A large French study tracking more than 100,000 people over a decade has found that higher consumption of certain food preservatives—commonly found in processed foods and drinks—is linked to a modestly higher cancer risk. While many preservatives showed no association, several widely used ones, including potassium sorbate, sulfites, sodium nitrite, and potassium nitrate, were tied to increased risks of overall cancer and specific types such as breast and prostate cancer.

Carbohydrates don’t just fuel the body—they may also influence how the brain ages. A large long-term study found that diets high in fast-acting carbs that rapidly raise blood sugar were linked to a higher risk of dementia. People who ate more low-glycemic foods like fruit, legumes, and whole grains had a noticeably lower risk of Alzheimer’s. The quality of carbs, not just the amount, appears to matter for brain health.

A new genetic study suggests that obesity and high blood pressure may play a direct role in causing dementia, not just increasing the risk. By analyzing data from large populations in Denmark and the U.K., researchers found strong evidence that higher body weight can damage brain health over time, especially when it leads to elevated blood pressure. Much of the dementia risk appeared to be tied to vascular damage in the brain, which affects blood flow and cognitive function.

Home fireplaces and wood stoves are quietly driving a large share of winter air pollution, even though only a small number of households rely on wood heat. Researchers found that wood smoke accounts for over one-fifth of Americans’ winter exposure to dangerous fine particles linked to heart disease and early death. Much of this pollution drifts into cities, where it disproportionately harms people of color. Reducing wood burning could deliver major public health benefits.

A 5,500-year-old skeleton from Colombia has revealed the oldest known genome of the bacterium linked to syphilis and related diseases. The ancient strain doesn’t fit neatly into modern categories, hinting at a forgotten form that split off early in the pathogen’s evolution. This pushes the history of treponemal diseases in the Americas back by millennia and shows they were already diversifying long before written records.