Using diet to modulate Alzheimer’s disease
Researchers at the University of Washington School of Medicine, in Seattle, compared the effects of a high–saturated fat/high–glycemic index diet with a low–saturated fat/low–glycemic index diet on markers of Alzheimer disease and cognition in adults with mild cognitive impairment.
First, the details.
- 49 older adults (20 healthy and 29 with amnestic mild cognitive impairment) were assigned to a treatment group for 4 weeks.
- HIGH diet (fat, 45% [saturated fat, less than 25%]; carbohydrates, 35% – 40% [glycemic index, greater than 70]; and protein, 15% – 20%)
- LOW diet (fat, 25%; [saturated fat, less 7%]; carbohydrates, 55% – 60% [glycemic index, less than 55]; and protein, 15% – 20%)
- Cognitive tests, an oral glucose tolerance test, and lumbar puncture were conducted at before and during the fourth week of the diet.
- Cerebrospinal fluid concentrations of beta-amyloid (Abeta42 and Abeta40), tau protein, insulin, F2-isoprostanes, and apolipoprotein E, plasma lipids and insulin, and measures of cognition were measured.
And, the results.
- For the group with amnestic mild cognitive impairment:
- The LOW diet increased CSF Abeta42 concentrations, contrary to lowered CSF Abeta42 typically observed in Alzheimer disease.
- In healthy adults:
- The LOW diet decreased CSF Abeta42.
- The HIGH diet increased CSF Abeta42.
- CSF apolipoprotein E concentration:
- Increased by the LOW diet and decreased by the HIGH diet for both groups.
- More results
- The CSF insulin concentration increased with the LOW diet in the amnestic mild cognitive impairment group.
- The HIGH diet lowered the CSF insulin concentration for healthy adults.
- The HIGH diet increased and the LOW diet decreased plasma lipids, insulin, and CSF F2-isoprostane (marker for oxidative stress) concentrations.
- Delayed visual memory improved for both groups after completing 4 weeks of the LOW diet.
The bottom line?
The authors concluded, “Diet may be a powerful environmental factor that modulates Alzheimer disease risk through its effects on central nervous system concentrations of Abeta42, lipoproteins, oxidative stress, and insulin.
More about Abeta42 is here.
6/17/11 22:24 JR