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