Researchers are studying aging disagree on just about everything — including what aging is, whether it is a disease and when it begins — according to a survey of about 100 scientists working in the field.

One of the main goals of aging research is to help people live longer, healthier lives. But the exact causes of aging, as well as effective approaches to slow or reverse it, remain elusive. For the field to meet these challenges, researchers need to speak a common language, says Alan Cohen, who studies aging at Columbia University in New York. “There doesn’t have to be perfect consensus, but we need to get things straight,” he says.

Vadim Gladyshev, another researcher in the field based at Harvard Medical School in Boston, Massachusetts, and his colleagues agree. They decided to survey attendees at an international conference on aging in Newry, Maine, in 2022, to better understand researchers’ perspectives on the topic. Respondents included early career researchers, established scientists, and industry professionals. The results are described in Nexus PNAS Today¹.

Most researchers have a clear idea of ​​what aging is, but their views don’t match those of others, Gladyshev says. “People joke in the field that there are more theories than people.” Despite this, Gladyshev says he is surprised by the scale of the problem.

The latest results mirror those of a similar survey of 37 researchers conducted in 2019 by Cohen and colleagues². Today, “it is indisputably clear that there is enormous disagreement,” Cohen says.

What is growing old?

When asked to describe aging, a third of respondents consider it a loss of function over time, ranging from a decline at the cellular level to a decline in health and function. physical fitness in general. Others saw aging as a gradual accumulation of deleterious changes. Not all respondents associate aging with negative connotations, with some seeing it as a change of state – reversible or not – or a continuation of development. And others approached the topic from a demographic perspective, describing aging simply as a problem. increased risk of dying.

The question of the causes of aging has also elicited a wide range of responses, from accumulation of damage to evolutionary constraints, and from changes in the regulatory system to deterioration of repair mechanisms. A few admitted they didn’t know what underlies aging.

Researchers also disagree on whether aging is a disease. More than a third of those surveyed answered in the affirmative, 38% answered in the opposite way and the remaining 28% were neutral. Cohen is not in favor of describing aging as a disease because it implies that it is something that needs to be eliminated, even though many researchers in the field are, to some extent, work towards this goal.

For Gladyshev, the answer to this question is more complicated. “Aging is not a disease, but it’s not a disease either,” he says. He sees a lot diseases as essentially accelerated aging occurring in specific organs or in the body as a whole.

When does aging start?

Respondents generally said that aging begins early in life, but they could not agree on how early.

Some say the process begins before conception, when eggs and sperm are produced. According to this theory, if your parents are older when you were conceived, you are already further along in aging, Cohen explains. The problem with this view of the onset of aging, he says, is that it can go back in time forever. Cohen believes that aging begins where the egg and sperm meet – at conception.

Others believe that aging begins the day you are born. A few said it starts at puberty. Some consider that aging only begins when the body stops developing, when a person reaches their twenties, or a few years later, when the body reaches its peak performance, in the mid-twenties.

Ultimately, Gladyshev says, the wide diversity of responses reflects the many unknowns in the field. Gladyshev expects rapid progress in efforts to define aging, including the development of biomarkers follow biological age. “This is a time of opportunity.”