lysine and leucine claims in new study

[gupt1857]

Full Study:

Evaluation of protein intake and protein quality in New Zealand vegans

Dietary protein provides indispensable amino acids (IAAs) that the body cannot synthesise. Past assessments of total protein intake from vegan populations in western, developed countries were found to be low but not necessarily below daily requirements. However, plant-sourced proteins generally...

journals.plos.org

One news item

Even vegans who get enough total protein may fall short for some essential amino acids, findings suggest

In a new study of people with long-term vegan diets, most ate an adequate amount of total daily protein, but a significant proportion did not meet required levels of the amino acids lysine and leucine. Bi Xue Patricia Soh and colleagues at Massey University, New Zealand, present these findings...

medicalxpress.com

They claim that vegans consumer adequate overall protein but due to plants having less lysine and leucine and reduced digestibility, as many as 50% vegans are deficient.
I see several problems:

1. how do you know what is an adequate amount of protein and how much of essential amino acids one needs? Current recommendations are based on carnivorous diet.
2. No adverse effect was reported or measured. Even if you allow that the deficiency existed, did it result in any problem?
3. Lysine can be produced by gut bacteria and vegans have healthier guts (a researcher pointed to this issue)

etc
Do people see other problems?

 

[Lou]

I couldn't read the whole thing but it seems to repeat something that has been stated over and over again for 40 years: that plant based protein are low quality due to the fact that they don't have enough of every amino acid.

Anyway it seems like a lot of words and math was used to make a point that vegans and vegetarians have been disputing for a long time.

You don't need that much science to realize that plant based foods provide adequate amounts of protein. Just ask any elephant.

 

[Graeme M]

You don't need that much science to realize that plant based foods provide adequate amounts of protein. Just ask any elephant.

I find the whole nutritional science thing pretty confusing, I admit. But does it make sense to refer to actual herbivores to show that humans can get adequate protein from plants? I know it's a throwaway line but I do see that kind of thing a lot. Do you think we can assess human metabolic capabilities by looking to other species? The reason I ask is that each species is adapted to its diet such that the dietary and internal processing characteristics are tailored by evolution to maximising the animal's nutritional intake. The human diet has always included both animals and plant, so it seems reasonable to assume that our system has evolved to suit that food, meaning that we may not be able to obtain the same nutrition as easily from a purely plants-only diet. That's not the case for elephants.

This study is suggesting that after we take into account digestibility and absorption, some vegans in the test group were falling short of those two amino acids. I think that's an important finding though I didn't learn from the study just what food intake would redress that shortfall. The feeling I got was that vegans eating plenty of high protein food sources were actually fine (eg legumes and pulses).

Anyways, here's my pretty loosely informed take.

1. how do you know what is an adequate amount of protein and how much of essential amino acids one needs? Current recommendations are based on carnivorous diet.
2. No adverse effect was reported or measured. Even if you allow that the deficiency existed, did it result in any problem?
3. Lysine can be produced by gut bacteria and vegans have healthier guts (a researcher pointed to this issue)

1. That's a good point. Nutritional requirements don't necessarily allow for digestibility/absorption as far as I know. The recent paper about the low levels of calcium absorption from fortified plant-based milks shows we may not be using the right recommendations.

2. No, but I think that is due to the short time period and the study aims. Significant issues from that small a protein deficiency may not be apparent ever, but it may be noticeable when aging. Are there studies of long-term vegan populations that address their muscle mass loss over time compared to omnivores? Especially in the older groups?

3. Does a "healthier" gut necessarily mean the presence of the right kinds of bacteria for this job? We'd need research to evaluate the actual protein levels in the body etc to determine if that's so, wouldn't we? This study just evaluated protein availability.

 

[Lou]

Nutrition is a pretty soft science.
you can't put people in a cage and feed them and weigh them and then disect. so we glean most of our science from studying other species and making conclusions. It isn't optimal but it's the best we can do.
We also get some information from studies where human test subjects self report. Problems with that too.
Maybe the best studies are with populations. like the China Study.

As far as elephants go....

I first read Protein for Vegetarians by Michael Bluejay something like 20 years ago. And he has been editing and updating it every year since.

It's my. favorite article because it's easy to understand and not all that long. Also it is full of quotes and references.

Anyway, scroll down to the part on elephants. I was going to quote it but I'd end up quoting the whole thing.

Protein for Vegetarians (& the myth of incomplete proteins)

 

[gupt1857]

Thanks Lou, Graeme for your input.

The author should have looked into how people were doing: was this supposed deficiency causing any problem?
They just looked at people's food diaries and did some calculations but it is not useful unless we know if there were any problems.
It is unfortunate that this study is getting so much attention in the press.

 

[gupt1857]

But if the diet is not whole plants and contains say 40% fat and 10% pure sugar, there may be deficiency as the person will have to consume all proteins in 50% of the calories.
If you are consuming whole plants only, there is no way you can get deficient. But if a large percentage of your calories come from added oils or sugar (as they don't have any protein), there is some possibility.

