—DOUGLAS R. HOFSTADTER, PROFESSOR OF COGNITIVE SCIENCE
Recently several large studies have examined the contents of various supplements. Many were tested and found to contain allergens, little or none of the herb or vitamin on the label, or a banned substance. Others are potentially dangerous in their interaction with common medications. A few are worth mentioning.
St. John’s Wort
St. John’s wort is one of the 10 best-selling supplements in the U.S. It is marketed as a mood elevator and is arguably the most popular supplement to treat depression. But St. John’s wort can speed the breakdown of various prescription medicines by eliminating them from the body before they can take full effect. This includes anticoagulants (blood thinners), oral contraceptives, antidepressants, cancer drugs, and immunosuppressants (causing transplant rejection).
Vitamin K
Vitamin K helps in blood coagulation but in excess can block the effect of medications like warfarin (blood thinners) used to prevent blood clots. Because it is now added to many calcium supplements and found in multivitamins, it can quietly reach high levels in the body and trigger problems before someone is aware of any issue.
Vitamin C
Vitamin C will facilitate iron absorption. People with a tendency to absorb excess iron should be careful with this supplement.
Zinc
Taken by many to “shorten a cold,” zinc has numerous GI side effects and interacts with antibiotics and antihypertensive medications.
Ginseng
Used in Chinese medicine for heart issues, this is another popular herb that can interfere with anticoagulant drugs like warfarin and can interact with some antidepressant medications. It has been implicated in neonatal death when taken by the mother.
The list is long. Licorice, black cohosh, echinacea, ginkgo, and many of the most popular herbs are the subject of questionable claims, drug interactions, and lack of quality control.
You should limit vitamin intake to the vitamins you are deficient in—validated through testing and as directed by your doctor.
Supplements for Those Age 50 and Up
While taking supplements can be harmful at any age, older adults are more likely to encounter problems. Older adults also usually take more and a wider variety of prescription drugs than younger people, and this increases the risk of a dangerous interaction with supplements. In addition, many patients do not tell their doctors about the nonprescription pills they ingest, and many doctors do not ask about them—leading to potentially serious consequences.
Supplements, like many prescription drugs, are metabolized and eliminated through the kidney and liver. Since older people have higher rates of kidney and/or liver disease, it may be harder for their body to process compounds found in supplements. The interactions with the cardiovascular system can be particularly problematic. Taking blood thinners or cardiovascular drugs with St. John’s wort, vitamin K, zinc, or ginseng may cause serious problems.
Probiotic Intoxication
We think, each of us, that we’re much more rational than we are. And we think that we make our decisions because we have good reasons to make them. Even when it’s the other way around. We believe in the reasons, because we’ve already made the decision.
—DANIEL KAHNEMAN, PSYCHOLOGIST AND BEHAVIORAL ECONOMIST, NOBEL LAUREATE
Probiotic is the term currently used to name the live bacteria/microorganisms taken by people to supposedly correct and/or maintain the natural balance of their gut and microbiome. This raises the question of what is a “natural” and “healthy” balance of microbiota—proportions that science has not yet been able to determine.
The balance of different bacteria varies from person to person, as well as culture to culture, depending on eating habits, genes, and environment. And while we know that a diverse microbiome is desirable, not everyone needs “rebalancing” to stay healthy.
A recent study of a tribe of hunter-gatherers in Africa, the Hadza people of Tanzania, showed that they lacked Bifidobacterium, a bacterium that is found in probiotic foods and considered healthy. They also had other bacteria that are considered a sign of disease in Western populations.
The study underscores the need to redefine what is healthy and unhealthy in our microbiota and how different bacteria interact with each other. And more important, that a far more personalized approach to probiotics is needed if they are to be effectively utilized to treat human health.
Manipulating the gut microbiota may prove to be an effective way to control the development of diseases and influence treatment. While the benefits of probiotics are being actively studied, it is still scientifically unclear whether they work for specific diseases. You are consuming live bacteria with the assumption that it is a “good” versus “bad” bacteria. For those taking probiotics during antibiotic therapy, how do you know that the antibiotic is not killing the probiotic you are taking or interfering with its action? Probiotics are regulated as a food, not a drug. Which means that they are largely unregulated. They need to be reported to your doctor along with any pharmaceuticals that you are taking.
More important, the safety of their use by young children, older adults, and anyone with a compromised or weak immune system is unclear and potentially dangerous.
While many people have had symptomatic relief through the use of probiotics, the health claims related to these products are often questionable and derived from animal studies that may not translate to humans, as well as studies of different types of bacteria (e.g., lactobacilli and bifidobacteria) that have huge differences within each species. For example, there are 170 species of Lactobacillus, one of the most widely advertised and available probiotic bacterium. All are part of the normal gastrointestinal and vaginal flora and are used in a variety of commercial products. Yet only some strains have been tested; others lack any real data.
While probiotics are being tested in the treatment of many different medical conditions (allergies, obesity, liver disease, IBS, diarrhea caused by antibiotics, and stomach ulcers, to name a few), it is still too early to know if they are truly effective or safe for these conditions, though studies in irritable bowel syndrome look promising.
The Upside—Some Studies Are Very Promising
Some probiotics digest or alter gluten. One commercially available probiotic that contains eight different bacteria can reduce the toxicity of gluten when used in a fermentation process. A study of sourdough baked wheat products fermented by specific bacteria and funguses was shown to be safe for people with celiac disease.
Probiotics cannot at this point be recommended for the pharmaceutical treatment of celiac disease as they have not as yet been proven safe and effective, but they are an exciting area of research.
Clostridium Difficile and Fecal Transplants
Fecal transplants and certain probiotics have been proven to be effective in combating Clostridium difficile (also called C. difficile and C. diff)—a potentially deadly infection—especially its recurrence. This bacterial infection, formerly found mainly in older populations, causes diarrhea and inflammation of the colon and is increasing in younger people.
Fecal microbiota transplant is a procedure where fecal matter (stool) is collected from a healthy donor and transplanted into the affected patient, usually during a colonoscopy. The theory is to replace “good” bacteria that has been killed or suppressed by C. difficile