Can eating beets prevent dementia or memory loss?

While we don't know for sure if beets (specifically beet juice) can prevent dementia or memory loss, studies have been done that show that beets contain nitrates and that the digestion process turns nitrates into nitrites which have been shown to decrease blood pressure and increase exercise performance.  We also think that these nitrites may be important in increasing blood flow to the brain of older adults (thus bringing more oxygen and nutrients which may possibly stave off certain forms of dementia).

Other foods that contain nitrates include celery, cabbage, spinach and certain lettuces.

Beets are a great source of healthy nitrates, which have been shown to help lower blood pressure. Researchers have found that ~25% of nitrates from beets are absorbed in the stomach and, through enzymatic action, converted to nitrites. It has been hypothesized that nitrites provide a source of nitric oxide (NO) gas, which has a protective effect on arteries. Endothelial NO is responsible for blood vessel dilation. Although it has not been confirmed in research, the vasoprotective (dealing with protection of the arteries) and dilatory effects of NO may also be beneficial for arteries found in the brain. Small strokes in the brain can cause vascular dementia. This may explain the theory behind the vascular benefits of beets and other healthy nitrate containing-foods, thus giving rise to their potential prevention of dementia and memory loss. Other foods that contain nitrates include celery, cabbage, spinach and certain lettuces.