How human body ages?
Tokyo: Japanese researchers have discovered metabolites that are specifically related to aging and shed light on how the human body ages.
Metabolites, substances that are created during metabolism, can provide a wealth of information about an individual's health, disease, diet, and life-style.
The results of the study identified some metabolites in the blood that increased or decreased in the older adults.
The researchers found 14 age-related metabolites. Half of these decreased in elderly people and the other half increased.
Antioxidants and metabolites related to muscle strength decreased in the elderly, whereas metabolites related to declining kidney and liver function increased.
"Of the 14 compounds, half of the them had decreased in elderly people. The decrease was found in antioxidants and in compounds related to muscle strength. Therefore, elderly people had less antioxidants and less muscle strength," said lead researcher Yanagida, professor at Okinawa Institute of Science and Technology Graduate University (OIST) in Japan.
In addition, some of the age-related metabolites found on the same metabolic pathways have connected changes, which suggests that age affects them simultaneously.
"Functionally related compounds show the same tendencies to increase or decrease with age, or in other words, they show similar correlations," Yanagida noted, in the study published in the journal PNAS.
The decline in antioxidants and muscle strength suggest that it is important for individuals to consume foods high in antioxidants and to continue exercising, especially after the age of 65.
This could help increase the levels of the related metabolites in the body and improve body conditions, the researchers stressed.
"Longevity is a great mystery for us...We want to find how elderly people can live a happy final stage of life. This is the way we can contribute to human health," Yanagida maintained.
To find and analyse the metabolites, the team obtained blood samples, including red blood cells (RBCs), from 30 healthy individuals: 15 young adults and 15 older adults.
Then, they used Liquid Chromatography-Mass Spectrometry (LC-MS), a technique that separates liquids and detects substances, to identify the metabolites within the blood.
From there, they could calculate the coefficients of variation, or the standard deviation of metabolite abundance divided by the average, to identify which compounds had increased or decreased in the older adults.