Hygiene experts weigh laundry frequency for denim and bedding

Research and expert advice suggest varying frequencies for laundering different types of textiles based on hygiene and material durability.

Textile science professor Rachel McQueen of the University of Alberta conducted a study involving a student who wore unwashed jeans for 15 months. Microbiological analysis of the fabric revealed that bacterial growth after 15 months was similar to levels found just two weeks after a standard wash, suggesting that bacterial populations may reach a plateau. This supports the idea that denim, being a durable fabric, does not require frequent washing.

In contrast, microbiologist Primrose Freestone from the University of Leicester emphasizes the importance of regular bedding maintenance. Because humans spend approximately one-third of their lives in bed, sheets and pillowcases accumulate sweat, body oils, skin cells, and microorganisms such as staphylococci and dust mites. Freestone notes that regular washing is essential not just for cleanliness, but to manage allergens and bacteria that can impact sleep quality and respiratory health.