Study Links Obesity and Dementia, Recommends MedDiet

New research from the University College of London (UCL) has found that weight man­age­ment could play an impor­tant role in low­er­ing the risk of devel­op­ing demen­tia.

Adhering to a healthy and bal­anced eat­ing plan, such as the Mediterranean diet, is one of the best ways to main­tain an opti­mum weight level and mit­i­gate the risks of devel­op­ing the brain dis­ease, one of the study’s lead authors said.

“In recent years adher­ence to a Mediterranean-style diet has received con­sid­er­able inter­est in assess­ing its poten­tial role in low­er­ing the risk of heart dis­ease, high cho­les­terol, obe­sity, type 2 dia­betes, hyper­ten­sion, can­cer and cere­brovas­cu­lar dis­eases, includ­ing demen­tia,” Dorina Cadar, a senior research fel­low spe­cial­iz­ing in demen­tia at UCL, told Olive Oil Times.

“We found that peo­ple who had a body mass index (BMI) in the obese range had a 31 per­cent higher risk of demen­tia than those with a BMI in the nor­mal range, inde­pen­dent of their age, edu­ca­tional sta­tus, mar­i­tal sta­tus, smok­ing, dia­betes, hyper­ten­sion and apolipopro­tein E4 car­rier sta­tus,” she added.

Apolipoprotein E is a pro­tein that assists with the metab­o­lism of fats in the body, with the E4 ver­sion being the most promi­nent known genetic risk fac­tor for late-onset spo­radic Alzheimer’s dis­ease.

Cadar led the obser­va­tional study, which began in 2002 and includes data from 6,582 peo­ple aged 50 years or older. Study par­tic­i­pants were mon­i­tored bien­ni­ally, and are still being observed.

The UCL research has been done in asso­ci­a­tion with the English Longitudinal Study of Aging.

“A well-bal­anced diet is an essen­tial ele­ment of a healthy lifestyle that may be a facil­i­tat­ing fac­tor in main­tain­ing an opti­mal weight and suc­cess­ful, healthy aging for mind, body and soul,” Cadar said.

“The Mediterranean diet tends to avoid the red meat and dairy prod­ucts that are the source of most sat­u­rated fats in the typ­i­cal Western diet and to embrace mod­est alco­hol con­sump­tion – mostly wine – gen­er­ally dur­ing meals,” she added.

Besides a well-bal­anced diet, the recent study also found other key com­po­nents in achiev­ing a nor­mal body mass index (BMI) were phys­i­cal exer­cise and reduced alco­hol con­sump­tion.

“I think it is essen­tial to con­sider all the healthy lifestyle behav­iors holis­ti­cally. A healthy diet is not enough if exer­cise is miss­ing from someone’s life,” Cadar said. ​“My hypoth­e­sis is that pos­i­tive lifestyle behav­iors such as non-smok­ing, being phys­i­cally active, choos­ing health­ier diets, drink­ing in mod­er­a­tion and low­er­ing stress may pro­tect our hearts and slow cog­ni­tive decline in later life.”

“The fact that the lifestyle behav­iors are mod­i­fi­able implies that encour­ag­ing a healthy lifestyle may pre­vent or ame­lio­rate under­ly­ing cere­brovas­cu­lar and car­dio­vas­cu­lar risk fac­tors that could also present a demen­tia risk,” she added.

Cadar said it is also pos­si­ble that the asso­ci­a­tion between obe­sity and demen­tia might be indi­rectly caused by other con­di­tions, such as high blood pres­sure and anti­cholin­er­gic treat­ments.

Anticholinergics block the action of acetyl­choline, a sub­stance that trans­mits mes­sages in the ner­vous sys­tem.

However, some recent stud­ies have found that obe­sity could be con­sid­ered a pro­tec­tive health fac­tor in older peo­ple.

“Although it has become evi­dent that excess body fat increases the risk of demen­tia through meta­bolic and vas­cu­lar path­ways, as pre­sented in our study, we also need to acknowl­edge that there are some con­flict­ing infor­ma­tion from pre­vi­ous stud­ies sug­gest­ing that the asso­ci­a­tion between obe­sity and demen­tia remains unclear or that obe­sity may even be a pro­tec­tive fac­tor for demen­tia among older indi­vid­u­als,” Cadar said.

She added that there could be a num­ber of expla­na­tions for this, with more research across life stages needed.

Cadar explained that when obe­sity is seen as pro­tec­tive in older peo­ple, it is gen­er­ally because those diag­nosed with demen­tia have lost weight prior to a diag­no­sis.

“Eating and drink­ing well are impor­tant for stay­ing healthy at any age,” she said. ​“A healthy diet is likely to improve a per­son’s qual­ity of life.”

Significantly, the UCL study found a gen­der dif­fer­ence in the risk of demen­tia asso­ci­ated with obe­sity.

“Interestingly, women with abdom­i­nal obe­sity (a high waist cir­cum­fer­ence) had a 39 per­cent increased risk of demen­tia com­pared with women with­out abdom­i­nal obe­sity, but this par­tic­u­lar asso­ci­a­tion was not found among the men,” Cadar said.

The find­ings of the study were pub­lished in the International Journal of Epidemiology.

At the time, Andrew Steptoe, a co-author of the study, said demen­tia is one of the major health chal­lenges of the 21^st cen­tury that could threaten suc­cess­ful aging. He added their find­ings sug­gest ris­ing obe­sity rates will exac­er­bate the prob­lem.

• International Journal of Epidemiology
• EurekAlert