Table 3.

Summary of the included studies assessing the association between flavonoid intake, exercise performance, and immune status biomarkers in humans.

Reference	Flavonoid	Dosage	Exercise	Effect on Performance	Measurement	Outcome
Quercetin
[59]	quercetin + Tang powder	1000 mg/d for 3 wks	Three 3-h cycling bouts	NS	plasma inflammatory cytokines (IL-6, IL-10, IL-1ra, IL-8, MCP-1, TNF-α) leukocyte mRNA muscle mRNA	= plasma inflammatory cytokines ↓ leukocyte gene expression of IL-8 and IL-10
[52]	quercetin + Tang powder	1000 mg/d for 3 wks	Three 3-h cycling bouts	NS	NK cell activity proliferative activity PMN oxidative-burst activity salivary IgA incidence of URTI	= NK cell activity = proliferative activity = PMN oxidative-burst activity = IgA ↓ incidence of URTI
[60]	quercetin + vit C + niacin	1000 mg/d quercetin + 1000 mg/d vit C + 80 mg/d niacin for 3 wks	160-km Western States Endurance Run	NS	CRP Plasma inflammatory cytokines (IL-1Ra, IL-6, IL-8, IL-10, G-CSF, MCP-1, MIP-1β, TNF-α, MIF-1) leukocyte gene expression of some cytokines	= CRP = plasma inflammatory cytokines = leukocyte gene expression
[56]	quercetin-3- glucoside + 6% carbohydrate sports drink	1000 mg/d for 1 wk	Running repeated sprints	NS	plasma IL-6	= plasma IL-6
[61]	Quercetin + isoquercetin + EGCG	1000 mg quercetin + 120 mg EGCG + 400 mg/d isoquercetin for 14 d	Cycling	NS	plasma CRP plasma IL-6 and IL-10 blood leukocyte counts salivary IgA	= plasma CRP = plasma IL-6 and IL-10 ↓ blood leukocyte counts = salivary IgA
[50]	Quercetin + vit C + tocopherols	1000 mg/d quercetin + 20 mg/d vit C + 14 mg/d tocopherols for 1 wk	Eccentric contractions of the elbow flexors	NS	plasma IL-6 plasma CRP	= IL-6 = CRP
Extracts with flavanols
[85]	Green tea extract	159 mg/d catechins for 3 wks	Cycling	NS	plasma IL-6 plasma CRP	= IL-6 ↓ CRP
[97]	Blueberry–green tea–polyphenol soy protein complex	1001 mg/d flavanols for 17 d	Running in a treadmill for 2.5 h	NS	WBC count serum CRP plasma IL-6, MCP-1	= WBC = CRP = plasma IL-6, MCP-1
[98]	Blueberry–green tea–polyphenol soy protein complex	1001 mg/d flavanols for 17 d	Running in a treadmill for 2.5 h	NS	ex vivo antibacterial activity ex vivo antiviral activity	= ex vivo antibacterial activity ↑ ex vivo antiviral activity
[65]	Flavanol-rich lychee fruit extract	100 mg/d flavanols for 2 months	Running training, combining low, medium, and high intensities	NS	Total and differential WBC counts CRP serum inflammatory (IL-6) and anti-inflammatory cytokines (IL-10, TFG-β1, TFG-β2)	↓ WBC counts, = neutrophil and lymphocyte counts = CRP = absolute IL-6, IL-10, TFG-β1, TFG-β2 ↓ % IL-6 and TFG-β1 from pre-training to mid-training period
[67]	Nonalcoholic beer	1.0–1.5 L/d with 47 mg/L catechin and 33 mg/L procyanidins for 3 wks	Munich marathon race	NS	IL-6 CRP total blood leukocyte counts incidence of URTI	↓ IL-6 ↓ CRP ↓ WBC ↓ URTI incidence
[26]	Dark chocolate	197.4 mg flavanols for 2 wks	Incremental cycling	NS	inflammatory and anti- inflammatory cytokines WBC, neutrophil counts	= IL-6, IL-1ra, IL-10 = WBC, neutrophil counts
Extracts with anthocyanins
[77]	New Zealand blackcurrant	210 mg/d anthocyanins for 7 d	Chichester half-marathon	NS	urine IL-6	= urine IL-6
[82]	Montmorency tart cherry concentrate	547.02 mg/d anthocyanins for 7 d	Cycling trial	NS	hs-CRP blood inflammatory cytokines	↓ hs-CRP ↓ IL-6 = IL-1β, IL-8, TNFα
[84]	Montmorency tart cherry	66 mg/d anthocyanins for 10 d	Running (half-marathon)	Improvement	serum inflammatory cytokines (TNF α, IFN-γ, IL-1β, IL-2, IL-6, IL-8, IL-12p70) serum anti-inflammatory cytokines (IL-4, IL-5, IL-7, IL-10, IL-13) total and differential WBC GM-CSF	↓ IL-6, ↓ IL-2, = remaining cytokines ↓ IL-13, = remaining cytokines = WBC = GM-CSF.
[86]	Integral purple grape juice	10 mL/kg/d containing 52.6 mg/L anthocyanins for 28 d	Treadmill running	Improvement	serum AGP hs-CRP WBC	↓ AGP = hs-CRP = WBC
[87]	Blueberry powder	345 mg/d anthocyanins for 2 wks	Cycling	NS	Inflammatory cytokines Oxylipins	= IL-6, IL-1ra ↓ some oxylipins
Extracts with ellagitannins
[91]	Pomegranate juice	50 mL/d juice containing 220 mg/100 g polyphenols for 2 months	Rowing ergonometer	NS	Serum inflammatory cytokines	= IL-6, IL-1ra

↓ = decrease, ↑ = increase, AGP = α-1-acid glycoprotein, CRP = plasma C-reactive protein, GM-CSF = granulocyte colony-stimulating factor, hs= high-sensitivity, IFN = interferon, IgA = immunoglobulin A, IL = interleukin, MCP-1 = monocyte chemoattractant protein-1, NK = natural killer, PMN = polymorphonuclear leukocytes, TGF = transforming growth factor, TNF = tumor necrosis factor, URTI = upper-respiratory tract infections, vit = vitamin, WBC = white blood cells.