For how we live.
US regulators class MSG as generally recognised as safe, and when the symptoms are tested under blinded conditions they largely disappear. The clearest signal is a nocebo effect, not the additive.
A systematic review of human trials found the evidence weak and inconsistent. Where MSG seemed to trigger headaches, it was given in large doses dissolved in water without food, in studies that were not properly blinded.
The US banned Red No. 3 in 2025 on a rat-specific cancer finding, not human data. The separate question — whether dyes affect children's behaviour — has better, and more unsettling, evidence.
Additives such as carboxymethylcellulose stabilise processed food. A large cohort links some to slightly higher heart-disease risk, and a small trial shows one disturbs the gut — but proof of harm is not settled.
The agency revoked Orange B and proposed dropping Citrus Red No. 2 because neither has been used in decades. It said the safety of synthetic colours is outside the scope of these orders.
The dye is being pulled under a 1958 law that bans any additive found to cause cancer in animals, at any dose. FDA's own review calls the rat finding of limited relevance to people.
A UK Biobank analysis broke ultra-processed food into 37 specific ingredients rather than treating it as one block. Flavours, colourings, sweeteners and sugars carried the signal; processing aids and added fibre did not.
In 105,260 people followed for 7.6 years, higher intakes of sorbates, sulfites, nitrates and acetates tracked with modestly higher cancer incidence. This is an observational study of self-reported diets.