Did consumption of flour bleached by the agene process contribute to the incidence of neurological disease?

The present report proposes the hypothesis that increased levels of neurodegenerative disorders in humans may have arisen due to inclusion in the diet of methionine sulfoximine (MSO), a byproduct of the bleaching of flour by nitrogen trichloride. This method of bleaching, the 'agene process' was in use from early in the century and continued until at least 1949/1950. Estimates indicate that, at least in the UK, as much as 80% of all flour during this period was produced by this process. MSO acts directly to inhibit the production of two crucial molecules, glutathione (GSH) and glutamine. Decreases in GSH, a key antioxidant and free radical scavenger, diminish the body's antioxidant defenses and may lead to increased oxidative stress. Decreases in glutamine synthesis may act to increase free glutamate and give rise to increased levels of ammonia. Cells in the nervous system are particularly sensitive to a decline in either GSH or glutamine. The combined effects of decreases in these molecules, particularly with long-term exposure to MSO in bleached flour, may have had quite drastic effects on neuronal health and survival. The present hypothesis may provide clues to the etiology of neurological disorders such as Alzheimer's disease (AD), Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS), suggesting that such disorders may arise in part due to toxic actions of some compounds in processed human foods.

Natural occurrence of methionine sulfoximine in the Connaraceae family.

The toxic principle of Cnestis glabra, identified as methionine sulfoximine has been found as a permanent constituent of the soluble amino acid pool of this plant. In the roots the toxin concentration varies markedly according to the developmental stage of the plant. The poisonous principles of Cnestis polyphylla and Rourea orientalis, two other Connaraceae species, were purified to homogeneity. Similarity of their physiochemical and biological properties, their behaviour in thin-layer and gas chromatographies and their infrared spectra to those of the toxin of Cnestis glabra established their identity to methionine sulfoximine. This methionine derivative, never reported as a natural product, seems to be characteristic of toxic Connaraceae species.