We all know someone who has developed some form of cognitive decline, dementia or Alzheimer's Disease, and whom among us doesn't worry about this for ourselves or our loved ones? We also all know that there are a variety of risk factors for developing any disease, but the ones we should be concerned with are those that can be modified. Diet is a good place to start and it turns out that a well researched risk factor has been definitively tied to cognitive deterioration and that is the biomarker found in the blood called homocysteine. Homocysteine reflects the vitamin status of three B vitamins - folate, vitamin B12 and vitamin B6, and is elevated when any or all of these vitamins are deficient. In an extensive review of the literature over the past 20 years, an international panel of experts has calculated that 12% - 31% of cases or Alzheimer's Disease or dementia could be prevented by ensuring adequate intake of these three B vitamins to lower homocysteine.