2nd May 2020, 5 min read

Science and Technology links (May 2nd 2020)

1. As we age, we tend to produce less of NAD+, an essential chemical compound for our bodies. We can restore youthful levels of NAD+ by using freely available supplements such as NMN. It is believed that such supplements have an anti-aging or rejuvenating effect. Some scientists believe that restoring NAD+ might make the powerplants (mitochondria) of your cells youthful again. A recent paper shows that we can reverse cognitive aging in mice using NMN. The treated mice were more agile, comparable to young mice. The paper suggests that it might be beneficial for some neurodegenerative diseases. (Note: I caution you that many things that work in mice may not work in human beings.)
2. While we reject at a visceral level discrimination based on ethnicity, sexual orientation or gender, we are collectively happy to discriminate against older people. Nobody would think it is acceptable to fire women when they become pregnant, but it is acceptable to terminate someone’s employment because they are too old. Professor Paul Ewart from Oxford University fought his employer in court because while he was force to leave his post. He is now 73 years old. I do not know Ewart, but he was a co-author of over 10 papers in 2019 and he still held research grants, so I take it that he is still active in research. Ewart wrote:
   

It cannot be right to dismiss active physicists, or indeed any productive academic, at some arbitrary age. It is traumatic to be forcibly retired, especially when one’s work is still in full swing and there are new ideas to be explored. The “emeritus” status offered by Oxford, instead of full employment, is of no use to experimental scientists who need a research team and principal-investigator status to apply for their own research funding. It is simply ageism that underlies many of the arguments used to justify mandatory retirement. Age is often used as a proxy for competence and this lazy stereotype feeds off the myth that scientists have their best ideas when they are young. Indeed, studies have shown that a scientist’s most impactful work can occur at any stage in their career. (…) It is ageism that sees a 40-year-old as “filling” a post whereas a 65-year-old is “blocking” a post. Apart from providing the dignity and fulfilment of employment, there are general imperatives for people to work longer, including the growing pension burden and increases in life expectancy. Recent studies by the World Health Organization also highlight the physical and mental health benefits of working longer. (…) Ageism is endemic in our society and attitudes persist that would be recognized as shameful if they related to race, religion or sexual orientation. The University of Oxford’s claim that dismissing older academics is necessary to maintain its high standards is simply ageism, implying that academic performance deteriorates with age. If retirement policies are to be truly evidence-based, they need to be justified by reasoned estimates of proportionality that are consistent with the available data.

Ewart showed, both with a model and hard data, that forcing older people to go only had marginal benefits for younger people and gender diversity. It can be fair for an employer to seek to review the performance of its staff and to let people go when they fail below a productivity threshold. You may object that it is warranted to let 73 years old go since they are, maybe, less productive than younger folks. But on the same account, would we let young female professors who choose to have young children go if we can establish, statistically, that female professors with young children are less productive? Of course, we would not. The basis of our policies against older people are rooted in prejudice. On the basis of reason, we should encourage older people who are productive to keep working as long as possible. So what happened? Ewart went to court and won. How did Oxford respond? They are considering an appeal. No doubt, they will have to argue that forcing older productive people to leave is good…

1. Economists tell us that our economies do not grow as fast as they once did and thus, we are getting richer (or less poor) at a slower rate than what might have been expected a few decades ago. There is debate regarding these numbers since it is hard to tell how much Facebook, Zoom and the iPhone XR would be worth to someone in 1980.What might be causing this stagnation? If we believe that the problem lies with economics, then financial and fiscal tools might be the solution. Ramey argues for a different cause: she suggests that we might be in a technological lull. If she is correct, then the fix might be to encourage more technological innovation rather than jump at fiscal or financial interventions.
2. Most of the cells in our bodies can only divide so many times. This is known as the Hayflick limit and was once argue to fundamentally limit the lifespan of animals. However, we now know that stem cells, the cells that produce our specialized cells, do not face such a limit normally. The Hayflick limit comes from the fact that with each division, the tail end of our chromosome (the telomeres) get shorter. However, stem cells benefit from telomerase and thus may replenish their telomeres. Yet there are diseases where stem cells lose this ability to restore their telomeres. Researchers have shown that we can restore telomere lengths in such cases, in mice.
3. As we age, we accumulate “senescent cells”. They are large and dysfunctional cells that have often reached the Hayflick limit. They should normally die, but some of them stick around. Removing them is believed to form the basis for a rejuvenation therapy. The difficulty is to find effective compounds that kill senescent cells but nothing else. A paper in Nature presents a new approach that is apparently safe and selective, in both human beings and mice. In old mice, the therapy restored physical function and reduced age-related inflammation.