There may be some tax advantages available to the sandwiched generation for helping out their elderly parents.
If your elderly parent has little or no income, he may be considered a “qualifying relative” for your income tax purposes. He loses his own exemption, but that is probably of little worth since he would be paying little or no taxes himself.
You can claim the exemption if you can show that
1) you provided over half of his support (food, shelter, clothing, medical care, dental care, etc.) for 2011;
2) he has gross income of less than the exemption amount in that year;
3) he has not filed a joint return with his spouse;
4) your parent is an American citizen, resident or national, or a resident of Canada or Mexico for 2011.

Your parent’s gross income calculation excludes his social security and SSI benefits.

the dependency exemption isn’t limited to claiming just parents; it also applies to descendants, grandparents or other ancestor, stepchild, stepparent, sibling, aunt, or uncle.