For today’s edition of Dear Mark, I’m answering a bunch of questions from comment sections. First, did I get AMPK and mTOR mixed up in a recent post? Yes. Second, I give a warning for those who wish to add ginger to their broth. Third, is it a problem that we can’t accurately measure autophagy? Fourth, how does coffee with coconut oil affect a fast? Fifth, is there a way to make mayonnaise with extra B12 and metformin? Actually, kinda. Sixth, should you feel awkward about proposing hypotheses or presenting scientific evidence to your doctor? No.
Great article, but a couple of amends are required with regards to mTOR. Firstly, you mention in the last paragraph that curcumin activates autophagy by activating mTOR. Reading the actual article abstract though, it states the opposite, ie the effect of curcumin “downregulating AKT/mTOR signaling pathway in human melanoma cells”.
Great catch. I’m not sure how I flipped that around. AMPK triggers autophagy, mTOR inhibits it.
What you say about curcumin goes for all the other broth ingredients I mentioned. Ginger, green tea, and curcumin all contain phytonutrients which trigger AMPK, which should induce autophagy, or at least get out of its way. What remains to be seen is whether the amino acids in broth are sufficient to inhibit fasting-and-phytonutrient-induced autophagy. I lean toward “yes,” but is it an on-off switch, or is autophagy a spectrum? Does inhibition imply complete nullification? I doubt it.
Regarding autophagy and health and longevity, it’s important to note the manner in which glycine, the primary amino acid found in broth and gelatin, opposes the effects of methionine, the primary amino acid found in muscle meat and a great stimulator of mTOR.
One notable study found that while restricting dietary methionine increased the lifespan of lab rodents, if you added dietary glycine, you could keep methionine in the diet and maintain the longevity benefits. That doesn’t necessarily speak to the effect of broth on autophagy during a fast, but it’s a good reminder that broth is a general good guy in the fight for healthy longevity.
Funny you mentioned ginger and turmeric as I add both, along with a whole lemon and/or lime, to my list of ingredients when cooking my broth. Here’s another great tip: I juice turmeric root, ginger & lemon together in my Omega juicer and freeze in ice cube trays. I add a cube to curries and other dishes.
That’s a great idea. One cautionary note about the raw ginger: it will destroy your gelatin.
Raw ginger has a powerful protease, an enzyme that breaks down protein. If you grate a bunch of ginger into a batch of finished broth, or juice a few inches and dump it in, there’s a good chance you’ll lose the gel. The amino acids will remain, but you’ll miss out on the texture, the mouthfeel, the culinary benefits of a good strong gelatinous bone broth.
Heating the ginger with the broth as it cooks, or even just reducing the amount of raw ginger you add, should reduce the protease activity.