Healthy food, COVID rebound — the week in infographic

Healthy foods are green foods

A analysis of 57,000 foods reveals which ones have the best and worst environmental impacts. A team of researchers used an algorithm to estimate the amount of each ingredient in thousands of products sold in major UK supermarket chains. The scientists then gave the food an environmental impact score out of 100 – 100 being the worst – by combining the impacts of the ingredients in 100 grams of each product. They considered several factors, including greenhouse gas emissions and land use.

Healthier foods tend to have lower environmental impacts, the team found. Products containing lamb and beef, such as ready-made meat pies, had the most severe environmental impact. Low-impact foods were generally made from plants and included baked goods, fruits, vegetables, grains, and high-sugar drinks. There were some notable exceptions: nuts and seafood had a good nutritional score but relatively high environmental impacts.

Source: Mr. Clark et al. proc. Natl Acad. Know United States 119e2120584119 (2022).

COVID-19 rebound

After the COVID-19 antiviral Paxlovid began use in late 2021, researchers noticed that some people experience a rebound of the virus and symptoms after taking the drug. Two recent studies suggest that it is surprisingly common for the return of SARS-CoV-2 in untreated cases of COVID-19 too. To determine rebound frequency, Jonathan Li, a physician-scientist at Brigham and Women’s Hospital in Boston, Massachusetts, and his team analyzed data from hundreds of people who were randomized to receive a placebo in a large-scale COVID trial. -19 antibody drugs. More than a quarter of participants infected with SARS-CoV-2 reported a rebound in their symptoms, according to the study, which has not yet been peer-reviewed. “The main take-home message is that recovery from COVID-19 will not be a linear process,” Li said.

Covid comeback: People who receive the antiviral Paxlovid may experience a rebound in symptoms and viral levels.

Source: Deo, R. et al. Preprint at medRxiv (2022).

How trees grow in a warmer world

This graph shows how the early arrival of spring, due to climate change, affects tree growth and the amount of carbon they sequester. In a paper in Nature, researchers studied the consequences of an early start to the growing season in deciduous forests. The emergence of leaves is followed by carbon uptake through the process of photosynthesis. Over time, carbon can be captured for long-term sequestration if it contributes to radial stem growth or wood formation. The areas under the curves represent the annual growth in terms of: amount of carbon taken up by the leaves (upper curves, brown); annual radial growth (lower left curve, blue); and increase in woody biomass (lower right curve, red).

The authors report that the early onset of spring, which shifts the margins of the growing season (lighter curves), has little impact on the final width of annual rings or on the amount of woody biomass produced, whereas the High temperatures in summer have a negative effect on radial growth (dotted curve). Other studies (shown here as dashed curves) indicate that high temperatures and associated drought can suppress carbon capture and woody biomass production.

The study provides evidence that warmer springs advanced leaf emergence in temperate hardwood forests, but did not significantly increase their timber production. This suggests that the additional uptake of carbon dioxide does not contribute to sustainable carbon sequestration in the trunks of long-lived trees, such as our The News & Views article explains.

Figure 1

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