Some manufacturers of nutraceutical products try to differentiate themselves from their competitors by emphasizing that they do not use magnesium
stearate in their products. Worse, in their effort to market their products, they cast a negative picture on magnesium stearate claiming that it is deleterious
to health and that it affects bioavailability of nutrients. However, the scientific data to support their point of view is very weak and some of the scientific
references cited are taken out of context to support their point of view.
What are Magnesium Stearate and Stearic Acid
Magnesium stearate (C36H70MgO4) is the magnesium salt of stearic acid (octadecanoic acid; C18H36O2), mainly derived from plant and animal sources.
Magnesium stearate and stearic acid are among the most commonly used excipients in the pharmaceutical and food industry. An excipient is an inert,
non-active ingredient to assist in the physical process of making tablets and capsules, either as fillers, glidants or lubricants. Many dry powder ingredients
would not quickly and evenly (uniformly) flow into capsules without an excipient to enhance the free flow of the powder particles.
Safety and Toxicity of Magnesium Stearate and Stearic Acid
Magnesium stearate is a US FDA approved food and cosmetic ingredient and is classified as GRAS, a food substance that is not subject to premarket
review and approval by FDA because it is generally recognized, by qualified experts, to be safe under the intended conditions of use (1). Of the
more than 3,000 substances that comprise the US FDA EUFUS (Everything Added to Food in the United States) database, magnesium stearate has the
notation “ASP” which means that a “fully up-to-date toxicology information has been sought” (2). An extensive search of the scientific literature did not
unearth any documented toxic and safety concerns with magnesium stearate. One study that evaluated the effects of magnesium stearate on rats concluded
that the no-effect-level is estimated to be 5% magnesium stearate in the diet, equivalent to an intake of 2.5 grams per kg body weight per day (3). This
would be the equivalent of a daily intake of approximately 170 grams per day for a 150-pound individual.
Stearic acid, the parent compound of magnesium stearate, is also GRAS and has the same “ASP” notation in the US FDA EUFUS database (2). A search of
published articles on stearic acid did not show articles documenting adverse effects of stearic acid to human health. Instead, there is an emerging body of
literature supporting beneficial effects of stearic acid. One study showed that stearic acid-rich diet has positive effects on thrombogenic and atherogenic
risk factors in males (4). In another study, food high in stearic acid favorably affected blood lipids and factor VII coagulant activity in young men (5).
Stearic acid-rich diet did not result in significantly higher plasma cholesterol concentrations compared to low-fat diet (6).
Effect on Nutrient Bioavailability
A thorough search of published peer-reviewed literature did not show any published data showing that the presence of magnesium stearate has a negative
effect on dietary supplement absorption due to poor dissolution. Dissolution refers to the rate and effectiveness at which a tablet dissolves. One study reporting lower dissolution with magnesium stearate as a lubricant was more due to the form of starch excipient used rather than magnesium stearate. The
report goes to conclude that “the rate of dissolution was not affected when the drug and pregelatinized starch were mixed with magnesium stearate for a
prolonged time due to the absence of magnesium stearate flaking and film formation” (7). In fact other studies with pharmaceutical drugs show that
magnesium stearate has no significant effect on drug dissolution (8, 9). One dietary supplement manufacturer making an issue of magnesium stearate
negatively affecting nutrient absorption made a case with niacin. It claims that niacin with magnesium stearate will cause the nutrient to be delivered to
the small intestine, thus decreasing absorption. Granting that absorption of niacin happens in the stomach (in contrast to most nutrients that are known
to be absorbed in the small intestine), Bechgaard and Jespersen in 1976 (10) concluded that “By using the GI tube technique, niacin was shown to be
equally well absorbed from the stomach and the upper small intestine…Thus, the physiological prerequisites for a physically retarded niacin preparation
were established.”
THIS INFORMATION IS PROVIDED FOR THE USE OF PHYSICIANS AND OTHER LICENSED HEALTH CARE PRACTITIONERS ONLY. THIS INFORMATION IS INTENDED FOR PHYSICIANS AND OTHER LICENSED HEALTH CARE PROVIDERS TO USE AS A BASIS FOR DETERMINING WHETHER OR NOT TO RECOMMEND THESE PRODUCTS TO THEIR
PATIENTS. THIS MEDICAL AND SCIENTIFIC INFORMATION IS NOT FOR USE BY CONSUMERS. THE DIETARY SUPPLEMENT PRODUCTS OFFERED BY DESIGNS FOR HEALTH ARE
NOT INTENDED FOR USE BY CONSUMERS AS A MEANS TO CURE, TREAT, PREVENT, DIAGNOSE, OR MITIGATE ANY DISEASE OR OTHER MEDICAL CONDITION.
Magnesium Stearate and Stearic Acid Fact Sheet
At Designs for Health, we are committed to delivering high quality nutritional
supplements, educating healthcare practitioners as to their optimal therapeutic use, and
providing an accurate and objective method by which to measure their effectiveness.
