8. Age related dementia inrcrease in the following

         A.homocystiene

        B. cystiene

        C. taurine

         D . methionine

Ans Homocysteine

References

Homocysteine and Dementia New england journal of medicine

Studies in cultured neurons demonstrate not only that homocysteine potentiates β-amyloid-peptide neurotoxicity6 but also that potentiation of β-amyloid-peptide–induced neuronal apoptosis may be enhanced by homocysteine levels that are themselves benign. These findings suggest that homocysteine may have major effects on the onset and progression of neurodegeneration in Alzheimer's disease

Taurine prevents the neurotoxicity of ß-amyloid and glutamate receptor agonists: activation of GABA receptors and possible implications for Alzheimer’s disease and other neurological disorders

A diet rich in methionine, an amino acid typically found in red meats, fish, beans, eggs, garlic, lentils, onions, yogurt and seeds, can possibly increase the risk of developing Alzheimer's disease,.

S-allyl cysteine attenuates oxidative stress associated cognitive impairment and neurodegeneration in mouse model of streptozotocin-induced experimental dementia of Alzheimer's type.-PUBMED