British Journal of Nutrition

Full Papers

Tomato juice decreases LDL cholesterol levels and increases LDL resistance to oxidation

Marja-Leena Silastea1a2, Georg Alfthana3, Antti Aroa3, Y. Antero Kesäniemia1a2 and Sohvi Hörkköa2a4 c1

a1 Department of Internal Medicine, University of Oulu, P.O. Box 5000, 90014 Oulu, Finland

a2 Biocenter Oulu, P.O. Box 5000, 90014 University of Oulu, Oulu, Finland

a3 National Public Health Institute (KTL), Mannerheimintie 166, 00300 Helsinki, Finland

a4 Department of Farmacology and Toxicology, University of Oulu, P.O. Box 5000, FIN-90014 Oulu, Finland

Abstract

High dietary intakes of tomato products are often associated with a reduced risk of CVD, but the atheroprotective mechanisms have not been established. This study was conducted to investigate the effects of increased dietary intake of tomato products on plasma lipids and LDL oxidation. The diet intervention included a baseline period, a 3-week low tomato diet (no tomato products allowed) and a 3-week high tomato diet (400 ml tomato juice and 30 mg tomato ketchup daily). Twenty-one healthy study subjects participated in the study. Total cholesterol concentration was reduced by 5·9 (sd 10) % (P = 0·002) and LDL cholesterol concentration by 12·9 (sd 17·0) % (P = 0·0002) with the high tomato diet compared to the low tomato diet. The changes in total and LDL cholesterol concentrations correlated significantly with the changes in serum lycopene (r 0·56, P = 0·009; r 0·60, P = 0·004, total and LDL, respectively), β-carotene (r 0·58, P = 0·005; r 0·70, P < 0·001) and γ-carotene concentrations (r 0·64, P = 0·002; r 0·64, P = 0·002). The level of circulating LDL to resist formation of oxidized phospholipids increased 13 % (P = 0·02) in response to the high tomato diet. In conclusion, a high dietary intake of tomato products had atheroprotective effects, it significantly reduced LDL cholesterol levels, and increased LDL resistance to oxidation in healthy normocholesterolaemic adults. These atheroprotective features associated with changes in serum lycopene, β-carotene and γ-carotene levels.

(Received January 24 2007)

(Revised April 26 2007)

(Accepted April 30 2007)

Correspondence:

c1 Corresponding author: Dr Sohvi Hörkkö, Department of Farmacology and Toxicology, fax +358 8 5375247, email sohvi.horkko @oulu.fi