GALACTOSE-Project
Until the year 2050 the number of people with Alzheimer's disease within the EU will go up from today's 5.7 millions to about 20 millions. Added to the suffering of the affected individuals and their families the costs of coping with this enormous social burden that society has to bear will be tremendous. While numerous approaches for treatment do exist, a real breakthrough in therapy is probably still far away because, just as with cancer, of the many different mechanisms that underlie the pathogenesis of this dreadful neurodegenerative disorder. The consequence is that we have to make use of any reasonable chance that might delay the onset of Alzheimer’s disease.
The human brain needs glucose to maintain its normal energy and nutrient metabolism. The uptake of glucose in the brain cells is exclusively mediated through insulin via the insulin receptor at the cell membrane. If the function of the insulin receptor is impaired or even abolished, the glucose metabolism of the cells is reduced and subsequently the energy production diminished. The defect of the insulin receptor is most significant in diabetes mellitus type 2. Furthermore, it is well known that individuals with diabetes suffer more often from Alzheimer's disease than individuals without diabetes.
Professor Werner Reutter from the Institute of Biochemistry and Molecular Biology at the Charité in Berlin demonstrated that the performance of the memory was considerably reduced in rats if their insulin receptors were damaged, which is obviously due to the decreased glucose supply. Surprisingly, there was no memory loss when the rats were given galactose together with drinking water during the experiments. On the basis of these results, patients with Alzheimer's disease received galactose in different liquids, and most of them showed a considerable overall improvement of memory. This effect was realized mainly in their social behaviour (especially by their caregivers), but also in the well-being of the patients.
The explanation for these newly obtained results in rats and also in humans is probably very simple. For the cellular uptake of glucose the insulin receptor system cooperates with the glucose transporter GLUT4. In spite of the close structural relationship between glucose and galactose, the latter is only partly taken in via GLUT4. The uptake of the far larger portion occurs via the glucose transporter GLUT3 that functions independently of insulin. Thus, galactose reaches the brain depending almost exclusively on its concentration in the blood sream on a direct way and in the brain cells it is then immediately transformed by highly active enzymes into glucose. The glucose deficiency due to the impaired insulin receptor system in individuals with diabetes will thus be repaired and the starvation of the brain cells be stopped.
The results from these basic experiments speak in favour of the assumption that galactose may be successfully used to improve the memory of the large number of patients with Alzheimer's disease combined with diabetes mellitus. To check this hypothesis numerous additional biochemical and clinical investigations are required. For this purpose, Professor Werner Reutter and Professor Jens Wiltfang, Director of the Clinic for Psychiatry and Psychotherapy of the Duisburg University in Essen are at present preparing a research proposal with all the details needed for the reviewing process.
According to its statute, the Pandora Foundation will raise the necessary funds of about 300.000 Euro. Professor Reutter, who created the scientific basis for this research project, was not successful in receive the necessary support in spite of intensive efforts for many years. The suspicion seems justified that the missing interest of the industry and others can be explained with the rather low commercial expectations. Even if the hypothesis is fully confirmed and followed by the therapeutic application of the method, the profits are limited to the patients, since galactose is a cheap substance, available in any quantity and this without further chemical modification.