If you feel you are losing your ability to reason or think clearly, or if you suffer mood disorders such as depression, ask your doctor to do blood tests for homocysteine, folic acid, pyridoxine and vitamin B12. If these tests are normal, you should get tests for thyroid function, cholesterol and other causes of arterial damage.

People with high levels of homocysteine levels or low levels of B12, folic acid or pyridoxine levels should eat plenty of whole grains and leafy green vegetables for folic acid and pyridoxine, and 1000 micrograms of B12 in a pill each day.

You can suffer from B12 deficiency even if your blood levels are normal. When you body lacks B12, your red blood cells do not mature properly and are much larger than normal, and homocysteine accumulates in your bloodstream, damaging your arteries and brain cells.

Also be sure that your doctor checks for diabetes, which can damage blood vessels that supply the brain, heart and other organs. Diabetics may suffer loss of memory long before they are diagnosed as having diabetes.

While we await further studies, protect your memory with a lifestyle that will help you avoid diabetes, heart attacks and strokes. Control your weight, eat a wide variety of plants, limit refined carbohydrates and get plenty of exercise.