A vanilla milkshake for Alzheimer's patients provides energy to the brain, says the company that sells it. A company-funded clinical trial found short-term positive effects in cognition and memory, but scientists say so far there is insufficient evidence that the drink is effective.

An estimated 5.4 million Americans have Alzheimer's disease, according to the Alzheimer's Association. The disease, which affects 1 in 8 people over 65, causes memory loss, decreased judgment as well as mood and personality changes. As the disease...