Had a similar case just the other day. Advised the daughter to use State Savings plans. Interest rates are low but they can access the money at any time without penalty. Your grandparents don't need investment risk at their age. Yes, there is inflation risk with leaving the money on deposit but they won't be worrying about their money falling by more than that.
On another point, most life companies have an age limit for new business. They don't want to be on Prime Time because an 85 year old was told to put money into an equity fund that has fallen by -40% and there are 5 years early exit penalties for taking their money out early.
Steven
http://www.bluewaterfp.ie (www.bluewaterfp.ie)