First you have to differentiate between good advice handed down by previous generations and things which were used against you as a child to control your behaviour. For instance, is it unlucky to have peacock feathers in the house? Only for the peacock.
I have experience of the world of whole foods going back to 1971. Superstition is rife amongst brown-rice eaters. Tomatoes are poisonous. Potatoes make you stupid. Monosodium glutamate slows you down mentally. Free salt is far worse for you than salt used in cooking. Never use boiling water when making tea. Even if you do not believe some of the things you are told, they stick in your head like ear-worms and unless you have a mind of steel it is next to impossible to rid yourself of them as you, say, eat a tomato or enjoy the umami effect of the naturally-occurring monosodium glutamate in crunchy, mature Cheddar cheese.
I believe in magic. That is to say that I believe that the belief in magic makes it real whether it is or not.
Paul Bowles has a wonderfully disturbing set of short stories written when he was living in Morocco and smoking hashish from the moment he woke up until the time he should have gone to bed, had he got out in the first place.
In one, a local woman seeks revenge on her unfaithful husband. She steals his folding pocket knife and throws it down a well where it would remain permanently closed. By doing this she is casting a spell on him to make him impotent - which it did. The reason why this spell worked is because she told him what she had done and why she had done it when he asked her what had happened to his knife. The fear and paranoia (exacerbated by habitual kif smoking) of impotence was enough to make the spell come true.
Here is a statistical fact which I always think of when I buy a lottery ticket: You stand more chance of being killed on your way to buy a lottery ticket than you do of winning it.