Clinical trial NCT01342666: Tomato Consumption and High Density Lipoprotein-cholesterol
Official title: Effect of Tomato Consumption on Serum High Density Lipoprotein-cholesterol Levels. A Randomized, Open-label, Single Blind, Clinical Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hypoalphalipoproteinemia
Keywords: High density lipoprotein cholesterol
Tomato
Lycopene
Hypoalphalipoproteinemia
Dyslipidemia
Lead sponsor: Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran
Sponsor class: OTHER
Collaborators: name: Instituto Nacional de Cardiologia Ignacio Chavez
First posted: 2011-04-27
Enrollment: 50
Sex: ALL
Minimum age (years): 18
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: * This is a randomized, open-label, single blind, clinical trial
* The study evaluated the effect of tomato consumption in serum HDL-cholesterol levels.
* The hypothesis was that two daily tomatoes during one month will increase the HDL-c levels.
* Since a placebo of tomatoes cannot be done, the control group will receive same proportion of cucumber because 1) it was not possible to have a tomato placebo; 2) cucumber does not have any lycopene; 3) both can be prepared similarly; and 4) the required quantity can be measured in the same way.
* The intervention was during 1 month and was assigned by randomization.
* Personnel who did the clinical and biochemical evaluation were blinded for the intervention.
* Lipid profile was measured before and after the intervention.
* Confounding factors such as daily physical activity, diet, consumption of fish or alcoholic beverages, smoking status were considered during statistical analyses.

Detailed description: Cardiovascular disease (CVD) is a main cause of death worldwide (1) and there are well recognized risk factors associated with its development. Low high density lipoprotein-cholesterol (HDL-c) rank among the most common lipid abnormalities associated with CVD (2). Low HDL-c is currently defined as an HDL-c value below 40 mg/dL for men and below 50 mg/dL for women (3). Factors related with low HDL-c are cigarette smoking (4), high triglycerides (5), sedentary lifestyle (6), and insulin resistance (7). Non-pharmacologic strategies to increase HDL-c concentration are increasing alcohol (8) and fish consumption (9), weight reduction (3), increment in physical activity (10), and smoking cessation (8). Some of these strategies are not applicable or hard to implement in individuals affected with low HDL-c. Moreover, in low-income countries, these interventions could be costly for the general population. Vegetables consumption could be a more affordable and accessible option to treat low HDL-c. Epidemiologic evidence indicates that high consumption of vegetables reduces the risk of cardiovascular disease (11) and particular attention has received tomato-based products. Growing evidence from several epidemiological studies has indicated that lycopene, the major carotenoid in tomato (12), might be more important than other carotenoids in preventing atherosclerosis and CVD (13, 14). The consumption of more than 7 servings per week of tomato-based products has been associated with a 30% reduction in the relative risk of CVD (15). Such potential benefits to vascular health from a tomato-rich diet could be related to low arterial intimal wall thickness (13, 16), reduction of LDL cholesterol levels (17), and inverse correlation with markers of inflammation and vascular endothelial dysfunction (18). However, HDL-c levels could also be positively influenced by tomato consumption. In a pilot study we found that tomato juice consumption did not increase HDL-c after one month (unpublished data), this finding also was recently reported by another group (19). In contrast, other study showed that daily consumption of 300g of uncooked tomatoes, during one month significantly increased HDL-c levels by 15.2% (20). However, this study was not controlled, not blinded, and neither randomized. Roma tomatoes consumption could be an accessible intervention to improve HDL-c levels; however, a longitudinal clinical trial is necessary to evaluate this association. Therefore, we performed a randomized, open-label, single blind, clinical trial to specifically evaluate if consumption of two uncooked tomatoes per day (14 servings/week) during one month could produce a favorable effect on HDL-c.

Eligibility criteria: Inclusion Criteria:

* Males with HDL-c less than 40 mg/dl
* Females with HDL-c less than 50 mg/dl
* Age between 18 to 65 years old
* Acceptance for participation with signed informed consent

Exclusion Criteria:

Previous diagnosis of:

* Diabetes,
* Hypertension,
* Kidney, liver or heart insufficiency,
* Hyperuricemia,
* Hyperandrogenic anovulation,
* Thyroid dysfunction (hypo or hyperthyroidism),
* Any difficulty to swallow appropriately, or
* Hospitalization in the previous six months.

