Natural Disasters Can Speed Up AGING In Monkeys, Study

Natural disasters cause devastation in people, but a recent study suggests that they can also speed up aging in monkeys over the long run.

in 2017 Hurricane Maria, a category 5 storm, devastated Puerto Rico killing over 3,000 people, knocking out electricity to nearly all of the island’s 3.4 million citizens, and causing more than $100 billion in damage.

In order to follow the monkey’s behavior, a multinational team of researchers collected DNA samples from rhesus macaques on Cayo Santiago, known as ‘Monkey Island,’ off the coast of Puerto Rico, prior to and following Hurricane Maria.

Despite the devastation of Cayo Santiago’s natural habitat and scientific facilities, as well, just 2.75 percent of the macaque population died.

But the findings were amazing. The disastrous cyclone genetically aged the macaques by an average of two years, which corresponds to 7-8 years of human life.

The results indicate that an increase in extreme weather occurrences may have ‘biologically detrimental effects’ for monkeys.

‘Our findings suggest that differences in immune cell gene expression in individuals exposed to a severe natural disaster were similar in many ways to the effects of natural aging,’ said study author Noah Snyder-Mackler, an assistant professor in the School of Life Sciences at Arizona State University.

‘Most significantly, we find a fundamental mechanism – immune cell gene regulation – that may explain how adversity, particularly in the setting of natural disasters, may eventually “get under the skin” and promote the beginning and progression of age-associated diseases.’

The connection between difficult occasions and biological ageing

It is generally recognized that those who have experienced significant adversity have a greater risk of acquiring heart disease and other ailments that are more prevalent in older adults.

It is uncertain how these negative experiences ‘permeate the skin’ and produce disease. One explanation for this phenomenon is that great adversity may ‘age’ the body.

‘While we all age, we do not age at the same rate, and our lived experiences, both positive and negative, can influence our rate of aging.’ According to author Noah Snyder-Mackler, an assistant professor in the School of Life Sciences at Arizona State University.

‘Surviving an intense incident can result in persistent inflammation and the early beginning of some age-related disorders, such as heart disease.’

However, scientists still do not understand how these events become lodged in our bodies, resulting in detrimental health impacts that may manifest decades after the incident.’

The researchers analyzed blood samples given from a cross-section of macaques between one and four years prior to and one year following Hurricane Maria.

The team compared genetic data from over 400 rhesus macaques collected four years prior to the hurricane to data from over 100 rhesus macaques collected one year after the hurricane.

‘Through this study, we were able to quantify the molecular changes associated with aging, such as disruptions of protein-folding genes, increased expression of inflammatory immune cell marker genes, and older biological aging,’ explained study author Marina Watowich of the University of Washington.

After doing a thorough examination of the genes expressed in the macaques’ immune cells, the researchers discovered that hurricane-induced adversity may have hastened the immune system’s aging process.

The downregulation of so-called ‘heat shock genes,’ which promote the normal function of protein synthesis in human cells, was the most severe, with some genes experiencing a twofold decrease in activity following Hurricane Maria.

Additionally, these genes have been linked to cardiovascular and Alzheimer’s disease.

Surprisingly, they discovered a substantial association between storm exposure and aging effects on gene expression, where the hurricane’s effect was comparable to the immune system aging.

‘On average, monkeys that survived the Hurricane had immune gene expression profiles that were two years older, or around seven to eight years longer than a human lifespan,’ Watowich explained.

They discovered that after the hurricane, 4% of genes expressed in immune cells were changed.

Among these, genes implicated in inflammation had increased expression following the hurricane, while those involved in protein translation, protein folding, the adaptive immune response, and T cells had decreased expression following the hurricane (one of the white blood cells of the immune system).

The findings imply that severe weather events – which are growing more intense and frequent as a result of climate change – may have biologically negative repercussions for those who are exposed to them.

Interestingly, not all monkeys behaved equally to the hurricane; for example, the biological ages of some monkeys grew far more than those of others.

The researchers believe that other components of the monkeys’ environment, such as social support, may influence their response to adversity.

‘Social support can protect people and other animals from the impacts of unpleasant occurrences,’ according to University of Exeter Professor Lauren Brent.
‘People who are socially integrated – and monkeys as well – have longer, better lives.’

‘While the immediate implications of natural disasters are well-known, we know little about the long-term effects on human health and disease development.’ James Higham of New York University, the study’s author, stated.

‘Our findings indicate that natural catastrophes have the potential to accelerate the aging process, which is critical given that age is the leading predictor of risk for the majority of non-infectious diseases.’

One disadvantage of the study was that the researchers were unable to compare the aging rates of identical individuals before and after the hurricane. They expect that future research will expand to include longer-term investigations of each individual within a group.

The complete findings were published in the Proceedings of the National Academy of Sciences.

The ‘Monkey Island’

Cayo Santiago in a home for around 1,000 rhesus macaques roam freely on the 38-acre island. Macaques initially arrived on Monkey Island in 1938, when 409 monkeys were imported from India to construct the Western Hemisphere’s first colony for research.

Although the island is uninhabited, the monkeys are accustomed to human experimenters. Researchers and staff of the Caribbean Primate Research Center, which operates the field station daily visit the island.

The multinational team led by scientists at the Caribbean Primate Research Center, the University of Pennsylvania, the University of Exeter, New York University, and North Carolina Central University undertook the new study.