Another Study on Diet and Alzheimer's Disease

A doctor friend of mine shared with me a study that correlated larger hippocampal volume with good dietary habits.  You will see from my earlier post of December 17 that I discussed a Finnish study of diet, and this new study referenced the Finnish study.  The new study is Effect of Diet on Hippocampal Volume in a Population at Risk for Alzheimer's Disease.  It found a strong correlation between scores on the Alternative Healthy Eating Index 2010 (AEHI) and hippocampal volume.

The "alternative" AEHI is an alternative to the earlier Healthy Eating Index.  The AEHI emphasizes low carb eating over low fat eating.  A Mediterranean diet gets you pretty close to the top of the AEHI, but maybe not so much with the earlier index.

This study caught my attention because hippocampal volume is an important biomarker for Alzheimer's disease.  My care team at Harborview in Seattle used it to diagnose my own Alzheimer's disease.  You will recall from Beating the Dementia Monster that an MRI in 2015 measured my hippocampal volume in the 36 percentile of the general population, but two 2017 MRIs found it at the one percentile.  The radiologist in the 2017 MRIs said that the decrease might be due to differences in technique, but, taken together with the changes in the size of my ventricles, even the 2015 reading was sufficient biomarker evidence for the diagnosis.  (Biomarker evidence must be taken together with cognitive testing evidence to produce a diagnosis of Alzheimer's disease.)

The researchers in the new study studied a cohort 459 British civil servants with an average age of 60 years.  Nineteen percent were female.  Subjects were evaluated every five years over an 11 year period.  They were followed with respect to diet and other possible confounding factors, such as physical activity.  (They didn't say "exercise."  Not sure what that means.)  Hippocampus volumes were measured by MRI once near the end of the study.  Volumes were compared between study subjects. 

The study drew from an earlier cohort of about 10,000 subjects that was selected in the 1985-1988 time frame.  The earlier cohort was used by the same researchers to study long-term outcomes with respect to cardiovascular disease.  The study explained little about the earlier study, but I speculate that the large cohort formed a rich population of subjects with similar characteristics who were already known to the researchers.  

The results were remarkable.  Each 8.7-point increase in the AEHI score (one standard deviation for you statistics nerds) correlated with an eye-popping 92.5 cc increase in hippocampal volume.  I want that kind of increase in my hippocampal volume.  Do I need to wait 11 years to get it?