Fertility is a woman's nature and a human instinct. But what effect does fertility have on a woman's body and longevity?Is it to reduce life expectancy or increase life expectancy?Is it to accelerate aging or slow down aging?In recent years, scientists have conducted a number of studies on this and discovered some interesting phenomena and laws.
According to the news of science and technology ** on December 12, a study by the University of Michigan in the United States2 reviewed the genetic and health information of more than 276,000 people, providing strong support for a decades-old evolutionary theory - Williams Hypothesis 3. The results of the study were published in the latest issue of the journal Science Advances.
The Williams hypothesis is a theory that explains aging by arguing that natural selection is less interested in human lifespan and more concerned with human reproduction. Therefore, some genetic mutations that promote reproduction may negatively affect longevity after the end of reproduction.
This study found that reproduction and longevity are strongly negatively correlated genetically, that is, people with higher fertility rates have shorter lifespans. The researchers analyzed some of the genetic variants that affect fertility and found that these variants were inversely correlated with the likelihood of living to the age of 76. That is, people who carry these mutations are more likely to die early than those who do not.
However, the researchers also point out that these genetic variants are only one aspect of fertility and longevity, and that there are many environmental factors that also play a role, such as the impact of contraception and abortion on fertility, and the impact of medical advances on longevity. Therefore, it cannot simply be assumed that having more children means having a short life, or having fewer children means having a long life.
In addition to genetic mutations, there is another biological marker that measures aging, and that is telomeres. Telomeres are a repeating sequence at the end of a chromosome that protects the integrity of chromosomes. Each time a cell**, the telomeres shorten a little until they disappear, and the cells stop** and go into senescence or death. Therefore, the length of telomeres can reflect the longevity of the cell and the rate of aging.
So, what effect does fertility have on the length of telomeres?In 2018, a study in the United States found that women who had children had telomeres that were on average 4.4 shorter than those who had not2%, which is equivalent to 11 years of accelerated cellular senescence. The study also found that the more children you have, the more telomeres are shortened, and the more you age.
This result seems to be consistent with the Williams hypothesis, which states that women who have more children have a shorter lifespan. However, this study has also been questioned by some people, because the length of telomeres is not only affected by genes, but also by factors such as environment, lifestyle, stress, etc. Moreover, this study is only observational and cannot prove the causal relationship between fertility and telomeres, only that there is a correlation between them.
In addition to the number of children, the age of childbearing also affects the lifespan of a woman. On July 14, a study by Leiden University Medical Center in the Netherlands found that women who gave birth later lived longer than women who gave birth earlier. These women have given birth to at least one child without the use of assisted reproductive technology and have lived to be over 50 years old.
The researchers analysed the reproductive age and longevity of these women and found that for each year of age at the end of childbearing, life expectancy increased by 22 days. After comparing women aged 40 or younger who had their last child with women who had their last child at age 45 or older, they found that the latter lived an average of 17 months longer.
This result suggests that women who give birth later are likely to be in good overall health and therefore have a longer life expectancy. However, this study does not rule out the influence of genetics and lifestyle, nor does it prove that late childbearing is necessarily long-lived, but only that there is a correlation between late childbearing and longevity.
So, what is the effect of the number of births on a woman's lifespan?Is it better to have as many children as possible, or to have fewer children as possible, or to have an optimal number?In November 2020, a study found that after menopause, mothers with 3-4 children age more slowly than mothers with fewer or more children.
The study analyzed some biological indicators that affect aging, such as telomere length, thyroid function, blood sugar levels, cholesterol levels, etc., and found that mothers of 3-4 children performed better on these indicators, indicating that their bodies age more slowly.
This result differs from the previously mentioned study of short telomeres in fertile women, possibly because the study considered more indicators of aging and only focused on postmenopausal women. This study also does not explain why mothers with 3-4 children age the most slowly, nor can we draw a causal relationship, only a correlation.
In summary, fertility has a complex relationship with women's lifespan and aging, which is affected by various factors such as genes, environment, and lifestyle. It cannot be generalized that it is better to have more children, or to have fewer children, or to have children late, or to have children early. Every woman's situation is different and she needs to make fertility decisions that are right for her based on her physical and psychological condition.
Childbearing is not only a woman's right, but also a woman's responsibility. Fertility not only affects a woman's longevity and aging, but also her health and well-being. Childbirth will not only bring happiness and satisfaction to women, but it will also bring stress and challenges to women. Childbearing is not only a woman's personal choice, but also a woman's social role.
Therefore, in the process of childbearing, women need to pay attention to their physical and mental health, maintain good living Xi, reasonable diet and exercise, proper rest and relaxation, positive attitude and emotions, and harmonious family and social relationships. Women also need to be supported and respected by the family, society and the world, enjoy the rights and benefits of childbearing, overcome the difficulties and obstacles of childbearing, and realize the autonomy and equality of childbearing.
Childbirth is a woman's life, and it is also the beauty of a woman's life. Let's bless all women, whether they have children or not, no matter how many they have, no matter when they give birth, to have a healthy body, a long life, and a happy life.
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