The first study to analyze the life histories of thousands of naked mole rats has found that their risk of death doesn’t go up as they grow older, as it does for every other known mammalian species. Although some scientists caution against any sweeping conclusions, many say the new data are important and striking.
“This is remarkably low mortality,” says Caleb Finch, a biogerontologist at the University of Southern California in Los Angeles who was not involved in the new study. “At advanced ages, their mortality rate remains lower than any other mammal that has been documented.”
Scientists have long noted that naked mole rats—burrowing rodents with wrinkled, pink skin and large protruding teeth that live in large, subterranean colonies—show few signs of aging and far surpass the life span expected of a rodent this size. Mice in captivity live at most 4 years; based on their size, naked mole rats would not be expected to live past 6 years. Instead, some live beyond 30 years, and even at that age breeding females stay fertile.
Anew research model from the Penn Wharton Budget Model (PWBM) has brought clarity to the immigration debate in the U.S. by analyzing the macroeconomic implications of different policy scenarios. The model is at the core of a paper titled “Immigration and the Macroeconomy” authored by PWBM experts – Efraim Berkovich, director of computational dynamics; Daniela Costa, economist; and Austin Herrick, senior analyst.
“We find that, after an initial period, increasing legal immigration improves both the government’s fiscal balance and the economy on a per-capita basis,” the paper stated. “Legalization policies [or regularizing undocumented immigrants], on the other hand, worsen the government’s fiscal balance due to increased spending, while having modest effects on the economy broadly.” Lawful immigrants receive government transfers over their lifetime such as Social Security benefits, Medicaid, and the Supplemental Nutrition Assistance Program (SNAP); if they are not sufficiently productive, they create a “retirement benefits imbalance,” the paper pointed out.
The legalization plan the paper modeled is similar to the legalization provisions in the Biden immigration plan. That plan was akin to “a one-shot legalization for people who are already in the U.S.,” said Herrick.
David Sinclair – Harvard professor, celebrity biologist, and author of Lifespan – thinks solving aging will be easy. “Aging is going to be remarkably easy to tackle. Easier than cancer” are his exact words, which is maybe less encouraging than he thinks.
There are lots of ways that solving aging could be hard. What if humans worked like cars? To restore an old car, you need to fiddle with hundreds of little parts, individually fixing everything from engine parts to chipping paint. Fixing humans to such a standard would be way beyond current technology.
Or what if the DNA damage theory of aging was true? This says that as cells divide (or experience normal wear and tear) they don’t copy their DNA exactly correctly. As you grow older, more and more errors creep in, and your cells become worse and worse at their jobs. If this were true, there’s not much to do either: you’d have to correct the DNA in every cell in the body (using what template? even if you’d saved a copy of your DNA from childhood, how do you get it into all 30 trillion cells?) This is another nonstarter.
Sinclair’s own theory offers a simpler option. He starts with a puzzling observation: babies are very young . If a 70 year old man marries a 40 year old woman and has a baby, that baby will start off at zero years old, just like everyone else. Even more interesting, if you clone a 70 year old man, the clone start at zero years old.
So Sinclair thinks aging is epigenetic damage. As time goes on, cells lose or garble the epigenetic markers telling them what cells to be. Kidney cells go from definitely-kidney-cells to mostly kidney cells but also a little lung cell and maybe some heart cell in there too. It’s hard to run a kidney off of cells that aren’t entirely sure whether they’re supposed to be kidney cells or something else, and so your kidneys (and all your other organs) break down as you age. He doesn’t come out and say this is literally 100% of aging. But everyone else thinks aging is probably a combination of many complicated processes, and I think Sinclair thinks it’s mostly epigenetic damage and then a few other odds and ends that matter much less.
Developments in life expectancy and the growing emphasis on biological and ‘healthy’ aging raise a number of important questions for health scientists and economists alike. Is it preferable to make lives healthier by compressing morbidity, or longer by extending life? What are the gains from targeting aging itself compared to efforts to eradicate specific diseases? Here we analyze existing data to evaluate the economic value of increases in life expectancy, improvements in health and treatments that target aging. We show that a compression of morbidity that improves health is more valuable than further increases in life expectancy, and that targeting aging offers potentially larger economic gains than eradicating individual diseases. We show that a slowdown in aging that increases life expectancy by 1 year is worth US$38 trillion, and by 10 years, US$367 trillion. Ultimately, the more progress that is made in improving how we age, the greater the value of further improvements.
Author(s): Andrew J. Scott, Martin Ellison, David A. Sinclair
It turned out that, indeed, people varied widely in biological aging: The slowest ager gained only 0.4 “biological years” for each chronological year in age; in contrast, the fastest-aging participant gained nearly 2.5 biological years for every chronological year.
And by age 45, rapid biological agers were already showing some health indicators normally associated with old age.
Compared with their peers, they moved more slowly, had weaker grip strength, and more problems with balance, vision and hearing.
Differences in mental sharpness were clear, too, the researchers found.
In one sense, there is an enormous wealth of research on the economics of longer lives. This is a byproduct of the operations of sizable pensions and life insurance industries, dependent as they are on successfully predicting future trends in life span. On the other hand, outside this somewhat narrow scope, most concerned with the gain of a tenth of a year here and the loss of a tenth of a year there, there is comparatively little economic work that is directly tied to the research and advocacy communities engaged in trying to treat aging and greatly lengthen healthy human lifespan. That will change as the longevity industry both grows and succeeds in introducing age-slowing and rejuvenating therapies into the clinic.
The paper and commentary that I point out today might be taken as a sample of what lies ahead for the economics profession. At least some economists are at present managing to convince grant-awarding bodies in their field that, yes, there is real movement towards the treatment of aging, and perhaps someone should look into how that will likely play out in markets and societies. It should come as no great surprise to the audience here that even modest gains in slowing or reversing aging have vast economic benefits when they occur across an entire population. The cost of coping with aging is vast, the cost of incapacity and lost knowledge and death due to aging equally vast. It is by far the biggest and most pressing issue that faces humanity, and now we enter an era in which we can finally start to do something about it.
Throughout history, it was typical to see both birth and death rates at higher levels. But today, in most parts of the world, women are having fewer children, and innovations in healthcare and technology mean we are all living longer. The average person today lives to 72.6 years old, while the rate of births per woman has fallen to 2.5.
These trends have drastically altered the demographics of mature economies, resulting in a much older population. In many developing countries, however, births still outweigh deaths, resulting in populations that skew younger.
This visualization uses data from the World Bank to examine the countries with the highest shares of old and young people.