“Plant sterols are present in various combinations in nuts, seeds and plant oils. As plant sterols are the equivalents of animal cholesterol, they can in principal influence metabolic processes, where cholesterol is involved,” explained Marcus Grimm, Head of the Experimental Neurology Laboratory at Saarland University. “Because they also lower cholesterol levels, they are extensively used in the food industry and as dietary supplements.”
One particular sterol, called Stigmasterol, was strongly associated with the formation of plaque proteins. “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.
The research specified that various plant sterols influence different cellular mechanisms and therefore have to be assessed individually. “Particularly in the case of Alzheimer’s disease, it seems expedient to focus on the dietary intake of specific plant sterols rather than a mixture of sterols,” explained Dr Grimm. The exact underlying mechanisms underlying the impact of plant sterols on amyloid plaques still needs to be identified.
V. K. Burg, H. S. Grimm, T. L. Rothhaar, S. Grosgen, B. Hundsdorfer, V. J. Haupenthal, V. C. Zimmer, J. Mett, O. Weingartner, U. Laufs, L. M. Broersen, H. Tanila, T. Vanmierlo, D. Lutjohann, T. Hartmann, M. O. W. Grimm. Plant Sterols the Better Cholesterol in Alzheimer’s Disease? A Mechanistical Study. Journal of Neuroscience, 2013; 33 (41): 16072 DOI: 10.1523/JNEUROSCI.1506-13.2013