DO BRAIN STUDIES POINT THE WAY TO A 'LEARNING VACCINE'?

DO BRAIN STUDIES POINT THE WAY TO A 'LEARNING VACCINE'?

By PAUL DAVID NUSSBAUM

Perhaps the greatest challenge ahead for health and longevity will be to help people nurture, develop and maintain healthy brains across the lifespan. The United States has accomplished much regarding cardiovascular health. Americans have welcomed changes in diet, exercise and stress reduction to assist in slowing the rise of cardiac disease. Now would be a good time to launch a similar national agenda dedicated to the health of the human brain.

Recent research has produced a new understanding of proactive brain health, which has the potential to reduce risk for late-life neurodegenerative disease. One of the behaviors shown to contribute positively to brain health is learning, and a growing body of evidence suggests that learning is a health-promoting behavior that might limit development of neurodegenerative diseases late in life. If research continues to support this idea, the educational system and such ancillary arenas of knowledge as libraries and lifelong-learning programs might be recognized as wellness centers. Furthermore, I propose that the physiological and psychological aspects of learning actually represent a potential vaccination against late- life neurodegenerative diseases of the brain. Alzheimer's disease, which affects nearly 4 million Americans, is a classic example of such a disease. Much research is aimed at slowing and possibly curing the disease, yet little work is focused on lifestyle behaviors, such as learning, that might minimize the risk of developing Alzheimer's and other dementias.

RATS ENRICHED

In her book Magic Trees of the Mind (New York City: Dutton, 1998, written with science writer Janet Hopson), University of California, Berkeley, neuroscientist Marion Diamond describes experiments showing the positive relationship between an enriched environment (cages with toys and other rats) and brain development in rats. "The enriched rats had a thicker cerebral cortex than the rats [in impoverished environments]," Diamond found. Peter S. Eriksson and colleagues (Nature Medicine, April 1998) found that human brains, just like the rat brains studied by Diamond, have a similar capacity to regenerate neurons in the hippocampus. The hippocampus is the primary structure for learning.

Furthermore, multiple studies have discovered an inverse relationship between number of years of education and risk for Alzheimer's. This finding has been explored by several researchers such as Columbia University neuropsychologist Yaakov Stern, Harvard University's Marilyn Albert and others.

Taken together, these and other studies support the finding of a direct relationship between environmental factors and the integrity of the human brain. Ronald Kotulak, author of Inside the Brain (Kansas City, Mo.: Andrews McMeel, 1997), based on his Pulitzer Prizewinning series for the Chicago Tribune, has reported on findings by scientists at the University of California, Los Angeles (ucla), showing that autopsied brains of university graduates who remained mentally active had up to 40% more connective dendrites, or brain wiring, than the brains of high school dropouts. In his book Kotulak comments, "But education alone is no guarantee of a better brain, the ucla researchers found. Unless the brain is continuously challenged, it loses some of the connection that grew out of a college experience. The brains of university graduates who led mentally inactive lives had fewer connections than those of graduates who never stopped letting the light in." He quotes ucla neuroscientist Robert Jacobs: "The bottom line is that you have to use it or you lose it."

SNOWDON'S NUN STUDY

Despite the wonderful opportunities raised by the prospect of lifelong brain enrichment, the years of early human development may represent a critical time for a kind of inoculation against late-life dementia. In Aging With Grace (New York City: Bantam, 2001) University of Kentucky neurologist David Snowdon describes findings of the "Nun Study," his examination of 678 elderly Catholic sisters who were ages 75 to 106 when his research began in 1986. The sisters donated their brains for study post-mortem. Among Snowdon's most interesting findings was that the women's linguistic ability at around age 20 correlated significantly with the presence of autopsy- based neuropathological markers of Alzheimer's in their brains after death.

In the course of their research, Snowdon and colleagues discovered autobiographies that the nuns had been required to write at about age 22. The researchers compared the complexity of each nun's writing to her score on the Mini-Mental State Exam administered when the study participants had reached an average age of 80. Snowdon wrote, "Somehow, a one-page writing sample could, 58 years after pen was put to paper, strongly predict who would have cognitive problems." The key was in the "idea density" of the writing samples. Those whose sentence structures were complex at 22 showed no signs of dementia at 80. Although Snowdon admits in the book that "we do not know for sure" why this happens, he stresses that "the idea of brain density relates to two important learned skills: vocabulary and reading comprehension." Quite simply, one of his colleagues suggested, people should read to their children early in their lives.

