Remember when health advice was to limit egg consumption, that they had too much cholesterol, and to only eat egg whites? Well.... studies in the last decade have proven that advice as being 100% wrong for a number of reasons. It turns out that eggs are a great source of a number of nutrients (e.g., choline) needed for brain health and memory function.
A recent study found that frequent egg consumption by persons (mean age 59 years at the start of the study) lowers the risk of developing Alzheimer's disease (AD). The researchers found that there was a 27% decreased risk of developing Alzheimer's disease among persons who ate at least 5 eggs a week, but even eating fewer eggs was beneficial. The participants were followed for 15 years.
Other studies have also found a decreased risk of AD in persons eating eggs frequently - with one study finding that more than one egg consumed per week reduced the risk of developing AD up to 47%.
Some key nutrients necessary for brain health that are provided by eggs are: choline, the carotenoids lutein and zeaxanthin, tryptophan, phospholipids, and an omega-3 fat known as DHA (docosahexaenoic acid). The researchers viewed the nutrients in eggs as being "neuroprotective" (protecting neurological function).
From Medical Xpress: Egg consumption associated with a lower risk of Alzheimer's disease
Consumption of eggs is associated with a lower risk of being diagnosed with Alzheimer's disease for those 65 years and older, according to researchers at Loma Linda University Health. Eating one egg per day for at least five days a week reduces the risk of Alzheimer's by up to 27%, researchers found.
"Compared to never eating eggs, eating at least five eggs per week can decrease risk of Alzheimer's," said Joan Sabaté, MD, DrPH, a professor at Loma Linda University School of Public Health and the study's principal investigator.
Even less frequent consumption of eggs significantly reduced the risk of Alzheimer's. Researchers found that eating eggs one to three times per month had a 17% decrease in risk, while eating eggs two to four times per week had a 20% decrease in risk, Sabaté said.
Eggs are known to be a source of key nutrients that support brain health, Sabaté said. Eggs provide choline, a precursor to acetylcholine and phosphatidylcholine, both of which are critical for memory and synaptic function, the study stated.
Eggs also contain lutein and zeaxanthin—carotenoids that accumulate in brain tissue and are associated with improved cognitive performance and reduced oxidative stress. Eggs also contain key omega-3 fatty acids, and yolks are particularly rich in phospholipids, which constitute nearly 30% of total egg lipids and are essential for neurotransmitter receptor function.
Researchers said they studied the consumption of eggs in visible ways—such as eating eggs in various forms, like scrambled, fried, boiled, etc.—and hidden ways, such as eggs included in baked goods and packaged foods.
The cases of Alzheimer's disease in the Adventist Health Study 2 cohort were diagnosed by physicians, according to Medicare records, among the study population of 40,000 subjects. Eligibility was determined using the Medicare Master Beneficiary Summary Files. The average follow-up period was 15.3 years.
The team emphasized that moderate egg consumption should be part of a balanced diet.