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SupplementQuality.com's Wyn Snow talks with Allison Sarubin, MS, RD, author of The Health Professional's Guide to Popular Dietary Supplements

8 June 2000

This milestone book is the first acknowledgment by "the traditional medical establishment" that supplements can play a vital role in optimizing health.

Allison Sarubin, a San Francisco-based nutritionist, has examined more than 1300 articles and abstracts describing research on 69 popular supplements -- and summarized these findings in 452 very readable pages. Ms. Sarubin holds a master's degree in clinical nutrition, and is a registered dietitian (RD) with the American Dietetic Association. (ADA is a national accrediting organization for nutritionists.)


How did you come to write this book?


I needed the information myself. Patients were asking questions and I needed better answers than I could find in any of the available books. In schools of nutrition, the "official position" is that we don't need supplements, that we get enough nutrition from the food we eat, but for some populations and individuals, that answer clearly wasn't good enough. I'm a nutritionist, so I should know -- and I began to look into it. In 1996, I wrote reviews of sports supplements for the annual Guide of ADA's Sports, Cardiovascular, and Wellness Nutritionists practice group (SCAN), then began working on this book in 1997.

Sources of research information


How did you find research materials and decide which ones to review?


Basically through a Medline search on each supplement. I also looked through the list of references for individual articles. If one of the references wasn't already on my list from Medline, I went and read those I could find. However, if an article hadn't been translated into English, I didn't include it in the book unless there was an abstract in English or a meta-analysis report describing the research.

Plans for updating new editions


One point you make in your book is that new research is being published about supplements all the time. Do you or the American Dietetic Association plan to publish new editions with updated research?


Yes. The next edition will come out in roughly two to four years (mid 2002-2004). As better research becomes available, we can replace the less reliable studies so the book doesn't become impossibly thick.

Characterizing research


In the summary appendix at the back of the book, what criteria did you use in deciding how to characterize the research for each claim? What do the up, down and sideways arrows mean?


It's a "snapshot in time" of the current research. If the evidence is solidly in support of a particular supplement, such as folate for neural tube defects or calcium for osteoporosis, then I gave it an up arrow. For results that are suggestive but not strong enough to be definite -- perhaps most of the research is flawed in some way, or there might be only 3 or 4 small supporting studies -- those I gave an up arrow with a question mark. A sideways arrow indicates that the research doesn't show a clear result either for or against the claim. If none of the research supported the health claim, I gave those a down arrow -- for example: most of the sports nutrition supplements. And of course "NR" for cases where there is little or no research for a particular health benefit claim.

Health claims about supplements


Where did you get information about health claims being made on behalf of individual supplements?


Largely from reading magazines and health-news websites, although I also obtained some directly from supplement manufacturers, labels, websites or literature.

Derivation of "tolerable upper limits"


How are "tolerable upper intake levels" (UL) arrived at for each supplement?


The National Academy of Sciences (NAS) has a team of scientific experts that reviews the research on each supplement -- then establishes a set of four values that make up the Dietary Reference Intakes (DRIs). [See glossary.] This team sets the UL at a level that does not pose any risk of any kind of side effect for most healthy people. With vitamin C, for example, people who take as much as 2000 mg a day can get diarrhea. Also, the NAS team concluded that at 1500 IU of natural vitamin E, some people might have excessive bleeding. Generally speaking, they prefer to set rather conservative limits in order to protect public health.

Judging quality


In judging whether a supplement is of reliably high quality, what are the most important criteria -- and what would you recommend that people do?


First I want to know if there is enough research to back the health benefit claims. Call the manufacturer and ask them about the research. At the very least, they should be able to give a list of articles and where they were published. At best, the manufacturer will send copies of the articles.

Second, I prefer a manufacturer that tests every batch for purity, strength, and accuracy. Otherwise, you cannot be sure what you are getting. And herbals need to be tested all the way from beginning to end of the manufacturing process. ConsumerLab.com is doing a terrific job of randomized, off-the-shelf testing -- but it's just a drop in the bucket: only a few products and approximately two dozen brands.

Third, I'd like to see contraindications and warnings on all the labels, even if it's just to say "none known." That tells you the manufacturer has at least considered that question. But there are many products that should not be taken with various kinds of drugs or medical conditions, or during pregnancy and lactation, that kind of thing, and it's really important for consumers to know.

Fourth, I prefer a company to be using pharmaceutical-level GMPs -- good manufacturing practices. Supplements need to be produced to a higher manufacturing standard. Too much variation in potency levels is allowed in the currently required standard of manufacturing practices for supplements.

Improving supplement quality


What do you think needs to be done to move the supplement industry toward more reliable, high quality products?


First of all, I'd like to see more independent testing -- the kind of thing that ConsumerLab is doing. But ultimately? Force companies to be afraid not to have perfect products.

About the book

The Health Professional's Guide to Popular Dietary Supplements by Allison Sarubin, published by the American Dietetic Association, 2000.

Comprehensive, thoroughly researched and highly readable, The Health Professional's Guide . . . contains alphabetical entries from acidophilus to zinc. The book provides a variety of information about individual supplements, including media and marketing claims, a useful way of characterizing information that is often not scientific in origin. Also included are food sources, dosage information & bioavailability, as well as brief discussions of relevant research, safety issues, and a list of references.

Approximately two years in the making, The Health Professional's Guide . . . was edited and published by the American Dietetic Association, and is available in bookstores and on-line [see entry in our bookstore].end-of-story


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