Other recent work by John M. Starr and colleagues in Scotland (Age and Ageing, November 2000) supports the theory that higher early-childhood mental ability protects against late-life dementia. This research showed that, like Diamond's mentally impoverished rodents displaying minimal brain development, children raised in poverty without resources or adequate mental stimulation are more likely than others to incur dementia later in life.

Complementing the studies demonstrating the positive effects of maintaining mental stimulation from an enriched environment, Shari S. Bassuk and colleagues at the Harvard School of Public Health published a study involving 2,812 older participants (Annals of Internal Medicine, Aug. 3, 1999) that demonstrated a relationship between social disengagement and cognitive decline in community-dwelling elders.

PROACTIVE STEPS

In his new book, The Aging Brain (New York City: Columbia University Press, 2001), Lawrence Whalley of the University of Aberdeen, Scotland, notes the alternative views among scientists about environmental effects of brain development. He explains that some researchers have developed "elegant mathematical models" to demonstrate links between unhealthy lifestyles, many associated with poverty, and chronic disease or premature death. Others, he continues, take a more positive approach. They surmise that, looking beyond the degenerative effects of negative behaviors, there are compensatory or protective factors in healthier lifestyles "that may reduce risk" for dementia, stroke and other chronic afflictions.

Whalley says that it remains unknown whether people can take proactive steps to guard against late-life neurological illness, but I would like to propose that the evidence for doing so is compelling enough to begin taking action now toward implementing practical brain-health promotion strategies. I am currently writing a book regarding such applications to be published by the American Psychological Association in late 2002. At present, I believe that active learning--lifelong mental stimulation--appears to offer a "vaccination" against neurodegeneration. The key principles for this vaccination are presented below.

INGREDIENTS OF THE LEARNING VACCINE

Following are the eight ingredients of the learning vaccine to protect human beings from chronic brain diseases in old age:

Learning, as a physiological and psychological event, must now be considered a health-promoting behavior.
Language ability seems to represent a far greater asset to the human brain than previously considered. Davis Snowdon's findings reported in Aging With Grace (New York City: Bantam, 2001) supports the significant value of early linguistic acumen, suggesting that it may forestall Alzheimer's disease--an illness unique to human beings. Snowden suggests reading to children at the earliest ages. Linda P. Acredolo, a psychologist at the University of California, Davis, has reported in numerous academic articles and books that teaching American Sign Language (ASL) to hearing babies results in increased IQ scores two years later. ASL can be taught to children before they are able to speak in order to nurture their language neural systems.
The learning vaccine should be a national priority, initiated early in life and supported throughout the lifespan. The U.S. educational system ought to be recast away from its emphasis on schools as places to receive diplomas and toward recognition of schools as wellness centers for neuronal development.
A team of teachers, neuroscientists, language specialists and related professionals should craft a brain-development curriculum in each school system. Schools should have ready access to advanced neuroimaging procedures for use in measuring students' brain responses to learning approaches and curriculum design.
Brain health mandates a lifespan approach. There is no artificial age threshold. We must reinforce a continuity of learning opportunities, and lifelong learning should be supported and reinforced on a national level. Existing lifelong learning programs could be enhanced, if research demonstrates that adult education enhances health and reduces neurodegenerative disease.
The brain requires environmental enrichment at any age. Approached from a health and wellness perspective, increased social integration of elders is indicated. Customary ways of thinking of retirement as a time of leisure tend to work against brain enrichment. I would argue for retiring this idea of retirement.
The United States adheres to invalid age thresholds for outdated social policies aimed only at those above age 60 or 65. It would be wise to implement a 21st-century policy focused on lifelong health and mental health promotion.
Learning is a significant life practice for overall health and brain wellness. It should be regarded as a standard part of any existing health-promotion program in this country. Ways should be developed to subsidize learning across the lifespan through the educational, employment--and even healthcare--systems, with specific curricula developed and implemented to complement the progressive development of the human brain. Outcome measures could be established, such as the reduction in healthcare utilization for dementia care late in life.

--Paul David Nussbaum is a clinical neuropsychologist and adjunct professor at the University of Pittsburgh School of Medicine. The author of many publications, he is now writing Neural Plasticity and Aging, to be published by the American Psychological Association. He is on the advisory committee of the American Society on Aging's MindAlert program, which disseminates resources on aging and mental fitness. For more information about the program visit www.mind alert.org. Nussbaum has been selected to deliver the MindAlert lecture at the National Council on the Aging-ASA Joint Conference in Denver, April 47.

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