Standardized vs. Liquid Extracts: Which is Better?
Dr. Gordon Chang
The use of herbal extracts and the medicinal effects of herbs have been substantiated through historical use and proven to be efficacious without any "active compounds" having been actually measured. Liquid herbal extracts have been used for millennia yet standardized extracts are relatively new to the world of herbs. Why do some manufacturers use standardized extracts while others use liquid extracts? Are standardized extracts superior to liquid extracts as far as their effects on the body are concerned? Let's explore the science behind these questions.
The Reductionist View
With the advent of modern chemistry and modern medicine scientists endeavoured to find cause-and-effect relationships between compounds found in an herb in relationship to the herb's curative effects. This way of thinking evolved from our simplistic reductionistic view of science and the way systems interact with each other. Or, to amplify this statement; in order for humankind to make sense of our natural world, science has attempted to reduce all interactions into its most simplistic forms. While this way of thinking has helped our understanding of the most fundamental aspects of the natural world it has led us to believe that the entire world operates in isolated systems. When we apply the basic rules gleaned from our reductionistic views of the natural world, we realize that the complex real world does not fully follow these rules.
While the reductionistic views of modern science have advanced our understanding of basic fundamental principals we realize that we have a very poor understanding of the way systems interact and therefore we cannot accurately predict the outcome of these interactions.
In the world of modern pharmaceuticals we have applied the reductionistic view that one pure isolated compound will produce a net change on the human system. Acetylsalicylic acid (or ASA, also known as Aspirin) helps to illustrate this point. The precursor of aspirin was first isolated as a pure compound from the bark of the white willow tree. In this first extract there were a group of compounds which had similar (not identical) chemical compositions. The chemists of the day then tried to separate and purify this group of compounds. Each separate compound was tested and one of these compounds was then synthesized from simpler compounds, modified to give it a better shelf life, and then patented as "Aspirin" (a brand name). While ASA is a synthesized compound, its existence resulted from the initial extraction of compounds from white willow bark. Pharmaceutical science has attempted to apply these same rules to the production of modern herbals, e.g. - extracts of white willow bark have been manufactured and standardized to the amount of salicins in the extract. If we measure the effect of ASA on pain relief we find that we can get the same analgesic effect from a white willow bark extract which contains a significantly lower quantity of salicins as compared to ASA. This implies that either the salicins are much more effective or there are other compounds in the extract that contribute to the net pain relieving effect.
Applying Pharmaceutical Principles To Herbs
From time immemorial, in all societies that used herbs as medicines, herbs were eaten in their raw form, or dried and powdered, added to water and brewed, and then consumed. Our knowledge of the effects of these herbs was passed down from generation to generation either verbally or in a written form. With these herbs we knew of its effects on the body without necessarily knowing much about which compound or group of compounds produced the net beneficial effects.
Standardization of herbal extracts is an attempt to follow in the footsteps of modern pharmaceuticals, in that we must attribute the beneficial effect of an herb to a particular compound. While standardization is a very simple process when used in a pharmaceutical setting it is very difficult when applied to herbal extracts.
Firstly, the beneficial effect of any herb is usually not due to a single compound but is most likely due to a series of compounds. Some of these compounds may have similar chemical structures and some may not. Secondly, many herbs have different effects on the body; e.g. - Panax ginseng may increase sperm production in some men at the same time that it is lowering blood sugar levels. These two effects of Panax ginseng are usually not related to each other. It is thus unlikely that the effects are from the same compounds but may be due to different compounds working together. When we attempt to standardize an herbal extract we usually pick a chemical marker and attempt to quantify it in the final extract even though it may not correlate with the effect that we are looking to achieve. So the question that science must ask is what exactly is it that we are trying to quantify?
The Quantification QuotientThe process of quantification is fraught with many problems. The general public is frequently led to believe that the quantification of these compounds is absolute and that all of the methods used will produce the same results. Currently there are two major techniques commonly used to quantify and hence standardize herbal extracts; spectrophotometry and high pressure liquid chromatography (HPLC). Each of these techniques has their shortcomings, primarily because many of the herbs commonly standardized are not standardized to a single pure compound but are usually standardized to a group of compounds that have a chemically similar structure. There may be interference from other compounds present in the herbal extract that interfere with the quantification process resulting in higher or lower values detected. There are also many different spectrophotometry methodologies used to detect the compounds of interest, each of which are valid but will give different values.
Additionally, it is very well known that two extracts of the same herb with the same standardization specifications will have different effects on the body. For example, two ginseng extracts standardized to 8% total ginsenosides may have different effects on the body. This is due to several reasons: firstly, the compounds that produce the effect on the body are not the ones actually measured; secondly, each compound from the measured group of compounds may have different effects on the body and their ratios to each other in the final extract may be different; thirdly, many standardized extracts are usually powdered and the process of producing powdered extracts may damage the active compounds rendering them useless. This third alternative is not usually an all-or-nothing process, that is, the extracts may be partially active. Because of these problems associated with the production and quantification of standardized extracts it is suggested that standardized extracts are not necessarily better than liquid extracts.
Health Disclaimer. Copyright © Omega Alpha Pharmaceuticals Inc. Published with permission. Dr. Gordon Chang holds a Ph.D. in Physiology and Biomedical engineering from the University of Toronto and has years of post-doctoral experience in biochemistry. Aspirin is a registered trademark of Bayer HealthCare LLC.