The risk factors for dementia include insulin resistance (and hyperinsulinemia), high blood pressure, obesity, smoking, depression, cognitive inactivity, low educational attainment, as well as physical inactivity and incorrect diet. One of the most modifiable risk factors appears to prevent dementia may be nutritional interventions. Flavonoids, found in many foods, have been shown to influence many of the above risk factors and be protective against cognitive impairment and dementia.
Orhan IE, Daglia M, Nabavi SF, Loizzo MR, Sobarzo-Sánchez E, Nabavi SM. Flavonoids and dementia: an update. Curr Med Chem. 2015;22(8):1004-15. PMID: 25515512.