Post-operative cognitive dysfunction is exacerbated by high-fat diet | Hacker News Reader

Post-operative cognitive dysfunction is exacerbated by high-fat diet

sciencedirect.com

20 pointsgnabgib12 comments

...in rats:

  Subjects were young adult (3–5 months) and aged (22–24 months) male F344xBN F1 rats obtained from the National Institute on Aging rodent colony managed by Charles River. F344xBN F1 rats are particularly useful for the study of aging and aging-associated conditions as aged rats of this strain remain relatively healthy and show good cognitive function at baseline. Unfortunately, female rats of this strain were not available from this or any other vendor at the time these studies were completed.

Isn't the real mis-step of this study that they put the rats on a HFD 3 (three!) days before testing? I thought it was common knowledge that the transitory periods of ketosis elevate blood lipids until your body adapts to its new food source / arrives at a new equilibrium. I would think their conclusion should be

"Taken together, the present data indicate that (!__consumption of__) -> <__transition onto__> a HFD prior to laparotomy prolongs the neuroinflammatory response to surgery and induces persistent memory deficits in young adult and aged rats. We demonstrated that both age groups who ate HFD for 3 days prior to surgery displayed robust cued-fear memory deficits, and aged rats additionally exhibited contextual memory deficits. These memory impairments were associated with exaggerated and prolonged (3 weeks post-surgery)"

Which is just another way to say, don't inflame your entire body with a new diet prior to undergoing surgery (which in and of itself is massively stressful).

> We have previously shown that surgery alone, or 3-days of HFD can each evoke sufficient neuroinflammation to cause memory deficits in aged, but not young rats.

The surgery + transition onto HFD seem to be more damaging than either one alone, which makes sense that doing two harmful things is worse than doing one harmful thing.

Dude. “In rats” is such an easy cliche. Should we create an LLM to post it on every HN story regarding animal studies? Rats are a decent model. Would you prefer we test hypotheses on your body to get started instead? Let’s look at the experimental methods and develop better intuitions about what can reasonably hypothetically extrapolated to humans and what doesn’t instead of just saying “in rats.”

When you remove a rats arm, it cannot use it. This effect does not occur in humans because when you amputate a human’s arm they can still use it.

Rats are unlike humans so feel free to amputate your arm. You will still be able use it because rats are not humans duh

Instead of DHA supplimentation, have the patient go on a low fat diet for three days before anesthesia.

Or, possibly, not worry about it -- how many patients expect to make difficult post-operative decisions? They expect to be woozy due to painkillers anyway.

Both of my parents had surgeries in their 80s that were followed by severe post-operative cognitive dysfunction that lasted the rest of their lives. This wasn't normal dementia, this was a sudden and apparently permanent step change in cognition. Subsequently, I discovered the phenomenon is pretty common, but hardly being studied at all. It seemed the surgeons say it's an anesthesia problem and the anesthetists say it's a surgical problem, so nobody studies it.

Anyway, its good to see somebody paying attention, because I want this fixed before it happens to me!

Anecdotally I had general anesthesia a couple times in my 30s and both times I felt like I came out of it permanently stupider. No complications or other observable side effects either. I’ve done fine in spite of it but this makes me interested again!!

I feel like if this was just caused by anesthesia, it would be a lot more common. Think of how many people go in for a colonoscopy each year.

In Europe, anesthesia is uncommon for colonoscopies. Probably a good idea.

https://www.sandiegocan.org/2019/02/07/you-arent-crazy-to-wa...

Anecdotally: I had surgery under general a couple of years ago no side effects. I’m 60.

Anesthesia is poorly understood. How can a noble gas be anesthetic? We understand it so poorly that both your experience and mine could be common

The few studies seem to show it’s not correlated with anesthesia. There was a supposed “pumphead syndrome” that blamed cardiopulmonary bypass machines for it, but one of the few studies done didn’t find that correlation either. The most plausible thing I’ve seen is that it’s somehow an effect of inflammation, as more and more things seem to be. Surgery is a major trauma, and although you aren’t awake for it, your body is just as traumatized.

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