A dietary shift from animal-based foods, such as red or processed meat and eggs, to plant-based foods, such as nuts, pulses and whole grains, is associated with a reduced risk of death and diabetes or cardiovascular disease. For example, replacing 50 grams of processed meat per day with 28-50 grams of nuts is associated with a 27% decrease in cardiovascular risk. These are the conclusions of a systematic review of 37 studies published in the journal BMC Medicine.

A review of 25 studies conducted over nearly 50 years has found an association between insecticide exposure and lower sperm concentration. According to the authors, "insecticides are a public health concern for all men, who are exposed mainly through consumption of contaminated food and water". The results are published in the journal Environmental Health Perspectives.

A study led by the University of the Balearic Islands proposes a mathematical model to understand quantitatively the impact of ideologies on the coexistence of various languages. The more groups of people with different linguistic preferences mix, the more challenging it becomes for different languages to coexist within the same society, say the authors, whose study is published in the scientific journal Chaos. The team says this model could be useful to design policies aimed at preserving minority languages.

We often see the term 'vaccine' used in the media to refer to drugs that target diseases that are not even infectious, such as cancer and cholesterol. In this article we explain when it is correct to talk about vaccines and when it would be wrong. 

A review of more than 100 meta-analyses and nearly 2500 studies has analysed the use of screens by children and young people and the consequences for their learning and health. Their conclusions are that, in general, the effects are small and vary according to the type of use and context. The results are published in the journal Nature Human Behaviour.

The absence of visits from friends and family is associated with a higher mortality rate, according to an analysis of data from more than 450,000 people followed for more than a decade in the UK. The study, published in BMC Medicine, focussed on five indicators of loneliness, and concluded that having no visits from family or friends was associated with higher all-cause mortality and cardiovascular disease mortality. According to the authors, this kind of study helps to identify at-risk populations and measures of social connectedness that could provide the most benefit.

A Chinese research team has reported the birth of a crab-eating macaque that is a chimera: an animal generated from the mixing of embryonic cells from two different individuals; in this case, from the same species, according to the journal Cell. Until now, this type of chimera had only been developed with rodents. This is the first time it has been achieved in non-human primates.

An international study involving ISGlobal in Barcelona has studied almost one million people and concludes that having a CT scan before the age of 22 increases the risk of developing blood tumours in later years by 16%. According to the authors, who publish the results in the journal Nature Medicine, "in terms of absolute risk this means that, for every 10,000 young people who undergo a CT scan, we can expect to see around 1-2 cases of cancer in the 2-12 years following the examination.

An attribution study by Climate Central concludes that from November 2022 to October 2023, global temperatures will set a new record, exceeding pre-industrial levels by more than 1.3°C above pre-industrial levels. This would be the warmest 12-month period on record to date. The analysis shows that during this period, 5.7 billion people were exposed to at least 30 days of above-average temperatures, including most of the Spanish population.

A team of researchers has managed to combine more than seven synthetic chromosomes made in the laboratory in a single yeast cell. This involves developing for the first time a eukaryotic cell with more than 50% synthetic DNA, which survives and replicates in a similar way to wild yeast strains. The results, which are part of the Synthetic Yeast Genome Project (Sc2.0), are published in the journal Cell.