GOT CHOLINE?
You may never have heard of choline. I hadn’t. But now I see articles on it popping up and found that choline is an essential nutrient—which means it’s a vital ingredient for human health. (Similar to B vitamins.) Choline is made in small amounts in the liver and found in such foods as meats, fish, poultry, nuts, beans, broccoli and eggs.
New research, led by scientists at Arizona State University (ASU) suggests that lack of adequate choline is linked with profound changes in the brain associated with Alzheimer’s disease. Here are excerpts from the January 17, 2023 ASU online article, Study explores effects of dietary choline deficiency on neurologic, system-wide health:
Getting enough choline in your diet is crucial for protecting your body and brain against Alzheimer’s, other diseases
A new study explores how deficiency in dietary choline adversely affects the body and may be a missing piece in the puzzle of Alzheimer’s disease.
It’s estimated that more than 90% of Americans are not meeting the recommended daily intake of choline. The current research, conducted in mice, suggests that dietary choline deficiency can have profound negative effects on the heart, liver and other organs.
Lack of adequate choline is also linked with profound changes in the brain associated with Alzheimer’s disease. These include pathologies implicated in the development of two classic hallmarks of the illness: amyloid plaques, which aggregate in the intercellular spaces between neurons, and tau tangles, which condense within the bodies of neurons.
The new research, led by scientists at ASU, describes pathologies in normal mice deprived of dietary choline as well as choline-deficient transgenic mice, which already exhibit symptoms associated with the disease. In both cases, dietary choline deficiency results in liver damage, enlargement of the heart and neurologic alterations in the AD mice typically accompanying Alzheimer’s disease, including increased levels of plaque-forming amyloid-beta protein and disease-linked alterations in the tau protein.
Further, the study illustrates that the deficiency in mice causes significant weight gain, alterations in glucose metabolism, which are tied to conditions such as diabetes, and deficits in motor skills.
Growing Awareness of Choline’s Importance
In the case of humans, “it’s a twofold problem,” according to Ramon Velazquez, senior author of the study and assistant professor with the ASU-Banner Neurodegenerative Disease Research Center (NDRC) and ASU’s School of Life Sciences. “First, people don’t reach the adequate daily intake of choline established by the Institute of Medicine in 1998. And secondly, there is vast literature showing that the recommended daily intake amounts are not optimal for brain-related functions.”
The research highlights a constellation of physical and neurological changes linked to choline deficiency. A sufficient amount in the diet reduces levels of the amino acid homocysteine, which has been recognized as a neurotoxin contributing to neurodegeneration and is important for mediating functions such as learning and memory, through the production of acetylcholine.
The growing awareness of choline’s importance should encourage all adults to ensure proper choline intake. This is particularly true for those on plant-based diets, which may be low in naturally occurring choline, given that foods high in choline are eggs, meats and poultry.
Plant-based, choline-rich foods, including soybeans, Brussels sprouts and toast, can help boost it in these cases. Also, inexpensive, over-the-counter choline supplements are encouraged to ensure system wide health and guard the brain from the effects of neurodegeneration.
Brain-boosting nutrient
Choline is needed to produce acetylcholine, a neurotransmitter that plays an essential role in memory, muscle control and mood. Choline also builds cell membranes and helps regulate gene expression. The established recommendations set forth by the Institute of Medicine were based on evidence preventing fatty liver disease in men. New lines of evidence imply that the established recommended daily intake of dietary choline for adult women (425mg/day) and adult men (550mg/day) may not be optimal for proper brain health and cognition. Additionally, about 90% of Americans are not meeting the recommendation levels and may not even be aware that it is required on a daily basis.
Gathering storm
Alzheimer’s disease is the leading cause of dementia and the fifth leading cause of death among Americans aged 65 and older. Today, Alzheimer’s affects 6.5 million in the U.S. alone and is projected to strike close to 14 million Americans by 2060. By this time, the costs of managing Alzheimer’s are expected to exceed $20 trillion, threatening the healthcare infrastructure while causing immense suffering.
The new study highlights the effects of low dietary choline on the brain and other organs in mice. A low amount in the diet is associated with obesity, liver pathology and enlargement of the heart. Choline deficiency was also shown to be correlated with pathologies associated with Alzheimer’s disease, and the low-choline mice performed poorly in tests of motor skills.
Multifaceted effects
The new study examines mice at 3–12 months, or early-to-late adulthood, roughly equivalent to 20–60 years of age for humans. Translating these findings to humans, this implies that people who are predisposed to Alzheimer’s disease or in the throes of the illness should ensure they are getting enough choline.
The study also involved a detailed exploration of proteins in the hippocampus, an area of the brain acutely affected by Alzheimer’s disease, as well as proteins detected in blood. Dietary choline deficiency altered important hippocampal networks. These pathologies include disruption of pathways associated with microtubule function and postsynaptic membrane regulation — both essential for proper brain function. In blood, proteins produced in the liver that play a role in metabolic function were particularly dysregulated with the choline-deficient diet.
“Our work provides further support that dietary choline should be consumed on a daily basis given the need throughout the body,” Velazquez says.
Ultimately, controlled human clinical trials will be essential for establishing the effectiveness and appropriate dosages of choline, before encouraging lifelong supplementation. Nevertheless, the powerful new findings offer hope that choline may be one tool in the arsenal needed to defend the brain from neurodegeneration and age-related cognitive decline.