New York, Dec 27 (IANS): A little extra income can significantly improve the health and well-being of poor, elderly people in developing countries, says a new study.

They poor spend a significant portion of the extra money on doctor visits, medications and food, the findings showed.

"We found strong evidence that supplementing the income of poor, elderly populations can have significant benefits to health and well-being, even in the short run," said study co-author Arie Kapteyn, professor of economics at University of Southern California.

For the study, the researchers compared 2,474 residents aged 70 years and older of two cities in Yucatan state of Mexico.

Those in Motul received no extra income, while those in Valladolid received an additional $67 (around Rs.4,300) per month, a 44 percent increase in average household income.

After six months, participants in Valladolid showed significant improvement in lung function and memory.

The average participant with supplemented income saw improvements in immediate and delayed memory.

Participants were also more likely to visit a doctor and buy medicine.

"Elderly populations are growing around the world," said study co-author James Smith from RAND Corporation, a research organisation in the US.

"This work provides insight on what pension programmes might accomplish in developing nations, which are beginning to address these issues," he added.

The study appeared in the journal Proceedings of the National Academy of Sciences.