Disease prevention Archive

Daily nasal irrigation (also called nasal rinses) may reduce symptom severity and the duration of a cold. It can also relieve the congestion caused by sinus infections and allergies. It is unclear whether it can prevent colds. By means of a squeeze bottle, neti pot, or battery-powered system, saline (salt water) is inserted into one nostril and flows out the other. It's important to always use sterile water, meaning distilled or cooled boiled water. The rinse helps wash away mucus and some inflammatory chemicals, reducing the swelling that's responsible for congestion.

Elderberry syrup or tea may help reduce the duration and severity of cold and flu symptoms. But the evidence for these benefits is uncertain, since the studies are small and most did not compare elderberry to standard treatments. Claims that elderberry products can prevent viral infections or boost immunity are unproven. Elderberry supplements appear to be relatively safe; in clinical trials, effects such as nausea, vomiting, or diarrhea were mild and rare.

A 2025 study of over 5,600 women and men followed for over 30 years found that following a Mediterranean diet may reduce the risk of Alzheimer's disease and improve cognitive function. The effect is strongest in people who carry two copies of the Alzheimer's risk gene APOE4.