Assessing Supplement Quality

supplementsOur previous blog articles looked at supplement purity, potency, and the importance of formulation.  Today’s article will look at how to assess supplement quality.

More people are using supplements than ever before.  According to one study, about 40% of the population takes vitamins or minerals and about 15% take an herbal supplement.  As I mentioned in the previous articles in this series, since there are currently few enforceable standards on the manufacturing of dietary supplements, assessing quality largely falls to the consumer.  Unfortunately, most consumers are ill equipped to make such an assessment, since significant pharmaceutical and medical knowledge is essential to properly assessing the quality of nutraceuticals.  It is therefore especially important for a physician or other healthcare professional to guide their patients’ use of supplements.  Yet, a recent study from the National Institute’s of Health Office of Dietary Supplements (ODS) suggested that over three quarters of consumers – 77% – take dietary supplements without the advice of a healthcare practitioner! (At the Block Center, detailed assessments provide us with information that enables us to tailor each supplement regimen to a patient’s unique needs).  Here is some information to consider when assessing the quality of a supplement:

A. Ingredient quality

  • Make sure the herb or supplement in the bottle is the plant species or phytochemical that you are looking for, and that it includes the right plant part.
  • It may be useful to get a product that is standardized to contain a specific amount of an active phytochemical.
  • Quality seals such as USP (U.S. Pharmacopeia) or NF (National Formulary) given by independent organizations are useful, though not absolutely necessary indicators of quality.  No quality seals have yet been developed for products that contain multiple herbs or other ingredients, so you should not expect to see seals on these products.
  • Look for the name and contact information of the manufacturer.  The company may have information on quality control procedures available by phone or on their website.
  • Avoid supplements promoted as “miracle cures,” or ones that use testimonials rather than science to support their use.
  • Organically grown ingredients and wild herbs that give some indication (on the packaging or the website) of sustainable harvest practices are best for the environment – and for you!  You may also want to look for special information such as Kosher processing, or vegetarian/vegan capsules.
  • Avoid getting the cheapest supplement you can find.  Supplements that are priced much lower than similar products may be of lower quality or have much lower levels of active ingredients.

B. Stability

  • Look for a lot number or batch number on the packaging.  This enables the manufacturer to trace products back to their origin.  It doesn’t guarantee the product’s quality, but does suggest a responsible manufacturer.
  • An expiration date may be useful, and can be used as an indication of freshness, although we do not always know accurate ways to determine the expiration for some types of supplements.

C. Minimum safety information

  • Make sure you understand the dose of the herb or supplement you will be taking, and the instructions for taking the supplement (i.e. should you take an entire dropper or only a drop or two of a liquid supplement?  How many tablets per day, and should they be taken with or without food?)
  • Supplements should be tested for toxic substances such as pesticides, lead or mercury and this information should be available on the packaging or the manufacturer’s website. Look for hypoallergenic products if you have problems with food sensitivities.

D. Expanded safety information

Look for information about drug interactions or other safety considerations on the supplement package.  These would include possible side effects, use during pregnancy, use by children, whether the supplement should be taken with food,etc.

As more information becomes known about an herbal or supplement through clinical trials, a physician can guide their patient’s use of such agents based on more classical parameters of pharmacologically relevant data.  As mechanisms of action are elucidated, and supplement-drug interactions become better-understood, a physician can identify potential adverse effects as well as toxicities and contraindications that may occur with that product.

As an example, it is widely known that St. John’s Wort (SJW) can interfere with some pharmaceutical agents.  Several recent studies have shown that SJW is a potent activator of a detoxification enzyme called CYP450 3A4.  CYP450 3A4 helps the body break down about 50% of all medications on the market today, a critical process in how our bodies handle drugs.  Because of this activity, SJW can significantly reduce the therapeutic blood levels of many commonly prescribed drugs, including antidepressants, oral contraceptives and anticoagulants!  This speaks directly to the importance of making sure your physician (or healthcare practitioner) is actively involved in overseeing your use of all supplements.

E. Efficacy

Clinical trials are the best indication of whether a supplement is efficacious for a particular condition.  The packaging may show data about a clinical trial; you may also be able to find information about whether a particular extract or phytochemical has been clinically tested on the manufacturer’s website.

F. Bioavailability

One problem with some supplements is that they don’t dissolve in the stomach. Clearly if a tablet doesn’t even dissolve, it’s unlikely that your body will adequately absorb the ingredients.  Dissolution and disintegration studies of a particular product can show that the dosage form is appropriate for the herbal or supplement used.  These studies indicate whether a product’s active components are appropriately being made available to the body when in that dosage form.

There are other aspects to bioavailability.  Some phytochemicals (and this is true of some medications as well) are simply not absorbed very well by the gastrointestinal tract.  There are ways to get around these challenges.  For instance, it is known that eating some kind of fat or oil with carotenoids (red or orange phytochemicals such as beta-carotene or lycopene) improves their absorption.  You may thus see instructions to take certain supplements with meals (although sometimes instructions to take supplements or medications with meals are simply to prevent stomach upset).  In some cases, manufacturers will put specific substances into supplements, such as bioperine, a pepper extract, to help optimize your ability to absorb them.

Some new ways of formulating supplements also improve bioavailability, in particular the use of nano-technology or liposomes, which “package” supplements or phytochemicals in extremely tiny molecular “envelopes” that enter cells more easily.  Supercritical extracts provide highly concentrated herbal extracts that enable the user to take high doses of an herb in a small number of capsules.  One of the well-known strategies for regulating the availability of a supplement is the use of timed-release formulations.  Familiar to many people from their use in medicines, these formulations are especially useful in cases where a supplement needs to be available to the body throughout a long portion of the day.  An example would be timed-release capsules of melatonin, a sleep aid.

In our final installment on supplement quality, I’ll provide some reliable resources – including books and websites – where you can find additional information about herbs and supplements.

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