People with a family history of Alzheimer's can reduce their risk with diet changes, scientists say. Here's how to start.

• A long-term study suggests a healthy diet can play an important role in lowering Alzheimer's risk. • People who carry high-risk gene variants may derive even bigger benefits from diet tweaks. • Everyone would benefit from eating lots of vegetables, leafy greens, nuts, berries, and olive oil.

A big, new long-term study suggests that sticking to a healthy diet can cut your risk of developing Alzheimer's, especially if you were born with genetic risk factors.

The study, from nutrition and genetics researchers at Harvard Medical School, compared the genes and diets of 16,497 women and 9,828 men across the US, over three decades. The study tracked cognitive changes in the participants, keeping tabs on what people ate and to what extent they followed a typically Mediterranean diet patter