2. March 29, 2016 and April 11, 2016
Professional Primary Research Article and Website Article (Combination Report)
1. Kothapalli KS, Ye K, Gadgil MS, et al. Positive selection on a regulatory insertion
deletion polymorphism in FADS2 influences apparent endogenous synthesis of
arachidonic acid. Molecular Biology and Evolution 2016:1–33.
doi:10.1101/042549.
URL:http://mbe.oxfordjournals.org/content/early/2016/03/09/molbev.msw049.full.pdf
+html
2. Andrews R. No, Being A Vegetarian Won't Kill You. IFLScience 2016. Available at:
http://www.iflscience.com/health-and-medicine/no-being-vegetarian-wont-kill
you. Accessed April 25, 2016
Key Points:
Researchers hypothesized that a genetic polymorphism in the endogenous
synthesis of long chain polyunsaturated fatty acids (LCPUFA) appeared in
humans whose ancestors consumed primarily vegetarian diets.
Using genotype frequencies in 234 Indian people with vegetarian diets versus
311 individuals from the United States, they found a higher frequency of the I/I
genotype in the Indian population (68%) than in the U.S. population (18%).
Additionally, the support for this insertion allele and its enhancement of n-6
LCPUFA synthesis was included in experimentation from basal plasma
phospholipid arachidonic acid status (comparing the I/I genotype versus the I/D
and D/D genotypes)
The consumer article discussed the false belief that the research identified in this
study supported the lethality of a vegetarian diet.
The article clearly stated that vegetarian diets do not, in fact, cause death. This
falsity aroused from the excess production of fatty acids in vegetarians who
suddenly consumed meat and resulting inflammation in the body (thus,
potentially leading to cancer or heart disease).
3. Critical Appraisal:
Strengths-
Both the primary research and the consumer article have numerous strengths that I
believe ultimately outweigh their limitations.
The primary research article used whole-genome sequencing data to identify
populations in which the rs66698963 allele was prevalent. The presence of this allele
resulted in higher expression of FADS1, a fatty acid desaturase gene essential for the
production of various fatty acids. As far as I know, genome sequencing has little room
for error, so I think the identification of a specific allele in the two sample populations
has a very legitimate basis. Furthermore, the researchers identified that their data used
only two sample populations, so they examined the genotype frequency distributions of
the rs66698963 allele from a global database. This analysis led to further examination
among continental populations due to a large distribution in the frequency differences
of the allele. The extensiveness of experimentation definitely supports the validity of the
researcher’s genotyping in their initial sample populations. The researchers answered a
lot of their own questions that arose in experimentation (i.e. the dramatic difference in
the allele frequency in the continental populations).
The consumer article does a very good job of simplifying the main concepts of the
research article because the research is very dense. This is obvious because the main
discussion in the consumer article is how the research results were misinterpreted by
the general population. The belief was that vegetarian diets resulted in increased death,
but the article explains that this was just a misconstrued concept. I think the use of
defining terms like allele and omega-3/omega-6 fatty acids is useful for the audience
because these could be confusing to a lot of people and could ultimately lead to more
confusion. The consumer article also makes a point to its readers that not everything
they read in the media is true. This is an essential message that all consumers should
know because it is how false beliefs arise.
Limitations-
There are a few limitations in both the primary research article and the consumer
article, but they do not undermine the validity of both.
My first concern with the primary research article is how difficult it is to potentially
understand, even to a scientific audience. I think this ultimately led to its
misinterpretation by a consumer audience. The researchers are clearly very
knowledgeable about their research, but I think they could have done a better job of
being more concise and clarifying in their writing. The article itself is rather lengthy and
its organization is confusing upon first reading. Within the research itself, the one big
limitation that I identified was the lack of diversity in the populations sampled. The
4. researchers used only Indians and Americans to seek a difference in genotype frequency
of the “vegetarian” allele. While these populations are good to contrast against one
another because Indians definitely eat more strict vegetarian diets than do Americans,
the results are really only useful for these specific populations. For example, it would be
deleterious to state that all vegetarian populations endogenously produce more fatty
acids than do non-vegetarian populations when, in fact, this was only found in two
sample populations.
The single limitation that I found in the consumer article is its confusing arrangement of
main ideas. The author explains why the research was misinterpreted at the very end of
the article. I think the article would be more clarifying to its audience if the author had
placed the reason for misinterpretation into the first few paragraphs of the text.
Implications:
For a nutrition professional, I think the results of the study are very interesting
and potentially informative for vegetarian clients. However, I don’t think they should be
used to alter diet patterns in clients. The research found that individuals consuming
vegetarian diets produced more endogenous fatty acids than did non-vegetarian
individuals, but it did not identify whether this led to positive or negative results.
Obviously, having this allele in vegetarians arose as an evolutionary advantage, so
nutrition professionals need not have their clients eat more or less fatty acids based on
this research. I think the information provided in the consumer article is actually more
advantageous to a nutrition professional than the primary research because it can help
a professional explain to his or her client how easily the media can cause
misinterpretation of nutrition information.
As stated above, I think the consumer article is actually more advantageous to
both a nutrition professional and a consumer audience because not only does it simplify
the research, but can help consumers see how easily they can be duped by the media.
The information provided in both the research and consumer articles should not be
used by consumers to alter their diets in any way. I think that it is potentially interesting
to a reader that vegetarians potentially produce more fatty acids based on genetic
evolution, but this idea should not lead to a change in food consumption.
