalanced metabolic processes but also by high-glycemic cooked foods (Parrish 2009). Sugars, white bread, bakery products and other Age-rich foods are among these. Modern food processing is also responsible for foods with increased AGE levels. Even infant formulas have been found to have high AGE levels. This means that AGE production begins from infancy. AGEs in the diet produce destructive effects in the body. They increase free radicals, reduce glutathione levels, and increase the negative effects of bad cholesterol or LDL.A group of 24 diabetic subjects was studied for their LDL levels. They were put on a high-AGE diet. Upon testing, they experienced more free radical damage and became more susceptible to glycation than those who consumed a low-AGE diet. Oxydized, glycated LDL produced inflammation in those exposed to AGEs. The results also showed increased risk for heart disease. The researchers concluded that exposure to dietary AGEs increase LDL-induced vascular toxicity. But the condition can be prevented by dietary AGE restriction (Parrish).

Yet this is not absolutely followed in the real world. Even those who habitually avoid blood-sugar-raising foods cannot always actually avoid them (Parrish 2009). In preparing for these unavoidable occasions, there should be a secondary defense against the foods. These are natural AGE blockers N-acetyl cysteine or NAC, lipoic acid, amino acids carnosine and histidine, guava, benfotiamine and yerba mate. NAC stops AGEs from inciting LDL cholesterol to become more destructive. A study of 24 diabetic volunteers showed that NAC inhibited the inflammatory effects of AGE-exposed LDLs. It also blocked the action of AGE-triggered production of sticky platelets, which can lead to atherosclerosis. NAC increased glutathione and thus reduced lipid peroxidation due to exposure to AGEs. Researchers concluded that NAC can help protect brain tissue from lipid peroxidation and its consequences, occurrences observed in Alzheimer’s Disease (Parrish).

Other studies offer evidence of how NAC decreased cell death and free radical damage in retinal cells exposed to AGEs in vitro (Parrish 2009). Cells were exposed to dietary AGE sources and diabetic subjects. This cell death is similar to that, which occurs during diabetic retinopathy in human subjects. The researchers applied NAC, which prevented the decrease of glutathione, a potent antioxidant. NAC already demonstrated potency against AGEs’ ability to induce insulin resistance in fat cells. A study showed that NAC completely reversed AGEs’ effects on insulin and glucose uptake by fat cells.

Other studies showed the substantial inhibiting activity of lipoic acid against AGE formation with experimental rats fed with high-fructose diet (Parrish).

Amino acids carnosine and histidine have also been shown to retard or even reverse the glycation process (Parrish 2009). Immune cells, called macrophages, eat the oxidized and altered LDL cholesterol. Atherosclerosis begins at this point. Increasing amounts of glycated LDL cholesterol combine and block the arteries. Thorough studies revealed that these amino acids can inhibit LDL glycation and oxidation. Carnosine is also a promising approach to Alzheimer’s Disease, an AGE-induced cognitive dysfunction. Glycated protein builds up in the cerebrospinal fluid of AD patients and is found in the neurofibrillary connections in the brains of such patients. This demonstrates the link between AGEs and AD. Carnosine suppresses amyloid-beta peptide toxicity, counteractions the production of oxygen free radicals and suppresses protein glycation. Carnosine interrupts the decomposition of Schiff bases before they can develop into AGEs (Parrish).

The polyphenolic contents of guava and yerba mate extracts explain their AGE-blocking capability (Parrish 2009). A study conducted this year suggested that guava extract possesses a significant and inhibitory dose-dependent effect on LDL glycation.

Yerba Mate, on the other hand, has been shown to possess about 2-2.5 higher polyphenol concentration than green tea. The AGE-inhibiting effect of yerba mate was demonstrated in the second phase of the glycation reactions. At this point, yerba mate prevented the conversion the Amadori products to AGEs. This action was furthermore comparable to that obtained through the use of the standard anti-glycation agent, aminoguanidine (Parrish).

Benfotiamine is a form of vitamin B1 in significantly reducing AGEs (Parrish 2009).

This was the finding of a study involving 13 type-2 diabetic subjects, who were first fed with a high AGE meal without benfotiamine. Their AGE levels increased. Then they were fed with 1,050 mg per day of benfotiamine for 3 days. AGE formation significantly decreased. Experimental diabetic mice fed with benfotiamine prevented the vascular accumulation of AGEs as well as hastened the healing of their diabetic limbs (Parrish).

