First a report on a study from Oxford University: Daily dose of Vitamin B 'can fight memory loss and help protect against Alzheimer's'

More than 250 people took part in the study, at Oxford University, including people with mild cognitive impairment who were aged 70 years or older.

They were given vitamin B - found naturally in food such as [fish, potatoes,] beans, meat, wholegrains and bananas - or a placebo over a two-year period.

Taking the food supplement appeared to help maintain mental processes, such as planning, organising and recalling information.

Next, a report on a study at the University of Pittsburgh Medical Center: Eating fish tied to dramatic drop in Alzheimer's risk

"This is the first study to establish a direct relationship between fish consumption, brain structure and Alzheimer's risk," study author Dr. Cyrus Raji of the University of Pittsburgh Medical Center said in a written statement.

Dr. Raji and his colleagues scanned the brains of 260 healthy adults, including 163 who said they consumed fish at least once a week. After controlling for age, gender, race, physical activity, and other factors, the researchers found that the fish eaters were less likely to have shrinkage of their gray matter. That's a component of the brain involved in memory, emotions, and other high-level functions.

Decreases in the amount of gray matter indicate that individual brain cells (neurons) are shrinking - and Dr. Raji said regular fish consumption makes neurons in gray matter "larger and healther." But he stressed that he was talking only about baked and broiled fish. Eating fried fish was not shown to boost brain volume or protect against cognitive decline.