Getting the recommended 150 minutes of moderate-to-vigorous exercise each week may offer only modest protection against heart attacks and strokes. A large study suggests that substantially greater benefits may require roughly 560 to 610 minutes a week—nearly 9 to 10 hours of brisk walking, running, cycling, or similar activity.

A protein that evolved long before the human circulatory system may help unlock stronger cancer treatments. When C3 is produced inside tumors, it blocks immune-suppressing cells and gives immunotherapy a better chance to work. Researchers were even able to recreate this effect in resistant tumors, significantly improving survival in mice.

Changing how much sweet-tasting food people eat may not change how much they crave or enjoy sweetness after all. In a six-month trial, researchers found that people assigned to high-, low-, or average-sweetness diets showed no meaningful differences in their preference for sweet foods, body weight, or markers linked to diabetes and heart disease. Many participants also drifted back toward their previous eating habits once the trial ended.

Teens who start using cannabis may experience slower growth in memory, attention, language, and processing speed. Their abilities often developed normally at first, then began leveling off while nonusers continued improving. THC appeared to be the most likely driver, especially for worsening memory.

Linus Pauling was widely mocked for claiming that vitamin C could fight cancer, especially after trials using vitamin C pills showed no benefit. Researchers now know that intravenous vitamin C reaches vastly higher concentrations and can behave more like an experimental cancer drug than an ordinary supplement. Early studies suggest it may damage vulnerable cancer cells, reduce treatment side effects, and possibly improve outcomes for some patients.