Sat fats hamper brain function and memory: study

20-May-2012 - Last updated on 21-May-2012 at 14:33 GMT

Related tags Nutrition Cognition Saturated fat

The type of fat we consume could play an important role in how well our brains function as we age, say the researchers.

Consumption of saturated fats may be associated with decreases in memory and reductions in brain functioning, and could lead to an increased risk of Alzheimer’s disease, according to new research in women.

It has been long suggested that excessive consumption of ‘bad’ fats – such as saturated and trans fats – could be bad for heart health. But according to new research, consumption of saturated fat could also be associated with declines in overall cognitive functions and memory in women. In contrast, consumption of ‘good’ (mono-unsaturated) fats may be associated with better overall cognitive function and memory, suggest the US-based researchers.

Writing in the Annals of Neurology the research team analysed data from more than 6,000 women – finding that women over 65 who consumed the highest levels of saturated fats had worse overall cognitive functions than those who consumed the least.

"When looking at changes in cognitive function, what we found is that the total amount of fat intake did not really matter, but the type of fat did," explained study author Dr Olivia Okerek from the Brigham and Women's Hospital, Boston, Massachusetts, in the US.

Okereke said the findings “have significant public health implications," arguing that “substituting the good fat in place of the bad fat is a fairly simple dietary modification that could help prevent decline in memory."

The research noted that even subtle reductions in cognitive functioning can lead to an increased risk of developing more serious conditions, such as dementia and Alzheimer's disease.

Study details

The research studied data from the 40,000 strong Women's Health Study – focusing in on a subset group of 6,183 women, all over the age of 65.

The women all participated in three cognitive function tests, spaced out every two years. In addition the women filled out detailed food frequency surveys at the start of the study – prior to the cognitive testing.

Okereke and her team revealed that women who consumed the highest amounts of saturated fat had worse overall cognitive and verbal memory scores over the four years of testing, when compared to those who consumed the lowest amounts.

Women who ate the most of the monounsaturated fats had better patterns of cognitive scores over time, they said.

The researchers concluded that varying consumption levels of the major specific fat types, rather than total fat intake itself, appears to influence cognitive aging.

Source: Annals of Neurology
Published online ahead of print, doi: 10.1002/ana.23593
“Dietary fat types and 4-year cognitive change in community-dwelling older women”
Authors: O.I. Okereke, B.A. Rosner, D.H. Kim, J.H. Kang, N.R. Cook, et al

2 comments

Not necessarily, David Brown...

Posted by DA, 28 May 2012 - 15:29 GMT

WHI has been going on for over a decade, so at a minimum, this finding suggests that a diet lower in saturated fats, and higher in monounsaturated fats, has a real-time impact on mental health, irrespective of previous or present trans-fat intake.

In fact, the women with the higher mono- or poly-unsaturated fat intakes now would be more likely to have had a higher trans-fat intake in past (secondary to having eaten margarine that is now trans-fat free, or replacing it with oils).

That said, it's a weakness of the study that trans-fats weren't included in the questionnaires...and I agree, questionnaires are only so reliable. Still, as a middle-aged woman myself, I intend to stick with my Mediterranean diet -- high in mono- and poly-unsaturated fats, low in saturated fats.

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Saturated fats are beneficial

Posted by David Brown, 23 May 2012 - 13:28 GMT

Findings based on food questionnaires are not a reliable indicator of what is happening in the brain. Most likely the researchers were observing the effects of trans fats, for many years considered a "heart healthy" substitute for saturated fats. Saturated fats are beneficial to health if they are consumed in the context of adequate supportive nutrition. http://www.meandmydiabetes.com/2012/04/17/ron-krauss-saturated-fat-red-meat-it-depends/