“Dear Georgie, I’ve heard that MCTs (medium chain triglycerides) help improve brain function in older people? It really dramatically improved my grandmother’s mental function when her diet was switched…..do you know how this works?”
I’ll admit it. I had to look this one up! As far as fats and brain health go, much of what I’ve read has focused on the benefits of omega-3 fatty acids. DHA (docosahexaenoic acid) in particular has been implicated in have beneficial impacts on the the development and progression Alzheimer’s disease (1) but MCTs and Alzheimers? New to me!
What I found in reference to your query was really quite fascinating, and there is some research to support the usage of MCTs to assist brain function, particularly in age-related cognitive decline.
Brain cells run chiefly on glucose, but that’s not the whole story. They can and do use other fuels when needed, which is good news for you if you end up skipping lunch on hellish work days. Neurons can use lactate, glutamine, and ketone bodies from fat metabolism in addition to glucose. So when glucose isn’t readily available, alternative fuels take over.
There’s evidence that impaired glucose metabolism plays a role in Alzheimer’s disease. In fact, reduced glucose oxidation is the primary metabolic alteration seen in brains affected by mild cognitive impairment or Alzheimer’s disease (2). A decrease of 20-40% in glucose utilization has been reported, with glucose usage rates falling as cognitive decline progresses. Infusing glucose into the bloodstream directly has even been shown to enhance performance on several tests including orientation, word recognition and recall, narrative prose, and face recognition in subjects with Alzheimer’s disease (3). However, this isn’t desirable as a long term strategy, since the deleterious effects of high blood glucose cause other issues. But it looks like decreased fuel availability or usage might be part of the problem with the aging brain. Even with enough glucose on hand, something’s not quite right with it being taken up and used to fuel brain activity.
So providing one of those alternative fuels may help. That’s where MCTs can come in. Now, the triglycerides themselves don’t actually get used by the brain – but they are metabolized to beta-hydroxybutyrate, a ketone body which is readily used by neurons and may make up (partially or completely) for decreased utilization of glucose (4).
The Bottom Line: If you know someone affected by cognitive decline, including some coconut oil (a rich source of MCTs) might bring about some substantial improvements in their mental function and memory. And if you swap it in for longer-chain saturated fats like butter or cream, it shouldn’t cause any negative effects of blood lipids or increase cardiovascular risk.
Bonus Factoid 1: It’s not just for Alzheimer’s. Apparently the same ketones help provide some neuroprotection against Parkinsons’ disease (5).
Bonus Factoid 2: It’s not just for Grandma. MCTs will help keep your dog’s brain running better as well. (6)