In western countries there are 20 times more people aged 65 years andr older than one hundred years ago. With those demographic changes have come changes in brain research.  Understanding the mechanisms responsible for aging-related changes in cognitive processes, including spatial orientation, has become especially important for people’s everyday lives.

Aging is unavoidable - except perhaps for the brain, say researchers. They also present counterintuitive evidence that it is what you do in old age that matters when it comes to maintaining a youthful brain - not what you did earlier in life.

Education alone won't save your brain; PhDs are as likely as high school dropouts to experience memory loss with old age. Don't count on your job either - those with a complex or demanding career may enjoy a limited advantage, but those benefits quickly dwindle after retirement.

Instead, engagement is the secret to success. Those who are socially, mentally and physically stimulated reliably show greater cognitive performance with a brain that appears younger than its years.

Researchers have documented the first fossil-based evidence supporting an evolutionary theory of aging, which predicts that species evolving in low mortality and resource-limited ecosystems tend to be more long-lived.

But that is not an endorsement of banning guns and caloric restriction. It's a little more complicated than that.

Despite much research in the last few decades, the genetic causes of why animals have such different longevities remain largely unknown, mostly because aging results from so many myriad factors that to identify genetic effects is almost impossible. 

Illicit drug use is more common in older people than ever before - but that's because they did it the most when they were younger and they are more likely than ever to survive into old age.

New research published in Age and Ageing found that the lifetime use of cannabis, amphetamine, cocaine and LSD in 50-64 year olds has significantly increased since 1993 and is much higher than lifetime use in adults aged over 65. The study also found that drug use in inner London was higher than the overall UK average.

The study analyzed data on illicit drug use from two household surveys*. The most recent national survey included 2,009 people aged 65 and 1,827 people aged 55-65. The inner London survey included 284 and 176 people in these respective age groups

A group of proteins, known as sirtuins (we, mammals, have seven of these), has been thought to play a role in the aging process. However, recently, the effects of one of these proteins on aging has been challenged, leading to questions concerning the role of the whole protein group (see this Nature News article for some background).

Now, however, a new study, also in Nature, has shown that one of the sirtuins (SIRT6) does have an effect on the lifespan of mammals (in this case, mice). In the design of their experiments, the authors were well aware of the controversy surrounding the proteins. From the article:

You know it's true.  It's common sense.  Continue to exercise and you will have a better life. Muscle mass will decrease as you age unless you stop it but 12 weeks of training geared towards improving muscular power in older people were shown to be highly effective for improving their functional capacity and quality of life, according to studies carried out by the Biomechanics and Physiology of Movement research group at the Public University of Navarre.

Telomeres, regions of repetitive DNA, capping the end of chromosomes, protect said chromosomes from deterioration during subsequent cell divisions, and are thought to play an important role in the aging process. As such, many people believe/hope that preventing this deterioration from happening might mitigate the effects of aging (although aging is a very complex process, with, as of yet, many gaps in the understanding of it). The telomeres, however, appear to play a role of some importance. The discovery of telomerase, an enzyme that replenishes the telomeres, even led to the Nobel Prize in Medicine in 2009 for its discoverers, Elizabeth H. Blackburn, Carol W. Greider and Jack W.

Sex helps in multiple ways, it seems.  New research presented at The Gerontological Society of America's meeting, based on 2004 General Social Surveys, found that the more often older married individuals engage in sexual activity, the more likely they are to be happy with their lives and marriages.

Based on the survey responses of 238 married individuals age 65 years or older, the research showed that frequency of sexual activity was a significant predictor of both general and marital happiness. The association even remained after accounting for factors such as age, gender, health status, and satisfaction with financial situation.

As we reach old age, our bodies undergo several changes. And not for the better. More and more people are beginning to wonder whether we can do something about this. A lot of research is going on to uncover the mechanisms of aging, which should give us a better understanding of the origin of the changes that occur. Some claim that with this understanding comes the increasing possibility that we will actually be able to do something about it.