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 Arizona State University, 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 tau protein.
Further, the study illustrates that choline deficiency in mice causes significant weight gain, and alterations in glucose metabolism, (which are tied to conditions such as diabetes), and deficits in motor skills.
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. “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.”
Ramon Velazquez led the new study on the importance of dietary choline for the brain and other organs. He is a researcher in the ASU-Banner Neurodegereative Disease Research Center.
The research highlights a constellation of physical and neurological changes linked to choline deficiency. Sufficient choline 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, Brussel sprouts and toast can help boost choline in these cases. Further, inexpensive, over-the-counter choline supplements are encouraged to ensure system-wide health and guard the brain from the effects of neurodegeneration.
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, ~90% of Americans are not meeting the recommendation levels and may not even be aware that dietary choline is required on a daily basis.
Despite decades of research and billions of dollars invested since the discovery of the devastating ailment over a century ago, there remains no therapy capable of slowing the advance of the illness. Yet, new research findings suggest that environmental and lifestyle changes, including adequate choline, may help protect the brain from Alzheimer’s disease as well as improving overall health.
Velazquez is joined on the study by co-lead authors Nikhil Dave and Jessica Judd. The work is highly interdisciplinary, including researchers from the ASU Biosciences Mass spectrometry facility, and the Translational Cardiovascular Research Center at the University of Arizona College of Medicine in Phoenix, AZ.
“This collaborative work, spanning multiple institutions and surveying the molecular processes of aging at the systems level, adds to the body of evidence produced around the importance of dietary choline in healthy aging,” said Nikhil Dave.
“What I found particularly compelling about this project was that multiple organs, whose malfunction can have implications for brain health, were negatively impacted by a choline deficient diet,” said Jessica Judd.
The research appears in the current issue of the journal Aging Cell.