Potential Neuroprotective Effects of Dietary Omega-3 Fatty Acids on Stress in Alzheimer's Disease.

BACKGROUND: A large number of individual potentially modifiable factors are associated with risk for Alzheimer's disease (AD). However, less is known about the interactions between the individual factors. METHODS: In order to begin to examine the relationship between a pair of factors, we performed a pilot study, surveying patients with AD and controls for stress exposure and dietary omega-3 fatty acid intake to explore their relationship for risk of AD. RESULTS: For individuals with the greatest stress exposure, omega-3 fatty acid intake was significantly greater in healthy controls than in AD patients. There was no difference among those with low stress exposure. CONCLUSIONS: These initial results begin to suggest that omega-3 fatty acids may mitigate AD risk in the setting of greater stress exposure. This will need to be examined with larger populations and other pairs of risk factors to better understand these important relationships. Examining how individual risk factors interact will ultimately be important for learning how to optimally decrease the risk of AD.

Pilot Study of the Effects of Paced Breathing on Measures of Convergent and Divergent Thinking.

BACKGROUND: The ability of the autonomic nervous system's stress response to impair aspects of cognitive flexibility is known. However, the ability to modulate the sympathetic response and improve these cognitive impairments via nonpharmacological intervention, such as paced breathing (PB), requires further investigation. OBJECTIVE: To better elucidate the effects of PB on cognition. METHOD: We employed a PB protocol in a total of 52 healthy men and women and measured performance on convergent and divergent cognitive tasks, perceived stress, and physiological measures (eg, blood pressure, heart rate). Participants attended two experimental sessions consisting of either PB or normal breathing followed by cognitive assessments including convergent (compound remote associate, anagram) and divergent (alternate use, fluency) tasks. Experiment 2 consisted of more difficult versions of cognitive tasks compared with Experiment 1. RESULTS: In Experiment 1, PB significantly reduced the female participants' systolic and diastolic blood pressure immediately after the breathing protocol without affecting their cognition. In Experiment 2, PB significantly reduced perceived stress immediately after the breathing protocol, regardless of sex. There was no effect on cognition in Experiment 2, but a correlation was observed between perceived stress change and anagram number solved change. CONCLUSION: While PB modulates sympathetic activity in females, there was a lack of improvement in cognitive flexibility performance. At least for a single trial of PB, cognitive flexibility did not improve.