Ketchup Was Once Medicine: The Strange Pharmaceutical History of America's Favorite Condiment

Tomato Extract as Pharmaceutical Product

In the 1830s, an Ohio physician named John Cook Bennett began promoting tomatoes — and concentrated tomato preparations — as remedies for conditions ranging from indigestion and liver disease to diarrhea and bilious attacks. His claims were published in newspapers and medical journals of the day, and they sparked a minor commercial boom in tomato-based patent medicines. Tomato pills, tomato extracts, and tomato ketchup were all marketed with health claims that would raise immediate regulatory flags today.

The ketchup of the 1830s was a different product from what fills diner tables today. It was thinner, more acidic, and often contained significant amounts of vinegar and spices alongside the tomato base. It bore more resemblance to a condiment sauce than to the thick, sweet paste Heinrich Heinz standardized in the latter half of the century. But in its pharmaceutical incarnation, it was bottled, labeled, and sold in druggists' shops alongside other herbal and mineral remedies.

Why Tomatoes Were Considered Medicinal

The logic behind tomato's medical reputation was a mixture of genuine observation and the prevailing medical theory of the era. Early 19th-century medicine was still heavily influenced by humoral theory — the idea that health depended on balancing four bodily fluids — and by the doctrine of signatures, which held that plants resembling body parts or exhibiting certain colors had therapeutic uses for related conditions. Tomatoes, being red and somewhat resembling the liver in certain contexts, fit neatly into this reasoning.

There was also a practical observation underneath the speculation. Tomatoes contain lycopene, a powerful antioxidant, along with vitamins C and K, fiber, and various bioactive compounds. They are genuinely good for digestive health in a diet that was otherwise heavy on salted meats and refined starches. Whether 1830s ketchup delivered these benefits in therapeutically meaningful quantities is doubtful, but the folk medicine tradition that recognized tomatoes as beneficial was not entirely unfounded.

The Tomato's Journey From Poison to Medicine to Condiment

The medicinal ketchup era is even more remarkable when you consider that tomatoes had only recently shed their reputation as poisonous. As members of the nightshade family, they were regarded with deep suspicion in much of Europe and North America throughout the 17th and 18th centuries. The leaves and stems of the tomato plant are indeed toxic, containing solanine and other alkaloids, and early European encounters with the plant may have produced illnesses from eating acidic tomatoes on pewter plates that leached lead.

By the early 19th century, resistance to eating tomatoes was fading, and the pendulum swung with characteristic overcorrection from "dangerous poison" to "wonder medicine." Neither extreme was accurate, but the pharmaceutical era served the useful cultural function of normalizing tomato consumption among people who still regarded the fruit with suspicion.

By the 1870s, Heinz had reformulated ketchup as a food product rather than a medicine, adding sugar to balance the acidity and creating the thick, stable sauce that became an industrial staple. The medical claims faded as food science developed, but the product remained — transformed from pharmacy shelf to kitchen table without most people noticing that it had once tried to be something entirely different.

The Modern Science Perspective

Interestingly, some of what Bennett claimed has partial support in modern nutritional science, even if the mechanism he proposed was wrong. Lycopene, the compound responsible for the tomato's red color, has been associated with reduced risk of certain cancers and cardiovascular disease in observational studies. The acidity of tomato-based products can stimulate digestive secretions and modestly assist with digestion. None of this validates 1830s ketchup as pharmaceutical-grade medicine, but it suggests that the intuition behind the claim was not entirely without basis. Sometimes folk medicine gets the answer approximately right for entirely the wrong reasons.