Loss in Potency Caused by Processing?
Answered by: Conrad Richter
Question from: [No Name Given]
Posted on: January 23, 1999

Are a lot of the benefits of a given herb lost due to modern processing methods? If so, can raw herbs be purchased from you guys?

A simple enough question, but one requiring a complex answer. Why? Because it is impossible to give a blanket yes or no answer. It may be true that processing causes reduced potency – for some herbs and for some processing methods – but it is not always true.

First, we need to clarify what is meant by ‘processing’. Any operation that modifies herbs from their natural fresh state in which they are found growing in the garden or in the wild. That includes harvesting, drying, milling, screening, separating, cleaning, washing, storing, and other similar post-harvest operations. Any one of these steps can cause herb quality to drop. For example, the antibiotic and anti-cholesterol compound, allicin, found in garlic, begins to degrade as soon as you cut cloves and expose them to air. Some people are so concerned about the loss of active constituents during harvesting and post-harvest processing that they try to capture the maximum potency by manufacturing finished product right in the field. Tinctures made with fresh cut herbs are good examples of products made with this concern in mind. Other manufacturers freeze or freeze-dry fresh cut herbs direct from the field or extract the fresh juice and freeze that.

In the case of most medicinal herb products such as medicinal teas, pills, tablets and tinctures, the herbs are dried and subjected to some or much further processing. For example, many herbs are extracted in solvents such as alcohol or oil or chemical extraction solvents, usually to preserve, concentrate and standardize the active constituents.

The industry trend is toward standardization of herbal products. Standardization means bringing the active constituent levels of the final product in line with what is promised on the label. One of the big difficulties with standardization is that the constituents used to standardize the herb by are often not directly, or even indirectly, related to the medicinal action of the herb. For example, parthenolide was formerly thought to be the active anti-migraine compound in feverfew (but is no longer) but industry and governments still use parthenolide as the ‘marker’ chemical in feverfew, on the assumption that it tells you something about the strength of feverfew products. The trouble is that parthenolide is unstable and it is conceivable that a manufacturer might concentrate a feverfew product too much in order to bring the parthenolide content up to a level promised on the product label. Surprisingly, this situation – of inactives, or unimportant actives, being used to standardize herbs by – is quite common, largely because many herbs are still poorly understood medically.

The intent of standardization is to combat the problem that nature does not give us herbs with the same medicinal potency year to year or place to place. One batch of valerian roots may differ greatly from another. Even herbs gathered from the same plants can differ widely from one year to the next, or even from one day to the next. And, science is far from understanding the reasons for that, to the point that herb growers and herbal product manufacturers are reduced to guessing when trying to decide when to harvest them and how to process them.

While it may seem that raw herbs (either in their fresh form or in a minimally processed dried form) should be the best, this is not always true. As mentioned, batches vary in quality and with further processing these herbs can be concentrated to make up for the diminished actives content in poor quality raw material. In addition, some herbs require processing to extract the active constituents or to modify them, or to remove harmful constituents. A good example are the many Chinese herbs that must be boiled, roasted or treated in some special way in order to make the herbs medicinally active.

There are many professional herbalists who are deeply concerned with the quality of the herbal products on the market today. There are thousands of companies that have jumped on the herbal product bandwagon and many of them do not have the expertise to make good products. I still marvel at an echinacea product that was made with very hard gel caps that are supposed to be swallowed. (The prevailing wisdom on echinacea suggests that the active constituents are not absorbed in the gut, so it seems that the gel cap product would be medicinally useless. Instead, echinacea should be taken as a tincture that is swirled around the mouth to allow uptake into the bloodstream.) To some extent your question is prompted by concerns about the quality of the plethora of herbal products recently introduced to the market, and we share that concern.

For that reason, Richters has focussed on selling the raw herbs in their minimally processed dried form. Wherever possible we sell whole or cut and sifted grades of herbs instead of the more convenient powdered herbs. We carry very few finished herbal products such as tablets and capsules. Our dried herbs require more work to use as teas and poultices and ointments but we feel that our customers deserve to know what they are getting in their herbal medicines and the only sure way is to make them from raw dried material. In addition, making your own medicines is much cheaper than store bought pills and capsules.

Interestingly, over 80% of the U.S. market for herbs and herbal products consists of ready-to-take pills and capsules. That means that the U.S. market clearly prefers the convenience of these products no matter what their quality. Clearly, at Richters, we are not going to get rich sticking to our practice of selling only the raw dried material, but in the light of the concerns of modern products, and their cost, we will continue to concerntrate on bulk herbs instead of pills and capsules.

Richters carried hundreds of raw dried herbs. Our dried herbs are listed in our online catalogue at http://www.richters.com .

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