The ordinary requirement is that everyone, no matter their age, who receives Communion should abstain from food and liquid (with the exceptions of water and medicine) for one hour before Communion. However, anyone of any age for whom abstaining from food and liquid for an hour would cause medical problems is exempt from the requirement. Usually, only those homebound individuals who must receive Communion from EMHCs are the ones who could have a problem scheduling their food intake according to the EMHC’s schedule. However, if someone healthy enough to attend Mass does have a medical condition that makes it impossible for him to observe the fast, he is indeed exempt.
Bottom line: It is not age that is a factor, but medical condition.
