Unfortunately for the boomers, a recent study suggests that memory, reasoning and understanding can begin to decline from 45 years.

This finding contradicts the conventional wisdom that mental decline begins before age 60 the researchers added.


“Cognitive function in normal healthy adults begins to decline sooner than previously thought,” said study author Archana Singh-Manoux.

“The belief is that cognitive ability does not decline before age 60. We could show a robust cognitive decline in individuals 45 to 49 years,” Singh-Manoux said, research director of the Center for Research in Epidemiology and Population Health at INSERM Hospital Paul Brousse, Paris.

These findings must be made in the context of the relationship between cognitive function and dementia, Singh-Manoux said.

“Previous research shows that small differences in cognitive performance at a younger age predict larger differences in the risk of dementia later in life,” he said.

Understanding cognitive aging could allow early identification of those at risk of dementia, Singh-Manoux said.

The report appears in the January 5 issue of the BMJ.

For the study, Singh-Manoux and colleagues collected data on almost 5.200 men and 2,200 women who participated in the Whitehall II cohort study. The study, which began in 1985, followed British civil servants from 45 to 70 years of age.

We evaluated three times the cognitive function of participants in a period of ten years from 1997. The researchers tested memory, vocabulary, hearing and vision.

The Singh-Manoux group found that over time, scores of tests for memory skills, reasoning and vocabulary down. The decline was faster among older participants, they added.

Among men 45 to 49, the reasoning skills declined by almost four percent, and for 65 to 70, almost ten percent.

Among women, the decline in reasoning went to five percent for those with 45 to 49, and was about seven percent for those with 65 to 70, researchers found.

“Greater awareness of the fact that our cognitive state does not remain intact into old age may lead individuals to make changes in lifestyle and improve cardiovascular health, to reduce the risk of adverse cognitive outcomes in old age” said Singh-Manoux.

Research shows that “what is good for the heart is good for the head,” which makes having a healthy lifestyle is part of the delay of cognitive decline, he said.

Targeting patients who have risk factors for heart disease such as obesity, hypertension and high cholesterol may not only protect their hearts but also prevent dementia in old age, researchers said.

“Understanding the cognitive aging will be one of the great challenges of this century”, especially as people live longer, they said.

In addition, knowing when it is likely that cognitive decline starts in the treatment can help, because the sooner treatment begins, the more likely to be effective, the researchers noted.

Francine Grodstein, associate professor of medicine at Brigham and Women’s Hospital Boston and author of an accompanying editorial, said more research is needed on how to prevent early cognitive decline.

“If cognitive decline may begin at an earlier age, efforts to prevent it can also begin at this age,” he said.

“New research should focus on understanding the factors that may contribute to cognitive decline among younger people,” Grodstein said.

“This is consistent with what we have seen in other studies and cognitive changes that occur as we age,” said Heather M. Snyder, principal associate director of medical and scientific relations for the Alzheimer’s Association (Alzheimer’s Association).

These changes do not mean that all these people will develop Alzheimer’s or other dementia, noted Snyder. “It’s important to remember that the cognitive changes associated with age are very different from those associated with Alzheimer’s disease,” he said.

Although perhaps some of these people eventually develop Alzheimer’s, there is currently no way to tell who is at risk, lamented Snyder. “It is therefore important to further investigate the biological changes that occur in the early stages, it is difficult to [determine] the cognitive changes associated with Alzheimer’s,” he said.

Snyder noted that Alzheimer’s disease may begin 15 to 20 years before symptoms are apparent, which makes finding a biomarker is so important. “If there is therapy available, we can intervene at that time,” he said.