How the world can fight climate change without the help of the United States. Plus, the benefits of walks long and short and whether attitudes to controversial ‘CRISPR babies’ are changing.
Hello Nature readers, would you like to get this Briefing in your inbox free every day? Sign up here.
Even people who don’t reach the recommended 8,000 steps per day can reap health benefits if they take relatively long walks. Credit: Ina Fassbender/AFP/Getty
Taking as few as 3,000 steps per day seems to stave off mental decline by around 3 years in people whose brains have begun to show molecular signs of Alzheimer’s disease, but who have yet to display any cognitive symptoms, compared with those who stay sedentary. Up to 7,500 steps per day slows the decline by an average of 7 years, but the effect tails off after that.
Meanwhile, people who rack up most of their daily steps in long walks have a lower risk of cardiovascular disease than do those who take walks lasting less than five minutes. The benefits of longer rather than shorter walks were most pronounced among people who took fewer than 5,000 steps per day.
Nature | 4 min read & Nature Research Highlight | 3 min read
Reference: Nature Medicine paper & Annals of Internal Medicine paper
Several ventures in the United States have launched with a focus on altering the genome of human embryos to prevent genetic disorders — a field that labours under the shadow of biophysicist He Jiankui, who ended up in jail for creating the first ‘CRISPR babies’. Unlike gene editing in non-reproductive cells, editing an embryo means that changes will be passed down to the next generation, a concept riddled with safety risks and ethical quandaries. Biotech founder Cathy Tie (who publicized a romance with He on social media) says that “a majority of Americans are in support of this technology”, and that her company will conduct extensive research and safety testing before attempting to create gene-edited babies. But many scientists say that it is much too early to consider commercializing the process.
Nature | 7 min read
Global cases of COVID-19 increased by more than 19,000 last month compared with the previous month, according to the World Health Organization. But the true number of infections is probably much higher, say researchers, because surveillance of the virus has dropped off since the pandemic. This data gap can leave health organizations unprepared to recommend vaccine formulations and their roll-out, says clinical epidemiologist Antonia Ho. Some researchers also question whether COVID-19 is really a seasonal virus, the current basis for vaccine offerings in some countries being in the autumn.
... continue reading