Accord­ing to a new study, the pop­u­la­tion with Alzheimer’s Dis­ease in the US will triple by 2050: from 4.7 mil­lions in 2010 to 13.8 mil­lions. This empha­sizes the urgent need for more research to find pre­ven­tive mea­sures, and for more enlight­ened pub­lic health ini­tia­tives and indi­vid­ual lifestyles designed to decrease demen­tia risks and delay onset of symptoms.

Between 1993 and 2011, researchers fol­lowed more than 10,000 indi­vid­u­als 65 and older. Par­tic­i­pants were inter­viewed and assessed for demen­tia every three years. Age, race and level of edu­ca­tion of the par­tic­i­pants as well as US death rates, edu­ca­tion and pop­u­la­tion esti­mates from the US Cen­sus Bureau were used in the analysis.

Researchers found that in 2050 the num­ber of peo­ple diag­nosed with Alzheimer’s would likely be 13.8 mil­lions, with 7 mil­lions over the age of 85. This is 3 times the num­bers of 2010: 4.7 mil­lions peo­ple diag­nosed, with 1.8 mil­lion over the age of 85. This increase can be explained by the aging Baby Boomer gen­er­a­tion. Indeed, the risk of Alzheimer’s dis­ease is high­est in those over age 85. In 2050, the youngest baby boomers will be 86.

As one of the authors of the study points out, these num­bers empha­size the urgent need for more research to find treat­ments and pre­ven­tive strate­gies. Addi­tion­ally, we need enlight­ened pub­lic health ini­tia­tives and indi­vid­ual lifestyle deci­sions designed to pro­long cog­ni­tive vital­ity, delay­ing the onset of Alzheimer’s related symptoms.

The best study so far that looked at what may help pre­vent Alzheimer’s and/ or delay cog­ni­tive decline is a 2010 meta-analysis con­ducted by the NIH. It ana­lyzed the results of 25 review stud­ies and 250 sin­gle stud­ies to under­stand which fac­tors were asso­ci­ated with decreased risks of Alzheimer’s dis­ease and cog­ni­tive decline. Only high-quality stud­ies were included in the analy­sis, which makes its results quite reli­able. The analy­sis looked at sev­eral fac­tors and inter­ven­tions at the same time (the Mediter­ranean diet, omega-3s, dia­betes, drugs, phys­i­cal exer­cise, cog­ni­tive engage­ment, etc.), which allowed to com­pare and eval­u­ate the effects of each.

The NIH analy­sis iden­ti­fied six fac­tors asso­ci­ated with both Alzheimer’s dis­ease and cog­ni­tive decline:

• Four fac­tors were asso­ci­ated with increased risks: hav­ing dia­betes, hav­ing the APOE e4 gene, smok­ing and suf­fer­ing from depression.
• Two fac­tors were asso­ci­ated with decreased risks: being phys­i­cally active and being cog­ni­tively active.

Of note, the authors of the analy­sis pointed out that other fac­tors may also be asso­ci­ated with decreased risks, but could not be strongly iden­ti­fied because of the lim­ited avail­able evidence.

In sum, there may be ways to change the num­bers and decrease our risks of devel­op­ing Alzheimer’s dis­ease and expe­ri­enc­ing cog­ni­tive decline. Most of all, we need to exer­cise more, both our body and brain. This brings a wealth of ben­e­fits, includ­ing increas­ing our so-called brain reserve — that is the num­ber of con­nec­tions and neu­rons we have avail­able to make our brain more resilient to damage.

The best reg­i­men in terms of phys­i­cal activ­ity is to prac­tice aer­o­bic exer­cise at least 3 times a week for at least 30 min­utes. A recent study high­lighted that walk­ing at least 5 or 6 miles per week can pos­i­tively impact brain vol­ume in healthy peo­ple (see Erik­son et al., 2010) and extend such find­ing to indi­vid­u­als suf­fer­ing from cog­ni­tive impair­ment. Aer­o­bic exer­cise seems to bet­ter vas­cu­lar health by increas­ing cere­bral blood flow. It also helps cre­ate and strengthen con­nec­tions between neu­rons (hence the increased brain vol­ume or the reduced atro­phy), by trig­ger­ing the increased release of growth fac­tors such as brain-derived neu­rotrophic fac­tor (BDNF).

The best reg­i­men in terms of men­tal activ­ity is to stim­u­late the brain through var­ied and chal­leng­ing activ­i­ties. These activ­i­ties have to be var­ied because we need to stim­u­late all brain func­tions: mem­ory, lan­guage but also spa­tial skills, atten­tion, social skills, etc. They also have to be chal­leng­ing because it is only through atten­tion, chal­lenge and learn­ing that con­nec­tions in the brain can be cre­ated and strengthened.

Researchers are actively look­ing for the cause of Alzheimer’s dis­ease in the hope to find cura­tive and pre­ven­tive treat­ments tar­get­ing the under­ly­ing pathol­ogy. As indi­vid­u­als, our best bet so far to decrease risks of demen­tia and cog­ni­tive decline is to include good amounts of phys­i­cal exer­cise and men­tal chal­lenge in our lifestyle, and to reduce those iden­ti­fied risk fac­tors we have influ­ence over (dia­betes, smok­ing, depression).

Ref­er­ences

• Hebert, L. et al. (2013). Alzheimer dis­ease in the United States (2010–2050) esti­mated using the 2010 cen­sus. Neu­rol­ogy, Pub­lished online before print Feb­ru­ary 6, 2013, doi: 10.1212/WNL.0b013e31828726f5
• Raji et al. (2012) Walk­ing Slows Pro­gres­sion of Alzheimer’s. Annual meet­ing of the Radi­o­log­i­cal Soci­ety of North Amer­ica (RSNA).
• Williams, J. et al. (2010). Pre­vent­ing Alzheimer’s Dis­ease and Cog­ni­tive Decline. NIH Evi­dence Report. Evi­dence Reports/Technology Assess­ments, No. 193.

— This arti­cle was writ­ten by Pas­cale Mich­e­lon, PhD. Dr. Mich­e­lon was a Research Sci­en­tist at Wash­ing­ton Uni­ver­sity in Saint Louis, where she is now an Adjunct Fac­ulty. She teaches mem­ory work­shops in the St Louis area, and con­tributes to SharpBrains.com as the Research Man­ager for The Sharp­Brains Guide to Brain Fit­ness.

Related arti­cles:

• Build Your Cog­ni­tive Reserve: An Inter­view with Dr. Yaakov Stern
• Brain Plas­tic­ity: How learn­ing changes your brain
• Phys­i­cal Exer­cise and Brain Health,
• Does cog­ni­tive train­ing work? (For Whom? For What?)

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