[folk wisdom] What's the connection between preparing preserved fruits, juices and vegetables and having your period?

I don't know if it's the right thread but i'm gonna give it a try anywyay. So my family is Slavic and basically every female relative says you absolutely cannot prepare preserved food for winter like pickles, sauerkraut, kompot and so on when you're menstruating because it won't come off, get rotten etc. When I ask them why is that, they don't know what to say besides "that's how it is, i don't know the explanation but i've made this mistake in the past and had to throw away all i prepared". Do any of you know if this is really true and why? I don't think it is but every aunt and cousin i asked says it's true and they've experienced it.