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LONDON — For many women, their menstrual cycles function like clockwork. This natural process of life isn’t always easy for everyone however. While the average period lasts for a few days, women can experience longer periods which come at irregular times. A study of nearly 80,000 women finds this isn’t just inconvenient, it can also lead to heart disease or premature death later in life.

Researchers based in the United States say irregular and long menstrual cycles during adolescence and adulthood increase the risk for death before age 70. The strongest connection to early death was tied to cardiovascular disease. Women who smoke and have irregular or long cycles also saw a increase in poor health outcomes.

The menstrual cycle is the hormonal process which prepares a woman’s body for pregnancy. These cycles occur between puberty and menopause; acting as a sign that the female body is functioning normally. Aside from being irregular, heath experts say periods which are heavy or painful can also be warning signs of a problem.

The study says it’s common for women within the pregnancy window to experience abnormal menstrual cycles. While it may be common, it increases the risk of chronic diseases such as ovarian cancer, heart disease, type 2 diabetes, and mental health problems. Researchers add that even though these risks are known, evidence linking menstrual cycles to premature death has been thin.

Two decades of fact finding

Their report looks at 79,505 premenopausal women around the age of 38. These women had no history of cardiovascular problems, cancer, or diabetes at the start of the study. Each participant documented their menstrual cycle history between ages 14-17, 18-22, and 29-46. Researchers then followed up with the group over the next 24 years to see how each woman fared health-wise.

Unfortunately, 1,975 women died prematurely during the study, including 894 from cancer and 172 from heart disease. When factoring in age, weight, lifestyles, and medical histories, the study reveals a noticeable difference between women having normal periods and those who didn’t.

When looking at the mortality rates, the study reveals 1.05 for every 1,000 women with regular periods at age 14-17 die prematurely. That number is 1.23 for every 1,000 women experiencing irregular cycles at the same age.

At age 18-22, the mortality rates were 1.00 for regular cycles and 1.37 for irregular cycles. At age 29-46, the rate was again 1.00 for regular periods and 1.68 for women having irregular ones.

For women, timing of menstrual cycle is everything

The length in between periods was also found to be a predictor of early death, the study authors say. Cycle lengths coming every 40 days or longer were at higher risk for death than women with a 26 to 31-day cycle.

While study authors point to a clear connection, the decades-long study does not determine the cause of this higher risk. Researchers also caution that their study is observational; relying heavily on the self-reporting of patients which may not be 100-percent accurate.

Despite these drawbacks, the U.S. team contends that the bulk of their findings “emphasize the need for primary care providers to include menstrual cycle characteristics throughout the reproductive life span as additional vital signs in assessing women’s general health status.”

The study appears in The BMJ.

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About Chris Melore

Chris Melore has been a writer, researcher, editor, and producer in the New York-area since 2006. He won a local Emmy award for his work in sports television in 2011.

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