Low Saturated Fat, Low Sugar Diet Can Protect Against Development of Alzheimers


A good number of research studies have linked a healthful lifestyle – proper diet and daily exercise – with a reduction in the risk of Alzheimer’s disease. Self-management of chronic conditions such as insulin resistance, diabetes, obesity, high cholesterol and cardiovascular disease also contribute to a “pathological brain aging.” While many nutrition experts suggest the Mediterranean diet as the plan to adopt to protect the brain, studies of specific foods have not found conclusive evidence on Alzheimer’s risk, until now.

Researchers with the Veterans Affairs Puget Sound Health Care System in Seattle have found that following a low-saturated fat diet and a low-glycemic index diet appears to modulate the risk of developing dementia that proceeds to Alzheimer’s Disease. Unfortunately, however, the diet does not appear to protect those who are already experiencing mild cognitive impairment or MCI.

Adopt Diet Before Cognitive Issues Take Place for Best Results

Jennifer L. Bayer-Carter MS and colleagues evaluated the effects of diet in 20 older adults who were healthy and 29 older adults who had amnestic mild cognitive impairment (aMCI), memory problems that are considered a precursor to Alzheimer’s disease. The participants were randomized to receive either a high saturated fat/high glycemic index diet or a low-saturated fat/low glycemic index diet.

The glycemic index, or GI, is a measure of the effects of carbohydrates on blood sugar. Carbs that break down quickly during digestion and rapidly release glucose (sugar) into the bloodstream are considered HIGH GI foods. In general, a lower glycemic response usually equates to a lower insulin demand and improves blood glucose control.

During the four week trial, the researchers studied the participants’ performance on memory tests as well as their levels of certain biomarkers for Alzheimer’s disease such as insulin, cholesterol, blood glucose levels, blood lipid levels, and components of cerebrospinal fluid (CSF).

Read: Treating Vascular Risk Factors May Reduce Dementia Risk


Among the healthy participants, those who consumed a low saturated fat/low GI diet had decreased some CSF biomarkers of Alzheimer’s disease as well as total cholesterol levels. Both the healthy patients and those who had progressed to aMCI showed improved performance on delayed visual recall tests, but neither group showed positive association to scores on other cognitive measures.

Read: More Good Cholesterol Associated with Less Chance of Alzheimers

The findings indicate that “for healthy adults, the high saturated fat/high GI diet moved CSF biomarkers in a direction that may characterize a presymptomatic stage of AD,” explain the authors. In addition, the identification of changes caused by diet may also reveal important therapeutic targets in future studies.

As mentioned, one of the best diets for overall good health and prevention of disease is the Mediterranean diet, which focuses eating on fruits, vegetables, whole grains, and nuts; replacing red meats and other saturated fats with unsaturated fats and omega-3 fatty acids (such as fish); plus avoiding high-fat dairy, processed foods, and sugary/salty treats.

Journal References:
Jennifer L. Bayer-Carter; Pattie S. Green; et al. Diet Intervention and Cerebrospinal Fluid Biomarkers in Amnestic Mild Cognitive Impairment. Archives of Neurology, 2011; 68 (6): 743-752 DOI:10.1001/archneurol.2011.125

Yian Gu; Jeri W. Nieves; Yaakov Stern; Jose A. Luchsinger; Nikolaos Scarmeas. Food Combination and Alzheimer Disease Risk: A Protective Diet. Arch Neurol, 2010

JAMA and Archives Journals (2006, October 12). Mediterranean Diet Associated With Reduced Risk Of Alzheimer's Disease. ScienceDaily. Retrieved June 14, 2011, from http://www.sciencedaily.com-/releases/2006/10/061010022729.htm