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big_man_ting | 2 years ago
It's such a delicate balance to maintain that without significant investment into monitoring, you're better off just consuming substantial amounts of complete protein and proper omega fat ratios + complex carbs. No need to overcomplicate things for the greater population.
xk_id|2 years ago
Except restriction of essential amino acids, as well as the total amount of protein, was consistently shown to improve health markers and longevity in many animal models, as well as in human epidemiological studies. It's not even news, the first evidence for methionine restriction in rodents dates to the early 90s.
I can't figure out what motivates some people to go online and assert their baseless suggestions with so much authority.
https://www.cell.com/article/S1043-2760(14)00127-1/fulltext
https://www.thelancet.com/journals/ebiom/article/PIIS2352-39...
https://nyaspubs.onlinelibrary.wiley.com/doi/abs/10.1111/nya...
https://www.cell.com/cell-metabolism/pdf/S1550-4131(23)00374...
big_man_ting|2 years ago
First things first, different groups of humans have different protein requirements (pregnant women, elderly, athletes, sedentary non-active adults etc) so generalizations in nutrition science are always dangerous.
Secondly, the studies you cited have been experimental on yeast and mice, but observational and correlational with humans - nothing conclusive about how a practical reduction in methionine and leucine in the real world for real humans would work, and how it would affect them long term. Those are two completely different scenarios, with the former being highly controlled studies of non-human species.
Thirdly, even if methionine reduction did positively affect lifespan/healthspan, the reality is that most people are simply not equipped to take on such a dietary change, leading to more harm done than good.
The reality is that, yes, many animal foods contain much more methionine than plant based. However, you also have to consider that if regular people tried to switch to plant-based (aside from lacking general education about plant-based diets), in order for them to consume sufficient amounts of protein from plants, they'd end up consuming a lot more calories (not only fibre but other simpler carbs) due to the higher calorie-to-protein ratio. This, especially if they don't live very active lives, would contribute to weight gain, all the while them thinking they're being healthier by being plant-based.
I understand that these are promising studies that have been around for a while, and I was a vegetarian for 5 years before switching back to omnivore due to becoming more disillusioned by the vegetarian diet, especially as I was trying to build muscle while on veggie+fasting, and failing.
But context matters, real world conditions matter.
Correlational/observational studies don't mean shit because they cannot possibly account for the diverse lifestyle practices of the participants living in the real world, try as they might.
Hence why I'm advocating for people to simply consume more protein, because, even though there might be benefits to restricting certain AAs, a lot of other implications to this dietary change might be overlooked, causing more harm to the health long term.
Let me know if I'm missing something crucial.