Monthly Archives: May 2017

Herbalism

Herbalism (also herbal medicine or phytotherapy) is the study of botany and use of plants intended for medicinal purposes or for supplementing a diet. Plants have been the basis for medical treatments through much of human history, and such traditional medicine is still widely practiced today. Modern medicine recognizes herbalism as a form of alternative medicine, as the practice of herbalism is not strictly based on evidence gathered using the scientific method. Modern medicine makes use of many plant-derived compounds as the basis for evidence-based pharmaceutical drugs. Although phytotherapy may apply modern standards of effectiveness testing to herbs and medicines derived from natural sources, few high-quality clinical trials and standards for purity or dosage exist. The scope of herbal medicine is sometimes extended to include fungal and bee products, as well as minerals, shells and certain animal parts.

Archaeological evidence indicates that the use of medicinal plants dates back to the Paleolithic age, approximately 60,000 years ago. Written evidence of herbal remedies dates back over 5,000 years, to the Sumerians, who compiled lists of plants. A number of ancient cultures wrote about plants and their medical uses in books called herbals. In ancient Egypt, herbs are mentioned in Egyptian medical papyri, depicted in tomb illustrations, or on rare occasions found in medical jars containing trace amounts of herbs. Among the oldest, lengthiest, and most important medical papyri of ancient Egypt, the Ebers Papyrus dates from about 1550 BC, and covers more than 700 drugs, mainly of plant origin. The earliest known Greek herbals come from Theophrastus of Eresos who in the 4th c. B.C. wrote in Greek Historia Plantarum, from Diocles of Carystus who wrote during the 3rd century B.C, and from Krateuas who wrote in the 1st century B.C. Only a few fragments of these works have survived intact, but from what remains scholars have noted a large amount of overlap with the Egyptian herbals. Seeds likely used for herbalism have been found in archaeological sites of Bronze Age China dating from the Shang Dynasty (c. 1600 BC–c. 1046 BC). Over a hundred of the 224 drugs mentioned in the Huangdi Neijing, an early Chinese medical text, are herbs. Herbs also commonly featured in the medicine of ancient India, where the principal treatment for diseases was diet. De Materia Medica, originally written in Greek by Pedanius Dioscorides (c. 40 – 90 AD) of Anazarbus, Cilicia, a Greek physician, pharmacologist and botanist, is a particularly important example of herbal writing; it dominated for some 1500 years until the 1600s.

Herbalists tend to use extracts from parts of plants, such as the roots or leaves but not isolate particular phytochemicals. Pharmaceutical medicine prefers single ingredients on the grounds that dosage can be more easily quantified. It is also possible to patent single compounds, and therefore generate income. Herbalists often reject the notion of a single active ingredient, arguing that the different phytochemicals present in many herbs will interact to enhance the therapeutic effects of the herb and dilute toxicity. Furthermore, they argue that a single ingredient may contribute to multiple effects. Herbalists deny that herbal synergism can be duplicated with synthetic chemicals They argue that phytochemical interactions and trace components may alter the drug response in ways that cannot currently be replicated with a combination of a few potentially active ingredients. Pharmaceutical researchers recognize the concept of drug synergism but note that clinical trials may be used to investigate the efficacy of a particular herbal preparation, provided the formulation of that herb is consistent.

In specific cases the claims of synergy and multifunctionality have been supported by science. The open question is how widely both can be generalized. Herbalists would argue that cases of synergy can be widely generalized, on the basis of their interpretation of evolutionary history, not necessarily shared by the pharmaceutical community. Plants are subject to similar selection pressures as humans and therefore they must develop resistance to threats such as radiation, reactive oxygen species and microbial attack in order to survive. Optimal chemical defenses have been selected for and have thus developed over millions of years. Human diseases are multifactorial and may be treated by consuming the chemical defences that they believe to be present in herbs. Bacteria, inflammation, nutrition and reactive oxygen species may all play a role in arterial disease. Herbalists claim a single herb may simultaneously address several of these factors. In short herbalists view their field as the study of a web of relationships rather than a quest for single cause and a single cure for a single condition.

