Do Maine Coon cats shed and can it be prevented and reduced?

To the first part of the question the answer is Yes. To the second part of the question the answer is No. To the third part the answer is Yes, by grooming your cat which will thin out the fur and take away some of the fur that would have been shed naturally by the cat. I guess you know that already. Maine Coon cats are just like any other and that they will shed fur. 

Maine Coons shed fur like any other so grooming your cat should be a daily ritual that you both enjoy and which will improve the bond.

The Maine Coon is a medium-longhaired cat and perhaps it is fair to say that cats with this hair length tend to shed more or the shedding is more apparent because the hair is longer! That sounds a bit daft but I think it's true.

Glorious Maine Coon photographed with a ring flash - look at the reflection in the eyes.
Picture in the public domain.

It shouldn't be a problem to groom your cat because they normally love it provided it is done with gentleness and plenty of love. In fact it becomes a daily ritual as good as if not better than petting your cat. You can buy a range of brushes and combs to do the job. Flea combing your cat daily is also the sort of ritual that they love and that too will remove some fur that might be due for shedding. Plus of course you can check for fleas although this should be unlikely in a Maine Coon cat because they should be kept inside where there is less chance of there being fleas.

That does not mean that there will be no fleas in the home of a full-time indoor cat because fleas can be brought in by people or other animals that might live in the home.

Shedding of fur takes place because of the change in light which makes it seasonal. What I mean is the trigger is the change in the amount of ambient light which of course is also linked to the temperature. But as I understand it is the ambient light which biologically triggers the increased shedding during the warmer seasons. Of course all domestic cat shed their fur as it is entirely natural except I guess the hairless cats! Although they do have some very fine down for but I don't think that that is shed.