The average age of a woman having her last period is 51, but many women have surgical menopause at an earlier age.

Early surgical menopause is when both ovaries are removed before natural menopause and often accompanies a hysterectomy.

Now, researchers at Harvard have found a link between early menopause, cognitive decline and memory problems. Their study included data from more than 18-hundred women over the age of 53. 33-percent of them had undergone surgical menopause. The participants were given a variety of tests measuring thinking skills and memory.

The results showed those who underwent surgical menopause at a younger age had a faster decline in long-term memory as well as memory that relates to time and places and in overall thinking ability. There was also a significant link between age at surgical menopause and the plaques linked to Alzheimer's disease.

The good news? Women on hormone replacement therapy showed slower decline. Further research is needed to see how hormone replacement therapy may offer a neuro-protective effect.

I'm Dr. Cindy Haines of HealthDay TV, with the news that doctors are reading health news for healthier living.