Dr Norman thought that as the diet in the Richmond Asylum in Dublin was better than elsewhere, the beri-beri like disease could not have a nutritional basis. However, evidence for a dietary connection, especially with polished white rice, had emerged, and a precedent for a deficiency disorder – scurvy – was known if not fully understood. It was not until Casimir Funk in 1912 published ‘The etiology of the deficiency diseases’ that this concept began to take hold, and was the start of ‘vitamin theory’.
The deficiency in beriberi is of Vitamin B1, also known as thiamine, which is found more in brown rice and bread than the ‘white’ versions. Beriberi is less common in complete starvation than when extra but refined carbohydrate such as sugar is introduced. White bread may have been used in the asylum, and thiamine’s absorption is impaired with dysentery, in alcoholism, and even by tea drinking. There were no cases among the medical staff.
Unbeknownst to Dr Norman, a remedy akin to Marmite was at hand along the River Liffey at the Guinness Factory. The Brewery’s Chief Chemist, Dr Millar, developed the popular and tasty savoury spread, Guinness Yeast Extract or GYE, from the surplus yeast generated in the fermentation process. It was launched in Ireland in 1936 and was discontinued in 1968.
Garlic is a good source of thiamine too.