NEW YORK (Reuters Health) – High intake of saturated and trans fats along with low intake of polyunsaturated fats is associated with cognitive decline in women with type 2 diabetes, according to an analysis of data from the Nurses’ Health Study (NHS).

Prior research has indicated that diabetics are at increased risk for cognitive impairment in late life. Whether there are any lifestyle factors that can be modified to reduce this risk, however, was unclear.

Dr. Elizabeth E. Devore, from Harvard Medical School, Boston, and colleagues hypothesized that by affecting glucose and lipid metabolism, dietary fat intake could influence cognitive changes in older adults with diabetes.

To investigate, the researchers assessed cognitive function in 1486 women with type 2 diabetes who were at least 70 years of age and were enrolled in the NHS. Cognitive function was assessed once from 1995 to 1999 and then again two years later. Dietary fat intake was recorded starting in 1980.

The findings are reported in the April issue of Diabetes Care.

The decline in the average score on six cognition tests was 0.15 standard units worse in women in the highest trans fat intake tertile than those in lowest tertile (p = 0.002). “This mean difference was comparable with the difference we find in women 7 years apart in age,” the investigators point out.

Substituting polyunsaturated fats for saturated and trans fats, by contrast, reduced cognitive decline, the findings indicate.

“Further research is needed to confirm these findings and explore additional strategies for maintaining cognitive health in diabetics — especially in women, who have a higher lifetime prevalence of both type 2 diabetes and cognitive impairments than men,” Dr. and colleagues conclude.

Reference:
Diabetes Care 2009;32:635-640.