Dietary (Poly)phenols, Brown Adipose Tissue Activation, and Energy Expenditure: A Narrative Review

Abstract

The incidence of overweight and obesity has reached epidemic proportions, making the control of body weight and its complications a primary health problem. Diet has long played a first-line role in preventing and managing obesity. However, beyond the obvious strategy of restricting caloric intake, growing evidence supports the specific antiobesity effects of some food-derived components, particularly (poly)phenolic compounds. The relatively new rediscovery of active brown adipose tissue in adult humans has generated interest in this tissue as a novel and viable target for stimulating energy expenditure and controlling body weight by promoting energy dissipation. This review critically discusses the evidence supporting the concept that the antiobesity effects ascribed to (poly)phenols might be dependent on their capacity to promote energy dissipation by activating brown adipose tissue. Although discrepancies exist in the literature, most in vivo studies with rodents strongly support the role of some (poly)phenol classes, particularly flavan-3-ols and resveratrol, in promoting energy expenditure. Some human data currently are available and most are consistent with studies in rodents. Further investigation of effects in humans is warranted.

Keywords: brown adipose tissue; dietary (poly)phenols; energy expenditure; flavan-3-ols; obesity; resveratrol; uncoupled protein 1.

FIGURE 1

Adrenergic stimulation of thermogenesis. AC, adenylate cyclase; ATF2, activating transcription factor 2; CPT1, carnitine palmitoyltransferase 1; CREB, cAMP response element binding protein; FAO, fatty acid oxidation; Gs, Gs α subunit; HSL, hormone-sensitive lipase; NE, norepinephrine; p, phosphate group; PKA, protein kinase A; p38, p38 mitogen-activated protein kinase; TAG, triacylglycerol; UCP1, uncoupling protein 1; β-AR, β-adrenergic receptor.

FIGURE 2

Transcriptional regulation of beige and brown adipocytes. Ac, acetyl group; AMPK, 5′-AMP–activated protein kinase; ATF2, activating transcription factor 2; C/EBP α/β/δ, CCAAT/enhancer-binding protein α/β/δ CREB, cAMP response element binding protein; FOXC2, forkhead box protein C2; FOXO1, forkhead box protein O1; p, phosphate group; PGC-1α, PPAR-γ coactivator-1α PPAR-α/γ, peroxisome proliferator–activated receptor α/γ PRDM16, PR domain zinc finger protein 16; p38, p38 mitogen-activated protein kinase; RXR, retinoid X receptor; SIRT1, sirtuin 1.

FIGURE 3

Chemical structures and food sources of the (poly)phenols described as modulators of energy expenditure.

FIGURE 4

Dietary (poly)phenols in the stimulation of energy expenditure. AMPK, 5′-AMP–activated protein kinase; BAT, brown adipose tissue; COMT, catechol-O-methyl transferase; PGC-1α, PPAR-γ coactivator-1α SIRT1, sirtuin 1; SNS, sympathetic nervous system; WAT, white adipose tissue.