Postprandial Inflammatory Responses and Free Fatty Acids in Plasma of Adults Who Consumed a Moderately High-Fat Breakfast with and without Blueberry Powder in a Randomized Placebo-Controlled Trial.
Saturated fatty acids (FAs) released from triglyceride-rich lipoproteins (TGRLs) activate Toll-like receptor 2 (TLR-2) and induce the expression of proinflammatory cytokines in monocytes. Certain plant polyphenols inhibit TLR-mediated signaling pathways.



We determined whether plasma free FAs (FFAs) after a moderately high-fat (MHF, 40% kcal from fat) breakfast modulate the inflammatory status of postprandial blood, and whether blueberry intake suppresses FFA-induced inflammatory responses in healthy humans.



Twenty-three volunteers with a mean ± SEM age and body mass index (in kg/m(2)) of 30 ± 3 y and 21.9 ± 0.4, respectively, consumed an MHF breakfast with either a placebo powder or 2 or 4 servings of blueberry powder in a randomized crossover design. The placebo powder was provided on the first test day and the blueberry powder doses were randomized with a 2-wk washout period. Plasma concentrations of lipids, glucose, and cytokines were determined. To determine whether FFAs derived from TGRL stimulate monocyte activation, and whether this is inhibited by blueberry intake, whole blood was treated with lipoprotein lipase (LPL).



The median concentrations of FFAs and cytokines [tumor necrosis factor-α, interleukin (IL)-6 and IL-8] in postprandial plasma (3.5 h) decreased compared with fasting plasma regardless of the blueberry intake (P < 0.001 for FFAs and P < 0.05 for cytokines). However, concentrations of FFAs and cytokines including IL-1β increased in LPL-treated whole blood compared with untreated blood samples from participants who consumed the placebo powder. Blueberry intake suppressed IL-1β and IL-6 production in LPL-treated postprandial blood compared with the placebo control when fasting changes were used as a covariate.



The plasma FFA concentration may be an important determinant affecting inflammatory cytokine production in blood. Supplementation with blueberry powder did not affect plasma FFA and cytokine concentrations; however, it attenuated the cytokine production induced by ex vivo treatment of whole blood with LPL. This trial was registered at clinicaltrials.gov as NCT01594008.
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA; Department of Nutrition and.
Kikumi D
KD
Ono-Moore
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA; Department of Nutrition and.
Ryan G
RG
Snodgrass
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA;
Shurong
S
Huang
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA;
Shamsher
S
Singh
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA;
Tammy L
TL
Freytag
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA;
Dustin J
DJ
Burnett
Department of Nutrition and.
Ellen L
EL
Bonnel
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA;
Leslie R
LR
Woodhouse
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA; Department of Nutrition and.
Susan J
SJ
Zunino
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA; Department of Nutrition and.
Janet M
JM
Peerson
College of Pharmacy, The Catholic University of Korea, Bucheon, South Korea.
Joo Young
JY
Lee
Department of Internal Medicine, School of Medicine, University of California, Davis, CA; and.
John C
JC
Rutledge
Western Human Nutrition Research Center, Agricultural Research Service/USDA, Davis, CA; Department of Nutrition and daniel.hwang@ars.usda.gov.
Daniel H
DH
Hwang
D000328:Adult; D029798:Blueberry Plants; D018592:Cross-Over Studies; D016207:Cytokines / Q000097:blood / Q000378:metabolism; D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000378:metabolism / Q000517:prevention & control; D062407:Meals; D009000:Monocytes / Q000187:drug effects / Q000502:physiology; D019518:Postprandial Period; D011208:Powders
D016207:Cytokines; D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified; D011208:Powders
antioxidants; blueberries; cytokines; diet and dietary lipids; lipoprotein lipase; monocyte activation; plasma free fatty acids; postprandial inflammation; postprandial lipemia