Poisons That Heal and Foods That Harm

Poisons That Heal

In the 1920s, cattle in the US and Canada began dying of internal bleeding after eating moldy sweet clover hay (Melilotus species, particularly Melilotus officinalis or Melilotus alba). Mold converted natural coumarins in the plant to dicoumarol, which acts as a vitamin K antagonist and prevents blood clotting. Scientists isolated dicoumarol in 1940, and it was developed into early anticoagulant drugs (later leading to warfarin).

Digoxin (or more broadly, digitalis/cardiac glycosides from foxglove, Digitalis purpurea or Digitalis lanata)  is a cardiac glycoside that increases the force of heart contractions and is still used to treat heart failure and atrial fibrillation. William Withering's 1785 book documented foxglove leaf preparations for treating dropsy (edema from heart failure).  

Curare refers to plant-derived curare alkaloids such as d-tubocurarine from species like Chondrodendron tomentosum. Indigenous hunters in the Amazon used it on blowgun darts for centuries; it blocks neuromuscular transmission, causing flaccid paralysis and death by respiratory failure. It appeared in a Tintin adventure (The Shooting Star & related stories). 

In medicine, the active alkaloid tubocurarine revolutionized surgery. In the 1940s, purified forms (and synthetic analogs) were introduced as muscle relaxants, revolutionizing anesthesia for abdominal surgery by enabling controlled relaxation without deep general anesthesia.

Botulinum toxin (or botulinum neurotoxin, often abbreviated BoNT, produced by Clostridium botulinum). It is the most potent known toxin by weight, blocking acetylcholine release at neuromuscular junctions and causing paralysis. In microgram doses (as Botox or similar preparations), it is used therapeutically for chronic migraine, muscle spasms, and cosmetically to reduce wrinkles by temporary muscle relaxation.

Ancient Egyptians and Greeks used willow bark (Salix species) for pain and fever relief; it contains salicin, which the body converts to salicylic acid. In the 19th century, salicylic acid was isolated and used, but it caused gastric irritation. Felix Hoffmann at Bayer chemically modified it (acetylating salicylic acid) in 1897 to create a less irritating form, patented and marketed as aspirin (acetylsalicylic acid) in 1899—one of the most widely used drugs ever.

Arsenic has been used as a poison for centuries due to being nearly tasteless and odorless in some forms, making it a tool for murderers. In the late 1990s/early 2000s, Chinese researchers demonstrated its efficacy against acute promyelocytic leukemia (APL) by inducing differentiation and apoptosis in cancer cells at controlled low doses. It was approved by regulators (e.g., FDA in 2000) as a treatment for this specific leukemia. Arsenic trioxide was approved by the FDA in 2000 to treat Acute Promyelocytic Leukaemia (APL) after it was shown to induce "differentiation" or death in cancer cells.

Throughout history, humans have discovered that many potent natural poisons—such as dicoumarol from spoiled sweet clover, cardiac glycosides from foxglove, curare from Amazonian vines, botulinum toxin from bacteria, salicylic acid from willow bark, and arsenic—can become valuable medicines when isolated, purified, and administered in precisely controlled micro-doses.

Foods That Harm

In the modern food system, a parallel dynamic has emerged with ultra-processed foods (UPF) - industrially formulated products which often contain high levels of added sugars, unhealthy fats, salt, cosmetic additives (colors, emulsifiers, preservatives, artificial sweeteners), neo-formed contaminants from processing (such as acrylamide), and chemicals migrating from packaging (including phthalates, bisphenols, and PFAS).

Ultra-Processed Foods (UPF) represent a biological inversion: they take life-sustaining whole foods and "refine" them into systemic disruptors.

UPFs act as "slow poisons." They don't paralyze respiratory muscles; they paralyze metabolic flexibility and satiety signaling over decades.

While individual components may be deemed safe at regulatory limits in isolation, chronic high consumption of UPF delivers cumulative exposures that observational and mechanistic studies link to increased risks of obesity, type 2 diabetes, cardiovascular disease, certain cancers, gut microbiome disruption, inflammation, and other harms.

- forked from a quiz on poisons turned medicines in The Hindu; co-authored with Grok