Brain functioning is known to naturally decline as we age, and mild cognitive impairment (MCI) is a transitional state when small changes in memory and other mental abilities coexist with normal functioning.
Such declines in functions are often a warning sign of dementia – a term used to describe various different brain disorders that a progressive loss of brain functioning in common. Oxidative stress has been reported to be a contributing factor to this process.
New data published in the Journal of Nutritional Biochemistry indicates that increased intakes of EPA and DHA may decrease oxidative stress markers in elderly MCI patients.
“These observations, although not widely explored, are promising for the importance of EPA and DHA metabolism in modulating lipid peroxidation among cognitively impaired elderly patients,” wrote the researchers.
“Future investigations should provide a better understanding of the clinical significance of EPA and DHA levels, especially during the incorporative phase, and genetic susceptibility in elderly MCI patients.”
Data from 67 people with MCI was compared with data of 134 health elderly people. Omega-3 intakes were assessed using a food frequency questionnaire, and blood samples were taken to measures levels of lipid hydroperoxide, a marker of oxidative stress.
Results indicated that people with MCI had significantly higher LPO levels than the healthy control group.
In addition, higher DHA and EPA intakes were associated with significantly lower LPO levels in the MCI group, a result described by the researchers as “an important finding”.
“Omega-3 PUFA intake was found to be positively correlated with the cognitive function, particularly attention, short term memory and recall capabilities,” they wrote.
“Meanwhile, LPO concentrations were inversely associated with global cognitive function, attention, short-term memory and immediate and delayed learning.”
Commenting on the potential mechanisms, the researchers said these had not been well established, but one possibility was that DHA could accelerate the production of antioxidant enzymes, which subsequently activate the antioxidant defence system.
“This is an early study investigating the impact of omega-3 PUFA consumption on lipid peroxidation status among the elderly MCI patients, and it bridges a gap in the current research literature.”
Source: Journal of Nutritional Biochemistry
May 2013, Volume 24, Number 5, Pages 803-808, doi: 10.1016/j.jnutbio.2012.04.014
“The role of long chain omega-3 polyunsaturated fatty acids in reducing lipid peroxidation among elderly patients with mild cognitive impairment: a case-control study”
Authors: Lee LK, Shahar S, Rajab N, Yusoff NA, Jamal RA, Then SM.