Theory of “aging plateau” debunked: Aging does not “stop” in old age

A recently published study refuted the long-standing belief that the aging process will slow down or even stop once a person has reached a certain age. Instead, it declared that there is no such thing as an “aging plateau” – people were going to continue getting older as the years went by.

Researchers came up with the aging plateau theory after evaluating the risk of death during every certain year of life. They noticed that people who turn 90 years old are much more prone to dying compared to those who are 75 years old. However, if a person managed to reach the ripe old age of 105, his or her chances of dying did not appear to get much higher than during their 90th year of life.

This phenomenon was formally called “late-life mortality deceleration.” It theorized that the aging process – which increased mortality rate with every passing year – more or less halted at that point in a person’s life.

Based on that premise, a person would not get any older past a certain point called the aging plateau. He or she would put on more years, but the body was not going to age any further. (Related: Getting your leafy greens every day slows brain aging by a decade or more, scientists discover.)

A recurring statistical error could be responsible for the “aging plateau” phenomenon

However, a researcher from the Australian National University Acton (ANU Acton) claimed that the aging plateau theory was a big mistake. Specifically, it was a statistical error that somehow kept getting repeated.

Saul Justin Newman came up with a list of errors that could be committed when aging data were being gathered and evaluated during earlier studies. These mistakes could supposedly account for the “evidence” of an aging plateau in people.

He noted that many researchers accepted the idea of an aging plateau. Yet these same experts could not agree upon a biological reason for the existence of the plateau.

Newman argued that the pro-plateau researchers assumed the age data derived from scientific databases were completely accurate. He, on the other hand, believed that at least some of the data were incorrectly entered.

For example, some of the participants could actually be 75 years old, but the database could have listed them as 85. Likewise, there could be participants who were actually much older than the age given to them.

Are research databases recording people’s ages incorrectly all this time?

Newman said that there were many more younger participants compared to older ones. Statistically speaking, the average participant therefore stood a greater chance of getting incorrectly entered into the database as having died at an older age than he or she actually did.

He added that the errors did not need to take place very often. A small number of incorrectly recorded ages of death were enough to cause what most researchers considered an aging plateau.

A separate paper, also published by Newman, challenged the findings of a 2018 study by Sapienza University of Rome. The Sapienza study drew from an Italian database of people’s lifespans and claimed to have found evidence supporting the existence of an aging plateau.

Newman’s counter-study dismissed the findings of the Italian study. The Australian researcher said that if one person out of every 500 participants in the database was listed under an incorrect age of death, the results would match the findings of the Sapienza researchers. He added that the human body will only last for so long before its functionality finally gives out.

“Aging does not ‘stop’ in old age,” he concluded in his study. “Your biological machinery will get relentlessly worse from puberty until death.”

Sources include:

LiveScience.com

Journals.PLOS.org

Science.ScienceMag.org