Stearic acid and Magnesium Stearate update

How much stearic acid is in chocolate? 

We were looking at a chocolate bar yesterday. Dark chocolate is supposed to be a health food. 

As we happened to be nutritionists, the topic of the chocolate bar's stearic acid content came up, which is a controversial fatty acid. So I did a little calculating...

The bar in question is a 72% Dark Chocolate from Belgium, with the fat coming almost exclusively from cocoa butter (except a tiny bit of lecithin; but typically under half a percent is used in chocolate manufacturing, according to Chocolate University Online). The bar weighs 1.65 oz (47 grams), contains 280 calories, and is labeled as being one serving.  

The product label says that the bar supplies 19 grams of fat, including 12 grams of saturated fat. Since about one-third of cocoa butter’s fat - and over half of its saturated fat - is known to be stearic acid, a one-bar serving of this chocolate conservatively can be assumed to contain at least 6 grams of stearic acid, which is equivalent to 6,000 milligrams (mg.). 

How does that compare to the amount of stearates commonly found in tablets and capsules?

That amount in the single small chocolate bar is equivalent to more than 1,000 tablets or capsules worth of stearate content, assuming the highest likely amount of stearic acid or magnesium stearate was used in those pills. Five milligrams is the highest I've seen on supplement Master Formulas, but many products use less or none. (Assuming 5 mg. per pill x 1,000 pills = 5,000 mg. of stearates per bottle).

So if someone had a jumbo, family-sized bottle of a thousand pills, each containing a few milligrams of stearic acid or magnesium stearate that's primarily stearic acid, that whole bottle would contain less stearic acid than a single serving 47 gram dark chocolate bar. 

Doesn't that put stearic acid consumption into perspective? Each pill contains less than 1% of what you'd get in a serving of chocolate. 

How much stearic acid is found in other common foods?

Butter contains about 12% stearic acid, by weight, as do the average beef, pork, or lamb product. Healthy olive and coconut oils contain between 2-3% stearic acid. Salmon oil naturally contains about 4% stearic acid. 

More fun facts:

• Milligrams (mg.) are thousands of a gram; micrograms (mcg.) are millionths of a gram.
• Stearic acid tends to be converted into oleic acid in the liver.
• Stearic acid is abundant in the food supply as a natural component of the fat in those foods; milk and meat fats are the primary sources. 

How much magnesium is in magnesium stearate?

The molecular weight of stearic acid (Octadecanoic acid) is 284.484 grams/mol. There are 2 stearic acid molecules in one molecule of magnesium stearate, which has a molecular weight of 591.257 grams/mol. The molecular weight of magnesium is about 24.305 grams/mol. So the amount of magnesium in a 5 mg portion of magnesium stearate is about 200 micrograms (not milligrams); about half of one one-thousandth (half of 1/1,000 or 0.0005 or 0.050%) of the 400 milligram RDA. That's also 1/20th of a percent of the RDA. 

So the amount of magesium in a pill containing magnesium stearate is negligible; it would be insignificant unless another magnesium source is added. Magnesium stearate is a form of chelated magnesium that contains only about 4% elemental magnesium by weight and about 96% stearic acid.

REFERENCES:

• Kelly FD, Sinclair AJ, Mann NJ, Turner AH, Abedin L, Li D. A stearic acid-rich diet improves thrombogenic and atherogenic risk factor profiles in healthy males. Eur J Clin Nutr. 2001 Feb;55(2):88-96. PubMed PMID: 11305631.
• https://pubchem.ncbi.nlm.nih.gov/compound/5281
• https://pubchem.ncbi.nlm.nih.gov/compound/magnesium_stearate
• https://pubchem.ncbi.nlm.nih.gov/compound/5462224
• http://www.chocolateuniversityonline.com/lecithin-in-chocolate/ 
• https://www.scientificamerican.com/article/why-is-dark-chocolate-good-for-you-thank-your-microbes/
• http://www.cnn.com/2017/10/06/health/dark-chocolate-healthy-food-drayer/index.html
• https://www.nowfoods.com/now/nowledge/stearic-acid-and-magnesium-stearate
• https://epi.grants.cancer.gov/diet/foodsources/sat_fat/sa.html
• http://honestnutrition.blogspot.com/2008/04/myths-about-stearate-risks.html 
• http://spo.nmfs.noaa.gov/Circulars/CIRC276.pdf

Myths about stearate "risks"

There are some common myths about stearates. Please allow me to describe the stearates that are utilized in making nutritional supplements, and how they are used, and other pertinent information on their safety and use in dietary supplements and foods.

