Dementia: Education, language skills may reverse cognitive decline

• Dementia is a syndrome that severely impedes thinking, communication, memory, and other cognitive functions.
• Contrary to popular opinion, mild cognitive impairment does not always lead to dementia.
• In fact, an examination of the long-spanning Nun Study links high education levels with decreases in mild cognitive impairment.
• This study also found that advanced language skills may help preserve cognitive function in older people.

Over 55 million people live with dementia globally, with almost 10 million new cases every year. It is the seventh leading cause of death and a major cause of disability among older individuals.

To date, dementia has no cure.

Health experts characterize mild cognitive impairment (MCI) as a slight decline in mental function that does not limit most everyday activities. It is widely considered a precursor to eventual dementia.

However, a group of researchers from the United States, Canada, and China has uncovered more evidence to refute this.

Their recent analysis suggests that people with higher education may be up to twice as likely to recover from MCI.

Suzanne Tyas, Ph.D., professor in the School of Public Health Sciences at the University of Waterloo, was the lead author. She reported:

“Even after considering age and genetics — established risk factors for dementia — we found that higher levels of education more than doubled the chances that people with mild cognitive impairment would return to normal cognition [NC] instead of progressing to dementia.”

Tyas and her team also observed that reverse transitions — going from MCI back to typical — can occur more often than dementia onset in younger individuals with high academic achievement and language skills. These younger people also did not carry certain genetic risk factors for dementia.

This work appears in Neurology.

Exploring the Nun Study

The researchers reviewed assessments in the Nun Study, a long-term study involving highly educated, religious women aged 75 years and older.

The team estimated transition rates between typical cognition, mild cognitive impairment, and dementia.

They studied the effect of age and levels of apolipoprotein E (ApoE), a protein involved in metabolizing fats. ApoE is the strongest genetic risk factor for Alzheimer’s disease, the most common type of dementia.

Cognitive reserve

Yaakov Stern, Ph.D., is the Florence Irving Professor of Neuropsychology in the Departments of Neurology, Psychiatry, and Psychology, and at the Taub Institute for the Research on Alzheimer’s Disease and the Aging Brain at Columbia University, NY. He is also the chief of the Department of Neurology’s Cognitive Neuroscience Division.

Dr. Stern was not involved in the current study.

In an October 2021 podcast, Dr. Stern explained:

“The concept of cognitive reserve is focused on: given the amount of brain changes that people have — either age-related or disease-related — some people do better than others. So, some people can cope with those brain changes better than others […] Cognitive reserve is a process that allows people to cope better with brain change.”

Dr. Stern stated that, while cognitive reserve is not a measure, we can analyze proxies — indirect measures — of cognitive reserve.

Dr. Tyas and her co-authors considered such proxies in their study: education, high school grades, and written language skills.

Good grades pay off

Tyas and her team analyzed data on 619 participants. Of these individuals, 472 had a diagnosis of MCI.

Out of the 472 women the researchers studied, 143 reverted at least once to NC. Of these 143, 120 never developed dementia within 8 years.

Additionally, higher academic levels more than doubled the chance of recovery compared with severe cognitive decline.

And participants with higher English grades were more likely to regain typical mental function than those with lower grades. These grades reflected creativity in writing and mastery of complex grammar skills.

Reassurance for cognitive impairment

The current study shows that some people with MCI can improve without medical intervention.

It also suggests that cognitive reserve proxies, such as education levels and writing skills, might serve as predictors of cognitive well-being as people age.

The findings show that building academic skills early in life may substantially reduce the risk of dementia.

For women only?

This study only involved people of one gender with similar upbringings, education, and life experiences.

However, Stella Panos, Ph.D., sees this as a rare advantage. Dr. Panos is a neuropsychologist and director of neuropsychology for the Pacific Neuroscience Institute at Providence Saint John’s Health Center in Santa Monica, CA.

In an exclusive interview with Medical News Today, Dr. Panos commented:

“It’s really neat because you actually find a study that’s all women […] The nun studies have been remarkable because [they were] homogeneous, they were able to control for a variety of other things, and [the nuns] have the same healthy diet, same type of work they do, so in some ways that controls for extra noise.”

However, Dr. Panos acknowledged that dementia research should include more inclusive and diverse populations to help address persisting disparities in treatment.

The participants of the Nun Study are uniquely homogeneous in lifestyle and access to healthcare. They also had prospective scheduled assessments, which controls for and minimizes confounders that scientists would encounter in clinical populations.

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