More than 10,000 individuals turn 65 every day. In fact, the proportion of those over the age of 65 is projected to triple from 11% in 1950 to more than 33% in 2050 (Ubeda, Achon, & Varela-Moreiras, 2012). Thus, healthcare providers are challenged to explore strategies that may enhance wellbeing as individuals age. One area that has received considerable attention is the role that nutrition may play in promoting healthy aging. In fact, "nutrition is one of the major determinants of successful aging, defined as the ability to maintain three key elements: low risk of disease and disease -related disability, high mental and physical function, and active engagement in life" (Ubeda et al., 2012, p. S137). Of particular interest are those nutritional interventions that may delay the cognitive losses associated with aging. Dacks, Shineman, and Fillit (2013) indicate that "The development of a therapy to delay the onset of Alzheimer's disease by 5 years could decrease the number of diagnosed people from 5.6 million to 4 million in 2020 and lower the cost of care by almost $170 billion dollars by 2030" (p. 240).

What do we know about nutrition and mental function?

Although there are inherent limitations to research approaches that may be used to obtain nutritional data, there is a growing body of evidence to help healthcare providers appreciate the contribution of various nutritional options (Dacks et al., 2013). One nutritional option is ingestion of long-chain n-3 polyunsaturated fatty acids (n-3 LC-PUFA). Docosahexenoic acid (DHA) and eicosapentaenoic acid are the primary n-3 LC-PUFA; DHA accumulates significantly in the brain and is considered to have a greater impact on brain function (Dacks et al., 2013). One of the best sources of these fatty acids is fish, especially salmon, mackerel, and sardines. Moreover, "levels of n-3 LC-PUFA vary depending on the specific seafood and its method of preparation" (Dacks et al., 2013, p. 241). There is evidence from epidemiologic studies that n-3 LC-PUFA may protect against age-related cognitive decline independent of dementia or Alzheimer's disease, but conflicting information obtained from RCTs exists.

Another consideration is nutritional pattern. "Prospective studies have shown that the Mediterranean diet is associated with slower cognitive decline and a reduced risk of progression" (Ubeda et al., 2012, p. S148). Ye et al. (2013) obtained similar findings in a sample of middle-aged and older Puerto Rican adults; participants had better cognitive functioning and less likelihood of cognitive impairment when they followed a Mediterranean diet. The Mediterranean diet may be effective because of olive oil, a key component of which is oleic acid, "recently shown to have a satiety factor, oleylethanolamide, which enhances memory consolidation without crossing the blood-brain barrier" (Ubeda et al., 2013, p. S148). The Mediterranean diet includes plant-based foods, fruits, and vegetables, replacing butter with olive oil, using less salt and more herbs and spices, eating fish several times a week, and reducing red meat consumption.

What can nurses do?

It is important for nurses to recognize that although evidence remains inconsistent about the effect of nutrition on cognitive functioning as individuals age, nurses can encourage patients to adopt and maintain a nutrition pattern such as the Mediterranean diet, associated with greater overall health benefits. Taking time to assess nutritional patterns can help address potential areas for intervention before cognitive decline occurs.

References