Genetic preferences for vegetarian and seafood-heavy diets

[MarcR]

From WaPo:

Cornell study finds some people may be genetically programmed to be vegetarians

The full study:

FADS2 indel determines arachidonic acid status

While the study focuses on an insert/delete polymorphism that can't be identified with SNP scanners like the ones 23andMe has used, it does identify a few correlated SNPs. Unfortunately, none of them are in my 23andMe results. Rats! There's also nothing about ApoE status.

Even so, I like the discussion in the study of the ways in which the flood of seed oils into global diets over the past half century may be interacting with regional genetic distributions to varying biochemical effect.

[Julie G]

This is fascinating, Marc. Almost makes me want to do the full exome scan when I see exciting new data like this

FWIW, from Rhonda Patrick’s site, I learned I was heterozygous for both of the FADS1 & FADS2 snips below leading me to guess I don’t have the pure vegetarian gene. Can we deduce that a pure vegetarian would be CC on rs174548 (FADS1) and AA on s1535 (FADS2?)

FADS1:rs174548(C/G)
This polymorphism in the fatty acid desaturase FADS1 gene affects phosphatidylcholine levels. The genotype rs174548(C;G) is associated with having intermediate phosphatidylcholine levels (more than the lower genotype (G;G), but less than the high (C;C) genotype).
Phosphatidylcholine is a key component in all cell membranes and plays a very important role in the structure of the cell, which affects all biological functions. It is also a precursor for the neurotransmitter acetylcholine, which has been shown to play a role in promoting REM sleep. Damage to the cholinergic system in the brain has been shown to be plausibly associated with the memory deficits associated with Alzheimer's disease and possibly other neurodegenerative diseases, and for this reason has also been a therapeautic target through the action of acetylcholinesterase inhibitors, which prevent the enzymatic breakdown of acetylcholine.
Phosphatidylcholine can be found in supplement form and its precursor choline can be found in dietary sources, which include things like organ meats and egg yolk.

FADS2:rs1535(A/G)
This is a common polymorphisms in the delta(6) desaturase gene FADS2. FADS2 is responsible for elongating polyunsaturated fatty acids like alpha­linolenic acid (ALA) and converting it into eicosapentenoic acid (EPA). The rs1535(A;G) genotype is associated with a roughly 26.7% decrease in the efficiency at which ALA is able to be converted into EPA relative to the most efficient genotype, which is rs1535(A;A). Since ALA is found in plants and EPA is found in fish, having one of the genotypes associated with a reduced efficiency of FADS2 may influence how much fish or algae you choose to consume.
This polymorphism may also be particularly relevant to vegetarians or vegans, since many may rely predominantly on ALA (from flaxseed or chia seed, for example) as their source of EPA and DHA, instead of fish or fish oil, which contains both EPA & DHA, and circumvents the need for conversion. Another option, microalgae oil, may be an alternative source that could be attractive to vegetarians or vegans since it has EPA & DHA. Interestingly, curcumin has been demonstrated to increase the level of FADS2 enzyme, leading to an increase in brain DHA content.

[MarcR]

Love your insight, Julie - thanks so much for connecting the dots to Rhonda's Genetic Report. I agree that the rs174548 and rs1535 SNPs are likely to be good proxies for the FADS2 and FADS1 polymorphisms discussed in the paper. And I also agree that rs174548(CC) and rs1535(AA) likely support vegetarian diets best. I suppose people with rs174548(GG) and rs1535(GG) are the Inuit-like people who thrive on seafood-rich diets?

I realize now that I erred in my search for rs1535, which is mentioned in the paper and is indeed in my 23andMe results. I'm rs174548(CC) and rs1535(AG), which I suppose makes puts me in the middle with you albeit closer to the vegetarian end of things.

[Thx4thegenes]

Hi Juliegee, heterozygous as well. So, I guess that means to continue eating both fish and plant sources like flax and chia and call it a day and we should hopefully be ok?

[Starfish77]

I'm rs174548 GG and rs1535 GG.

[KatieS]

So Starfish, it's fish and low carb for us! The Intuits ate 50% fat, 30% protein & 20% carb. However, this paleo-type diet did not seem to decrease their CV disease, Wiki did not mention AD.

[Julie G]

Interesting Katie & Starfish!

Per the wisdom gleaned from recent evidence, being GG on rs174548 seems to indicate that you need to ensure your diet is high in choline (egg yolks & organ meat) and/or you need to supplement with choline (or both.) I also wonder if this subtype would also be more susceptible to the effects of anticholinergic medications, like antihistamines?

And, being GG on rs1535 does seem to indicate that you need more fish or EPA/DHA than those carrying other polymorphisms. In this clip, Rhonda Patrick talks about this around the 6 min. mark.

KatieS, how did you deduce a low carb diet would be preferable from these snips? Just curious .

[Starfish77]

Julie,
The part about eggs is very interesting. For many years I ate very few eggs. About 3 years ago I began eating an egg a day. I also gave up wheat at that time. My cholesterol continued to drop and it was 133 last year at this time. A month or so ago I began eating 2 eggs a day. I find myself sleeping so much better. I wonder if I needed those eggs. I don't eat red meat and I'm about chickened out. I'm fine with more fish after all these years of chicken.

I did not know which drugs were included in your statement "anticholinergic medications, like antihistamines" so I looked it up online. I'm including a link of the drugs that were in that group. I do not take any of them.
http://www.agingbraincare.org/uploads/p ... l_size.pdf

Thanks for your ideas.

[Julie G]

Good for you, Starfish! It looks like you could greatly benefit from the choline in eggs. I think Dr. Gundry has approved up to 4 a day for ε4 carriers. I recently learned through another ε4+ patient that he prefers that we eat them poached so as to protect the choline and to prevent oxidation.

[GenePoole0304]

Good insight from all thanks for posting!!
rs174548 CC
rs1535 AA

in my 30s was a vegetarian for about 8 years


I'm also supplement with phosphdytlcholine some costly stuff but eggs I eat at 3 at a time in an onion/mushroom omelet once a week.

I also came across this is the comment section of this technie blog
http://high-fat-nutrition.blogspot.ca/2 ... ptors.html