He often inadvertently tells the old man, ‘Now stop working and rest in peace.’ But scientifically, this may not be the case. In recent years, evolutionary biologists have been publishing research results one after another that humans have evolved to keep moving even as they age.
A joint research team at Harvard University’s Department of Human Evolutionary Biology and Harvard Medical School has secured biomedical evidence that humans evolved to remain physically active as they age. This paper will be published in the international academic journal ‘Proceedings of the National Academy of Sciences (PNAS)’ on the 14th of next month.
○ Human aging and evolution differently from animals
It is well known that physical activity slows aging and reduces mortality. However, there is insufficient evidence or explanation for this from the point of view of human evolution. Humans are animals that show unique characteristics in terms of physical activity in old age. When most animals lose their ability to reproduce, their activity decreases and they die soon after. Even great apes, which are genetically close to humans, go into menopause and become less active and spend most of their lives sedentary before dying. The average lifespan of apes is only 35-40 years. On the other hand, after menopause, people continue to be active as usual and live for decades. In the past, there are traces of more active physical activity than the present. According to the research team, during the hunter-gatherer period about 40,000 years ago, humans engaged in vigorous physical activity for an average of 135 minutes per day. Compared to the current World Health Organization (WHO) recommendation of more than 75 minutes of vigorous physical activity per week, this is a huge amount of physical activity. The research team estimated that they would have lived to the age of 70 even 40,000 years ago if they had not suffered from diseases as a child and provided adequate nutrition.
○ Physical activity helps prevent aging
The researchers pointed out that while physical activity initially causes stress and damage to body cells, it helps improve health during the recovery process. In the process of self-healing from damage, it was confirmed that it repaired muscle rupture and cartilage damage and healed microscopic fractures. In addition, it was confirmed that it helps the secretion of antioxidants that prevent cell aging and anti-inflammatory agents that suppress inflammation. On the other hand, it was found that these responses were less active when the body was not moved or were less active. In addition to burning calories stored in the body, the research team emphasized that physical activity can lower the risk of diabetes, obesity, cancer, osteoporosis, Alzheimer’s and depression through cell and DNA repair.
Daniel Lieberman, a professor of human evolutionary biology at Harvard University, said, “I think it’s normal to work less and retire as you get older, but it’s a physiologically wrong decision. have to do more,” he said.
However, as machines and technology replace human labor, physical activity is on the decline. “Even as little as 10 or 20 minutes of physical activity a day can significantly lower the risk of death,” Lieberman said.
○ Housework has an exercise effect and cognitive improvement effect
Some point out that as we age, our body’s response becomes dull, so we need to be more careful. Scientists believe that if you are reluctant to exercise for fear of getting hurt, such as a fall, simple chores can be substituted. In February, a research team from Baycrest Hospital, Canada, published a study in the international scientific journal ‘BMC Geriatrics’, showing that housework helps the elderly’s cognitive abilities. It is the first medically proven fact that chores other than exercise can help brain health.
The research team asked 66 people, an average of 71 years old, how much time they usually spend cleaning, preparing meals, washing dishes, shopping, home repairs and gardening, and measured their brain capacity and cognitive ability. As a result, it was found that the hippocampus and frontal lobe, which are responsible for brain memory and learning, had larger volumes as the elderly spent more time doing housework, even without exercise. The research team analyzed that the effects of low-intensity aerobic exercise can be seen through housework, and that a new brain neural network is formed in the process of generating ideas to take good care of the house.
Nicole Anderson, a senior researcher at Baycrest Hospital, said, “Many people can do housework naturally in their daily lives. The research team is conducting a study to measure the amount of time and types of activities older people spend at home. Identifying which activities are beneficial for brain health will help develop strategies to reduce cognitive decline and risk of dementia in the elderly.
Dong-Jun Seo, reporter for Dong-A Science [email protected]
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