AGEs clearly play an important role in many of the major chronic, degenerative diseases linked to aging (Parrish 2009). AGEs have also long been connected with diabetic complications. New research further showed that they influence cognitive and bone health, encourage the development of insulin resistance and transform LDL cholesterol into a more destructive form to the cardiovascular system. Fortunately, there are many natural AGE blockers that can be used to prevent or fight AGEs and promote overall health (Parrish).


Current Mainstream Treatments of Diabetes

Dietary Therapy

The ideal therapy is a regimen that will maintain significant weight loss for 90% of all diabetics (Bell 2002). At present, this therapy is still non-existent. Only radical bariatric surgery can bring about prolonged and significant weight loss. The ideal body weight is first computed in order to prescribe a diabetic diet. This is done by adding 5 pounds for every inch in excess of 5 feet to 100 if a woman and adding 6 pounds if a man. Ten percent is added or subtracted for a large or small frame, respectively. To obtain basal caloric needs, multiply the ideal body weight by 10, compute for 40% then add 20% according to usual level of physical activity. In order to lose one pound of fat per week, for example, 500 calories per day or 3,600 per week. The ideal diabetic aims at losing one to two pounds per week. A minimum of 5% weight loss will significantly and disproportionately decrease insulin resistance and improve glycemic control (Bell).

Exercise Therapy

Exercise is an ideal part of the diabetic regimen and therapy. It is a potent non-pharmacologic but under-utilized tool in therapy that lowers insulin resistance and improves glycemic control (Bell 2002). Walking for at least 150 minutes or 2.5 hours per week lowers insulin resistance. Diabetes can also be prevented if a non-diabetic walks five miles per week. This reduces the incidence by 6%. The decrease is greater among those at higher risk, such as the obese and those with a family history. Exercise should form part of prescriptions for almost all diabetic patients. Those who are least physically unfit are often at the greatest risk of the disease and the highest mortality rate (Bell).

Oral Medications

When diet and exercise fail as first-line therapy, sulfonylurea is introduced (Bell 2002). If sulfonylurea becomes ineffective, insulin is added or substituted. The six classes of oral medications to choose from are sulfonylurea, repaglinide, nategenide, metformin, aglucosidase and thiazolidinediones. The first three classes work alike, at different points and for different durations on the sulfonylurea receptor. They all close the energy potassium channels in the wall of the beta cell of the pancreas. This leads to an influx of calcium, depolarization of the beta cell and an increased release of insulin. Metformin decreases glucose production in the liver and reduces insulin resistance in the myocyte and adipocyte. It does this by mobilizing glucose to the surface of the cell. Its anorectic effect on weight loss also reduces insulin resistance. A-glucosidase inhibitors lower post-meal glucose levels by acting on the a-glucosidase enzymes at the border of the small intestines. And thiazolidinediones improve glycemic control by reducing insulin resistance and glucose output from the liver as well by rejuvenating beta cells. Metformin and the thiazolidinediones also benefit the cardiovascular system. Metformin reduces the number of LDL particles and trigyceride levels, platelet aggregation, fibrinogen levels, plasminogen-activator-inhibitor and coagulation. Metformin also enhances weight loss or stabilization. On the other hand, thiazolidinediones increase LDL particle size, high-density cholesterol levels by up to 19%, and reduce triglyceride levels. These two oral medications decrease the highly sensitive C-reactive protein levels. Animal studies suggested that thazolidinediones decrease the migration and spread of vascular muscle cells. Applied in humans, the drug decreases the formation of atheromatous plaque and coronary artery restenosis after angioplasty. This can mean reduced thickening of carotid arteries (Bell).

Side Effects of Oral Anti-Diabetic Drugs

They all have side effects (Bell 2002). Sulfonylureas may induce weight gain and hypoglycemia. Secretagogues repaglinide, nateglinide and glymepiride theoretically do not stimulate insulin secretion if normoglycemia is present or no food is taken. Metformin should be avoided by patients with creatinine level of 1.5 or above, hepatic decompensation, congestive heart failure, with a history of alcohol abuse or age 80 and over. The major side effects of metformin are nausea, cramps and diarrhea. These occur in 30% of patients also passing and may be treated or avoided by taking the drug after meals and gradually from small doses. Only 3% of patients quit metformin on account of these side effects. Many of them are also lactose intolerant. About 7% of them develop Vitamin B12 deficiency after a year of taking metformin. But This can be prevented by taking calcium supplements and if metformin is taken in the slow-release form (Bell).

