It seems our golden years may come with a hidden price.

A new study published in the Journal of Economic Perspectives has found that the sooner you retire, the sooner your memory and cognitive abilities begin to decline.

The study relied on surveys of adults in their 50s and 60s from 11 European countries and the U.S., and found that the countries where people retired at an earlier age also had a higher rate of adults with problems like memory loss, dementia, difficulty with reasoning and an overall lack of sharpness.

Of the countries in the survey, the U.S. had older adults with better cognitive abilities than most, largely because they stay employed longer. According to the study, there are 30%-35% fewer men employed in their 60s than in their 50s in the U.S. In countries like France and Austria, the employment rate among men in their 60s is up to 90% lower than that for men in their 50s.

As the researchers note, the workforce typically allows workers to “engage in cognitively demanding activities that exercise the mind.”  But once you step out of the workforce, you lose much of this mental stimulation. This is particularly dangerous for the elderly, who are already more at risk of suffering a cognitive decline.

The study’s authors do mention several tricks one can use to help stay sharp while in retirement, including reading and doing crossword puzzles, but they caution that these exercises have not been “unequivocally proven” to make much of a difference. That said, other recent studies show that taking the time to learn an extra language can help stave off dementia and keep you mentally fit.

The study raises the larger question of whether it even makes sense for one to retire full-time, and when the best time to do so might be.

Previous studies have found that those who retire full-time are more likely to suffer bouts of depression, as well as health issues like high blood pressure, heart disease and stroke.

As PsychologyToday noted last year when reviewing one of these studies, “The benefits of continuing to work, other than financial resources, are social interaction, and opportunities to use your brain… And perhaps most important of all, people who continue to work past retirement age have a sense of purpose, which has a positive impact on their health.”

Of course, beside the mental and physical effects of retirement, there is also a growing concern about whether we can afford retirement, both as individuals and as a country. One estimate found that families nationwide are now short as much as $6 trillion to pay for retirement. And that situation may only get worse. At the moment, estimates show that the average amount Americans need to get them through retirement is climbing close to a half million dollars in savings.

Other countries, facing similar problems, have decided to raise the retirement age in response and in the U.S., prominent politicians like House Minority Leader John Boehner (R-Ohio) have proposed upping our retirement age to 70.

Then again, in the end, even the prospect of declining cognitive ability might not be enough to counteract the satisfaction some will take at never again having a boss.

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