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Bill Fagan's avatar

Nick, I'm a new (paid) subscriber. This is very interesting. Can you take a rough stab at a high-low range of daily Krill oil required, for an average person, to potentially get the benefits described in this study?

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Nick Norwitz MD PhD's avatar

Thanks Bill. I wish I could give you an evidence-based recommendation. If supplementing EPA/DHA omega-3, I think the benefits start around 2g/d. For Krill oil, hard to say. I see options online w/ 1 - 1.6g/d, with ~300mg being from omega-3. That sounds reasonable. Sorry I can't be more specific on KO dosing.

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Bill Fagan's avatar

Let's also make the assumption that a person is doing all the basics, and has been for years, yet was recently found to have significant amyloid plaque (without clinically significant cognitive decline). So, supplementing with Krill oil may be warranted. Thanks

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Nick Norwitz MD PhD's avatar

Well something we've not discussed is resilience to the presence of amyloid. If one can somehow maintain inflammation at a low level, and insulin sensitivity in the brain... I'd suspect one's tolerance for amyloid would be much higher.

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Bill Fagan's avatar

Thanks for the reply Nick. I am not suggesting that there's long term resilience to the presence of amyloid plaque. The situation is this: I've always been very bright, but like many people my age (66), I have some memory problems. Unlike most people my age, I insisted on a PET scan for amyloid plaque. To every one's surprise, I was found to have significant levels of it. More than likely, I have significant neuroinflammation also. Basically, we caught the problem at a time when I am functioning totally normally (per standard cognitive tests) and before MCI has set in, but there is a high likelihood that I will suffer cognitive decline over time. So I'm working very hard on this problem, getting advice from multiple highly credible ALZ experts, and the LPC/Krill Oil idea is one I had not heard of. Does this information cause you to change your thoughts at all about the 1-1.6g/day amount? (And to be clear, I know you are not providing medical advice! You are doing nothing other than making a rough suggestion based on limited information! I'm just going to share your thoughts and this article with some of my experts.) Thanks much.

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Nick Norwitz MD PhD's avatar

If I were in your position and had the means, I'd probably dose double that to 'be safe.' You may also check out this paper, and the tables therein: https://pubmed.ncbi.nlm.nih.gov/33921683/

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Bill Fagan's avatar

I will do that. And I will review your paper. Not too shabby co-authoring a paper with Richard Isaacson! Thanks for your thoughts, and your helpful youtube channel!

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Nick Norwitz MD PhD's avatar

Thanks. And very welcome :).

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Agent 1-4-9's avatar

I'm no scientist, but I'm guessing LPC is somehow made by splitting or breaking down (the lyso part) PC. I'm allergic to some, but not all, shellfish and I'm scared to try krill oil. Does krill oil have the allergens filtered out? PC is a much cheaper supplement than LPC. Can supplementing PC lead to higher levels of LPC? If so, are there any necessary cofactors for lysing PC? I ask because my mom and dad both succumbed to Alzheimer's, albeit in their 80s.

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Nick Norwitz MD PhD's avatar

I wouldn't trust the krill oil is filtered for allergens, and I wouldn't assume supp. PC would increase LPC in that way, no. As mentioned in the video coverage, your best bet is still the basics (including eating fatty fish). Rarely are supplements necessary, esp if you could be allergic.

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Agent 1-4-9's avatar

Hey, I also want to say thanks for taking the time to answer me. You popped up in my YouTube feed and I watched a few videos. I was impressed and thought, "I wonder if he has a Substack?" I subscribed instantly. Keep up the good work! I'm 60 and all the things I was taught about good health through the mainstream in the 90s and 2000s are being rewritten. Guys like you are making a difference.

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Agent 1-4-9's avatar

Thanks, but, haha, isn't krill oil a supplement? I eat sardines once a week. Do they contain appreciable amounts of LPC?

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Nick Norwitz MD PhD's avatar

Krill oil is a supplement. But I didn't say it was necessary. Generally when producing a YouTube video the audience likes action items. Sometimes, this includes supplements. I stand by what I said in the video, but that's still consistent with supplements not being "necessary." Sardines don't have as much as krill oil, but they're great. Once per week isn't that often so one could considering making them more routine? I see little downside to doing so.

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Agent 1-4-9's avatar

Haha, except they're not the tastiest things on the planet. You have to enjoy what you're eating or what's the point? I guess I'll try. I guess a couple times a week sardines beats Alzheimer's!

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Darren Zhu's avatar

just saw this paper in Nature this week on dietary fructose enhancing tumor growth in vitro and in vivo via increased LPCs...https://www.nature.com/articles/s41586-024-08258-3

I haven't read much about LPC metabolism and mechanism of action but interesting to try to reconcile that with this paper

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Nick Norwitz MD PhD's avatar

LPCs are a diverse group of biomolecules. Long-story short (I've seen the data), the liver can convert fructose into LPCs (again, many diff LPCs) that the tumor can use as substrate. This isn't particularly shocking or contradictory to the Alz LPC data. There's not really much to reconcile. It doesn't mean Krill oil will feed tumors. And keep in mind that a lot of rules of metabolism change when a person has cancer.

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