Arginine Could Slow Dementia Damage, Study Finds

Some research suggests that those already genetically predisposed to developing dementia could benefit from fish oil supplements. And another paper said that getting enough vitamin D in midlife could reduce risk, too.

Now, a study published in Neurochemistry International has found that an amino acid already present in many medications and supplements could target dementia before it has a chance to cause major damage.

In this research, arginine – an amino acid naturally found in fish, nuts, and meat, and which is commonly used in medications for heart conditions and erectile dysfunction – appeared to reduce the buildup of amyloid plaques in animal and in vitro trials.

Amyloid plaques are sticky bundles of abnormal protein fragments, the accumulation of which has long been associated with dementia.

Alzheimer’s, the UK’s most common form of dementia in the UK, is also linked to stringy proteins called tau tangles. Amyloid plaques and tau tangles have been compared to the “trigger and bullet” in the development of the condition.

In the latest research, scientists noticed that arginine seemed to stop amyloid plaques from clustering together to create that troublesome buildup during in vitro (cells in glass test tubes or petri dishes) trials.

They then tested whether this worked for fruit flies and mice. After administering carefully-titrated amounts of arginine to the creatures, they noticed that the amino acid both prevented plaque accumulation and reduced the harm caused by that buildup.

Excitingly, as we already use arginine in medications and supplements, we know it can be safe for humans.

Study author Professor Yoshitaka Nagai said: “Our study demonstrates that arginine can suppress [amyloid plaque] aggregation both in vitro and in vivo.

“What makes this finding exciting is that arginine is already known to be clinically safe and inexpensive, making it a highly promising candidate for repositioning as a therapeutic option for AD [Alzheimer’s disease].”

It doesn’t mean that any arginine supplement will work as well as the specific, carefully-calculated concentrations the scientists used in these animal trials, as the researchers note. (Additionally, animal trials don’t always map onto human health well).

But Professor Nagai said it could open an avenue for looking into the effects of the amino acid on human dementia risk.

“Our findings open up new possibilities for developing arginine-based strategies for neurodegenerative diseases caused by protein misfolding and aggregation,” the academic shared.

“Given its excellent safety profile and low cost, arginine could be rapidly translated to clinical trials for Alzheimer’s and potentially other related disorders.”