Is There a Cap on Human Life Span?


But is it possible that attempts at preventing early death have also raised the maximum human life span and may continue to do so? Studying trends in maximum human life span over time could give an answer. But this kind of actuarial calculation is always complex and often wrong. For example in 1921 it was "demonstrated" that ages above 105 were "impossible." Estimating the limits to longevity has since been criticized because every "maximum limit" to life span so far proposed has been surpassed.

Do bacteriophage guests protect human health?


A century after they were discovered killing diarrhea-causing bacteria in the feces of World War I soldiers, the viruses known as bacteriophages, or simply phages, are drawing new attention for the role they might play within the human body. Phages have been found most everywhere, from oceans to soils. Now, a study suggests that people absorb up to 30 billion phages every day through their intestines. Though where those viruses end up is unclear, those data and other recent studies have some scientists wondering whether a sea of phages within the human body--a "phageome"--might play a key role in our physiology, perhaps by regulating our immune system.

South African law may impede human health research


South Africa's varied population makes it a magnet for research on public health and human diversity. But a new privacy law called The Protection of Personal Information Act, scheduled to go into effect in 2020, could upend such research. The law aims to protect South Africans from abuse of their personal data and says that such information, including genetic data, must be collected for a specific purpose--and that data subjects need to be "aware of the purpose." But giant sample and data repositories called biobanks are transforming health research around the world by allowing multiple researchers to ask new questions of the same data. At a meeting in Cape Town on 4–5 February, lawyers, ethicists, and researchers discussed how the new South African rule could limit such secondary use of data and hamstring international collaborations.

Hazards of human spaceflight


In Einstein's famous twin paradox, the effect of special relativity causes aging to slow in one twin during travel in a high-speed rocket through space while the body of the Earth-bound twin undergoes the same wear and tear that all humans experience on Earth (1). However, real space travels present far more realistic challenges that can potentially compromise the health of the more adventurous twin. On page 144 of this issue, Garrett-Bakelman et al. (2) investigate the manifold biological consequences of a journey in space endured by an astronaut during a 1-year mission onboard the International Space Station (ISS) compared with his identical twin on Earth. The challenges encountered in space include noise, isolation, hypoxia, and disrupted circadian rhythm (body clock). Furthermore, exposure to ionizing radiation (IR) and weightlessness, also called microgravity, could cause important health risks.

Human genome editing is here – now we have to decide who is in charge

New Scientist

The World Health Organization (WHO) will convene a meeting this month to develop global standards of governance for human genome editing. This is a welcome move. Although the committee has no powers to enforce compliance – it is still a matter for individual nations to decide on regulations, with China reportedly updating its rules earlier this week – the WHO committee's recommendations will be influential and far-reaching in their ambition. But I hope committee members will bear a few points in mind in their discussions.