Work by the Institute for Health Metrics and Evaluation (IHME) estimates that by 2050, more than three quarters (155 out of 204) of countries will not have fertility rates high enough to maintain their population size. The percentage will rise to 97% by the year 2100. The authors warn that national governments must plan for the threats these changes will pose to the economy, food security, health, the environment and geopolitical security. The findings are published in the journal The Lancet. 

In 2022, 62 million tonnes of e-waste were generated worldwide, a figure 82% higher than the 34 million tonnes recorded in 2010, according to a United Nations report. The 2022 figure represents an average of 7.8 kilograms per capita per year worldwide, compared to 19.6 kg in Spain. Only 22.3% of this amount of global e-waste was documented as properly collected and recycled, says the Global E-waste Monitor 2024. 

An international team of researchers has examined the epigenetic effects of tobacco and e-cigarettes over time in more than 3,500 samples. Their results indicate that e-cigarettes can also cause changes associated with an increased risk of cancer even shortly after starting to use them. They publish the study in the journal Cancer Research. 

According to an unpublished study presented at a conference of the American Heart Association and not peer-reviewed, an analysis of over 20,000 American adults found that individuals who restricted their food intake to less than 8 hours a day, following a time-restricted eating plan, were more likely to die from cardiovascular diseases compared to those who ate during 12-16 hours a day.

Two investigations published in the journal JAMA conclude that there is no evidence of brain injury detectable by magnetic resonance imaging or biological abnormalities in people suffering from the so-called Havana syndrome. This syndrome has been described in overseas civil servants and their family members, who suffer from symptoms including noise, pressure and pain in the head, and cognitive dysfunction, called abnormal health incidents. Studies did find differences in symptoms of imbalance, fatigue, post-traumatic stress disorder and depression. 

A study published in the journal PLOS ONE, which includes data from over 3,000 Spanish adolescents and children, has shown that those living in more walkable areas report spending more minutes per day engaging in active transportation compared to those from less walkable neighborhoods. Along those lines, the lowest average minutes spent playing outdoors are observed among participants from neighborhoods with lower socioeconomic status and less walkability. The research is part of the PASOS study, coordinated by the Gasol Foundation.

Research involving more than 3,000 adolescents and children from all Spanish autonomous communities concludes that those living in less walkable neighbourhoods with lower socioeconomic status walk less and engage in less physical activity at weekends than those living in more walkable areas with higher socioeconomic status. The paper, published in the journal PLOS ONE and part of the PASOS study, was presented by two of its authors at a briefing organised by SMC Spain. 

Two studies published in the New England Journal of Medicine evaluate colorectal cancer screening tests that could be alternatives to the existing faecal immunochemical test (FIT), which detects occult blood in stool. The first study uses a new generation test that detects DNA in stool and has a higher sensitivity than FIT, 93.9% for colorectal cancer and 90.6% for advanced neoplasia (tumour formation). The second uses a blood-based DNA detection test with a sensitivity of 83% for colorectal cancer and 90% for advanced neoplasia.   

A group of trans scientists and family members of trans people have called on their peers to help build a trans-inclusive academic world and rigorous research on sex and gender issues. In an article published in the journal Cell, the authors describe their experience in academia and propose actions that individuals and institutions can take to support trans scientists, such as creating gender-neutral spaces, collecting environmental data, or obtaining information on trans academic outcomes.   

The NEJM publishes the results of a phase III clinical trial conducted by GSK that had to be suspended due to a safety signal. The study shows that newborns of vaccinated mothers had a lower risk of experiencing severe events associated with the respiratory syncytial virus (RSV), but also a higher risk of being born prematurely.