Can microplastics in food cause muscle wasting or muscle weakness?

What's actually in it

Polystyrene microplastics come from disposable cups, food containers, takeout packaging, and styrofoam. These particles shed into food and drink, especially when heated or with oily, acidic foods. Once consumed, they're absorbed into the bloodstream and reach muscle tissue.

Muscles constantly break down old or damaged proteins through a process called autophagy, and build new ones. This recycling process is essential for maintaining muscle mass.

What the research says

A 2026 study in Environment International found that polystyrene microplastics disrupt autophagy and AMPK signaling in skeletal muscle. AMPK is a master regulator of energy balance and protein recycling in muscle cells. When it's disrupted, protein breakdown accelerates and muscle cells shrink.

Mice exposed to polystyrene microplastics showed measurable muscle fiber atrophy: smaller muscle fibers and reduced grip strength compared to controls. The effect was dose-dependent, meaning higher microplastic exposure led to more muscle loss.

Muscle atrophy matters for long-term health. It reduces metabolic rate, strength, and resilience. The main way to reduce polystyrene microplastic exposure is to avoid heating food in styrofoam or polystyrene containers and to switch to glass or stainless steel for hot food and drinks.