Two drugs approved decades ago not only counteract brain damage caused by Alzheimer's disease in animal models, the same therapeutic combination may also improve cognition. A promising series of early studies is highlighting two well known medicine cabinet standbys—gemfibrosil, an old-school cholesterol-lowering drug, and retinoic acid, a vitamin A derivative. Gemfibrosil, is sold as Lopid and while it's still used, it is not widely prescribed. Doctors now prefer to prescribe statins to lower cholesterol. Retinoic acid has been used in various formulations to treat everything from acne to psoriasis to cancer. The two drugs are being studied for their robust...