The discovery of vitamins at the turn of the 20th century led to new, diet-based treatments in medicine.
Can food be medicine, or medicine food? It’s not as simple as comparing apples and…syringes. According to Donna Messner, CHF’s current Gordon Cain Fellow in Technology, Policy, and Entrepreneurship, the distinction between what is food and what is medicine began to blur around the turn of the 20th century. I spoke with her about her research, which focuses on the discovery of a rare amino acid disorder and the development of a diet-based treatment for it, earlier this week.
Identified in Oslo, Norway, in 1934, phenylketonuria (PKU) is a rare genetic disorder that prevents the body from metabolizing an essential amino acid called phenylalanine (abbreviated Phe). Untreated, the disease will result in a buildup of Phe, which within six months of birth will severely slow cognitive development, and become worse as an infant ages.
The disease was discovered when a mother of two children afflicted with the disease took them to a resourceful biochemist and physician named Asbjørn Følling. Følling did a standard physical examination, finding everything normal. Then, in a move both intuitive and lucky, he put his chemical sleuthing skills to work and did an extra urine test, probably looking for odor-causing compounds that gave these children’s urine a strange, musty odor. He tested for ketones, expecting the samples to turn burgundy, which would indicate that the compounds were present. Instead, the samples turned deep green, a reaction no one had ever seen.
For the next two months the children’s mother collected a total of 22 liters of their urine. Using these samples, Følling found that the children were excreting an abnormal metabolic product called phenylpyruvic acid. He and other researchers realized that this abnormal substance resulted from a misfire of Phe metabolism. They also hypothesized that a diet low in Phe might treat or prevent PKU.
It took 20 years, however, to develop a protein substitute low in phenylalanine. Once it became available in the early 1950s, physicians immediately began testing the new protein on PKU patients. But the product tasted terrible. Many of the young patients accustomed to traditional foods threw up from eating it, had problems with dysentery, or simply refused to eat it at all. Doctors reasoned that the substance couldn’t simply be prescribed to children like a drug – it needed to be incorporated into family habits like a food. By the 1960s, some doctors had teamed with nutritionists to develop recipes that would hide the disagreeable protein product in familiar dishes. They even began publishing these recipes in scientific papers. Too often, however, the protein substitute just made everything it touched taste bad.
Some mothers with PKU children began to exchange and collect low-protein recipes, as well as general hints and tips for living with the disease. This family wisdom was eventually collected in a book, which stressed keeping the protein formula separate from regular food. The substance that was first medicine and then food was re-interpreted as medicine once again.
This back-and-forth was mirrored on the regulatory level; in the late-1950s, the Food and Drug Administration regulated the protein formula as a medicine because it needed to be prescribed by a doctor and fed to patients under a doctor’s care. But by the early 1970s, the FDA decided to regulate the product as a food – though with important exceptions from the way traditional foods are regulated.
PKU ended up being an important discovery for biochemistry, medical genetics, and psychiatry, and its dietary treatment became a model for approaching other metabolic diseases. Beyond treatments for formally recognized diseases, however, the list of “medical foods” continues to grow, as does debate about their regulation. Dr. Messner will publish a feature article on her work in the Spring 2012 issue of Chemical Heritage; until then, you can read about her research at CHF here.
"Food or Drug? The Advent of Medical Foods in the U.S." [Brown Bag Lectures]