Scientists may have found the immunity secret

The life expectancy of humans on our planet has more than doubled since 1900. Global life expectancy has increased from 31 years in 1900 to 73.2 years in 2023, and is expected to further increase to 77.1 years in 2050.

Also increasing is the number of people reaching the age of 100 or more. Known as centenariansTrusted Source, researchers estimate there were about 450,000 centenarians globally in 2015, with that number projected to increase to 3.7 million in 2050.

PreviousTrusted Source research in the early 2000s estimated that globally, the number of people living to 100 years or older would more than quintuple between 2005 and 2030.

One thing still unknown is what allows some people to live into their 100s, while others do not.

Led by researchers from Tufts Medical Center and Boston University School of Medicine, a new study is helping to answer this question by finding that centenarians possess a unique immune cell composition and activity, giving them a highly-functional immune system and allowing them to live longer.

Scientists believe these findings could be used potentially to develop healthy aging therapeutics.

The study was recently published in the journal Lancet eBioMedicine

As we age, all parts of the body experience changes, including the immune system.

According to Dr. Scott Kaiser, a geriatrician, and director of Geriatric Cognitive Health for the Pacific Neuroscience Institute in Santa Monica, California, there are two main concepts when it comes to how the immune system changes as we get older.

“One is immunosenescence and that’s the age-related process of immune dysfunction,” he explained to Medical News Today.

“So changes in our immune system composition and function over time can lead to poor immune function in older people. And that’s closely related to people’s vulnerability to infection, autoimmune disease, and even various types of

cancer,” he said.

“And then there’s this issue of inflammagingTrusted Source, which is a term that’s been used to describe age-related increases in inflammation because of high levels of pro-inflammatory markers in the blood and different tissues in the body. That’s a strong risk factor for all sorts of diseases, including neurodegenerative processes like Alzheimer’s disease, for example,” Dr. Kaiser continued.

“So there’s a lot to look at in terms of the immune function over time and how our immune systems changes with age may either make us more vulnerable or protect us,” he added.

According to Dr. Tanya Karagiannis, a senior bioinformatician at the Center for Quantitative Methods and Data Science in the Institute for Clinical Research and Health Policy Studies at Tufts Medical Center, and lead author of this study, she and her team decided to study the immune systems of centenarians because with age comes changes in our immune systems including in their function and cell makeup, and these changes can lead to aging-related diseases.

Science Focus