Lead in Herbs and Herbal Products
By Joel Harvey, L.Ac.
If you're reading this, you probably heard that lead was found in food or herbs or water, or a consumer product. Modern detection equipment has revealed trace amounts of lead in plants and water, as well as the large amounts already found in petroleum, paint, toys, furniture, drugs, crayons, glass, and many other household items. Hearing these reports, we grow concerned and afraid. But is our fear really justified?
We all have a right to be warned, and must be warned about health hazards in our environment, but is the trace lead found in plants, animals, food, and water the same hazard as the gross amounts of lead found in gasoline, plumbing, and paint? Is this trace lead in the environment really something to be alarmed about?
My area of interest is medicinal herbs, which I prescribe, and which sometimes contain trace amounts of lead. When my patient's hear of this, they all wonder, are these herbs really safe? I assure them that these herbs have been used safely for many generations, and that they have always contained trace lead, and likely contain less now than ever before. These herbs have never been shown, or even suspected, of causing any disease associated with lead poisoning. I could also tell them that the compounds of lead found in herbal medicines are less likely than free lead to bind with molecules in our body, and are thus slower to be absorbed.
Unfortunately for all of us, facts such as these are missing from both government and media sources, which tend to provoke hysteria rather than educate. As a result, many people have become as mistrustful of herbs as they are of pharmaceuticals. Fanning the flames of mistrust are California Proposition 65 warnings appearing on many herbal medicines.
In California, many people have become accustomed to these ubiquitous Prop 65 signs, labels, and brochures warning of dangers lurking in their food and household products. Prop. 65 labels warn that products contain various substances that cause cancer, birth defects or other reproductive harm. In the case of herbal medicines, trace amounts of lead is almost always the reason.
But are these warnings really accurate? For example, labels warn that lead causes cancer, but what evidence supports such a conclusion. Apparently, the warning is based on evidence that high doses of lead have been shown to cause kidney cancer in laboratory animals bred to be susceptible to cancer. However, where is the evidence that such exposure causes cancer in humans? The one study of workers, exposed to high concentrations of lead, showed no increase in the incidence of kidney cancer. Is this really evidence enough to make people fearful of herbal medicines?
After surveying all the science available, Kyle Steenland, PhD and Paolo Boffetta, MD, in their article Lead and Cancer in Humans: Where Are We Now (The American Journal of Industrial Medicine, September 2000, vol. 38, issue 3, pages 295 - 299), conclude that the evidence that lead causes cancer in humans is weak.
This doesn't mean that lead is safe for us. Far from it, lead is toxic to humans because it can replace other metals in our body such as calcium, zinc, and iron, creating abnormal molecules in our enzymes which then fail to carry out normal body functions. Lead poisoning, also known as painter's colic or plumbism, can result in damage to the kidneys, heart, and nervous system. This is not new information. In ancient Rome, many ills were attributed to lead, which was used in medicine, jewelry, wine, plumbing, and make-up. As early as 250 BC, Nicander of Coloform wrote about lead-induced anemia. The Roman remedy for lead poisoning was documented to be mallow or walnut juice with wine. Lead has been with us since the beginning of civilization. Lead is an element found in all the earth's soils, rivers, lakes, and oceans. Lead is also found in the air as a component of dust. Lead levels vary from ½ per million (ppm) to about 10 ppm in soils sampled far from industrial pollution. Lead exists in anything eaten, including all food, beverages, drugs, and supplements.
There is no doubt that some environmental lead comes from industrial pollution. Over 300 million tons of lead, mined in the twentieth century, has returned to our environment via leaded paint, leaded fuels, leaded "tin" cans, and leaded plumbing. However it's incorrect to single out pollution alone for the presence of lead. Even without any human activity, lead would still exist everywhere, as it does in the ancient igneous rocks formed from our planet's natural volcanic activity. Our bodies always contain some lead, normally about .05 ppm. Healthy human bones contain 20-40 ppm of this element.