Additionally, those subjects under current treatment with fibrates, statins, nicotinic acid, steroids, allopurinol, hormone replacement therapy (testosterone, estrogens or progesterone), metformin, other oral hypoglycemic agents, insulin, sibutramine, or orlistat treatment and those with daily consumption of any non-steroidal anti-inflammatory drug were also excluded.

Primary outcomes:
measure: High Density Lipoprotein Cholesterol (HDL-c)
timeFrame: Baseline and after one month
Secondary outcomes:
Other outcomes:
Locations:
city: Mexico
country: Mexico
facility: Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran
state: Tlalpan
Study officials:
affiliation: Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran
name: Francisco J Gomez-Perez, MD, FACE
role: PRINCIPAL_INVESTIGATOR
References:
citation: Ali MM, Agha FG. Amelioration of streptozotocin-induced diabetes mellitus, oxidative stress and dyslipidemia in rats by tomato extract lycopene. Scand J Clin Lab Invest. 2009;69(3):371-9. doi: 10.1080/00365510802658473.
citation: Agarwal S, Rao AV. Tomato lycopene and low density lipoprotein oxidation: a human dietary intervention study. Lipids. 1998 Oct;33(10):981-4. doi: 10.1007/s11745-998-0295-6.
citation: Arab L, Steck S. Lycopene and cardiovascular disease. Am J Clin Nutr. 2000 Jun;71(6 Suppl):1691S-5S; discussion 1696S-7S. doi: 10.1093/ajcn/71.6.1691S.
citation: Blum A, Merei M, Karem A, Blum N, Ben-Arzi S, Wirsansky I, Khazim K. Effects of tomatoes on the lipid profile. Clin Invest Med. 2006 Oct;29(5):298-300.
citation: Denniss SG, Haffner TD, Kroetsch JT, Davidson SR, Rush JW, Hughson RL. Effect of short-term lycopene supplementation and postprandial dyslipidemia on plasma antioxidants and biomarkers of endothelial health in young, healthy individuals. Vasc Health Risk Manag. 2008;4(1):213-22. doi: 10.2147/vhrm.2008.04.01.213.
citation: Ashen MD, Blumenthal RS. Clinical practice. Low HDL cholesterol levels. N Engl J Med. 2005 Sep 22;353(12):1252-60. doi: 10.1056/NEJMcp044370. No abstract available.
citation: Fuhrman B, Elis A, Aviram M. Hypocholesterolemic effect of lycopene and beta-carotene is related to suppression of cholesterol synthesis and augmentation of LDL receptor activity in macrophages. Biochem Biophys Res Commun. 1997 Apr 28;233(3):658-62. doi: 10.1006/bbrc.1997.6520.
citation: Gianetti J, Pedrinelli R, Petrucci R, Lazzerini G, De Caterina M, Bellomo G, De Caterina R. Inverse association between carotid intima-media thickness and the antioxidant lycopene in atherosclerosis. Am Heart J. 2002 Mar;143(3):467-74. doi: 10.1067/mhj.2002.120776.
citation: Kohlmeier L, Kark JD, Gomez-Gracia E, Martin BC, Steck SE, Kardinaal AF, Ringstad J, Thamm M, Masaev V, Riemersma R, Martin-Moreno JM, Huttunen JK, Kok FJ. Lycopene and myocardial infarction risk in the EURAMIC Study. Am J Epidemiol. 1997 Oct 15;146(8):618-26. doi: 10.1093/oxfordjournals.aje.a009327.
citation: Re R, Mishra GD, Thane CW, Bates CJ. Tomato consumption and plasma lycopene concentration in people aged 65 y and over in a British national survey. Eur J Clin Nutr. 2003 Dec;57(12):1545-54. doi: 10.1038/sj.ejcn.1601723.