 

[Emma JC]

But if the diet is not whole plants and contains say 40% fat and 10% pure sugar, there may be deficiency as the person will have to consume all proteins in 50% of the calories.
If you are consuming whole plants only, there is no way you can get deficient. But if a large percentage of your calories come from added oils or sugar (as they don't have any protein), there is some possibility.

that is true of any diet so it can't be considered a 'vegan' issue IMO

Emma JC
Find your vegan soulmate or just a friend. www.spiritualmatchmaking.com

 

[christen_g]

i dont care what some study says
i go to the doc whenever i have issue
if i wasnt eating enough protein hed tell me and then i would try eating more protein

if the claim is that the average herbivorous vegan is not going to getenough of those amino acids, thats a pretty silly claim cuz thats an easily rectifiable situation... anyone can download cronometer and audit their diet and see if they are not hitting the RDA and if one cares, one can simply eat more vegetables, especially legumes, and less grain.... i eat a "junk food vegan diet" and hit my requirements easy peasy with no mock meats or supps

 

[christen_g]

my diet on a "low" day

 

[christen_g]

i suffer no ill effects from my "low protein" diet

 

[Raven]

I take a lysine supplement as I read about it on one of the other veg forums we were on. I haven't heard of leucine.

 

[Tom L.]

I don't see this as new. Way back around 1970, Frances Moore Lappe wrote "Diet For A Small Planet", which explained that how efficiently your body could use protein was limited by whatever essential(*) amino acid was in short supply: if you got all you needed of most amino acids, but got only 75% of one of the essential amino acids, it was as if you got only 75% of what you needed for ALL of them. (*: an "essential amino acid" is one which you body can't manufacture out of something else. I think I've recently seen a different term for this- it sounded like it was referring to the same thing.) Besides the technical info, the book has lots of good recipes- not all are vegan, but they're all vegetarian- and most of the non-vegan ones can be veganized (though our first attempts might lose something in the translation. No problem- I just eat my mistakes. ) I still use my copy of DFASP much more than the two "Vegetarian Epicure" books.

I think that later on, Ms. Lappe changed her mind somewhat: in the first book, it was generally thought that you had to consume this variety of amino acids at every meal: i.e., you couldn't get all your lysine at breakfast and all your sulfur-containing aminos at dinner. But more recently, the consensus is that so long as you get what you need in the course of a day, you should do fine.

I'd better do some googling to see if I've got this right.... Maybe the science has been updated.

 

[silva]

Even though I'm not committed to following Dr Greger s daily dozen, it will always be the formula I think about so I don't go too far off track.
The daily dozen is a list of food categories in portion sizes that make up a days complete nutrition. While food combining isn't necessary at each meal, it's good to understand the essential aminos of different types of food. In general, grains are higher in aminos that are lower in beans.
The Daily Dozen Checklist – The Endocrinology Wellness Institute

 

[Lou]

I'd better do some googling to see if I've got this right.... Maybe the science has been updated.

read that article I linked. its not that long. and its up-to-date. it discusses Lappe.

 

[Tom L.]

@Lou I re-read it, and you're right. Thinking more about it... although the information is correct, I think the article (which you linked to in post #4) could have been written better- specifically, more clearly. For example: there's the chart titled "Protein Content Of Various Foods"... and then at the bottom of the chart , we find "Protein given as a percentage of calories." In tiny print.

 

[Lou]

@Lou I re-read it, and you're right. Thinking more about it... although the information is correct, I think the article (which you linked to in post #4) could have been written better- specifically, more clearly. For example: there's the chart titled "Protein Content Of Various Foods"... and then at the bottom of the chart , we find "Protein given as a percentage of calories." In tiny print.

Tom, nitpicking? Don't you know that is my job??

I'm not sure this specific criticism is fair. Do you think it would be more "clear" if the font was larger?

the small print at the bottom of the chart is not that important to understand the chart. Bluejay included it in order to make things clear.

 

[Lou]

They claim that vegans consumer adequate overall protein but due to plants having less lysine and leucine and reduced digestibility, as many as 50% vegans are deficient.

oh shoot. Now its going mainstream.

New research is bad news for vegans — even if you eat plant-based protein

Even with produce-packed plates and plant-based protein, new research suggests vegans may still be missing essential vitamins and nutrients.

www.yahoo.com

 

[PTree15]

oh shoot. Now its going mainstream.

New research is bad news for vegans — even if you eat plant-based protein

Even with produce-packed plates and plant-based protein, new research suggests vegans may still be missing essential vitamins and nutrients.

www.yahoo.com

I just get so annoyed with the obsession that vegans don't get enough nutrients, etc., as the garbage that many omnis eat is pretty nutrient-deficient, given all the processed food/prepared food (restaurant meals, which are notoriously full of salt and fat) and junk in the SAD these days.

 

[silva]

I just get so annoyed with the obsession that vegans don't get enough nutrients, etc., as the garbage that many omnis eat is pretty nutrient-deficient, given all the processed food/prepared food (restaurant meals, which are notoriously full of salt and fat) and junk in the SAD these days.

When I hear vegan the only thing I expect from the diet is not animal products. When I hear omnivore all I expect is that they do eat animal products. Neither one implies health.
Vegan are always held to such harsher criticism, yet I do believe we perpetuate it when we say things like "a carefully planned diet" when defending it's health. It isn't that hard.
I've known so many omnivores with dangerously low potassium, iron, high BP, gout, type 2 diabetes, high cholesterol, heart disease......Where are the dietary concerns for them, yet we get questioned in advance

 

[silva]

Playing devils advocate though, it really is good to understand all the different essential amino acids in foods.
This also seems to put even more reason not to advocate vegan keto!