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Rethinking RDAs (Recommended Daily Allowances)


srid
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I wonder how many of you are basing off your plate based on RDAs. This presentation might be of interest: 

 

Summary from reddit:

Some takeaways:

  • Through faulty assumptions the RDA are applied in ways which are not warranted.

  • Lowcarb diet leads to microbiome with higher amounts of folate producing bacteria.

  • The requirment for dietary zinc may be as much as 50% greater for vegetarians.

  • a low carb diet increase DHA (might be misunderstanding this)

  • Many things affect a persons need for nutrients

    • Different rates of conversion
    • Different absorptions
    • Different breakdowns
  • Some RDA:s are highly speculative and based on trying to treat disease (not on trying to prevent a proven nutrient deficiency)

  • arctic voyagers have long known that scurvy can be treated with fresh meat. even though its low in vitamin-c (it has some)

  • USDA report on meat and vitamin-c states zero but it was never measured but instead assumed to be zero. (it has some)

  • Ignores sparing and synergistic effects.

    • Vitamin-C may be sparing collagen
    • second major function of vitamin c is making carnitine
    • Glutathione spares vitamin-c
  • RDA:s are statements of probability (worst case not average case)

  • Nutrient Need implications

    • Critical need now implies abundant availability evolutionary
    • deficiencies detected means mismatch
    • nutrient needs are highly contextual and interdependent
    • the internal environment must also be considered.
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RDA's for most vitamins and minerals were based on stuff from decades ago - it's not surprising that new research undermines, contradicts or complicates the picture in 2020... no doubt the same process will take place all over again in 2050.

That said, let's remember what the remit of establishing RDA's was. It was meant to be applicable to very broad populations with a large safety margin. It's not much of a surprise to point to the fact that if person A has a drastically different diet from person B (low carb or whatnot), your RDA requirements might not be the same. Duh. 

And we're living in a time of personalized medicine, or indeed biology. Every individual has a very specific physiological profile, and the interaction of genes, environment, diet, lifestyle, medication etc. certainly results in a very specific requirement for vitamins and minerals that might differ drastically from another individual. 

The reality is that is impossible to establish RDA's for many vitamins and minerals that would be equally valid for every human out there. That's an impossible task.

That said, could the various RDA's stand to be revised and adjusted in view of new research? Certainly. And that process is ongoing - just witness the vigorous discussion and controversy over vitamin D levels and recommendations.

With a remit this broad, you will never make everyone happy, and any RDAs you come up with will always be open to criticisms. This video is just an instance of such. Whatever anyone comes up with will also be critiqued. YMMV. 

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15 hours ago, TomBAvoider said:

... you will never make everyone happy, and any RDAs you come up with will always be open to criticisms. This video is just an instance of such. Whatever anyone comes up with will also be critiqued. ...

Yep, that's it in a nutshell. We have nothing better right now to base our guidelines oon, so RDA, as it continuously evolves, is our best bet.

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3 hours ago, mccoy said:

A presentation form Carnivorycon, of course, even though not without some rigorous points, tends to speak the party line, that meat has enough of everything, even vitamin C. Good luck to the carnivores!

Lots of fiber???

I’d hate to be on the pushing end of that rope 👍😁🤗

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Evacuation happens swiftly, about once a week.

I take this to be a sign of efficient functioning of the whole digestion/ elimination system of the body.

PS: The supposed benefits of fiber have not been confirmed on randomized control trials.

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An example of problematic absorption issues I had noticed whole sunflower seeds in my feces.  I add these to my oatmeal along with walnuts and almonds. They are small and some of them don’t get chewed obviously and they are totally going through me. I now grind them before adding. 

Edited by Mike41
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On 4/6/2020 at 10:20 AM, mccoy said:

Thanks but no thanks, I'm comfortable with my twice or thrice per day frequency. 

Well, of course, if you eat plants then having frequent bowel movements becomes a matter of necessity (not just comfort). My comment was in regards to consuming zero fibers.

Edited by srid
Grammar
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On 4/13/2020 at 1:02 PM, srid said:

Well, of course, if you eat plants then having frequent bowel movements becomes a matter of necessity (not just comfort). My comment was in regards to consuming zero fibers.

What exactly is your goal?

For weight loss, cutting carbs is likely to be helpful, especially since the carbs generally consumed by those of unhealthy weight are often highly processed and generally detrimental to health. But this is true for cutting out any other significant food group, as it results in a lower total calories consumption in most cases.

Now, if your goal is to improve general health and longevity, then cutting out fiber is likely to be a poor choice. There are numerous studies which show correlation between higher fiber intake and improved health and longevity, such as this one:

Dietary fiber intake and mortality in the NIH-AARP Diet and Health Study

 

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