OBSERVATIONAL AND ECOLOGICAL STUDIES OF DIETARY ADVANCED GLYCATION END PRODUCTS IN NATIONAL DIETS AND ALZHEIMER’S DISEASE INCIDENCE AND PREVALENCE.

After careful reading of the following abstracts obtained from a literature search of disease topic answer the questions provided. 

OBSERVATIONAL AND ECOLOGICAL STUDIES OF DIETARY ADVANCED GLYCATION END 

PRODUCTS IN NATIONAL DIETS AND ALZHEIMER’S DISEASE INCIDENCE AND 

PREVALENCE.

Perrone L1, Grant WB2.

Abstract

BACKGROUND:

Considerable evidence indicates that diet is an important risk-modifying factor for 

Alzheimer’s disease (AD). Evidence is also mounting that dietary advanced glycation end 

products (AGEs) are important risk factors for AD.

OBJECTIVE:

This study strives to determine whether estimated dietary AGEs estimated from 

national diets and epidemiological studies are associated with increased AD incidence.

METHODS:

We estimated values of dietary AGEs using values in a published paper. We estimated 

intake of dietary AGEs from the Washington Heights-Inwood Community Aging Project 

(WHICAP) 1992 and 1999 cohort studies, which investigated how the Mediterranean 

diet (MeDi) affected AD incidence. Further, AD prevalence data came from three 

ecological studies and included data from 11 countries for 1977-1993, seven developing 

countries for 1995-2005, and Japan for 1985-2008. The analysis used dietary AGE values 

from 20 years before the AD prevalence data.

RESULTS:

Meat was always the food with the largest amount of AGEs. Other foods with significant 

AGEs included fish, cheese, vegetables, and vegetable oil. High MeDi adherence results 

in lower meat and dairy intake, which possess high AGE content. By using two different 

models to extrapolate dietary AGE intake in the WHICAP 1992 and 1999 cohort studies, 

we showed that reduced dietary AGE significantly correlates with reduced AD incidence. 

For the ecological studies, estimates of dietary AGEs in the national diets corresponded 

well with AD prevalence data even though the cooking methods were not well known.

CONCLUSION:

Dietary AGEs appear to be important risk factors for AD.

J Alzheimers Dis. 2015;45(3):965-79. doi: 10.3233/JAD-140720.

1. What is the epidemiologic study design?

2. (a) Identify the exposure(s) of interest (independent variables) and (b) the 

outcome(s) (dependent variables) of interest in the study. 

3. (a) Suggest at least one possible bias (systematic error) that might be present in 

each study. Pay particular attention to how subjects were selected, and what 

information was gathered from them and how it was collected. (b) Explain 

specifically how this could introduce bias into the study.

4. (a) Suggest one or more possible confounding factors related to the data 

collected and analyzed in the study, and (b) explain how it/they might confound 

interpretation of the authors’ findings.

5. (a) Suggest at least one other epidemiologic study design that could address the 

same question(s), and (b) discuss the relative strengths and limitations of the 

other study design compared to the one actually used.