Why do they stick their nose in everything??
It's a European Union. To achieve that, the laws must be broadly similar in all EU countries.
It's the reason why I can jump in the car tomorrow, drive 2 hours, do a huge amount of shopping in Frankfurt (Oder) and drive back without anyone caring. The same EU allowed me to have a German-Polish party with a group of people without anyone caring or being bothered that we crossed the border about 20 times in the space of several hours.
Does the EU want Poles to develop more food allergies?
Uh - quite the opposite. The EU actually wants minimum standards for food production, so the food can be sold throughout the EU freely and without restraint.
Why did Poland join the evil EU??
You do realise that the same EU allowed 2 million Poles to find work in the EU, the same EU is pouring a lot of money into the country, the same EU is encouraging Poland to reach the same standard as the West, etc etc. Sure, some "Polish" things might be lost along the way - but the benefits far outweigh the negatives.
Please, leave the EU to the Europeans - you guys over the pond simply don't understand it.