The Fat That Fuels Alzheimer’s Disease

This is not about trans fats, or super-processed hydrogenated vegetable oils, or butter.

Although, you might want to check out: Can Saturated Fats Be Healthy? and, for that matter, A Word About Trans-Fatty Acids (TFAs) ← when you click this one, you’ll need to scroll down slightly for the bit about trans fats.

No, it’s about adipose tissue.

The Adipose-Brain Crosstalk

Body fat is blamed for many things, often unfairly.

By this we mean: there are many adverse health conditions that are associated with being in the “obese” category of a BMI scale, but this is very misleading if we don’t look at the actual causes at hand. It would be like saying that since black people die in the US at a higher rate than white people do, blackness itself is to blame, instead of looking at the systemic issues at hand, ranging from higher association with poverty due to generational disprivilege, to receiving lower quality medical care. We wrote previously about Fat’s Real Barriers To Health, shining a similar light on the actual problems at hand, often including such things as:

• medication dosages being tailored to thin people rather than calculated on a per-kg basis and guess what, now it doesn’t work and you might die
• surgeons being untrained and/or unwilling to operate on people unless they lose weight first (often resulting in a denial of essential surgery)
• hospital equipment that was built with smaller sizes in mind, ranging from blood pressure cuffs to MRI machines, resulting again in skipped (or substandard) medical care

You can read more about this kind of thing in: Shedding Some Obesity Myths

So, all that shows how in many cases, fat isn’t the real problem; it’s just a bodily attribute that people either see and decide to hand it problems, or else simply do not care enough to address a need going unmet.

However, this today is not one of those instances.

Researchers (Dr. Li Yang et al.) used a combination of human patient fat samples, mouse models, and lab tests of amyloid clumping, to discover that fat tissue releases extracellular vesicles that can cross the blood–brain barrier and accelerate amyloid-β plaque buildup, a hallmark of Alzheimer’s disease.

Furthermore, the more adipose (fat) tissue you have, the worse this seems to be.

Limitation: the researchers did not distinguish between different types of adipose tissue. We may hypothesize that white adipose tissue will be the worst, yellow adipose tissue not so bad, and we wouldn’t be surprised if brown adipose tissue turned out to be protective. For why we make that latter prediction, see: The BAT-pause! ← the title here refers to the production of highly beneficial brown adipose tissue (BAT) slowing down during the menopause, if we’re not careful—but there are things we can do to convert white adipose tissue to yellow and brown.

You can read the paper in full, here: Decoding adipose–brain crosstalk: Distinct lipid cargo in human adipose-derived extracellular vesicles modulates amyloid aggregation in Alzheimer’s disease

Before you decide on your next weight-loss plan, though, please be aware that over the age of 65, a BMI in the “overweight” category is protective against all-cause mortality

Thus, a potentially sensible plan if you’re already in a weight range you’re happy with (and an adiposity range you’re happy with, for that matter, since of course weight can come from more things than just fat, e.g. water weight, muscle mass), is to use what we talked about in the “BAT-pause” article linked above, to convert adipose tissue into its healthiest form. However, as a caveat, that’s just us doing a 2+2=4 on the evidence, and not a matter of interventional RCTs having been done to confirm the hypothesis. We’d love to see such studies, though, and will definitely keep an eye out for them!

Want to nourish your brain without fueling Alzheimer’s?

Check out:

A New Contender For “Best Diet For Heart & Brain” In Aging

Enjoy!