In selecting herbal treatments herbalists may use forms of information that are not applicable to pharmacists. Because herbs can moonlight as vegetables, teas or spices they have a huge consumer base and large-scale epidemiological studies become feasible. Ethnobotanical studies are another source of information. Herbalists contend that historical medical records and herbals are underutilized resources. They favor the use of convergent information in assessing the medical value of plants. An example would be when in-vitro activity is consistent with traditional use.

Antimicrobial resistance

Antimicrobial resistance (AMR) is the ability of a microbe to resist the effects of medication previously used to treat them. This broader term also covers antibiotic resistance, which applies to bacteria and antibiotics. Resistance arises through one of three ways: natural resistance in certain types of bacteria, genetic mutation, or by one species acquiring resistance from another. Resistance can appear spontaneously because of random mutations; or more commonly following gradual buildup over time, and because of misuse of antibiotics or antimicrobials. Resistant microbes are increasingly difficult to treat, requiring alternative medications or higher doses, both of which may be more expensive or more toxic. Microbes resistant to multiple antimicrobials are called multidrug resistant (MDR); or sometimes superbugs. Antimicrobial resistance is on the rise with millions of deaths every year.

Antibiotics should only be used when needed as prescribed by health professionals. The prescriber should closely adhere to the five rights of drug administration: the right patient, the right drug, the right dose, the right route, and the right time. Narrow-spectrum antibiotics are preferred over broad-spectrum antibiotics when possible, as effectively and accurately targeting specific organisms is less likely to cause resistance. Cultures should be taken before treatment when indicated and treatment potentially changed based on the susceptibility report. For people who take these medications at home, education about proper use is essential. Health care providers can minimize spread of resistant infections by use of proper sanitation, including handwashing and disinfecting between patients, and should encourage the same of the patient, visitors, and family members.

Rising drug resistance is caused mainly by improper use of antimicrobials in humans as well as in animals, and spread of resistant strains between the two. Antibiotics increase selective pressure in bacterial populations, causing vulnerable bacteria to die; this increases the percentage of resistant bacteria which continue growing. With resistance to antibiotics becoming more common there is greater need for alternative treatments. Calls for new antibiotic therapies have been issued, but new drug development is becoming rarer.

The WHO defines antimicrobial resistance as a microorganism’s resistance to an antimicrobial drug that was once able to treat an infection by that microorganism. A person cannot become resistant to antibiotics. Resistance is a property of the microbe, not a person or other organism infected by a microbe.

Bacteria with resistance to antibiotics predate medical use of antibiotics by humans; however, widespread antibiotic use has made more bacteria resistant through the process of evolutionary pressure.

Reasons for the widespread use of antibiotics include:

  • increasing global availability over time since the 1950s
  • uncontrolled sale in many low or middle income countries, where they can be obtained over the counter without a prescription, potentially resulting in antibiotics being used when not indicated. This may result in emergence of resistance in any remaining bacteria.

Antibiotic use in livestock feed at low doses for growth promotion is an accepted practice in many industrialized countries and is known to lead to increased levels of resistance. Releasing large quantities of antibiotics into the environment during pharmaceutical manufacturing through inadequate wastewater treatment increases the risk that antibiotic-resistant strains will develop and spread. It is uncertain whether antibacterials in soaps and other products contribute to antibiotic resistance, but they are discouraged for other reasons.

Food pyramid

A food pyramid or diet pyramid is a triangular diagram representing the optimal number of servings to be eaten each day from each of the basic food groups. The first pyramid was published in Sweden in 1974. The 1992 pyramid introduced by the United States Department of Agriculture (USDA) was called the “Food Guide Pyramid”. It was updated in 2005, and then it was replaced by MyPlate in 2011.

