New study for aging adults: egg intake associated with slower rate of memory decline
By 2030, one in five Americans will be aged 65 years and older, and for some of these aging adults, cognitive and memory issues can impact their day-to-day functioning and quality of life.1 There is growing interest in the possible role of healthy eating to protect against later cognitive impairment, and new data continue to support eggs as an important food to help support healthy aging.
A recent study supported by the American Egg Board found that consuming even limited amounts of eggs (about 1 egg per week) was linked to slower memory decline later in life compared to consuming no eggs.2 While more investigations are needed to evaluate if higher egg consumption may have a stronger impact, these data support an important role for eggs as part of the diet for older adults.
This new study evaluated data from 470 participants 50 years and older in the Adventist Health Study-2 to examine if egg intake levels predict the rate of memory decline. Egg consumption was divided into low (about half an egg), intermediate (half to 1 ½ eggs), and high (about two or more eggs). The low egg intake group had the largest rate of memory decline over time, and while there was no difference detected at age 50 or 60, lower memory performance was observed at age 70 and 80. Over time, the intermediate egg group had significantly lower rate of decline in memory performance compared to the low egg intake group. In other words, even a very small amount of egg included in the diet (as little as ½ to 1 egg per week) was associated with a beneficial impact on memory.
This study is unique not only because it evaluated memory over time (instead of just one point in time), but also because it evaluated the impact of eggs alone, with adjustment for other foods in the diet. More studies are needed to evaluate if higher egg consumption can have a stronger impact on maintaining cognitive function over time in aging adults. Further, while the large number of participants in this cohort helps to establish relationships, intervention trials are needed to establish causality.
The American Heart Association recommends up to 2 eggs per day for healthy (normocholesterolemic) older adults within a healthy dietary pattern.3 Eggs have a unique nutrient package that may be especially beneficial to aging adults, who generally have lower calorie requirements but increased nutrient needs.4 Eggs are a good source of high-quality protein and an excellent source of vitamin B12, as well as nutrients that are underconsumed by the entire population including choline (25% DV in a large egg) and vitamin D (6% DV in a large egg). Finally, the 252 mcg lutein + zeaxanthin give the yolk its yellow color. These carotenoids accumulate in the macula of the eye and have been associated with reduced risk of age-related macular degeneration.5
Centers for Diesease Control and Prevention. Chronic Diseases and Cognitive Decline — A Public Health Issue. 2020; Available from: https://www.cdc.gov/aging/publications/chronic-diseases-brief.html.
Lee, G.J., et al., Egg intake moderates the rate of memory decline in healthy older adults. Journal of Nutritional Science, 2021. 10: p. e79.
Carson, J.A.S., et al., Dietary Cholesterol and Cardiovascular Risk: A Science Advisory From the American Heart Association. Circulation, 2019: p. Cir0000000000000743
U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2020-2025 Dietary Guidelines for Americans. 2020; Available from: https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf.
Mares, J., Lutein and Zeaxanthin Isomers in Eye Health and Disease. Annu Rev Nutr, 2016. 36: p. 571-602.