Dietary Supplements: What Every Cancer Patient Needs to Know

Most people are surprised to learn that neither the FDA nor any other regulatory agency ensures the potency or purity of dietary supplements. Equally concerning, manufacturers don’t have to get FDA approval or provide the FDA with safety data prior to making them available for sale! It isn’t until a product is on that market that the FDA is charged with tracking the side effects reported by consumers, healthcare professionals and the supplement manufacturers themselves. So, let’s take a closer look at these two fundamental issues of supplement quality:  purity and potency.

Purity-related concerns are primarily about contamination and adulteration. A supplement can be contaminated by bacteria, heavy metals and/or drug residues; all three factors can be introduced at various points of the processing of supplements. Health-related concerns are different for each type of contamination:  bacteria might lead to infection, heavy metals to toxicity, and drug residues to untoward physiological effects.

Most of the reported problems concerning adulteration and contamination are around herbal products. For example, herbal producers in China are known to treat their raw materials with sulfur dioxide, which is presently not allowed here in the U.S. Among the major contributors to heavy metal contamination are mercury fungicides, lead and arsenic insecticides, and industrial and automobile emissions. Even many wild-crafted herbs (those harvested in the wild) frequently show a high concentration of heavy metals such as lead, mercury, and cadmium.

Some herbal formulas from Asia contain toxic heavy metal salts, as these can play a role in some traditional medicine systems. In addition, herbal producers in Asia will often add prescription and non-prescription drugs to their herbal preparations. Among the residues found in these herbs: acetaminophen, diazepam, hydrocortisone, indomethacin, methyltestosterone, phenylbutazone, and prednisone. As shocking as this sounds, in some countries, combinations of what we consider prescription drugs with herbal medicine are in line with local regulations and therefore, including them in herbal supplements is common practice. However, in the United States, supplements and drugs are clearly separated because of the potential harm in giving someone a prescription drug without their knowledge. Obviously, you should be very cautious about using any imported formulas without knowing exactly what is in them, as some may be so contaminated that they may put your long-term health in jeopardy.

Some of the contamination is a byproduct of the way these herbs are handled before they ever hit the marketplace. For example, many of the machines, utensils and brewing containers that are used in processing the herbs may contribute to heavy metal contamination. If the herbs have not undergone proper drying and storage, the crude plant material can become infested with microorganisms that are capable of producing mycotoxins. Several of these mycotoxins can in turn generate aflatoxins, which have actually been linked to various cancers.

Given these facts, quality issues must not be overlooked when selecting supplements. One of the ways supplement manufacturers can verify the potency, purity, and bioavailability of their supplement is to have the raw materials independently tested for both purity and potency. Of course, it’s important to be sure that the laboratory used for the testing has no ongoing fiscal relationship with the supplement manufacturer or with the supplier of raw materials. This kind of independent verification helps to prevent fraudulent misrepresentation by companies that simply want to promote their product.

Fundamental to ensuring a supplement is high-quality, is ensuring the ingredients used are high quality – that is, herbs that are grown under controlled conditions using seeds of a known species and variety of plant; harvested when their phytochemical cont

ents are most advantageous; processed quickly, cleanly and efficiently; and maintained under clean conditions while they are being shipped and incorporated in the process of manufacturing a supplement. Some companies specialize in obtaining and preparing herbs in this way, and then preparing extracts that simply concentrate the entire plant. In many cases, whole plant extracts are the best products to use. They include the full spectrum of phytochemicals in the plant. If an herbal extract is made using water (or some other solvents), for instance, only the water-soluble components of the plant will be in the extract. However, many herbs contain important non-water-soluble components, and these would be missing. You could, of course, simply take the entire unprocessed herb, but in many instances, you would need to take a large number of capsules to get as much herb as you need. A process called “supercritical extraction” – similar to the process used for decaffeinated coffee but without the use of potentially problematic solvents – yields a whole plant extract that is highly concentrated. Some excellent supplements are made through the combination of careful sourcing of the fresh herbal material and supercritical extraction. In general, we advocate the use of whole plants in both herbs and foods, since these are the closest to the natural forms of plants that humans have been eating for millennia. However, in some cases, we also will use whole plant extracts that have specific compounds of known biological activity added to them.

In our next blog posting, we’ll examine the issue of potency, which refers to both the strength and freshness of the supplement, as well as the quantity or concentration of active ingredients.

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