What Naked Mole Rats Can Teach Us About Alzheimer’s Disease

Yes, you read that title correctly. I’m talking about naked mole rats, the burrowing hairless rodents with a face only a mother could love. You might just know them for their strange appearance, but naked mole rats have fascinated scientists for decades due to their extreme longevity. They are by far the longest-lived rodent species, with a maximum lifespan of more than 30 years, compared to only 2 years for your typical mouse. They also are practically immune to cancer, for reasons we don’t entirely understand.

So what does this have to do with Alzheimer’s? Well, another one of the naked mole rat’s strange quirks is that it possesses extremely high levels of amyloid-beta, the toxic protein that is believed to cause Alzheimer’s disease. In humans, amyloid-beta aggregates into sticky plaques in the brain, which can cause a whole host of problems. Amazingly, naked mole rats have even higher amyloid-beta levels than 3xTg-AD mice, which are an Alzheimer’s mouse model genetically engineered to over-produce amyloid-beta. However, the amyloid-beta found in naked mole rats is less sticky and does not tend to form plaques, despite being just as toxic to neurons. Additionally, while amyloid-beta in humans increases as we age, its levels remain constant in naked mole rats. This suggests that amyloid-beta could be harmless (or possibly even beneficial) when it’s present in its non-sticky form. A 2015 report also found that the brains of old naked mole rats look more like what you’d expect to see in a baby animal’s brain, with high numbers of new neurons constantly being formed.

The fact that naked mole rats possess exceedingly high levels of amyloid-beta throughout their lifespan, yet do not develop Alzheimer’s disease, makes them an extremely useful research subject. If scientists can unravel what makes these rodents so resistant to amyloid-beta, we might be able to apply this finding to humans in the form of a treatment for Alzheimer’s disease. So even though they may not be the cutest creatures, you might someday have the naked mole rat to thank for keeping your brain healthy!

Here are some more fun facts about naked mole rats!

• They have no sense of pain and are nearly blind.
• They are almost entirely cold-blooded, relying on their environment to regulate body temperature.
• In order to live underground, naked mole rats have evolved very low rates of breathing and metabolism, and can survive for up to 5 hours in low-oxygen conditions.
• They live in eusocial colonies similar to ants or bees, with a single queen that produces all the colony’s offspring.

 

Enjoy this post? Help it to grow by sharing on social media!
Want more? Follow AlzScience via email, Facebook, or Twitter!

Alzheimer’s and Coconut Oil: What Does the Science Say?

Coconut oil has certainly been a health craze over the past few years, with people claiming it can do everything from whiten your teeth to promote weight loss. Recently I’ve had several readers ask me to look into claims that coconut oil could treat or cure Alzheimer’s disease. So let’s dive into the details and figure out whether coconut oil could really be healthy for your brain.

Ketones and Where to Find Them

Most explanations for coconut oil’s supposed miraculous properties focus on its high ketone content. The “ketogenic diet,” sometimes shortened to the “keto diet,” has recently seen a surge in popularity. The idea behind the keto diet is to shift your body’s primary energy source from carbohydrates to ketones. Normally, the carbs in the food you eat are converted into glucose (aka sugar), which your body then uses for energy. However, when your carb intake is very low, a backup mechanisms called ketogenesis kicks in. Your liver starts breaking down fat into ketones, another type of energy-storing molecule similar to glucose but with a different chemical structure.

To induce ketosis, people cut back on their intake of carbs to less than 20 grams per day (equivalent to half a cup of pasta or one slice of bread), compared to the 225 to 335 grams that most people consume daily. To compensate for the reduced calories, they also increase their consumption of fats. Coconut oil is especially popular in keto diets because it is rich in medium-chain triglycerides, a type of fat that your body can easily convert into ketones. By maintaining a low-carb diet for an extended period of time, your body shifts toward utilizing fat as its primary energy source. As a result, your pancreas starts producing lower levels of insulin, the hormone that tells your body to store glucose as fat. The idea then is that less of what you eat gets stored as body fat and more gets burned for energy, and so you lose weight.

An overview of the ketogenic diet. Image Source

How Ketones Affect the Brain

In general, most studies have suggested that the keto diet could be an effective weight loss tool, though research on its longer-term effects remains limited. But what effect does it have on the brain? The idea that coconut oil and other ketogenic foods could help with Alzheimer’s disease comes from studies showing that Alzheimer’s patients have lower glucose metabolism in their brains. This means that their brains have trouble utilizing glucose for energy, which could result in cognitive impairment. This tends to be worse in people with diabetes, perhaps one of the reasons why diabetics are at an increased risk of Alzheimer’s. (See Alzheimer’s Disease: Diabetes of the Brain?)

That’s where coconut oil might come in. Since their brains have trouble metabolizing glucose, perhaps Alzheimer’s patients could substitute ketones as an alternative source of energy. Research shows that ketone metabolism in normal in Alzheimer’s brains, providing hope that this could be a possibility. A recent study also showed that neurons incubated with coconut oil and then exposed to amyloid-beta (a toxic protein associated with Alzheimer’s disease) had increased survival compared to neurons not treated with coconut oil.

Unfortunately, clinical trials in humans are lacking. I was only able to find one small study from Spain, in which 22 Alzheimer’s patients were given 40 mL of coconut oil daily for three weeks. They found that these patients scored better on a memory test than others who did not receive coconut oil. However, the sample size was very small and they also did not include a placebo in the control group, so it’s difficult to say how meaningful these results really are. Other clinical trials studying different types of ketogenic compounds to treat Alzheimer’s disease have seen only limited success in a small subset of participants.

What’s the Verdict?

While it’s possible that it could help you lose weight or provide other health benefits, there’s just not enough evidence to say whether or not coconut oil and other ketogenic foods could reduce the risk of Alzheimer’s disease. On the other hand, there are some possible risks associated with it. Consumption of coconut oil in large quantities can lead to gastrointestinal problems, and its high saturated fat content also makes it a risk factor for heart disease or obesity. However, incorporating a small amount of coconut oil into your diet could be beneficial if you offset those calories with reduced carb intake. That being said, it’s unlikely that coconut oil or any ketogenic diet alone will be enough to dramatically alter your risk of Alzheimer’s disease. (To learn about real ways you can reduce your risk, see How to Reduce your Dementia Risk in 2017)

 

Enjoy this post? Help it to grow by sharing on social media!
Want more? Follow AlzScience via email, Facebook, or Twitter!