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Caution Always Key in Using Herbal Medicines

A recent study published in the New England Journal of Medicine offers another important reminder on careful use of herbal remedies. This caution is rooted in the absence of strict pharmaceutical controls in the manufacture of such products and how the lack of these requirements can leave room for tragic errors.


In the mid-1990s, doctors at a clinic in Belgium treated 43 patients with end-stage kidney failure, requiring dialysis or transplant. Not surprisingly, these individuals had something in common in their medical histories. Between 1990 and 1992, each had used a Chinese herbal remedy in combination with two other drugs for weight loss. The herbal preparation supposedly contained Stephania tetrandra and Magnolia officinalis. But the sudden appearance of kidney failure in these patients, caused their doctors to suspect that the herb Aristolochia fangchi, which is poisonous to the kidneys, had unintentionally been substituted for S. tetrandra. The Chinese names for A. fangchi and S. tetrandra sound similar and the two are often confused. Analysis showed that the herbal remedy did, in fact, contain aristolochic acids, which are derived from A. fangchi. Aristolochic acids cause cancer in rats and mutations in bacteria and mammals.

Reports of patients who had developed urothelial carcinoma (cancer of the tissues lining the bladder, ureter, and part of the kidney), as well as kidney failure related to the Chinese herbs, drew concern among the Belgian doctors. When one of their patients also developed this cancer, the doctors decided that all patients with end-stage kidney failure related to the use of Chinese herbs should be checked for cancer of these organs. By removing these organs, the doctors hoped to prevent cancer from developing in their patients. Thirty-nine of the 43 patients agreed to undergo the preventive surgery. Of these patients, 46% of them already had cancerous growths in the removed tissues. In addition, 19 of the remaining 21 patients had abnormal growths in the urinary system. The investigators also analyzed DNA samples taken from the kidneys and ureters of each patient. The DNA samples for every patient showed changes typically found after exposure to aristolochic acid. The researchers compared these results to analysis of DNA samples taken from eight patients with end-stage kidney failure unrelated to Chinese herbs. None of these control samples showed DNA changes formed by aristolochic acid.

The doctors calculated the cumulative dose of the implicated herb and other treatments for each patient. They found that the risk of cancer was related to the cumulative dose of A. fangchi. Because many of the patients had also taken appetite suppressants as well as a diuretic, the doctors noted that these drugs might enhance the toxicity of aristolochic acid.

This case study provides strong evidence suggesting a relationship between the Chinese herb A. fangchi and urothelial carcinoma. While a manufacturing mistake led to the introduction of this herb into an herbal preparation for weight loss, this study highlights the risks involved in taking herbal remedies. There is little control over the quality of herbal medicines. This means that the label on an herbal medicine may not accurately represent what is actually in the container, as was the case with S. tetrandra. Several countries have banned the use of herbs that contain aristolochic acid, yet Aristolochia is readily available in the United States in capsule form.

In the United States, the FDA does not have the authority to assess the safety and efficacy of a dietary supplement before it reaches the shelves of stores. The agency is allowed to restrict a supplement only after it proves the substance is harmful as commonly consumed, but there is no adequate system for reporting serious side effects associated with these products. Furthermore, the FDA does not have any way of knowing which herbal remedies contain harmful substances such as aristolochic acid. The case of the Chinese herbal diet pill and its association with urothelial cancer is just one of a number of cases that demonstrate the need for greater oversight of dietary supplements and caution in the use of supplements on the part of consumers.

Getting your vitamins and minerals through diet

The benefits of multivitamins are looking doubtful. Can we do without them?

The answer is a qualified yes – we can do without them, as long as you eat a well-balanced diet rich in fruits and vegetables.

In the past, doctors often suggested a standard multivitamin with minerals each day. They don't cost much, and earlier studies had shown some benefits. For example, it appeared that folic acid and other B vitamins might lower the risk of heart disease, stroke and possibly cancer. But more recent studies have shown no added benefit of multivitamins for healthy people that eat a balanced diet.