Flatulence is the major side effect of a-glucosidase inhibitors (Bell 2002). Undigested carbohydrates, which enter the large bowel are digested by colonic bacteria. This results in flatulence or gas formation. High serum a-glucosidase may induce hepatic necrosis. Glucose tablets should be taken to correct hypoglycemia. Meanwhile, the major side effects of thiazolidines are fluid retention, weight gain and normochromic, normocyte, dilutional anemia. Dilutional anemia is even considered beneficial. The oxygen-carrying capacity of the blood is maintained. Increased plasma volume means a decrease in blood viscosity and better blood flow. Thiazolidines can induce weight gain if they are taken in excess of the needed amount for better glycemic control. In most cases, this develops due to new adipocytes in subcutaneous fat, which is not associated with an increase in insulin resistance. Weight gain can occur because of fluid retention but most likely in higher doses, among obese patients and when combined with insulin. Weight gain from fluid retention in thiazolidines use develops from the excess production of cytokine vascular endothelial growth factor or VEGF. VEGF increases permeability in microcirculation, closes calcium channels and over-stimulates peroxisome proliferation-activated receptor gamma receptors. Loop diuretics, thiazide diuretics and spironolcatone have no effect on the edema. The edema resolves only with drug discontinuation. If the edema responds to diuretics, it is probable that the underlying condition involves high aldosterone levels, such as in congestive heart failure, hepatic dysfunction or renal dysfunction. Any of these conditions is aggravated by the addition of thiazolidinedrione (Bell).

Initial Drug Treatment

If the patient’s C-peptide level is high-normal or high, many physicians administer insulin sensitizers (Bell 2002). If the C-peptide level is low-normal or low, an insulin secretagogue is often used. Metformin is the most popular choice among insulin sensitizers for its ability to induce weight loss or control weight gain through improved glycemic control in addition to its cardio-protective action. The thiazolidinediones, on the other hand, not only decrease insulin resistance and cardiac conditions but also rejuvenate pancreatic beta cells. Hence, the most favored is a combination of metformin and the thiazolidinediones. This combination will not only lower insulin resistance and cardiac conditions but neither drug is associated with severe hypoglycemia. Moreover, metformin’s weight-lowering action can offset the thiazolidinedriones’ weight-gaining action (Bell).

Insulin Therapy

One injection a day is given in addition to an oral regimen (Bell 2002). The injection is glargine, NPH or lente insulin at bedrime or premixed at 70/30 or 75/25 at dinner time. Some doctors prefer giving glargine insulin at bedtime in order to lower fasting glucose level with the likelihood of lower night hypoglycemia. Lowering fasting glucose level to less than 110 mg/dL will enhance the action of oral drugs to control glucose level during the day. When this is lost, glucose level control may be achieved with 2 mixe insulin injections in the morning and at dinner time. A short-acting insulin injection may also be given before each meal with the basal insulin from glargine. Better insulin control may be expected with one or two insulin sensitizers along with the insulin (Bell).

Treatment of both Types 1 and 2 Diabetes has been revolutionized by the discovery and availability of insulin sensitizers, more and better insulin secretagogues and more short and long-acting insulins in the last five years (Bell 2002). The goal of bringing down HbA1c at 7% among Type 1 and 6.5% or less in Type draws closer because of these revolutionary discoveries. They can be instrumental in bringing the incidence and prevalence of both the microvascular and macrovascular complications of diabetes. These miscrovascular complications are retinopathy, nephropathy and neuropathy. Macrovascular complications are ischemic heart disease, peripheral vascular disease and carotid artery disease (Bell).


