Friday, April 25, 2008

Nettles: Potential Presence of Heavy Metals in Herbal Supplements

Ed. Note: I recently purchased some Stinging Nettles herb for allergies and was surprised to see the invoice posted the following warning: ***California Prop 65 Warning: The product above contains a chemical known to the State of California to cause birth defects or other reproductive harm. In checking this out, it seems the concern is for potential lead levels taken up by the herbs in their growth, as nettles are known for uptaking minerals from the soil, that's one of their nutritional attributes.

When checking The American Pharmaceutical Association's Practical Guide to Natural Medicines (1999), they list the following concerns with nettle (Urtica dioica): large amounts may cause stomach upset, urine suppression, burning sensations on the skin; drink plenty of fluids if you are using nettle as a diuretic; the herb may cause uterine contractions in rabbits, so avoid if pregnant, although there are no reported cases of miscarriage or pregnancy related complications; in rare cases nettle can cause an allergic reaction.

The journal Integrative Medicine, Vol. 6, No. 3, Jun/Jul 2007 has an article titled Facing the Problem of Dietary-Supplement Heavy-Metal Contamination: How to Take Responsible Action. This provides very specific information about evaluating toxicity levels in dietary supplements, including a formula to calculate daily toxicity load based on lab assay data. I found it very interesting to learn that, in the case of lead, the FDA's upper limit equals 150 times the California (Prop 65) limits for ingestion. The acceptable USP limit is 36 times California State law.

As with all products of this type, check with a licensed medical practitioner, pharmacist, or knowledgeable nutritionist or herbalist to be sure a supplement or herbal product is safe for you. And always use common sense! Be Well, Janis Davies

A Heavy Issue: the Potential Presence of Heavy Metals in Herbal Supplements

(Written: July 2006)

Are you concerned about the potential presence of heavy metals in your dietary supplements? You may be safer than you think.

When we first heard about this growing concern over the presence of toxic substances, especially heavy metals (a class of metallic elements most commonly including lead, mercury, cobalt, copper, manganese, molybdenum, vanadium, strontium), I’d say most of us were a little bit shocked.

Okay, so I know they’re bad, but what are “heavy metals?”
“Heavy metals” refer to a group of metallic elements – from that periodic table we learned about in high school – and includes arsenic, lead, mercury, cobalt, copper, manganese, molybdenum, vanadium, and strontium. Many of these are actually valuable to us in trace (very very small) amounts, but lead, mercury, and arsenic are toxic and are the most common concerns among the heavy metals.

These toxins? In herbal supplement products? That seems like a pretty big oversight.
There is a lot of media buzz about the lack of required quality controls for herbal supplements, and that has some people awfully scared of using any at all. But while it is true that supplement quality is not regulated by the FDA, much of what you take is subjected to thorough and voluntary quality control procedures.

Of course, it was important for someone to contact our vendors and find out what our manufacturers do to provide us with clean, quality products. We contacted a number of key manufacturers, either by phone or through their websites, to ask them about this issue as it pertains to their products.

Many manufacturers provide information to the public about what procedures they follow to prevent contamination of their products with any toxic or poor quality components. [Many] manufacturers were happy to let us know what they do or tell us where to find that information. So if you’re concerned about a particular product, we encourage you to check the product’s label for contact information and ask.

There were some things that were frequently mentioned – the Certificate of Analysis (CoA), current Good Manufacturing Procedure (cGMP), and Standard Operating Procedures

Certificate of Analysis (CoA)
This is a document provided by suppliers of raw material to manufacturers. Although it’s format can vary slightly, certain information is consistently included, based on tests of the raw material.
(SOP). All of these quality control procedures are very similar to or the same as those procedures mandated by the FDA for the manufacture of prescription drugs.

  • Botanical name and often the many common names of a plant, as well as a positive identification of the plant material
  • Heavy metal concentration
  • Presence or absence of yeasts, molds, and other microbiological (i.e. viruses) contaminants
Some manufacturers then repeat these basic raw material tests to verify that the material they received meets their specifications and that the CoA is accurate. Testing every single batch of raw material is expensive – and that cost feeds directly into the pricing of these companies’ products.

