A new Alzheimer’s study found people diagnosed with the disease in their 60s and 70s tend to go downhill with the disease faster than those who start to show symptoms in very old age.

Researchers at the University of California in San Diego, Calif., found Alzheimer’s hit the younger elderly harder.

Those in their 60s and 70s lost their mental sharpness quicker and brain mass faster than those in their 80s and 90s.

The study’s co-author said it could be that people diagnosed with Alzheimer’s at an older age had brains with a higher degree of cognitive reserve.