The chemistry of the Portuguese Empire III: Ascorbic Acid

This is the third post inspired by the book “Napoleon’s Buttons – 17 Molecules that Changed History” by Penny Le Couteur & Jay Burreson. While in the first two posts of the series we talked about piperine and eugenol, two molecules that inspired, so to speak, the Age of Discoveries, here we consider ascorbic acid which, or rather the absence of which, almost prevented it.

The functions that ascorbic acid, commonly known as vitamin C, performs in our body are several and important: it is in fact an antioxidant, the precursor of enzymes involved in the immune system and the production of neurotransmitters, and it is essential in the production of collagen and in tissue healing.

Molecule of ascorbic acid

But how is this related to oceanic navigation? Humans, as many other animals, are incapable of synthesizing vitamin C and can only acquire it from dietary sources, mainly from fresh fruits and vegetables. If sailors’ eating habits on land were not ideal, they became terrifying onboard, already after a few weeks of navigation. Preserving food in reasonable conditions was practically impossible and the crew had to rely on salty, dried meat and on hardtacks, biscuits made of water and flour and baked to become rock hard. Considering that voyages used to last for months, sailors very soon after their departure started to show symptoms of scurvy, a disease that is caused by vitamin C deficiency.

Not at all a pretty sight, since early symptoms are malaise and lethargy (that made some people think that lazy sailors got sick) then progressing to shortness of breath, but later symptoms are bleeding gums, loss of teeth, susceptibility to bruising, hemorrhaging from mouth and noise, poor wound healing, foul breath, and diarrhea, to finally evolve into fever, convulsions and eventual death. The scarce hygiene, the co-occurrence of other diseases and the general poor health conditions of the sailors, mainly recruited among the lowest social classes, were confounding factors that prevented a serious study of scurvy for a long time. The search for a cure lead to a series of proposals, including bloodletting, an ‘elixir of vitriol’ (a mixture of sulphuric acid and alcohol), salty water, and a number of other ineffective, when not harmful, alternatives.

Scurvy represented an issue until the 18th century.

Today we know that any citrus juice would be enough to avoid scurvy, but in the Age of Discoveries more people died of scurvy than those who died of war, other diseases and shipwrecks combined. [Silvana Munzi]