Good Manufacturing Procedure (GMP, cGMP, pGMP)
Good Manufacturing Procedures cover the manufacturing process from start to finish. An herbal supplement manufacturer’s GMPs may either be the same current Good Manufacturing Procedures (cGMP) as those required of prescription drug companies, or a very similar set of guidelines set down by the National Nutritional Foods Association (NNFA). They could also be the pGMP proposed by the FDA for dietary supplements, or the GMP guidelines of the World Health Organization (WHO). All are comprehensive and require careful attention to quality.

The NNFA has created a GMP certification application process; you may have seen their GMP label on a supplement product. Be aware though, that companies without this label may practice GMPs as well. GMPs are a complete start-to-finish set of guidelines for producing a clean, quality product.

They include:
employee education, cleanliness/sanitation, documenting procedures, lab tests, quarantine/release practices for raw materials, shipping

GMPs are a great sign that the company is controlling the quality of product, ensuring the excellence of every single dose you take.

Standard Operating Procedures (SOP)
Standard Operating Procedures are exactly what they sound like: written procedures that a company follows in precisely the same way each time it manufactures a product. It’s just like the administration of a standardized test, like the SAT. It doesn’t matter who is giving the test (or in this case, operating the machine.) When a process is standardized, everybody does it the same way every time. Following Standard Operating Procedures involves keeping rigorously detailed documentation of a product during the manufacturing process. It provides a written record of the very close watch a company has kept over every step, preventing low-quality batches.

There is no program of certification for herbal companies yet in regards to SOPs, but if the manufacturer of your herbal product follows them, it’s a very good sign. The more picky a manufacturer is about the quality of your product, the less you need be concerned about any kind of contamination.

But learning all this still didn’t answer one of my original questions – how do heavy metals get into herbs in the first place? Beth Lambert at Herbalist & Alchemist was able to provide some insight.

As vice chair of the American Herbal Products Association, she is thoroughly informed on all aspects of this issue. One common opinion on the subject holds that the big problem is the addition of heavy metals during processing of the herbs. After all, how else could lead or mercury get into them? It turns out that they aren’t added – they actually grow into the herbs.

Since it’s July and a great time to be patriotic, we should mention that the concerns in regards to heavy metal contamination really don’t include American-grown herbs. Hooray!

So why don’t American companies just use herbs grown in America?
While many companies try to source American herbs, or like Gaia, grow most of their own, it’s not always possible. Growth of the herbal and dietary supplement industry in the United States over the past few years has created a demand for herbs that far exceeds the growing capacity of America’s farmers. There are other countries both developed (especially European) and developing (China, India) that grow and manufacture vast supplies of herbal products for the world market. Certain herbs also grow better in climates found in countries other than our own... .

Why are Chinese herbs most often the ones focused on in regards to heavy metals?
The biggest challenge to providing clean herbs free of heavy metal contamination are based in the poor to nonexistent environmental protections in third world or developing nations.

Picture this: if a field is too close to a major road driven by cars using leaded gasoline, over time trace amounts of lead build up in the field and are drawn up from the soil. Many medicinal herbs are known and used for their high mineral content – like stinging
nettle (Urtica dioica). This is a direct result of their ability to draw nutrients present in the soil into their roots and up into their leaves, which we then harvest and use. Heavy metals are also naturally occurring in certain types of soil – so it isn’t only contaminated fields (caused by human pollution) that can produce these contaminated products, though they are certainly the greatest concern.

But try not to get carried away by all the media-driven panic over the presence of these substances in herbs. Though the toxicity of heavy metals is beyond doubt, Ms. Lambert of the
AHPA also pointed out to me that there are currently no existing protections to ensure that you are prevented from consuming heavy metals in our foods.

Think on this: how many cups of vegetables do you eat in a day compared to how many teaspoons of herbs?
Just like
nettles are great at drawing up minerals (and heavy metals) from the soil, so are many leafy green vegetables. And since much of our food is now grown in developing nations, it seems strange that the focus has fallen first on our herbs, not our food.

It is well known that certain foods can contain dangerously high levels of mercury and lead, but there are no requirements for testing every catch of tuna or salmon. Just think about how expensive fish would become if every catch had to be tested before being sold?

Although it might sound almost medieval to test one’s food before eating, these concerns are the result of our increasingly polluted, and therefore toxic, world. But you are just as much, if not more at risk for environmental toxins from the food you eat, the water you drink, and the air you breathe than you are from herbs.

