Tremetol

In 1818, Nancy Hanks Lincoln — mother of the future U.S. president — died of an illness called milk sickness at her family’s frontier homestead in Indiana. She was thirty-four years old. Across the Ohio Valley and Indiana frontier in the early nineteenth century, milk sickness was responsible for an enormous fraction of all deaths — the Missouri Department of Conservation states that in early 1800s Ohio and Indiana, up to half of all fatalities in some counties were caused by it. The cause — not identified until decades later — was a chemical compound called tremetol, present in two North American plants, transferred through the milk of cows that had grazed on them.

The Plants

White snake root (Ageratina altissima) is native to the eastern and midwestern United States, found in wooded habitats and pasture edges from Ohio and Pennsylvania through the Midwest dairy belt. Rayless goldenrod (Isocoma pluriflora, also called Jimmyweed), the regional analogue, is native to Texas, New Mexico, and the arid Southwest. Both plants produce tremetol. Both are documented livestock hazards in the Texas A&M and Ohio State range-plant databases. Both retain full toxicity when dried into hay.

The Mechanism

Tremetol is a complex of related lipophilic compounds (the principal toxin is tremetone) that disrupt mitochondrial function. The compound suppresses citrate synthase and impairs the cell’s ability to metabolize acetyl-CoA, producing a pathological ketoacidosis distinct from and opposite to the therapeutic ketosis of a controlled fast or ketogenic diet. The cow can consume the plant for weeks before showing symptoms herself; meanwhile her milk concentrates the toxin and delivers it to anyone who drinks it. The historical low-dose form, called “the slows,” produced gradual weakness and fatigue across months or years — a clinical picture that today would be diagnosed as chronic fatigue syndrome, depression, or fibromyalgia.

Why It Disappeared from Medical Literature

Milk sickness largely vanished as a recognized clinical entity in the United States after the 1920s, when modern dairy practices — pasteurization, herd consolidation, controlled feed regimens, and the systematic clearing of snake root from pastures — reduced the documented exposure load. The plant did not disappear. The toxin did not disappear. The recognition of the toxin’s presence in milk did. Modern dairy and beef regulatory testing panels do not screen for tremetol or its metabolites. The FDA, USDA, and state agriculture departments have no maximum contaminant level for tremetol in milk, butter, cheese, or beef. There is no requirement to test. The condition is not in the medical-school curriculum.

Modern Re-emergence Conditions

Tremetol concentrates in the fat fraction of dairy products. Whole milk is 3–4 percent fat; butter is approximately 80 percent; hard cheeses run 30–50 percent. The toxin follows the fat. Butter from contaminated milk could carry ten to twenty times the per-serving tremetol load of the raw milk. Hard cheeses concentrate it significantly as well. The compound is also lipophilic in the cow herself — accumulating in body fat across her productive lifetime. Dairy cows at end of productive life enter the beef supply, predominantly as ground beef. A 2025 peer-reviewed paper states directly that tracking lipophilic contaminants in lactating cows is “the cornerstone of safety for both dairy products and beef meat.”

The structural conditions that favor reappearance of the historical exposure pattern include: large concentrated animal feeding operations purchasing hay from anonymous regional suppliers; certified-organic dairy operations that cannot use herbicides to control weed encroachment; and pasture-raised beef cattle, by definition, eating whatever grows in their pasture. Any of these supply paths is structurally vulnerable to tremetol-bearing plants returning quietly to the food chain. The next episode looks at a different toxin entering through a different liquid — the bottled spring water supply.

Working draft. Sources include the historical record on Nancy Hanks Lincoln’s death; Missouri Department of Conservation and Indiana state-history documentation of frontier milk sickness; Ohio State and Texas A&M extension publications on white snake root and rayless goldenrod; peer-reviewed metabolic studies on tremetone toxicology; and FDA and USDA documentation of the absence of tremetol testing requirements.