The World Health Organization, in conjunction with the Food and Agriculture Organization, published guidelines that can effectively be represented in a food pyramid relating to objectives to prevent obesity, chronic diseases and dental caries based on meta-analysis though they represent it as a table rather than a “pyramid”. The structure is similar in some respects to the USDA food pyramid, but there are clear distinctions between types of fats, and a more dramatic distinction where carbohydrates are split on the basis of free sugars versus sugars in their natural form. Some food substances are singled out due to the impact on the target issues the “pyramid” is meant to address, while in a later revision, some recommendations are omitted since they follow automatically from other recommendations while other sub-categories are added. The reports quoted here explain that where there is no stated lower limit in the table below, there is no requirement for that nutrient in the diet.

A modified food pyramid was proposed in 1999 for adults aged over 70.

Vegetables

A vegetable is a part of a plant consumed by humans that is generally savory but is not sweet. A vegetable is not considered a grain, fruit, nut, spice, or herb. For example, the stem, root, flower, etc., may be eaten as vegetables. Vegetables contain many vitamins and minerals; however, different vegetables contain different spreads, so it is important to eat a wide variety of types. For example, green vegetables typically contain vitamin A, dark orange and dark green vegetables contain vitamin C, and vegetables like broccoli and related plants contain iron and calcium. Vegetables are very low in fats and calories, but ingredients added in preparation can often add these.

Grains

These foods provide complex carbohydrates, which are an important source of energy, especially for a low-fat meal plan. Examples include corn, wheat, and rice.

Fruits

In terms of food (rather than botany), fruits are the sweet-tasting seed-bearing parts of plants, or occasionally sweet parts of plants which do not bear seeds. These include apples, oranges, grapes, bananas, etc. Fruits are low in calories and fat and are a source of natural sugars, fiber and vitamins. Processing fruit when canning or making into juices may add sugars and remove nutrients. The fruit food group is sometimes combined with the vegetable food group. Note that a massive number of different plant species produce seed pods which are considered fruits in botany, and there are a number of botanical fruits which are conventionally not considered fruits in cuisine because they lack the characteristic sweet taste, e.g., tomatoes or avocados.

Oils and sweets

A food pyramid’s tip is the smallest part, so the fats and sweets in the top of the Food Pyramid should comprise the smallest percentage of the diet. The foods at the top of the food pyramid should be eaten sparingly because they provide calories, but not much in the way of nutrition. These foods include salad dressings, oils, cream, butter, margarine, sugars, soft drinks, candies, and sweet desserts.

Dairy

Dairy products are produced from the milk of mammals, usually but not exclusively cattle. They include milk, yogurt and cheese. Milk and its derivative products are a rich source of dietary calcium and also provide protein, phosphorus, vitamin A, and vitamin D. However, many dairy products are high in saturated fat and cholesterol compared to vegetables, fruits and whole grains, which is why skimmed products are available as an alternative. Historically, adults were recommended to consume three cups of dairy products per day. More recently, evidence is mounting that dairy products have greater levels of negative effects on health than previously thought and confer fewer benefits. For example, recent research has shown that dairy products are not related to stronger bones or less fractures.

Meat and beans

Meat is the tissue – usually muscle – of an animal consumed by humans. Since most parts of many animals are edible, there is a vast variety of meats. Meat is a major source of protein, as well as iron, zinc, and vitamin B12. Meats, poultry, and fish include beef, chicken, pork, salmon, tuna, shrimp, and eggs.

The meat group is one of the major compacted food groups in the food guide pyramid. Many of the same nutrients found in meat can also be found in foods like eggs, dry beans, and nuts, such foods are typically placed in the same category as meats, as meat alternatives. These include tofu, products that resemble meat or fish but are made with soy, eggs, and cheeses. For those who do not consume meat or animal products (see Vegetarianism, veganism and Taboo food and drink), meat analogs, tofu, beans, lentils, chick peas, nuts and other high-protein vegetables are also included in this group. The food guide pyramid suggests that adults eat 2–3 servings per day. One serving of meat is 4 oz (110 g), about the size of a deck of cards.

