Influence of Omega 3 fatty acids on osmosensation and thirst signaling

Stage1 (Questionnaire survey) : A self–structured questionnaire survey (assessment for eligibility to participate) and mini-mental state examination (MMSE- psychological assessment for cognitive impairment) will be conducted among all elderly residents from aged care group facilities in Victoria, (aged 65-85y, inclusive), to screen them for stage 2 and 3 studies. Each participant will be provided an information sheet and consent will be obtained (subjected to approval from Victoria University Human Ethics Committee). Stage 2 (Prospective study- 5 days) This phase study is designed to identify the subjects who are prone to dehydration, thirst deficit, low erythrocyte omega 3 fatty acid levels and whether it is possible accept omega 3 fatty acid supplementation. The fluid intake of the participants in stage 2 will be recorded for 5 days inclusive of a week end. A blood and urine sample will be collected for biochemical analysis. Other clinical assessments include blood pressure and heart rate (both standing and lying position), Body mass index calculation, presence of dry tongue, tongue furrows or dry oral membrane (physical examination) and thirst ratings. A sensory screening test will be conducted to evaluate the participant’s level of acceptance of the fish oil or the placebo oil. Stage 3:The recruitment will be based on subjects found to exhibit dehydration and thirst deficit (from prospective study). In this single blinded study, the participants will be randomly allocated based on age, sex, body weight to Intervention (a) Intervention group: 3 months consumption of omega 3 fatty acids (5 ml fish oil once a day(Melrose, Norwegian fish oil; which contains 815 mg of Eicosapentaenoic and 540 mg of Docosahexaenoic) will be given to intervention group or (b) Control Placebo group: 3 months consumption of 5 ml of cold pressed soya bean oil, both floated on fruit juice (lemon) once a day will be given to placebo participants . Both cohorts will be given additional 5 ml of fruit juice to rinse the mouth.