Downer of a diet?

Binging on Diet Coke and chocolate doughnuts might affect your mood, not just your waistline, according to a new study. A team of researchers at Harvard found that women who ate high amounts of processed foods were more likely to develop depression than women who did not.

The study, published Sept. 20 in JAMA Network Open, evaluated the eating habits of nearly 32,000 middle-aged women. Based on 15 years of data, women who ate nine servings of so-called “ultraprocessed” foods per day were approximately 50 percent more likely to develop depression than participants who consumed four servings or less. Ultraprocessed foods—high in salt, sugar, hydrogenated fats, and/or additives—include chips, soda, frozen meals, canned foods, sugary cereals, and packaged baked goods.

The researchers also examined whether specific types of ultraprocessed foods were more heavily associated with depression. Only artificially sweetened beverages and artificial sweeteners increased depression risk, they reported. Co-author Andrew T. Chan told USA Today that ultraprocessed foods may alter the gut microbiome, resulting in chronic inflammation that may lead to depression.

Asteroid bagged

The United States’ first asteroid sample has arrived on Earth. A ­capsule containing some 250 grams of material from the near-Earth asteroid Bennu, collected by NASA’s OSIRIS-REx probe, parachuted into the Utah desert on Sept. 24. Launched in 2016, the probe collected a sample from the asteroid’s ­surface—consisting of particles packed loosely together like a plastic ball pit—in 2020.

OSIRIS-REx team members will curate the asteroid specimen, the world’s largest, at the Johnson Space Center in Houston, Texas. While NASA will keep at least 70 percent of the sample, the remainder will be distributed to 200 mission members from 35 ­countries for analysis. OSIRIS-REx’s principal investigator, Dante Lauretta, hopes the ­samples contain organic molecules, the building blocks of life.

Japan was the first country to collect an asteroid sample, delivering several micrograms of Itokawa to Earth in 2010. —H.F.

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And the number of human cells is ...

How many cells are really in the human body? An international team of researchers ­compiled data from over 1,500 papers to evaluate the size and number of 400 cell types, including muscle, nerve, and immune cells. Their conclusion: The average adult male has 36 trillion cells, while the average adult female has 28 trillion. A 10-year-old child has about 17 trillion cells. The scientists published their work Sept. 18 in PNAS. —H.F.