4. Discussion
cognitive impairments, Alzheimer’s disease progress [
RECRUITMENT
The purpose of our study was to explore the effect of 12-week daily consumption of flaxseed oil containing 2.2 g of ALA on various cognitive functions in healthy older adults without cognitive impairments, living in the community. The results of this study showed that consumption of flaxseed oil, which is high in ALA contents, improves cognitive function in healthy older adults. In particular, the results indicated positive improvements in the verbal fluency performance. While vocabulary and other language functions are thought to remain relatively unchanged with age, verbal fluency is known to decline with age and may interfere with conversation with others. In this study, verbal fluency performance was assessed as part of the FAB, which evaluates comprehensive executive function of frontal lobe function. The executive function is a higher-level function of the verbal fluency task [ALA is the most commonly consumed PUFA in Japan, with a median PUFA intake of 2.09 g/day for men and 1.83 g/day for women aged 75 years and older [Compliance with the intake of the test substance was high during the period of this study, which may have had a positive effect on cognitive function. One of the factors that contributed to maintaining high compliance was the use of pouch containers. The pouch container was light-shielding and had the advantage of being packaged in single servings, which could be left on the table and carried on the go, making it suitable for preventing forgotten intake and maintaining quality. According to the subjects, the oil itself was tasteless, odorless, easy to use, and compatible with meals, so it had the same level of usability as salt and pepper in a meal. We believe that in this study, we were also able to create a mechanism to encourage continued intake.While the results of this study are encouraging, some limitations should be mentioned. Ideally, the recruitment of subjects should be unbiased to the general public when targeting community-dwelling older adults, but the recruitment was limited in some areas to newspaper readers, as opposed to internet users, because newspapers were used for this recruitment. It is also possible that the subjects may have been biased, as those with a particular interest in health, for example those who perceive a benefit from cognitive function tests, may have participated. Primary care centers and family physicians and researchers properly selecting the group of participants is more appropriate. To increase the generalizability of the study’s findings, it is necessary to diversify the target population in future studies. Various races and cultures also need to be considered. Second, although this study was exploratory in nature and subjects were asked to consume the test product daily in order to test its efficacy, the frequency, amount, and duration of consumption should be considered to accommodate a variety of dietary habits. Furthermore, since the effect on verbal fluency detected in this study was only detected using one item, a subscale of the FAB, it is necessary to use more specialized indexes related to verbal fluency in order to establish further evidence, and to increase the sample size, as this experiment is still at the preliminary research stage.Regarding the impact of the results of this study, the importance of maintaining and even extending one’s verbal fluency capacity is one of the most important functionalities for older adults to age healthily. Many people, and the general public are unaware that some cognitive functions do not decline with age. Even the elderly, if they learn, should be able to increase their knowledge and vocabulary, help social interactions with others, and possibly form societal roles. In this context, if ALA intake can support verbal fluency even with increasing age, which is important for communication with others, it could promote social participation among older adults.In summary, this RCT, evaluating the functionality of daily consumption of flaxseed oil containing 2.2 g of ALA, improved verbal fluency in healthy individuals aged between 65 to 80 years, with no abnormalities in cognitive function, despite declines with age. Since the improvement in verbal fluency is significant in cognitive health, as it is one of the factors of Alzheimer’s disease progress [