The possibility that a Covid infection could damage your brain is terrifying. Scientists have established that long Covid often manifests itself with neurological changes — brain fog, memory problems, fatigue. And some researchers have found changes in the brain after even mild cases of the virus…

This century’s worst-case climate scenario isn’t global warming of 4 or even 5 degrees Celsius. It’s a nuclear winter that would trigger global cooling up to 12 or 13 degrees C. That would happen within weeks of the start of a nuclear war, as smoke from burning cities blotted out the sun. The…

The possibility that the Covid pandemic started with a lab accident isn’t a conspiracy theory. Nor has science conclusively proven that it started in a Wuhan wet market. We simply don’t know — because China has set up numerous roadblocks to impede scientists’ ability to understand the origin of a…

Harlan Krumholz, a cardiologist at the Yale School of Medicine, says he worries about two kinds of long Covid. There’s the obvious version where people suffer prolonged virus symptoms like fatigue, and a stealthier version in which people recover yet carry an added risk of blood clots and strokes. …

For the first time, we’re heading into a Covid winter mostly free of restrictions. People are tired of mandates and rules, tired of lining up for tests and even, as booster rates show, tired of getting shots. And so public health needs a new approach to do any good — one based not on restrictions…

Patients and their doctors count on cancer screening tests to save lives, and yet a number of large, controlled studies are showing disappointing results for mammography and other mass screening tests. This month, the New England Journal of Medicine published a controversial study that cast doubt…

Researchers at Boston University sparked alarming headlines this week by creating a more lethal version of the omicron Covid variant. At the heart of the uproar is the fact that the researchers didn’t have any obligation to inform anyone beyond an internal review board about what they were doing…

What do Neanderthals have to do with medicine? More than enough, it turns out, to earn Svante Pääbo Monday’s Nobel Prize in medicine for sequencing the Neanderthal genome. It may sound more like a feat worthy of an anthropology prize, but scientists are already using Neanderthal DNA to make…

Scientific understanding is challenging the conventional wisdom about hunger — now framing it as a scourge that afflicts not only people who get too few calories, but also those who consume mostly sugar and refined starch. Under this new understanding, people eating the wrong kind of diet can…

The new US Covid booster campaign needs a dose of clarity about its goals and limitations. The latest “bivalent” vaccine — retooled to protect against the currently circulating BA.5 variant — will benefit some more than others. The oldest and most vulnerable citizens are likely to benefit most…