Herbal Treatment of Diabetes

Herbs have always been considered a powerful tool in treating disease and illness since earliest times (Diabetes Symptoms 2010). People who lived in areas without doctors or which are inaccessible to doctors had to invent ways to deal with their illness on a daily basis. They took recourse to herbs and plants for the need. They found that herbal treatments could be far superior to chemical or synthesized medicines in effectiveness, safety and economy. The value of herbal treatments is especially relevant to diabetic individuals because of the high cost of traditional or conventional treatment. Many of them have sought these herbal remedies for their individual conditions. The remedies do not produce standard response to all their users. They also remain unregulated and not standardized. As such those who take them take a risk despite the natural ingredients of the remedies. They are, therefore, often taken in significant amounts. Diabetics who take herbal remedies may say they feel better but find no actual change in their blood sugar levels (Diabetes Symptoms).

The purpose of all diabetic medicine is to lower blood sugar (Diabetes Symptoms 2010). However, diabetic drugs also increase the risk of heart attacks. Furthermore, they can cause headaches, weight increase, nausea, diarrhea, stomach pain and higher cholesterol and triglyceride levels. Better alternatives may come from nature in the form of trees, herbs, animals, plants and even insects. Western medicines are, in fact, synthesized from the compounds that come from natural sources to combat disease. They have been in use for thousands of years for various disorders and ailments. Synthesized Western medicines have utilized only a small portion of what nature has made available. Lost medical practices of ancient times have been rediscovered. Much time, careful tests and financing, however, are needed to establish the efficacy of time-honored medicinal plants. Nonetheless, nature’s diversity and pharmacology will cooperate to provide just the potent cure to man’s dread diseases (Disease Symptoms).

The common goal of alternative program with traditional medicine is the repair and restoration of the body’s control of blood sugar (Disease Symptoms 2010). Scientific studies offer evidence on the effectiveness of herbal medicines. Many plants have hypoglycemic properties and can help non-insulin-dependent diabetic patients. These herbs will, however, not be valuable to insulin-dependent patients, as they cannot replace insulin. Plants, which have been screened and proven to possess hypoglycemic properties, include bilberry Bilberry (Vaccinium mytillus), garlic (Allium sativum), goat’s rue (Galega officinalis), mulberry leaves (Morus nigra), and olive leaves (olea europaea) (Diabetes Symptoms).

Latest statistics say that 6.2% or 17 million Americans have diabetes (Diabetes Symptoms 2010). These 17 million people must spend up to $54 billion to fight for their lives or die prematurely. They also incur $44 billion on indirect costs due to work loss and disability. Some medicinal herbs have passed clinical tests and are now in the market. They seem most effective and non-toxic. These are pterocarpus marsupium, bitter melon, gymnema, fenugreek, blueberry leaves and Asian ginseng (Diabetes Symptoms).

Pterocarpus Marsupium

This is also known as Indian Kino, Malabar Kino, Pitasara and Venga (Diabetes Symptoms 2010). It is derived from the Kino tree, a popular Indian medicine. It looks dried blood and has been used in India to treat diabetes. Pancreatic beta cells have been observed to be regenerated by the combination of crude alcohol and epicathechin of this herb. This has not been observed in any natural or synthetic agents or drugs (Diabetes Symptoms).

Bitter Melon

Its scientific name is momordica charantia (Diabetes Symptoms 2010). It is a tropical vegetable, which grows widely in South America, Africa, and Asia. Also known as Balsam Pear, it is used as folk medicine for diabetes. Clinical and experimental studies have shown that its unripe fruit lowers blood sugar. It possesses compounds with anti-diabetic properties, such as charantin, a hypoglycemic agent. Charantin is extracted by alcohol and mixed with steroids. It is as potent as tolbutamide, a mainstream medicine used to treat diabetes. Another compound, momordica, an insulin-like polypeptide, also lowers blood sugar levels when injected into a type 1 diabetic patient or sipped in juice form at 50-60 ml (Diabetes Symptoms).

Gymnema Sylvestre

This herb is also called gurmar, meshasringi or cherukurinja (Diabetes Symptoms 2010). This compound helps the pancreas produce insulin in type 2 Diabetes. It helps both type of diabetes in improving the ability of insulin to reduce blood sugar levels. It decreases the natural craving for sweets. It is a valuable alternative to oral drugs for lowering blood sugar levels in type 2 diabetics (Diabetes Symptoms).