Vitamin

A vitamin is an organic compound and a vital nutrient that an organism requires in limited amounts. An organic chemical compound (or related set of compounds) is called a vitamin when the organism cannot synthesize the compound in sufficient quantities, and it must be obtained through the diet; thus, the term vitamin is conditional upon the circumstances and the particular organism. For example, ascorbic acid (one form of vitamin C) is a vitamin for humans, but not for most other animal organisms. Supplementation is important for the treatment of certain health problems, but there is little evidence of nutritional benefit when used by otherwise healthy people.

By convention the term vitamin does not include other essential nutrients, such as dietary minerals, essential fatty acids, essential amino acids (which are needed in greater amounts than vitamins) or the many other nutrients that promote health, and are required less often to maintain the health of the organism. Thirteen vitamins are universally recognized at present. Vitamins are classified by their biological and chemical activity, not their structure. Thus, each vitamin refers to a number of vitamer compounds that all show the biological activity associated with a particular vitamin. Such a set of chemicals is grouped under an alphabetized vitamin “generic descriptor” title, such as “vitamin A”, which includes the compounds retinal, retinol, and four known carotenoids. Vitamers by definition are convertible to the active form of the vitamin in the body, and are sometimes inter-convertible to one another, as well.

Vitamins have diverse biochemical functions. Some, such as vitamin D, have hormone-like functions as regulators of mineral metabolism, or regulators of cell and tissue growth and differentiation (such as some forms of vitamin A). Others function as antioxidants (e.g., vitamin E and sometimes vitamin C). The largest number of vitamins, the B complex vitamins, function as enzyme cofactors (coenzymes) or the precursors for them; coenzymes help enzymes in their work as catalysts in metabolism. In this role, vitamins may be tightly bound to enzymes as part of prosthetic groups: For example, biotin is part of enzymes involved in making fatty acids. They may also be less tightly bound to enzyme catalysts as coenzymes, detachable molecules that function to carry chemical groups or electrons between molecules. For example, folic acid may carry methyl, formyl, and methylene groups in the cell. Although these roles in assisting enzyme-substrate reactions are vitamins’ best-known function, the other vitamin functions are equally important.

In those who are otherwise healthy, there is little evidence that supplements have any benefits with respect to cancer or heart disease. Vitamin A and E supplements not only provide no health benefits for generally healthy individuals, but they may increase mortality, though the two large studies that support this conclusion included smokers for whom it was already known that beta-carotene supplements can be harmful. While other findings suggest that vitamin E toxicity is limited to only a specific form when taken in excess.

The European Union and other countries of Europe have regulations that define limits of vitamin (and mineral) dosages for their safe use as food supplements. Most vitamins that are sold as food supplements cannot exceed a maximum daily dosage. Vitamin products above these legal limits are not considered food supplements and must be registered as prescription or non-prescription (over-the-counter drugs) due to their potential side effects. As a result, most of the fat-soluble vitamins (such as the vitamins A, D, E, and K) that contain amounts above the daily allowance are drug products. The daily dosage of a vitamin supplement for example cannot exceed 300% of the recommended daily allowance, and for vitamin A, this limit is even lower (200%). Such regulations are applicable in most European countries.

500 mg calcium supplement tablets, with vitamin D, made from calcium carbonate, maltodextrin, mineral oil, hypromellose, glycerin, cholecalciferol, polyethylene glycol, and carnauba wax.

Dietary supplements often contain vitamins, but may also include other ingredients, such as minerals, herbs, and botanicals. Scientific evidence supports the benefits of dietary supplements for persons with certain health conditions. In some cases, vitamin supplements may have unwanted effects, especially if taken before surgery, with other dietary supplements or medicines, or if the person taking them has certain health conditions. They may also contain levels of vitamins many times higher, and in different forms, than one may ingest through food.