Our exposure through herbs, even in the worst case, would never be as high as we risk from our food. And your supplement manufacturers are concerned about what new government regulations in regards to heavy metal testing could do to the cost of their products.

Okay, so where is the government in all of this?
Isn’t there someone keeping a watch out for contamination with toxins? California’s Safe Drinking Water and Toxic Enforcement Act of 1986, usually known as “Proposition 65” is a piece of legislation primarily created by and voted into being by California’s own citizens. Proposition 65 requires any company selling a product in California that may potentially contain known toxins to be labeled with a warning of it’s potential to cause cancer and/or reproductive damage. The details of this legislation require warning labels for products that have almost any detectable levels of lead, mercury, or arsenic – levels so low that detection requires very sophisticated and expensive laboratory equipment.

Even for those companies who send samples of their products to labs to be tested or have had their own in-house lab for a few years, detecting such trace levels requires a new high-tech in-house lab. This sort of strain on their budgets could very well require that they increase the cost of their products to compensate.

In a perfect world, this price increase wouldn’t be a concern, but an unprofitable company of any kind is soon to be a nonexistent company. And then it would not be able to continue to bring its’ own unique contributions to the world of herbal supplements. Bear in mind that there is such a thing as safe levels of heavy metals, especially with the sophisticated and sensitive lab equipment of today, but many think that the levels considered safe within Proposition 65 legislation are too low to be reasonable.

Currently, the extension of Proposition 65 on a national level is not currently very likely or realistic. In May, there was legislation proposed in the Senate that would make Proposition 65 obsolete, although the merits of this competing bill, H.R. 4167 are dubious, at best.

At the moment, it’s up to us as individuals to use other methods to be sure that the supplements we purchase for ourselves and loved ones are safe and clean. This is easier than you might think. The well established brands are a safer bet to begin with than what you would find in stores that do not specialize in herbal supplements and/or natural foods.


What are signs of a clean, quality product?
Probably the most important feature to look for if you choose to research a manufacturer is their openness. If they want to tell you about their quality control procedure – either by directing you to the correct place on their website or answering your questions over the phone, that’s a good thing. If they’re proud or excited about their quality control, that’s an even better sign. You might be surprised how proud many companies are of their stringent quality control standards.

Look for the National Nutritional Foods Association’s GMP seal, or a statement regarding the potency or purity of the product on the bottle. If there isn’t anything on the bottle, don’t hesitate to check out the company’s website or call their product hotline.

Standard Operating Procedures, like those practiced by Enzymatic Therapy (and others!) are modeled after pharmaceutical manufacturing procedures and are another great sign of quality. Meanwhile some companies, like Flora, only purchase raw material from developed nations, where stricter environmental protections prevent the build up of heavy metals in soil that could eventually be deposited in herbs.

A final thing to look for is random sampling and verification of the Certificate of Analysis (CoA). This practice uses the well-established technique of randomly choosing batches of raw or finished material to test for contaminants, instead of every single batch. It is a reliable way to reduce the costs of testing while ensuring the overall safety of their products. And of course, don’t overlook the best option for ensuring the highest quality herbs! Many are easy to grow yourself.

Below we have listed some companies with excellent quality and purity. Bear in mind, this is not a comprehensive list. There are oodles of great companies out there – this is just a good start.

Enzymatic Therapy Flora
Gaia Herbs Herbalist & Alchemist
Herb Pharm Herbs, Etc.
Kyolic Nature’s Way
New Chapter Nordic Naturals
Organix South Planetary Formulas
Ridgecrest Herbals Smile Herb Brand
Source Naturals Trace Minerals Research

References
Bradley, Richard. “Food Fight.” Plenty. Aug-Sep 2006: 62-65.
“California Proposition 65 (1986).” Wikipedia: The Free Encyclopedia. June 30, 2006. http://en.wikipedia.org/wiki/Proposition)65.
“California’s Proposition 65: The Impact for Manufacturers.” Natural Products Insider. April 28, 2003. http://www.naturalproductsinsider.com/articles/351regupdate.html.
Official Proposition 65 Website, created and maintained by California’s Office of Environmental Health Hazard Assessment (OEHHA). http://www.oehha.ca.gov/prop65.html.
Official Proposition 65 list of substances. June 9, 2006. http://www.oehha.ca.gov/prop65/prop65_list/Newlist.html.

Author: Laura Place (2006), Edited by Janis Davies (2008)


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