Scientists have discovered that females who experience an early menopause may be aging faster overall.
They stipulate that the number of eggs a woman has may not only be indicative of her fertility, but also her overall life expectancy. It is also indicative of her risk of having a heart attack.
Females are born with all the eggs they will ever have and as they age, the number declines. Previous research suggested that the average female is born with 300000 potential egg cells.
The normal age for going through the menopause is between 45 and 55, and experiencing it prior to the age of 40 is considered as premature menopause.
A study undertaken by the University of Alabama found that women who experience an early menopause are at double the risk of a heart attack or stroke in later years. One of the possible explanations for this is the reduction in the natural supply of oestrogen at an earlier point in their life.
A woman’s menstrual cycle is regulated by the hormone oestrogen, which is produced by the ovaries. This means that when the ovaries stop their function, the oestrogen level declines.
However, oestrogen is known to have a protective effect on the heart. This implies that after the menopause, the risk of heart disease is increased.
Post-menopausal females often have to endure weight gain, particularly around their abdomen, which is a contributing factor to poor health.
This aging concept has been taken a step further by this new study.
The researchers undertook an investigation as to whether females who experience an early menopause age faster in general.
The lead researcher, Professor Marcelle Cedars, from the University of California, and her team undertook analysis of blood samples taken from more than 1000 females aged between 25 and 45 to determine their level of anti-Müllerian hormone (AMH), which can provide an estimate of the remaining egg supply.
They then confirmed the number of eggs by use of an ultrasound and estimated the biological age of each woman by assessing her telomeres, which are tiny structures that protect DNA from damage and a suitable health indicator. They are found at the ends of chromosomes and protect the DNA in a fashion similar to the caps on shoelaces, which prevent fraying.
As we age, our telomeres become shorter, which leads to the DNA being damaged and increases our risks of age-related diseases, such as heart disease, diabetes and Alzheimer’s. Telomeres that are shorter than average are viewed as a sign of premature death and ill health.
Three to five years after the commencement of the research, one quarter of the females returned to have their risk of heart disease assessed. This was based on particular factors, such as cholesterol levels, blood pressure and weight.
The researchers discovered that females with lower egg counts were at a considerably higher risk of heart disease. However, their telomeres were also shorter, which indicates that they were at higher risk of conditions such as diabetes and Alzheimer’s.
Professor Cedars said they believe that the ovaries may be more sensitive to the process of aging, which makes it similar to a canary in a coal mine for an overall view of accelerated aging.
Image Credit: Ed Uthman