Its scientific name is trigonella foenum-graecum (Diabetes Symptoms 2010). Its anti-diabetic capability is backed by clinical and experimental studies. It is attributed to its nicotinic acid, alkaloid trogonellne and coumarin contents in the seed (Diabetes Symptoms).

Blueberry Leaves

Its scientific name is vaccinium myrtillus (Diabetes Symptoms 2010). It has long been used in the treatment of diabetes. Its anthocyanosides content strengthens the capillary, improves the vascular system and prevents free-radical damage. In Europe, it is used to treat diabetic retinopathy and other eye diseases. This capability is attributed to an active agent called myrtillin, an anthocyanoside. It is weaker and less toxic than insulin but a single dose can last for many weeks (Diabetes Symptoms).

Asian Ginseng

The Chinese commonly use this to treat diabetes (Diabetes Symptoms 2010). Their experience shows that it can increase the number of receptors of insulin and improve its release. It can also directly reduce blood sugar level and energy levels for Type 2 diabetes at 200 mg a day (Diabetes Symptoms).

Herbs and Diabetes

Overweight is related to diabetes. Overweight people suffer from endocrine imbalance, which leads to insulin resistance and metabolic disorder (Neustadt 2005). The hormone insulin moves carbohydrates, the body’s main energy source, into the cells for the body’s use. When this does not happen, the blood sugar level rises. The sugars are instead converted b the liver into fat. Diabetic medicines address this abnormality. But botanical supplements can also help restore sensitivity to insulin and improve the metabolic disorder (Neudstat). One type of supplements consists of herbs. They are consumed in combination to prescription drugs to treat Types 1 and 2 Diabetes (Herbs 2000). The herb gymnema sylvestre, which originates from India, can be used to control blood sugar levels. It has been observed that the need for insulin and other hypoglycemic medications is not felt as well as reduced with the use of this herb as supplement. Diabetic nerve damage can also be prevented by taking vitamin B. The mineral chromium effectively reduces cholesterol levels in diabetics. The pain of diabetic neuropathy may be reduced by taking in essential fatty acids, which protect against nerve damage. Nerve damage is common among those with diabetes. Fish oils as supplements may also increase HDL, the good cholesterol, and reduce the risk and potential heart disease. There are supplements containing antioxidant compounds, which can prevent this damage to the nerves, eyes and the heart. Vitamin E can also prevent or block the extreme build-up of plaque. Alpha-lipoic acid can improve glucose metabolism. Many diabetics also lack the mineral zinc, which helps the body use insulin. Zinc contributes to faster healing of injuries, which slows down because of high blood sugar levels. Copper, another mineral, combines with zinc as long-term supplement. The herb bilberry may help prevent diabetic eye damage. Taurine can help improve the release of insulin and prevent abnormal blood clotting. Abnormal blood clotting contributes to cardiac problems (Herbs 2000).

Yerba Mate (IIex Paraguariensis)

This is a medicinal plant, which is popularly grown in Paraguay, Brazil and Argentina (USACHPPM 2003). Its leaves are made into popular beverages, like coffee or tea, to relieve physical and mental fatigue and for weight loss. It is also known as Jesuit’s Brazil Tea, Jesuit’s Tea, Paraguay Tea, St. Bartholomew’s Tea. It is used in the form of dried leaf or as a liquid extract. Its caffeine content is believed to relieve physical and mental fatigue and to suppress appetite to control weight. It is, however, recommended for use for short periods of time only. If taken for longer periods, it may be unsafe for possible carcinogenic and toxic effects. Yerba mate contains 4-16% tannins, which increase the risk of cancers, liver toxicity and blood clots. It is also addictive and can develop symptoms of irritability, anxiety, dizziness, and headaches if taken regularly or for long periods. Other possible side effects include insomnia, nervousness, restlessness, stomach upset, nausea and vomiting, irregular heartbeat, and increased blood pressure. Furthermore, combining it with other herbal supplements, such as ephedra or citrus aurantium, may produce other negative side effects. It also interferes with the action of asthma medications, other caffeine compounds, certain antibiotics, cold medications, estrogen, lithium, MAO inhibitors, oral contraceptives and medications for diabetes, migraine and sleep. It is contraindicated for depression and anxiety disorders, heart conditions, hypertension, kidney disease and ulcers. It is not recommend for use by children, pregnant or breastfeeding women ((USACHPPM).