Do omega-3s protect your thinking skills?

It may be helpful to eat a diet rich in omega-3 fatty acids.


 Image: Elena_Danileiko/Thinkstock

Maybe you're hoping to protect your thinking skills by eating oily fish like salmon or taking a daily fish oil supplement. After all, the media frequently talk about the benefits of omega-3 fatty acids in fish oil, and sales of fish oil supplements are more than $1 billion per year in the United States. But can fish oil keep us thinking clearly? "For people who are healthy, who don't have a decline in memory and thinking skills, the question of prevention has not yet been answered," Dr. Scott McGinnis, an assistant professor in neurology at Harvard Medical School, explains.

About omega-3s

Omega-3 fatty acids are polyunsaturated fats in food that are essential for health. There are three main types:

Can any vitamins stop my glaucoma from getting worse?

On call

Q. Are there any specific kinds of vitamins or nutrients I can take that will prevent my glaucoma from worsening?

A. There have been no convincing studies that show that vitamin intake or dietary supplements can treat glaucoma once it is diagnosed.

Ginkgo biloba: What's the verdict?

Q: A friend recently recommended that I take the herb ginkgo biloba to protect against getting dementia. Is it effective, and is it safe?

A: The first thing you should consider is that the FDA doesn't regulate the manufacture of any herbal remedy, so the purity and potency of the ginkgo biloba you buy hasn't been checked.

Can supplements save your sex life?

They'll tempt you with their marketing promises, but beware the dangers hidden within.


 Image: © FatCamera/Getty Images

It's February — time to think about roses, chocolates, sweethearts, and romance. And if those sentiments bring you to a certain drugstore aisle stocked with pills and potions promising to boost your sex life, you may want to think twice before buying any. "Most are a phenomenal waste of money, in my opinion," says Dr. Michael O'Leary, a urologist at Harvard-affiliated Brigham and Women's Hospital.

Unicorn juice?

With a few exceptions, most supplements for sexual function haven't been studied scientifically. At best, says Dr. O'Leary, they have a placebo effect (a beneficial result from an inactive treatment).

The hidden dangers of dietary supplements

News briefs

Dietary supplements marketed for sexual function — which are supposed to be free of conventional drugs — may contain hidden pharmaceutical ingredients. A study published online Oct. 12, 2018, by JAMA Network Open analyzed almost 800 supplements. Most were for sexual enhancement, weight loss, or muscle building. About 80% of the supplements contained one pharmaceutical ingredient, 20% contained more than one pharmaceutical ingredient, and some (33 products) contained three or more pharmaceutical ingredients. The most common hidden pharmaceuticals: erectile dysfunction drugs, weight-loss medications, antidepressants, anabolic steroids, and nonsteroidal anti-inflammatory drugs. Some of the hidden drugs have never been approved by the FDA; others have been removed from the market. And all, say the authors, have the potential to cause severe harm from accidental misuse, overuse, or interaction with other medications, underlying health conditions, or other drugs within the same dietary supplement. Talk to your doctor first before taking any dietary supplement.

Psyllium fiber: Regularity and healthier lipid levels?

Research we're watching

Psyllium, which comes from the seeds of the herb Plantago ovata, is a popular fiber supplement used to treat constipation (Metamucil is one familiar brand, but many similar products are available). Psyllium husk also helps lower LDL cholesterol levels as well as two other lipid markers for heart disease, according to a study in the Sept. 15, 2018, American Journal of Clinical Nutrition.

The study pooled findings from 28 trials in people with normal and high cholesterol levels. It found that a daily dose of about 10 grams of psyllium husk lowered harmful LDL cholesterol 13 mg/dL when taken for at least three weeks. It also led to a similar drop in non-HDL cholesterol (a number that includes LDL and other harmful lipoprotein particles) and ApoB (a substance found in many lipid particles, considered by some experts to be an even better predictor of heart disease than LDL or non-HDL).

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