Shea butter does not trigger allergic reactions

Shea butter is very widely used in skin and personal care products for babies, children and adults but despite the fact that there are no recorded allergic reactions to shea butter, it is classed by the US FDA  as a nut and has to carry a nut warning. (See blog post on this subject.)

However, a recent study by Dr Kanwaljit K. Chawla, a pediatrician in training at Mount Sinai School of Medicine in New York City, suggests that the allergenic potential of shea butter is virtually non existent.

Shea nuts are, in fact, almost entirely fat (which does not evoke an allergic response), but Chawla and her colleagues extracted the protein from the nuts to see whether they would provoke an immune response.

When the fat was separated out from shea nuts only a tiny amount of protein was left, less than 1/30th the amount present in cashews and less even than that in peanuts. Even trace amounts of nut proteins can pose problems for nut allergic people but when the researchers tested the shea protein on blood taken from several volunteers with known allergies to nuts they found that the principle immune molecule that would usually invoke an allergic response, immunoglobulin E, barely bound to the shea protein at al. This means that the immune systems of nut allergics did not appear to recognise it as a nut protein.

Although shea butter is only used in skin products in the US, it is occasionally used in chocolate products in Europe.

Journal of Allergy and Clinical Immunology

December 2010

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