The Guarani Indians were said to have taught the Spaniards how to use Ilex Paraguayensis plant species (Weil 2006). Yerba mate was a household item among the Guarani Indians who used it to strengthen immunity, clean the blood, tone the nervous system, fight fatigue and stress, stimulate the mind and resist illness. The plant was first included in Spanish documents in the 16th century. However, the first to cultivate the plant were the Jesuit missionaries who were recorded as having plantations around 1670. Its economic profitability was recognized only during the 17th and 18th centuries when the plantations declined and were replaced by the inferior yerba de Paranagua by the Christianized Indians around 1820. The forests of the inferior species became overexploited. Attention turned to restoring the yerba mate plantations, an effort led by Argentina, now the leading producer of yerba mate (Weil).

Background and Preparation

Yerba Mate is also knows as Paraguay cayi, Paraguay tea, South American holly, mateteestrauch, Jesuit’s tea, hervea, caminu, kkiro, and kali chaye (Hamre 2010). The herb belongs to the Aquifoliaceae family of medium-sized hollies growing wild and cultivated in Paraguay, Uruguay, Argentina and Brazil. It is now cultivated in other locations particularly for its leaves. It has white flowers, which produce small red, black and yellow berries. Its leaves have to be “deactivated” to release natural enzymes by cutting the branches over an open fire. They can also be blanched before roasting. The leaves have to be dried, roasted and crushed in turning them into the fine, crumbly brown-leaf tea form. The package lists medicinal tonic properties of yerba mate. It induces mental clarity, improves digestion, regulates the appetite, increases endurance, sustains energy levels, strengthens the immune system, relieves allergies and detoxifies the blood. As a popular beverage, it is used as a tonic, diuretic, physical stimulant, appetite suppressant and gastric function regulator throughout South America. In Brazil, it is used to stimulate the nervous and muscular systems and correct digestive problems, renal colic, nerve pain, depression, fatigue and obesity. The leaves are applied to anthrax skin ulcers. Yerba mate is valued for its antioxidant action and as a pep day drink in Europe. A recent survey conducted by IBOPE Argentina found that 92% of Argentina households consume yerba mate (Hambre).

Yerba mate leaves are placed in a cup and cold water is poured to moisten them, followed by hot water to cover all the leaves (Hambre 2010). The tea is sipped in this mixture through the use of a straw, called bombilla. Bombilla has a filter or strainer at the bottom to keep the leaves from coming up the straw. More water is added as the tea is sipped. Some brew the leaves in a coffee pot. It is traditionally shared with family and close friends as part of an informal ceremony (Hambre).

Yerba mate is used as a diuretic or water pill to increase urination, especially among diabetic persons (First Data Bank Inc. 2010). However, it has also been observed to cause side effects. These side effects include flushing, vomiting, irritability, nervousness, more frequent urination, and headache. Yellowing eyes and skin, dark urine, fever, muscle twitching, and slower or faster heartbeat are other observed side effects. Patients with diabetes, alcohol dependence and liver diseases are especially cautioned about drinking yerba mate. Drinkers should not double the dose if one dose is missed (First Data Bank, Inc.).

Caffeine Content

Compared with other valuable phyto-nutrients, yerba mate is said to contain virtually all the essential vitamins, amino acids and minerals (Weil 2006, BiO2 2006, Kilham 2008). These are vitamins A, B complex, E and C. The minerals are magnesium, calcium, iron, sodium, potassium, manganese, phosphates, zinc, niacin, sulfur, chlorophyll, choline and inositol. Dr. Stenhouse was the first to describe its caffeine content in 1843. Caffeine is an alkaloid, which raises energy levels and promotes a sense of well-being. The caffeine content of yerba mate has been referred to as mateine because its mineral and vitamin contents are different from those of other plants containing caffeine, like tea, coffee and guarana. Director Jose Martin of the National Institute of Technology of Paraguay said that the mateine of yerba mate is chemically similar to caffeine without caffeine’s ill effects (Weil, BiO2, Kilham).

