According to a new study, you shouldn't feel bad about misplacing those keys or forgetting something important especially if you find this happening to you more as you age. The study found that almost everyone will suffer more memory lapses as they age, but that this seems to affect men more often than it does women.

The study also found that people's memory skills and brain volume usually decline as they age but this decline has little to do with the buildup of brain "plaques" that are the early marks of Alzheimer's disease.

Experts have long assumed that when older adults begin to experience more frequent memory lapses that it may be an early sign on Alzheimer's disease and are likely related to abnormal clumps of protein known as beta-amyloid that have accumulated in the brain.

"But our findings suggest that memory actually declines in almost everybody, and well before there is any amyloid deposition in the brain," said Dr. Clifford Jack, a researcher at the Mayo Clinic in Rochester, Minn., who led the study.

These beta-amyloid deposits, or plaques as it is most commonly known, are still a hallmark of Alzheimer's disease, said Jack. But the new findings suggest that they do not "initiate" the disease process and instead enter the picture later.

"There seems to be a profound effect of aging, itself, on memory -- independent of amyloid," Jack said. "We think that [amyloid] pathology tends to arise late in life, to accelerate a pre-existing decline in memory."

"The memory decline that people often experience as they get older is usually not an indicator of underlying Alzheimer's pathology," he said. "So it in no way means you're inevitably going to become demented."

For the study, researchers examined 1,200 adults from one county in Minnesota ranging in age from 30 to 95. They all took standard memory tests and underwent two types of brain scans. What the team found was surprising. Overall, both memory and brain volume gradually decreased from age 30 to the mid-60s but showed very little amyloid buildup during that time. Beginning at around age 70 there was a substantial increase in the number of people who were "amyloid positive."

Other researchers consider this a "very important" find in the study of the human brain

"What this shows very clearly is that memory and brain volume are declining years before any amyloid is present," said Dr. Charles DeCarli, a professor of neurology at the University of California, Davis.

The bottom line is, age-related mental decline "is not as simple as we'd like it to be," said DeCarli, who wrote an editorial published with the study.