Stearic acid is converted into oleic acid in vivo, so becomes a similar fat as is found in olive oil. In fact, one jumbo olive is estimated to contain 13 milligrams (.013 g) of stearic acid (C 18:0), many times more than is used in any pills or capsules. http://www.oliveoilsource.com/olivechemistry.htm

“Stearic acid is well absorbed by the gut and is transported in chylomicrons and remnant particles before being picked up by the liver. Once there, an interesting paradox occurs in that excess stearic acid is simply converted to the 18-carbon monounsaturated oleic acid via a desaturase enzyme in the liver (3) and then recirculates in lipoprotein complexes as oleic acid, which is not hypercholesterolemic. Thus, conversion to oleic acid may explain why stearic acid does not elevate plasma cholesterol concentrations.”

Supplement manufacturers rarely use more than 2% and usually far less or none at all, even though common foods contain much more (beef fat is 19% stearates; cocoa butter is 30%) and stearates are Generally Recognized As Safe (GRAS). It is unusual that they would use more than1-2% in a product, and when they do use them it is typically used in microgram amounts to help process only sticky or non-flowing materials.

The hydrogenation process is not used for the stearic acid in the magnesium stearate. It is possible to convert oleic acid to stearic acid by hydrogenation, but that is not necessary (or desirable) with sources that are already high in stearic acid and low in oleic acid. Lipase-catalyzed interesterification is a viable alternative to hydrogenation these days, for example, if one were to want to convert oleic acid to stearic acid.

No consumer should be inhaling stearates, so the issue of being hazardous is also a bogus one that should be relegated to producers and manufacturers. You can actually say far worse about the hazards of inhaled enzymes, for example. Most supplement materials have MSDS handling sheets that mention the dangers of inhalation. There are no known significant dangers from normal oral consumption or skin contact.

The reason dietary stearic acid is considered benign is based on its failure to elevate plasma cholesterol concentrations (1, 2). Foods naturally rich in stearic acid and other saturated fats include: Red meat (beef, pork, or lamb) High-fat dairy products (whole milk, cheese, butter, and ice cream) Chocolate, Lard, Coconut oil.

For more on stearates, please see: http://www.nowfoods.com/index.php?action=itemdetail&item_id=93528.

Also, the accompanying chart has the percentages of stearic acid in common foods (4). As you can see, stearic acid is far more abundant in olive oil, butter and lard than in dietary supplements as a percentage, with grams in foods and micrograms (possible low milligram levels) in only certain dietary supplements:

A common reference is to a 1990 study in the journal Immunology, but the reference is hardly satisfactory as a demonstration of the alleged harm of stearic acid. This was a test tube study that has not been replicated in living beings, with an artificial situation providing high concentrations of stearic acid exposed to isolated immune cells for hours at a time. It was actually done as a way to investigate whether prolonged high dose stearic acid administration could possibly be used to suppress the immune system for an autoimmune disease treatment. (5) It was definitely NOT a demonstration that this would work the same way with dietary supplements or with foods containing stearic acid. The effect was dose- and time- dependent; with a sustained, prolonged exposure over an 8-hour period that is impossible to replicate in the living human body. For a test tube study, it would first have to be shown that the mechanism was valid in vivo before it could be considered reasonable to extrapolate it to actual living organsms. This study did not do that; nor has any other, to date.

In conclusion, since this mechanism has not been proven in humans or had additional verifying studies, since humans have much more complex metabolic activities, since stearic acid is easily absorbed from the gut and then readily converted to oleic acid in the liver (in vivo), since manufacturers use far less than this study gave and with only a brief exposure, and since people get stearic acid in many common oil-containing foods in far greater amounts than are used in dietary supplements, I conclude that the fears about the use of stearates in dietary supplements are unproven and speculative at best, slanderous and unscientific at worst.

For a second opinion, please see the website of Ray Sahelian, M.D. at http://www.raysahelian.com/magnesiumstearate.html

REFERENCES
1. Yu S, Derr J, Etherton TD, Kris-Etherton PM. Plasma cholesterolpredictive equations demonstrate that stearic acid is neutral and monounsaturated fatty acids are hypocholesterolemic. Am J Clin Nutr 1995;61:1129–39.
2. Aro A, Jauhiainen M, Partanen R, Salminen I, Mutanen M. Stearic acid, trans fatty acids, and dairy fat: effects on serum and lipoprotein lipids, apolipoproteins, lipoprotein(a), and lipid transfer proteins in healthy subjects. Am J Clin Nutr 1997;65:1419–26.
3. Lin DS, Connor WE, Spenler CW. Are dietary saturated, monounsaturated, and polyunsaturated fatty acids deposited to the same extent in adipose tissue of rabbits? Am J Clin Nutr 1993;58:174–9.
4. http://www.nebeef.org/post/lfu/Stearic_Acid.pdf
5. Tebby PW, Buttke TM. Molecular Basis for the Immunosuppresive Action of stearic acid on T Cells. Immunology. 1990;70:379-384.