The typical American diet is said to contain 15 – 25 micrograms or more of lead daily, mainly originating in fruits and vegetables. Other exposures to the air, water, and industry can result in up to 200 millionths of a gram consumed daily. Typical doses of herbal medicine can add 3 to 15 millionths of a gram per day.
Though these figures might sound high, they are actually quite low. The amount of lead in our bodies today is actually the lowest in recorded history. Thirty or more years ago, when lead was in gasoline and paint, we absorbed five to ten times as much as we do today, yet still there is no evidence, despite today's warnings, that our grandparents suffered any ailments whatsoever because of their exposure to lead. If lead really did cause cancer, might not the decline in lead exposure result in a similar decline in cancer rates? On the contrary, while lead exposure has declined precipitously, most cancer rates have risen. Is it possible that fears of lead may have been inflated, and that lead may not be the environmental bogey man we have presumed it to be.
No one doubts that lead is bad for you at toxic levers, but at what levels? Herbal practitioners know that lead can actually be good for you in certain instances. Lead has a long history of cautious use as medicine. The Chinese herbal formula "Lead Special Pill" harnesses the "weight" of lead to settle the lungs in certain cases of asthma. The formula is prescribed at precise doses for periods of no longer than two weeks, and is not given to children or pregnant women. It has been in use safely since the year 1040.
That lead can be medicine is not an apology for lead in the environment. Eight thousand years of observation has shown us that lead is mostly not good for you, so there is absolutely no reason to introduce it into the environment, no excuse for putting lead paint on children's toys. Laws have solved this problem to a great degree, drastically reducing the lead in our surroundings.
Removing lead from our plants, animals, earth and water is much more difficult. Eons of volcanoes and chimney smoke have dusted our planet with trace amounts of lead. The latest detection technology shows that both the ocean's foam and the organic greens you purchased at the health food store, probably contain lead. A chocolate bar may contain more lead than ten doses of herbal medicine.
If this is so, why are there no warning labels on a chocolate bar? The curious reason is, of course, money. The chocolate industry had the millions of dollars needed to go to court and prove that all the lead in chocolate occurs there naturally, so it cannot be considered a contaminant. Unfortunately, few of the small herb companies sued under proposition 65 had the resources to prove that all the lead occurring in all the herbs in all their products was also natural. That's the only reason why you'll find lead warnings on herbal medicines, but not on candy.
But is chocolate or herbs really a health problem deserving of warning? There's a lot of evidence that a lot of people have eaten a lot of chocolate and taken a lot of herbs without succumbing to mortal disease. Are California proposition 65 warning labels overly alarming? We know that reduced lead pollution has already reduced the amount lead in our bodies. The same process is already reducing the amount of lead in plants, and today's plant medicines probably have less lead in them than they might have a generation ago.
There is, and always has been, lead in every herbal medicine. This is why many governments throughout the world have created appropriate standards for lead in herbal medicines. For example, Japan allows 20 parts per million (ppm) for total metals in herbal medicines. The World Health Organization allows 10 ppm for lead. The Australian TGA allows 5 ppm for lead in a product. Germany allows 5 ppm as well. The US Pharmacopoeia has no standards for herbs, but allows 3 ppm in drugs.
Most Chinese herbal products test at an average of 1-3 ppm, which is considered safe and incidental by all international standards for medicine. However, California's Proposition 65 requires warning at only 1/2 ppm in food, and in California, herbal medicines are considered food rather than drugs. Prop 65 allows the sale of these products, however it requires a warning.
Though they might be technically correct, whether or not these warnings are actually educational or even informative is another matter. Certainly warnings create fear among consumers; fears that become associated not only with lead, but the product, the brand, and by association, all of herbal medicine. We believe that this fear of herbs, based on misinformation, is bad for everyone except the pharmaceutical industry, which by the way, is allowed six times as much lead in their products - without posting any lead warning.
Fear also causes people to lose their perspective. The next time you find yourself worried about trace lead in herbal medicine, please remember the 200,000 people who actually die every year from taking over-the-counter, non-prescription drugs.