Rabu, 03 September 2008

The Ezorb 92 % Calcium Absorption Claim

EZorb is Calcium Anhydrous Aspartate, and like most difficult-to-pronounce ingredients, is not the best thing to be ingesting. It costs little to manufacture, but with a very good marketing story it sells for a relatively high price. Most Calcium Brands are simply not complete products, but we find the Ezorb marketing story runs contrary to proven science and dangerously misleads people for several reasons.

In their website, they claim a “world record 92% Calcium absorption” which is “up to 20 times higher than any other calcium supplement”. They have presented no clinical evidence to support this exaggerated claim in spite of the scientific-looking graphs and text.

Arguably the leading Calcium researcher in America is Dr. Robert Heaney of Creighton University with more published papers on Calcium absorption than any other author. Dr. Heaney, an independent University research scientist, has tested dozens of calcium forms over the years and has found most to have acceptable absorption. Contrary to popular marketing hype, published studies show most Calcium supplements today are about 30% absorbed – quite acceptable compared to the 4.6% absorption implied by Elixir above. In a recent Journal of Nutrition article Heaney discusses “the usually exaggerated marketing claims of superior performance of one (Calcium) salt relative to another”, saying “this emphasis seems inappropriate and misdirected from both cost-benefit and nutritional considerations”(6). In other words, calcium bio-availability is constantly presented as a bigger problem than it really is by calcium manufacturers eager to demonstrate a market advantage. (1-15) We have no affiliation to Dr. Heaney, but find his independent research more compelling than the marketing hype of Elixir Industry. Most calciums are absorbed sufficiently so there is no advantage to one that is 92% absorbed. If you read on, you will see a significant disadvantage of highly absorbed calcium, though.

Ezorb’s Big Kidney Stone Fallacy

Their claim that any calcium supplement which is not completely absorbed contributes to kidney stones is based on very old, and highly speculative information which has long since been refuted over and over. In fact the very opposite is true – unabsorbed Calcium prevents kidney stone formation! We take great exception to companies trying to scare an often elderly population into buying their products with out of date information. Many recent studies show that the free calcium which is not absorbed combines with oxalates and other toxins, so it is very helpful for cleaning up the blood and PREVENTING kidney stones.

Discussing calcium and kidney stones, Professor Robert Heaney says “…nutritionally, there seems to be very little advantage to improving absorbability because unabsorbed calcium exhibits valuable functionality in it’s own right. Calcium remaining in food residue forms complexes with harmful substances left over from digestion, such as oxalic acid, unabsorbed fatty acids and bile acids. This complexation is the mechanism by which high calcium diets reduce the risk of kidney stones and colon cancer.”
Heaney continues “Theoretically, (calcium) sources with high intrinsic absorbability…could meet the body’s skeletal needs for calcium, but they would leave unmet the detoxification function that unabsorbed calcium serves… In brief, there is little or no nutritional advantage to ingesting one’s calcium in a form with absorbability higher than that of natural calcium sources (6).” In other words, if Ezorb really is 92% absorbed you are missing the protective effect against kidney stones and colon cancer that less absorbed Calcium forms offer.

Bone Growth, Not Calcium Absorption is Key

Ezorb has no reputable clinical research supporting bone growth, the study they refer to was done in China, a country known for scientific corruption. Just a few days ago the head of the Chinese FDA was sent to jail for allowing this kind of corruption to occur. Bio-availability is only one relatively unimportant first step. The real issue is bone growth which has not been demonstrated in any real clinical study. Testimonials are interesting, but they do not prove a product’s efficacy.

References

1: Heaney RP, Rafferty K, Dowell MS, Bierman J. Calcium fortification systems differ in bioavailability. J Am Diet Assoc. 2005 May;105(5):807-9.
3: Martin BR, Weaver CM, Heaney RP, Packard PT, Smith DL. Calcium absorption from three salts and CaSO(4)-fortified bread in premenopausal women. J Agric Food Chem. 2002 Jun 19;50(13):3874-6.
4: Heaney RP, Dowell MS, Bierman J, Hale CA, Bendich A. Absorbability and cost effectiveness in calcium supplementation. J Am Coll Nutr. 2001 Jun;20(3):239-46.
5: Heaney RP. Meta-analysis of calcium bioavailability. Am J Ther. 2001 Jan-Feb;8(1):73-4.
6: Heaney RP. Factors influencing the measurement of bioavailability, taking calcium as a model. J Nutr. 2001 Apr;131(4 Suppl):1344S-8S
7: Heaney RP, Dowell MS, Rafferty K, Bierman J. Bioavailability of the calcium in fortified soy imitation milk, with some observations on method. Am J Clin Nutr. 2000 May;71(5):1166-9.
8: Hanes DA, Weaver CM, Heaney RP, Wastney M. Absorption of calcium oxalate does not require dissociation in rats. J Nutr. 1999 Jan;129(1):170-3.
9: Weaver CM, Heaney RP, Martin BR, Fitzsimmons ML. Human calcium absorption from whole-wheat products. J Nutr. 1991 Nov;121(11):1769-75.
10: Heaney RP. Calcium supplements: practical considerations. Osteoporos Int. 1991 Feb;1(2):65-71.
11: Heaney RP, Weaver CM. Calcium absorption from kale. Am J Clin Nutr. 1990 Apr;51(4):656-7.
12: Heaney RP, Weaver CM. Oxalate: effect on calcium absorbability. Am J Clin Nutr. 1989 Oct;50(4):830-2.
13: Heaney RP, Weaver CM, Recker RR. Calcium absorbability from spinach. Am J Clin Nutr. 1988 Apr;47(4):707-9.
14: Smith KT, Heaney RP, Flora L, Hinders SM. Calcium absorption from a new calcium delivery system (CCM). Calcif Tissue Int. 1987 Dec;41(6):351-2.
15: Heaney RP. Calcium bioavailability. Bol Asoc Med P R. 1987 Jan;79(1):27-9.

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