Limes and Scurvy

A minor setback in keeping scurvy at a distance occurred in the 1850s when, for economic reasons, the British Admiralty contracts were changed so that the West Indian lime (Citrus aurantiifolia) was substituted for the lemon (Citrus limon). The superficial similarity between the two fruits had already led to the use of the terms “lime juicer” and “limey” by. Americans in referring to British ships and sailors. Furthermore, the terms “lemon juice” and “lime juice” were used carelessly and often without distinction in referring to the two species. In fact, at the beginning of the century the lime was sometimes referred to as the “sour lemon” (Green 1824: 316).

An unfortunate consequence of this change was the reported failure of stored lime juice to offer protection against scurvy - as in the ill-fated “Nares” expedition to the. Arctic in 1875 The apparent failure of lime to prevent scurvy led to the rejection by some observers of the thesis that lack of fresh fruit and vegetables was the only cause of scurvy. A. H. Smith, in a comprehensive article stimulated by outbreaks of scurvy among troops issued lime juice during the First World War, concluded that lime juice (as contrasted with lemon juice) as an antiscorbutic agent was “worthless” (Smith 1919).

The reason for this apparent lack of antiscorbutic potency on the part of lime juice preparations is still incompletely understood. It is true that lime juice has a lower vitamin C content than lemon juice, but it is still high enough to be regarded as a moderately good source of the vitamin. It is possible that the vitamin C molecule is much less stable in lime juice than in lemon juice - a belief that was apparently confirmed by Harriette Chick in 1918 using the guinea pig as an assay system. This observation would suggest that the protective and stabilizing factors present in lemon juice (high acidity, tannins, anthocyanins, etc.) are less potent in lime juice preparations. However, in a recent study, Carpenter found no essential difference between the rate of loss of ascorbic acid in lime and lemon juices (Carpenter 1991, personal communica-tion).Whatever the true explanation, the apparent discrepant protective capacities of the two forms was an important feature in the history of scurvy, introducing a puzzling diversionary element into an otherwise fairly smooth development.