Cacao is a food which may result in allergy symptoms in sensitised individuals.

Cacao Allergy Test: Allergen Exposure

Cacao is a seed which is obtained from the cacao tree, a small evergreen growing in the tropical region of the Americas. The seeds are used in the production of both cocoa powder and chocolate.

Cocoa and chocolate products are made from the seed, which is split open and left to ferment for about a week. This removes the raw taste and develops the oils. The beans are then dried, roasted and ground to make chocolate powder. About 300-600 seeds are required to produce 1kg of cocoa paste.

The cocoa is liquefied (cocoa liquor) and processed in one of three ways: it can be poured into moulds (for baking chocolate); pressed, to separate most of the butter from the cocoa (for cocoa powder); or sweetened and processed into chocolate.

Cocoa butter is used in manufacturing confections. Cocoa butter substitutes can be produced from soy, maize or corn, palm kernel oil, and cottonseed, and are used in chocolate-flavoured products.

Exposure to cacao occurs through chocolate, candies and pastries. The powder is used for drinks and confections, and also to make medicines more palatable.

Cocoa butter is used in chocolate manufacture. If not adequately purified, it may contain cocoa allergens. Chocolate, although containing cacao, may also contain many other ingredients including cocoa butter, sugar, cocoa liquor, milk or milk powder, and flavourants, e.g. vanilla, emulsifiers and butterfat.

Cacao Allergy Test: Allergen Description

No allergens have been characterised yet, although an albumin storage protein present in cacao seed has been isolated.

Cacao Allergy Test: Potential Cross-Reactivity

Mabinlin, a 2S albumin with similarity to 2S storage albumins of cotton and brazil nut and sweet protein, was isolated from cocoa bean. The allergenicity of the 2S cocoa albumin protein was not evaluated; therefore it is possible there is a degree of cross-reactivity between cacao and other 2S albumins.

It has been suggested that when a true chocolate sensitivity exists, cola drinks and karaya gum (often listed as ‘vegetable gum’) should be omitted, since the cacao bean, cola nut and karaya gum all belong to the same botanical family, Sterculiaceae.

Cacao Allergy Test: Clinical Experience

Anecdotal evidence suggests that cacao may induce symptoms of food allergy in sensitised individuals. However, few studies have been reported to date; it is possible that the allergy occurs more frequently than has been reported.

Specific IgE antibodies have been found in patients with symptoms such as bronchial asthma and allergic rhinitis after different food intake, of which chocolate was one such food.

Cocoa has been implicated as a cause of atopic dermatitis in an infant.

Sensitisation to cacao has been reported particularly in occupational settings, and especially in confectionery workers.

A case study on a confectionery worker complaining of symptoms in the nose and respiratory system reported the presence of specific IgE antibodies to cacao allergens.

Other reactions

Studies have reported that cacao and chocolate, among other foods, may be responsible for migraine headaches in children and young adults.

This may be as a result of a number of vasoactive substances present in cacao (including caffeine and tyramine) or others resulting in histamine release without IgE involvement, which may be responsible for other pseudo-allergic reactions.

Cocoa consumption has been reported to have an aspirin-like effect on primary haemostasis. Whether this may result in abnormal bleeding disorders has not been elucidated.