Evaluation of a novel food composition database that includes glutamine and other amino acids derived from gene sequencing data.
OBJECTIVE
To determine the content of glutamine in major food proteins.


METHODS
We used a validated 131-food item food frequency questionnaire (FFQ) to identify the foods that contributed the most to protein intake among 70,356 women in the Nurses' Health Study (NHS, 1984). The content of glutamine and other amino acids in foods was calculated based on protein fractions generated from gene sequencing methods (Swiss Institute of Bioinformatics) and compared with data from conventional (USDA) and modified biochemical (Khun) methods. Pearson correlation coefficients were used to compare the participants' dietary intakes of amino acids by sequencing and USDA methods.


RESULTS
The glutamine content varied from 0.01 to to 9.49 g/100 g of food and contributed from 1 to to 33% of total protein for all FFQ foods with protein. When comparing the sequencing and Kuhn's methods, the proportion of glutamine in meat was 4.8 vs 4.4%. Among NHS participants, mean glutamine intake was 6.84 (s.d.=2.19) g/day and correlation coefficients for amino acid between intakes assessed by sequencing and USDA methods ranged from 0.94 to 0.99 for absolute intake, -0.08 to 0.90 after adjusting for 100 g of protein, and 0.88 to 0.99 after adjusting for 1000 kcal. The between-person coefficient of variation of energy-adjusted intake of glutamine was 16%.


CONCLUSIONS
These data suggest that (1) glutamine content can be estimated from gene sequencing methods and (2) there is a reasonably wide variation in energy-adjusted glutamine intake, allowing for exploration of glutamine consumption and disease.
Lenders
C M
CM
Harvard School of Public Health, Boston, MA, USA. carine.lenders@bmc.org
Liu
S
S
Wilmore
D W
DW
Sampson
L
L
Dougherty
L W
LW
Spiegelman
D
D
Willett
W C
WC
D000328:Adult; D000596:Amino Acids / Q000008:administration & dosage / Q000032:analysis* / Q000235:genetics; D015331:Cohort Studies; D015930:Diet Records; D004034:Diet Surveys; D004044:Dietary Proteins / Q000008:administration & dosage / Q000032:analysis*; D005260:Female; D005973:Glutamine / Q000008:administration & dosage / Q000032:analysis / Q000235:genetics; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D020539:Sequence Analysis, Protein; D011795:Surveys and Questionnaires
D000596:Amino Acids; D004044:Dietary Proteins; D005973:Glutamine