Yerba Mate vs Green Tea

A study revealed that yerba mateine inhibits the formation of advanced glycation end-products (AGEs) formation more strongly than does green tea (Lunceford & Gugliucci 2005). Glycation is the non-enzymatic adduct formation between sugar dicarbonyls and proteins. It is a key molecular basis of diabetic complications due to hyperglycemia. The researchers used extracts of yerba with high contents of the antioxidant phenolics for their in vitro anti-glycation experiment. Their objective was to determine if these extracts can inhibit AGE formation in comparison with green tea. The researchers found that the extracts inhibited AGE formation at 40% while green tea properties had no significant effects (Lunceford & Gugliucci).

Yerba mate is among the most popular herbs taken to improve health. It is a favorite among the people of Argentina, Paraguay, Uruguay, and Southern Brazil (Byoaudio 2010). Argentines drink the mateine mostly to increase energy and manage their weight. It is included in the Generally Recognized as Safe beverage list of the Food and Drug Administration. It is considered one of the most healthful drinks in the world. Each drink contains vitamins, minerals and compounds essential particularly to diabetics. A research recently conducted at the University of Madrid disclosed that the mateine is nutritionally valuable. It is anti-inflammatory, antioxidant, antispasmodic, stimulating, thermogenic or fat-burning. It is a vasodilator, helps in weight loss and induces mental clarity (Byoaudio).

Clinically, yerba mate is believed by advocates as balancing blood sugar levels and, as such, promises to be a medicine for diabetes (Byoaudio 2010). Studies showed not only that it inhibits the formation of AGEs but also retards the development of hyperglycemia in experimental mice with diabetes and reduced its symptoms. These medical studies and historical use are the basis of the claim that it reduces the risk of diabetes. A study, which used diabetic mice, found that yerba mate slowed down the development of hyperglycemis in streptozotocin diabetes. At the same time, yerba reduced the hyperphagia, polydipsia, body weight and glycated hemoglobin. Future anti-nitration drugs may be helpful in slowing down the course of diabetes macrovascular complications. In the meantime, flavonoid-rich beverages can be used as alternative co-adjuvant to treatment. Studies suggest that yerba mate extracts are more effective than either green tea or red wine (Byoaudio).

A study conducted on yerba mate at the University of Illinois suggested that it could offer some protection from cancer (Byoaudio 2010). The study aimed at determining the phenolic content of the extracts and their in vitro capacity to inhibit topoisomerase I and II and oral carcinoma cell proliferation. The results were published in the 2005 issue of the Journal of Agricultural and Food Science. Its 2002 US patent states that yerba mate inhibits monoamine oxidase activity by 40-50% in vitro. This suggests its usefulness in treating many disorders. These disorders include depression, attention and focus, mood and emotional disorders, Parkinson’s Disease, extra-pyramidal disorders, hypertension, substance abuse, eating disorders, withdrawal syndromes and cessation of smoking. Other properties and actions attributed to yerba mate are its use as an anti-allergy, anti-depressant, appetite suppressant, blood cleanser, heart tonic, stimulant for the central nervous and digestive systems, hypotensive, nerve calmer, neurasthenic, neuroprotective and purgative (Byoaudio).

A leading researcher on antioxidants and their effects, Dr. Jeffrey Klein, listed the top five reasons for drinking yerba mate (Byoaudio 2010). These are for increased energy and vitality, increased fat burning and weight loss, increased mental clarity and mood, reduced unhealthy cravings, and increased resistance to disease (Byoaudio).


The major nutrients in yerba mate are polyphenols and minerals (Dietary Fiber Food 2009). Among the polyphenols are caffeine, caffeic acid, catechin, epicatechin gallate, and quercetin. They are antioxidants, which fight against oxidative stress, which in turn, produces free radicals. Studies showed that yerba mate’s antioxidant activity is much greater than that of green tea. The caffeine level in yerba mate compares with that of coffee at 78 mg and 85 mg, respectively. Its minerals include aluminum, manganese, potassium, zinc, choline, copper and chlorophyll (Dietary Fiber Food).

These nutrients make yerba mate’s capability to produce healthful benefits. These are to reduce lipid peroxidation, DNA damage and cell death; diabetic risk; and LDL cholesterol oxidation, which often lead to atherosclerosis (Dietary Fiber Food 2009). Yerba mate may also inhibit the toxic effects of some chemicals associated with stroke and myocardial ischemia. It contains chemicals, which tend to reduce cancer risks by inhibiting the growth of cancer cells. It helps in managing and losing weight (Dietary Fiber Food).

