Should you change brake fluid every three years?

My wife has a four year old Volkswagen Up with 16,700 miles on the clock. She's been advised that you should change the brake fluid every three years but I cannot find any information on this subject in the service handbook. I was once advised by an RAC service engineer that you only needed to change the brake fluid if you did a lot of driving in a hot climate and had to use the brakes a lot. Can you please advise?
Brake fluid is hygroscopic (absorbs moisture). If the brake fluid is contaminated with moisture or other contaminants it needs to be changed. It should be tested for contamination every year from two years onwards, but only changed if contaminated beyond the acceptable limit.
Answered by Honest John on

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