Remember this: Your lifestyle makes a difference

When it comes to preserving memories, we are sometimes our own worst enemies. The lives we lead often undermine the complex process of creating and retrieving memories. And they can boost the odds of our developing diseases -- including Alzheimer's -- that further ravage the brain's mechanisms of memory. Here are things that science tells us pose the greatest threat to our memories: Knowing them, says UCLA neurologist Dr. Gary Small, may allow us "to act early to prevent."

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Medications

Many medications prescribed widely in the U.S. can cause memory problems. Among the most likely to disrupt memory are benzodiazepines (including Ativan, Valium and Xanax). Any drug that can cause drowsiness can disturb concentration and absorption of new facts -- there are legions of those, including over-the-counter antihistamines.

Some drugs have been discovered by accident to have memory-disrupting qualities and have been hailed as possible treatments for those at risk of post-traumatic stress disorder. Beta blockers, prescribed widely, have been shown to reduce the emotional power of certain memories and are being investigated by the U.S. military. Propofol, a sedative colloquially known as "milk of amnesia," can also erase a few minutes of memory.

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Untreated heart disease

High blood pressure, high cholesterol, Type 2 diabetes and obesity all raise the risk of stroke, which can affect memory profoundly. Studies have also found those with Type 2 diabetes at three times greater risk for Alzheimer's as the general population. Those with high cholesterol and blood pressure in midlife are also at greater risk. And obesity (particularly excess fat around the middle) has been linked to higher dementia rates 30 years later.

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Stress

Researchers know that high emotion surrounding an event assures that it will be committed to memory. As the brain floods with adrenaline and norepinephrine, the mechanisms of memory are excited. Episodes of high stress, intense happiness, love and sadness can preserve a sharp memory. But when stress is constant and the brain is bathed chronically in stress hormones such as cortisol, attention grows weak and events are stored fitfully in short-term memory and fitfully committed to long-term memory. Established memories are poorly retrieved.