®
Prevalence of Stearic Acid in Foods
Stearic acid (C 18:0) is one of the most commonly occurring saturated fatty acids in animal and vegetable fats and oils. The stearic acid contained in one
serving of various foods based on the USDA Agricultural Research Service database (11) and in a typical dietary supplement capsule and powder product
is shown below:
Science First
Designs for Health is committed to making pure and effective products. We take our science-first underlying business principle very seriously and will never
make products that will compromise the health of our customers. DFH uses either magnesium stearate or stearic acid that is 100% plant-derived in several
of its dietary supplement capsule and powder products. When either is used, the application rate is about 1% (anywhere from 1 mg to 10 mg per capsule
or serving of powder). As shown in the table above, the amount of stearic acid in a typical dietary supplement product is insignificant compared to what
consumers get from food — 266 mg stearic acid/1 tbsp of olive oil, 1,599 mg/85 g (3 oz) of pan-broiled beef patty, 343 mg/slice of cooked bacon, 248 mg/42
g of chicken drumstick meat, for example. In fact, there is a move in the food industry to enrich fats with stearic acid as an alternative to hydrogenation
because of the beneficial effects of stearic acid on lipids and thrombosis (12).
The Designs for Health line is mainly capsules and powders. Most patients prefer to swallow capsules rather than tablets. Many health professionals choose
Designs for Health powders that are, as often as possible, free of all excipients and allow for more aggressive dosing as desired for efficacy. We are proud of
the results obtained with our product line and are gratified by the ability to help those in health crisis.
References
1. US Food and Drug Administration. Center for Food Safety and Applied Nutrition. CFSAN/Office of Food Additive Safety. October 2006. Alphabetical List of SCOGS Substances.
Internet: http://www.cfsan.fda.gov/~dms/opascogc.html (accessed 21 June 2007).
2. US Food and Drug Administration. Center for Food Safety and Applied Nutrition. EAFUS: A Food Additive Database. Everything Added to Food in the United States. 2007-May-21.
Internet: http://vm.cfsan.fda.gov/~dms/eafus.html (accessed 21 June 2007).
3. Sondergaard D, Meyer O, Wurtzen G. Magnesium stearate given perorally to rats. A short term study. Toxicology 1980;17(1):51-55 (abstr).
4. Kelley FD, Sinclair AJ, Mann NJ, et al. A stearic acid-rich diet improves thrombogenic and atherogenic risk factor profiles in healthy males. Eur J Clin Nutr 2001;55(2):88-96 (abstr).
5. Tholstrup T, Marckmann P, Jespersen J, et al. Fat high in stearic acid favorably affects blood lipids and factor VII coagulant activity in comparison with fats high in palmitic acid or high
myristic and lauric acids. Am J Cli Nutr 1994;59:371-77.
6. Nestel PJ, Pomeroy S, Kay S, et al. Effect of a stearic acid-rich, structured triacylglycerol on plasma lipid concentrations. Am J Clin Nutr 1998;68:1196-201.
7. Chowhan ZT, Chi LH. Drug-excipient interactions resulting from powder mixing. III: Solid state properties and their effect on drug dissolution. J Pharm Sci 1986;75(6):534-41.
8. Piscitelli DA, Bigora S, Propst C, et al. The impact of formulation and process changes on in vitro dissolution and the bioequivalence of piroxicam capsules. Pharm Dev Technol
1998;3(4):443-52 (abstr).
9. Eddington ND, Ashraf M, Augsburger LL, et al. Identification of formulation and manufacturing variables that influence in vitro dissolution and in vivo bioavailability of proplanolol
hydrochloride tablets. Pharm Dev Technol 1998;3(4):535-47 (abstr).
10. Bechgaard H, Jespersen S. GI absorption of niacin in humans. J Pharm Sci 1976;66(6):871-72 (abstr). Published Online: 17 Sept 2006: Internet:
http://www3.interscience.wiley.com/cgi-bin/abstract/113294625/ABSTRACT?CRETRY=1&SRETRY=0 (Accessed 20 June 2007).
11. US Department of Agriculture. Agriculture Research Service. USDA National Nutrient Database for Standard Reference. SR 19 – Page Reports. Fats and Oils. 09/01/2006. Internet:
http://www.ars.usda.gov/Services/docs.htm?docid=13725 (accessed 6 July 2007).
12. Liu Q, Singh S, Green A. High-oleic and high-stearic cottonseed oils: nutritionally improved cooking oils developed using gene silencing. J Am Coll Nutr. 2002;21(3 Suppl):205S-211S (abstr).
Soybean oil, salad or cooking 1 tbsp (13.6 g) 517
Canola oil 1 tbsp (13.6 g) 245
Corn oil, salad or cooking 1 tbsp (13.6 g) 251
Olive oil, salad or cooking 1 tbsp (13.6 g) 266
Sunflower oil, high oleic 1 tbsp (13.6 g) 588
Coconut oil 1 tbsp (13.6 g) 381
Palm oil 1 tbsp (13.6 g) 585
Beef patty, 80% lean meat/20% fat, pan-broiled 85 g (3 oz) 1,599
Bacon, cured, broiled, pan-fried or roasted 8 g (1 slice) 343
Chicken drumstick, fried, bone and skin removed 42 g 248
Dietary supplement, capsule (@1% magnesium stearate) 500 mg 4.8*
Dietary supplement, powder (@1% stearic acid) 1,000 mg (1 g) 10
TYPE OF FOOD SERVING SIZE STEARIC ACID
(mg/serving)
*Magnesium stearate is about 96% stearic acid.
To contact Designs for Health, please call us at (800) 847-8302, or visit us on the web at www.designsforhealth.com.