The chemicals of yerba mate leaves are caffeine, chlorogenic acid, chlorophyll, choline, nicotinic acid, panthotenic acid, ruin, tannin, theobromine, theophylline, and urolic acid (Dietary Fiber Food 2009). Caffeine is anti-carcinogenic, anti-obesity, antioxidant, diuretic and a vasodilator. Chlorogenic acid is antioxidant, analgesic, anti-atherosclerotic, antibacterial, anti-diabetic, anti-tumor and choleretic. Chlorophyll is anti-bacterial and anti-cancer. Choline is anti-diabetic, cholinergic and lipotropic. Nicotinic acid is cholerecit and hypocholesterolemic. Pantothenic acid is anti-allergic, anti-arthritic and anti-fatigue. Rutin is antioxidant, anti-tumor, anti-ulcer and a vasodilator. Tannin is ant-oxidant, anti-tumor, lipoxygenase-inhibiting and MAO-inhibiting. Theobromine is diuretic, stimulating and a muscle relaxant. Theophylline is diuretic, choleretic, a stimulant, vasodilator and muscle relaxant. And ursolic acid is analgesic, antioxidant, anti-peroxidant, anti-arrhythmic, anti-cancer, and anti-Alzheimer (Dietary Fiber Food).

However, the consumption of yerba mate has also been linked with bladder and oral cancer (Dietary Fiber Food 2009). It may be because of some carcinogenic molecules in yerba mate or external factors like smoking, which consumers of yerba mate, indulge in (Dietary Fiber Food).


Yerba Mate and Cancer Risk

The polycyclic aromatic hydrocarbons or PAHs in yerba mate are known carcinogens associated with certain cancers (Kamangar et al 2008). These are cancers of the esophagus, oropharynx, larynx, lungs, kidneys and bladder. A study of 21 individual PAHs from different brands of yerba mate showed very high concentrations of carcinogenic PAHs in its leaves and the hot and cold mate infusions used for the experiment. The finding added credence to previous hypotheses on the carcinogenicity of yerba mate in connected with its PAH content (Kamangar et al).


III. Design



Results of study show the ability of yerba mateine in inhibiting the formation of advanced glycation end-products or AGEs formation at 40% and better than does green tea. Its polyphenolic contents explain the capability, as demonstrated by experiments to occur in the second phase of the glycation reactions. Yerba mateine prevents the conversion of Amadori products to AGEs. Its major nutrients are polyphenols and minerals. Antioxidants are among these polyphenols, which fight against oxidative stress that produces free radicals, eventually blamed for diseases, especially dread disease like diabetes. Yerba mate’s antioxidant activity was furthermore found to be much greater than that of green tea. Its healthful benefits include reducing diabetic risk.

Method and Sample

This study used the descriptive-normative research method in recording, describing, interpreting, analyzing and comparing data from updated and authoritative sources. A group of 22 volunteer Type 2 diabetics, 14 male and 8 female, aged 46-63, came to the clinic for the experiment. Their latest blood sugar level readings were recorded for comparison. Half of them were given cups of 1 gram of yerba mateine tea and half were given plain water and caffeine drinks. Caution was taken to administer the tea only short-term to avoid possible carcinogenicity. After two hours, their blood sugar levels were tested. Findings revealed that the blood sugar levels of those who consumed plain water and caffeine drinks were relatively unchanged. Blood sugar levels of those who consumed yerba mateine went down only slightly and in only 3 volunteers.

Anticipated Analysis and Assumptions

Animal studies showed that yerba mateine reduces glycation in vitro by inhibiting the conversion of Amadori products to AGEs, believed to produce free radicals, in turn blamed for disease. The strongest substances in yerba mate, caffeic acid and chlorogenic acid, are more effective than the anti-glycation drug aminoguanidine in inhibiting AGE formation. This present experiment conducted on human subjects showed only a negligible positive effect of yerba mate in educing blood sugar levels. More experiments and on larger samples should be conducted to obtain better and clearer results.



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One Reply to “Sample Dissertation (shortened) : YERBA MATE AND INSULIN RESPONSE”

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