The research team based at Saarland University's medical campus in Homburg collaborated with scientists from Bonn, Finland and the Netherlands to examine how the sterols that we ingest influence the formation of these plaque proteins. It was found that one sterol in particular, stigmasterol, actually inhibited protein formation. "Stigmasterol has an effect on a variety of molecular processes: it lowers enzyme activity, it inhibits the formation of proteins implicated in the development of Alzheimer's disease, and it alters the structure of the cell membrane," explained Dr Grimm. "Together, these effects synergistically reduce the production of beta-amyloid proteins." The research team has been able to confirm the positive effect of stigmasterol in tests on animals.
Natural occurrences
Stigmasterol is an unsaturated plant sterol occurring in the plant fats or oils of soybean, calabar bean, and rape seed, and in a number of medicinal herbs, including the Chinese herbs Ophiopogon japonicus (Mai men dong), in Mirabilis jalapa[2] andAmerican Ginseng.
Occurrences in food
Stigmasterol is also found in various vegetables, legumes, nuts, seeds, and unpasteurized milk. Pasteurization will inactivate stigmasterol. Edible oils contains higher amount than vegetables.[3] Phytosterols normally are broken down in the bile.