The original reason why I switched to natural fabrics was because I liked the idea of everything in my life being natural. And natural fabrics generally feel better. After wearing soft cottons and smooth silks, the old polyesters and nylons feel itchy, heavy, and plastic-y. And they are plastic-y.
Synthetic fabrics are a petroleum-based product, and a fairly novel one; they've only been around since about WWII. Because synthetic fabrics are, essentially, made from plastic, they take thousands of years to decompose once they've worn out or gone out of style and been thrown into the landfill.
Synthetic fabrics--and by that I mean things like polyester, rayon, latex, nylon, acrylic, acetate, and spandex--are made using the chemicals sodium hydroxide and carbon disulfide, which are derived from fossil fuels. Traces of these chemicals can remain on the fibers of your clothing, where they come into contact with your skin. Sometimes other chemicals--often containing harmful toxins like formaldehyde--are added to make clothes wrinkle-free or stain-resistant.
It's not only the chemicals used in the manufacture of synthetic fabrics that can contaminate both our bodies and the environment, but the fabric itself. When fabrics like polyester are washed repeatedly, they begin to break down. Tiny fibers wash down the drain, where they accumulate in our rivers and oceans. Fish ingest these particles of plastic-fabric, and it begins to bio-accumulate in the food chain. Little fish eat the plastic. Medium and big fish eat lots of little fish, and all the plastic that all those little fish ate gets absorbed by the bigger fish. Then we eat the bigger fish, and we, too, take on that plastic load. Of course, this is also due to other sources of plastic pollution, but reducing our use of synthetic fabrics is an easy way to begin to address it.
Natural fibers also tend to last longer, reducing waste, and they are biodegradable. Why wear plastic when we can wear plants?
Of course, nothing is quite that easy. Even natural fabrics can be dangerous. Non-organic cotton, for example, is grown with a heavy dose of pesticides, which the workers who harvest the cotton are unjustly exposed to. It's best to buy organic, fair-trade cotton, hemp, linen, silk, and wool. These fabrics can be more expensive, so it's more about quality over quantity. You may end up with fewer, higher-quality, longer-lasting things. Think of your clothes and textiles (bedding, towels, handkerchiefs, etc.) like you'd think of your food, and ask yourself: Do I want potentially harmful chemicals against my body? Do I want to contribute to plastic pollution, or do I want to be part of the solution? Do I want to contribute to social and environmental injustices, or do I want to support small farmers, fair wages, and eco-friendly growing practices?
Switching to natural fabrics doesn't have to happen all at once. There's no need to throw out all your old clothing and replace it with new stuff. Maybe your goal will be to only buy natural fabrics whenever you buy new clothes. Or maybe your goal will be to make half your wardrobe natural. Or you could go for an all-natural wardrobe except for workout clothes and clothes for special occasions. Whatever choice you make, you'll be working towards a cleaner, less fossil-fuel-dependent world, and a softer, more comfortable lifestyle for yourself. Win-win!