George Williams, an American evolutionary biologist, proposed a theory in 1957 that genetic mutations that increase an animal's fertility can also cause damage late in life.
Over many generations, these mutations will create a burden that may ultimately lead to death.
A new study, published in the journal Science Advances, supports Williams' theory using a set of human DNA, where researchers found hundreds of mutations that can enhance a young man's fertility and that are linked to physical damage later in life.
In the past, smaller studies have provided some support for Williams' theory. In 2007, a team of researchers studying a tiny worm found a pair of mutations that extended the creature's lifespan while reducing the average number of its offspring.
But Jianzhi Zhang, an evolutionary biologist at the University of Michigan, was not satisfied with these experiments. He said: “These are case studies. "We don't know if there are a lot of these mutations in the entire genome."
Zhang took advantage of the UK Biobank, a database containing genetic material from half a million volunteers in Britain, along with information about their health and life experiences.
The biobank has allowed scientists to uncover precise links between genetic variations and thousands of traits, such as high blood pressure, schizophrenia and smoking habit.
Working with Dr. Erping Long, a medical researcher at the Chinese Academy of Sciences, Dr. Zhang studied the database for information about reproduction and longevity.
They found that genetic variations linked to fertility, such as the number of children a volunteer had, were also linked to shorter lifespans.
What's more, variables that affected reproduction were nearly five times more likely to affect longevity than variables unrelated to reproduction. Reproducible variants are likely to be poor for long life.
The research team also found that volunteers with a large number of reproductive-enhancing variants had slightly lower odds of surviving to age 76.
The idea that fertility variables shorten life expectancy may seem like a paradox, given how long people live these days.
Finding that these variables influence despite increased life expectancy makes the results even more impressive, said Steven Austad, an aging expert at the University of Alabama at Birmingham, who was not involved in the study.
He continued: “The pattern is so strong that it comes through these major changes in the history of our lives in the modern era.”
A medicinal plant that helps prevent heart attacks and thrombosis
Dr. Sergey Agapkin revealed the health benefits of the ripe fruits of the evergreen coniferous juniper plant, and the contraindications for their use.
The doctor points out that mature juniper fruits that are several years old contain aromatic and other beneficial substances, and can be used in food.
1- It helps digestion. Juniper fruits improve the digestion of food - stimulating the secretion of gastric juice. Therefore, it is traditionally added to various mixtures, and is also used in preparing meat dishes.
2- It raises the level of “good” cholesterol. The results of scientific studies have shown that the extract of these fruits raises the level of “good” cholesterol. In the blood, in exchange for reducing the level of “bad” cholesterol. This is especially important for patients with cardiovascular disease and for the prevention of atherosclerosis. Because “good” cholesterol It cleans the blood vessels of “bad” cholesterol, which reduces the risk of myocardial infarction.
3- Preventing blood clots. Some studies have revealed that juniper contains flavonoids, which are substances that affect the blood clotting process and reduce the risk of blood clotting.
According to him, we should know that there are contraindications to the use of juniper. That is, not everyone, without exception, can use it. Because it has an irritating effect on the kidneys and has a diuretic effect, so those who suffer from chronic kidney disease should not use it. It also stimulates stomach secretions. That is, it is not recommended for anyone who suffers from stomach ulcers to use it. Pregnant women are also prohibited from using it because it increases uterine contraction. In general, it is best to consult a doctor before using it in food.
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