Some researchers who are still drinking the mainstream “cholesterol Kool-Aid” got quite a surprise recently when they studied the effects of dietary cholesterol and egg consumption on brain health.
From the tone of their report, the clueless researchers apparently expected to find that eating more cholesterol and eggs would somehow be associated with negative effects on the brain.
Of course, they were wrong.
The researchers should have checked their food, metabolic, and nutritional biochemistry before forming their hypothesis. Egg yolks are loaded with cholesterol, essential fatty acids, and other healthy nutrients — such as carotenoids, which account for their bright yellow color.
These nutrients are essential to all cells in the body — especially brain and nerve cells.
Let’s take a closer look at this new research, along with another new study that shows specifically how the carotenoids in eggs and other foods have powerful brain benefits.
Investigating the cholesterol/cognitive function link
The first study investigated the association between cholesterol and egg consumption with Alzheimer’s disease, dementia, and cognitive performance.1
For an average of 22 years, the researchers followed 2,497 Finnish men between the ages of 42 and 60. All of these men were free of dementia at the beginning of the study. By the end of the study, 337 of the men had been diagnosed with dementia, and 266 were diagnosed with Alzheimer’s.
This study began during the mid-1980s — the same time period during which my colleagues and I recruited large cohorts of people to analyze dietary risk factors for chronic diseases as part of a U.S.-Finland health study at the National Institutes of Health.
In my early years at the NIH, I personally performed and published research with Finnish scientists on new techniques for assessing body weight and composition that were far better than falling back on the old, flawed body mass index (BMI).
Unfortunately, the NIH ultimately ignored our research, which is one of several reasons why the government’s nutritional data is so inadequate.
But I’m glad to see that Finnish researchers are still generating meaningful, relevant study results (especially when the findings are still surprising the mainstream).
Study finds eggs can actually make your memory better
One of the chief findings of this new study is that neither higher dietary cholesterol nor egg intake is associated with a higher risk of developing dementia or Alzheimer’s disease.
And, after overcoming their initial shock that eating eggs was not bad for you, the researchers further determined that egg consumption was actually associated with better memory.
Specifically, they discovered that the men who ate eggs performed better on neuro-psychological tests evaluating the frontal lobe of the brain and executive brain functioning (which includes skills like decision-making and verbal fluency).
Interestingly, these results held true even for a sub-group of the study participants who had a gene that affects cholesterol metabolism, and has also been associated with an increased risk of developing memory disorders.
Even when these genetically susceptible men increased their egg and dietary cholesterol intake, they had no higher risk of dementia or Alzheimer’s disease.
Why it’s safe — and even beneficial — to eat up to three eggs a day
The study participants with the highest dietary cholesterol intake consumed an average of 520 mg per day (the equivalent of almost three eggs). So not only should this level of cholesterol consumption be considered “safe,” but it’s also beneficial for your brain, according to this research.
Furthermore, the researchers concluded that eating just one egg per day, every day, could produce these positive results.
Of course, they laughingly considered one egg a day to be a “high intake,” but tell that to a chicken farmer, or to former U.S. Surgeon General C. Everett Koop (1917 – 2013), who I personally witnessed eating two or three eggs every morning. He remained as mentally keen and sharp as anyone I have ever known throughout his three different careers in health and medicine, and until his death at age 96.
Eggs also deliver a powerful dose of lutein
Another new study took a more comprehensive approach to diet, nutrition, and brain health — and also found that eggs yolks are good “brain food.”2
The researchers looked at foods that have higher contents of a carotenoid called lutein. This pigment is found in leafy greens, cruciferous vegetables such as broccoli…and egg yolks. Together with zeaxanthin, lutein is responsible for the yellow color of egg yolks.
As a young NIH research investigator, I helped lead research with the USDA Human Nutrition Research Lab that discovered the role of carotenoids in both the nutrient composition of foods and in human nutritional metabolism. While the National Cancer Institute was focused specifically on beta-carotene, without any real evidence, we found that the carotenoids of real importance in the diet and in human metabolism were actually ones nobody at the NIH had ever heard of — like lutein, lycopene, and even one called beta-cryptoxanthin. But the NIH instead chose to waste precious time and money chasing only beta-carotene.
Since then, there have been studies showing that lutein penetrates the blood-brain barrier and accumulates in the brain regions that are responsible for preserving healthy cognitive function during aging.
Specifically, lutein embeds itself in the membranes of brain cells, or neurons, where it appears to have neuro-protective effects as an antioxidant and/or anti-inflammatory factor, aiding in neuron-to-neuron cellular signaling. (I have also reported that lutein accumulates in the retina of the eye, which is also nerve-derived tissue, and is important for preservation of vision.)
Lutein helps you use your knowledge and skills longer
For the new study, researchers focused on portions of the temporal cortex of the brain. This region plays an important role in what is called “crystallized intelligence” — the ability to continue using knowledge and skills you’ve acquired over a lifetime.
Researchers asked 76 healthy men and women, ages 65 to 75, to solve problems and answer questions on a standard test of crystallized intelligence. They also collected blood samples from participants to measure their lutein levels, and conducted brain image studies to analyze the sizes of the different regions of the participants’ brains.
Those with higher lutein levels did better on the intelligence tests. And they also had more gray matter in regions of their temporal cortex lobes. Researchers concluded that this increased gray matter was the result of lutein, and was responsible for higher crystallized intelligence.
This new research provides more evidence that particular nutrients slow cognitive decline by influencing specific features of brain aging.
Why you need more than just plants in your diet
So what have we learned from these two studies? Well, first of all, the government is right to recommend eating leafy greens and cruciferous vegetables. Not only to fight chronic disease, but also to improve brain health. But it was all wrong, all along, when it came to avoiding eggs and dietary cholesterol.
You do need carotenoids like lutein in your diet. But for healthy brain function and to avoid Alzheimer’s disease and dementia, you also need nutrients — like cholesterol and essential fatty acids — that vegetables cannot provide.
As I have reported before, the drug-addled mainstream approach to dementia has become “fossilized” when it comes to preserving your “crystallized” memory. You can do a lot more without the ministrations of the mainstream medical minions.
And that includes eating eggs.
1“Association of dietary cholesterol and egg intakes with the risk of incident dementia or Alzheimer disease: the Kuopio Ischaemic Heart Disease Risk Factor Study.” Am J Clin Nutr. 2017 Feb;105(2):476-484.
2“Parahippocampal Cortex Mediates the Relationship between Lutein and Crystallized Intelligence in Healthy, Older Adults.” Front Aging Neurosci. 2016 Dec 6;8:297.