According to a recent study of more than 3,500 women in South Korea and Greece, women who gave birth five or more times would have a 70% chance of developing Alzheimer’s disease in old age.
The study was conducted by Dr. Ki Woong Kim, a neuropsychiatrist at Seoul National University. The study only included women over 60 years old and the average age of women tested in both countries was 71 years old.
Alzheimer’s disease, a neurological disorder where death of brain cells results in memory loss and cognitive decline. This is the most common type of dementia. It is a disease that is irreversible once it begins and according to scientists, it is caused by a buildup in the brain of beta-amyloid plaques and neurofibrillary tangles called tau.
According to the World Alzheimer Report 2016, more than 47 million people worldwide live with dementia and, according to the Alzheimer’s Association, women in their 60s are twice as likely to develop Alzheimer’s disease.
What about women who could increase chances of developing dementia?
The author of the study, Dr. Kim, explains
” Pregnancy is a hormonal roller coaster. During the first trimester, estrogen levels increase modestly and then skyrocket for the rest of the pregnancy. In the third trimester, according to Kim, estrogen levels can be up to 40 times higher than the peak level during natural menstrual cycles. Within four days of delivery, the estrogen level for most women drops rapidly to medium levels.
At the same time, the levels of progesterone and a stress hormone called cortisol increase rapidly during pregnancy, but drop after the baby is born, “ Kim said, continually exposing women to extremely high levels of estrogen and stress hormones.
Kim said the study discovered something they did not expect early in the research.
“Based on previous research, we expected pregnancy with delivery to be associated with the risk of Alzheimer’s disease,” she said. ” However, we were very surprised that incomplete pregnancy was associated with a lower risk of Alzheimer’s disease, which we did not expect early in our research. “
The study found that women who had undergone an incomplete pregnancy were much less likely to develop Alzheimer’s disease than women who had never been pregnant.
However, other scientists have stated that even if the results of the study were intriguing, further studies were necessary because it is possible that several factors contribute to pregnancy, and science requires a better understanding of these factors.