A prospective study of erythrocyte polyunsaturated fatty acids and risk of colorectal serrated polyps and conventional adenomas

Abstract

The influence of polyunsaturated fatty acids (PUFAs) on risk of colorectal cancer precursors remains largely unknown. We examined the associations of erythrocyte PUFAs, including n−3 and n−6 PUFAs, with risk of colorectal conventional adenomas and serrated polyps in 4517 participants from three US prospective cohorts who had provided a blood sample and undergone at least one endoscopic examination. We calculated the multivariable odds ratios (ORs) per 1 SD increment in individual PUFAs and the ratio of n−6/n−3 PUFAs. We considered P < .005 statistically significant to account for multiple testing. During a median of 20 years of follow-up, we documented 493 conventional adenomas and 316 serrated polyps. After adjusting for various CRC risk factors, no associations for PUFAs achieved the stringent statistical significance for either conventional adenomas or serrated polyps (ORs per 1 SD ranged from 0.90 to 1.14). Some associations achieved nominal significance (P < .05), including the association of dihomogammalinolenic acid (DGLA)

Omega-3 polyunsaturated fatty acids: moving towards precision use for prevention and treatment of colorectal cancer

“…This large US study (n=1 41 143 with follow-up for 18–20 years) found that increased intake of marine O3FAs was associated with lower risk of both CA (p<0.001) and SP (p=0.004) 21. However, a smaller study inside the same prospective cohort did not observe any relationship between red blood cell (RBC) O3FA (as the % total fatty acids) and risk of either CA (n=493, median RBC EPA level 0.44%) or SP (n=316, median RBC EPA 0.43%) 22…”

“…The difference in EPA content (as % total fatty acids) between these studies highlights heterogeneity in study populations that makes interpretation of the relationship between tissue O3FA levels and neoplastic risk challenging, even when detailed dietary data are available (table 1). 22 25 26…”

Association of Dietary Intake and Biomarker of α-Linolenic Acid With Incident Colorectal Cancer: A Dose-Response Meta-Analysis of Prospective Cohort Studies

“…Eleven cohorts of dietary intake of ALA were included, involving 10,583 cases and 854,818 participants in 9 prospective cohort studies ( 10 , 30 , 31 , 33 – 36 , 38 , 39 ) and 2 case-cohort studies ( 32 , 37 ), and dietary measurements were evaluated by food frequency questionnaires. For biomarkers of ALA, 5 prospective studies were included, involving 2,051 cases and 48,421 participants in 2 studies based on plasma ( 17 , 37 ), 2 on erythrocyte ( 18 , 40 ), and 1 on AT ( 16 ). ALA levels in different biospecimens were quantified by gas-liquid chromatography (GLC) and the measurement unit was set as a percentage, except for one study (μmol/L) ( 17 ).…”

“…Both male and female were reported in five articles ( 17 , 32 , 37 , 39 , 40 ), only male in two articles ( 10 , 30 ), only female in four articles ( 18 , 31 , 34 , 38 ), and 4 articles separately reported male and female ( 16 , 33 , 35 , 36 ). As for CRC locations, 13 articles reported total CRC ( 10 , 16 – 18 , 30 , 31 , 33 – 39 ), whereas 2 articles only separately reported colon cancer and rectal cancer ( 32 , 40 ). Among all of the included studies, quality scores assessed by the 9-star NOS ranged from 7 to 9, with a median quality (≤7 stars) in 2 studies ( 36 , 39 ) and high quality (≥ 8 stars) in 13 studies.…”

“…ALA levels in different biospecimens were quantified by gas-liquid chromatography (GLC) and the measurement unit was set as a percentage, except for one study (μmol/L) ( 17 ). Both male and female were reported in five articles ( 17 , 32 , 37 , 39 , 40 ), only male in two articles ( 10 , 30 ), only female in four articles ( 18 , 31 , 34 , 38 ), and 4 articles separately reported male and female ( 16 , 33 , 35 , 36 ). As for CRC locations, 13 articles reported total CRC ( 10 , 16 – 18 , 30 , 31 , 33 – 39 ), whereas 2 articles only separately reported colon cancer and rectal cancer ( 32 , 40 ).…”