Prion Disease and Alzheimer's Disease are two diseases that are the result of the formation and accumulation of insoluble protein aggregates in brain tissue; a protein that has assumed an abnormal conformation. This abnormal protein is called Amyloid Plaque. The accumulation of this aberrant protein results in selective cellular death in the brain. Both are related with diet and may, as a consequence, be prevented.
In the case of Alzheimer’s Disease, a normal protein found on the surface of nerve cells (neurons) is clipped, forming a protein called the Amyloid Precursor Protein. Further alteration of this protein produces a “sticky” molecule (Amyloid Beta Peptide) that clumps, forming the amyloid plaque deposition within blood vessels of the brain and on the surface of neurons. Eventually the neurons die. The actual death of these cells is the result of an immune/inflammatory response to the amyloid plaque by Immune System cells called Astrocytes and Microglia. The combined action of Astrocyte-induced inflammation and reactive free radicals by Microglia kill amyloid plaque-containing nerve cells. The result is progressive memory loss and eventually dementia.
Alzheimer’s Disease is incurable. Death occurs within an average of 8 years after diagnosis, the last 3 usually spent in an institution. This disease is the leading cause of institutionalization in the United States. In addition to memory loss,"…Alzheimer's patients show dramatic personality changes, disorientation, declining physical coordination, and an inability to care for themselves. In the final stages, victims are bedridden, lose urinary and bowel control, and suffer epileptic attacks. Death is usually due to pneumonia or urinary tract infection."
"Alzheimer Disease, (AD) characterised by a global impairment of cognitive functions, is more and more common in Western societies, both because of longer life expectancy and, probably, because of increasing incidence.
Several hints suggest that this degenerative disease is linked to western diet, characterised by excessive dietary intake of sugar, refined carbohydrates (with high glycaemic index), and animal product (with high content of saturated fats), and decreased intake of unrefined seeds--cereals, legumes, and oleaginous seeds--and other vegetables (with high content of fibres, vitamins, polyphenols and other antioxidant substances, phytoestrogens) and, in several populations, of sea food (rich in n-3 fatty acids).
It has been hypothesised, in fact, that AD, may be promoted by insulin resistance, decreased endothelial production of nitric oxide, free radical excess, inflammatory metabolites, homocysteine, and oestrogen deficiency. AD, therefore, could theoretically be prevented (or delayed) by relatively simple dietary measures aimed at increasing insulin sensitivity (trough reduction of refined sugars and saturated fats from meat and dairy products), the ratio between n-3 and n-6 fatty acids (e.g. from fish and respectively seed oils), antioxidant vitamins, folic acid, vitamin B6, phytoestrogens (vegetables, whole cereals, and legumes, including soy products), vitamin B12 (bivalve molluscs, liver), and Cr, K, Mg, and Si salts. This comprehensive improvement of diet would fit with all the mechanistic hypotheses cited above."
Mad Cow Disease is also caused by the formation and accumulation of amyloid plaque (a misshapen protein called: Prion Protein) in brain tissue that, as well, results in the death of nerve cells in the brain. This neuronal disintegration eventually produces dementia, severe loss of muscular coordination, and death. Unlike Alzheimer’s Disease, Mad Cow Disease can be transmitted by the ingestion of Prion infected tissue; such as, for example, tissue from an infected cow or sheep.
Generally, all Prion Diseases (spongiform encephalopathies; vacuolation of the cerebral gray matter, among other clinical manifestations) are a group of neurodegenerative fatal diseases in humans and other animals. The human diseases can be sporadic, inherited, or acquired, and include Creutzfeld-Jakob disease (CJD), Gerstmann-Straussler-Scheinker disease, fatal familial insomnia, and Kuru. Kuru is found among the Fore linguistic group in New Guinea. Infected individuals were usually involved in the preparation of a body (including the brains) for ritualistic cannibalism.
Prion disease is also found in sheep (scrapie), mink, mule deer, Rocky Mountain elk, nyala, gemsbok, cheetah, domestic cats, and cattle [bovine spongiform encephalopathy (BSE), "Mad Cow Disease"]. The disease is associated with the altered expression of a gene (codon 129); specifically the accumulation, in infected brains, of an abnormal form (PrPSc) of a cellular glycoprotein (PrPC) found on the surface of nerve cells. This neuronal protein may regulate Copper levels in neurons and participate in synaptic transmission. The disregulation of Copper may result in reactive oxygen molecules; a feature involved in the oxidative damage found in both Alzheimer's and Prion disease.