Disease
type

First
Author

Study Title and
Complete Citation

Date

Abstract

Study Type

G.Tom
+, N, -

P.Tom
+, N, -

F.Tom
+, N, -

Lyco
+, N, -

Other
+, N, -

Chronic Disease Risk

Stahl W

Lycopene: a biologically important carotenoid for humans?

Stahl W, Sies H.

Arch Biochem Biophys. 1996 Dec 1;336(1):1-9. 

1996

Lycopene is a carotenoid present in human blood (approximately 0.5 micromol/liter plasma), and the tissue levels vary from 1 nmol/g wet wt in adipose tissue to up to 20 nmol/g wet wt in adrenals and testes. Its biological activities include antioxidant activity (singlet oxygen quenching and peroxyl radical scavenging), induction of cell-cell communication, and growth control, but no provitamin A activity. Epidemiological studies suggest protective effects of lycopene on some types of cancer, e.g., prostate cancer. In vitro and in vivo studies on growth of tumor cells support this conclusion. The major sources of lycopene for the human are tomatoes and tomato products, and bioavailability from different food items varies considerably. Lycopene oxidation products have recently been identified in human serum. Suggested health effects of lycopene require further investigation.

Review

Chronic Disease Risk

Weisburger JH

Evaluation of the evidence on the role of tomato products in disease prevention.

Weisburger JH.

Proc Soc Exp Biol Med. 1998 Jun;218(2):140-3.

1998

During the last 30 years, research in the field of nutrition and chronic disease causation has led to exciting, significant progress in providing an understanding of specific risk factors and chemopreventive agents. The major health problems considered are cardiovascular diseases and the nutritionally linked cancers, including those in the stomach, colon, breast, prostate, ovary, and endometrium. The major elements considered were salt, type and amount of fat, and heterocyclic amines formed during cooking. Bran cereal fiber, as well as vegetables, fruits, and tea have been shown to inhibit the complex processes of initiation and development of these diseases. One aspect involved in initiation and development of both cardiovascular diseases and the cancers noted are abnormal oxidative processes leading to the generation of hydroxy radicals and peroxy compounds. In part, the protective role of vegetables, fruits, and tea is to provide antioxidant vitamins and specific polyphenols that display a powerful inhibition in oxidative reactions. Epidemiological studies as well as laboratory experimentation have yielded sound data and evidence in support of the fact that vegetables, fruits, and tea and specific antioxidants therein account mechanistically for inhibition. Geographic pathology has provided important data that populations with a regular intake of tomato products, such as in the Mediterranean region, have a lower incidence of the chronic diseases noted. The current Symposium is considering the varied mechanisms of action of tomato products in general, and one of the active principles, lycopene. Cooking is a factor in releasing the desirable antioxidants from tomatoes. Cooked tomato products may be preferable to the raw vegetable or juices derived from tomatoes bearing on absorption of the active principles. Optimally, absorption of lycopene, a highly lipid-soluble chemical, is improved in the presence of a small, but essential amount of oil or fat. Research in the field of nutrition and health has shown that monounsaturated oils such as olive oil or canola oil are most desirable, since such oils do not increase the risk of atherosclerosis, coronary heart disease, or the nutritionally linked cancers. The International Symposium on tea conducted in 1991 has provided worldwide interest in research on the beneficial effects of tea. It is now hoped that the present Symposium, dealing with another inexpensive and readily available food, tomatoes, will enhance interest in and funding for additional research, to underwrite future recommendations for possibly enhanced production and use of tomato-derived nutritional elements, with the goal of application to the prevention of major chronic diseases, the treatment of which is costly and often ineffective.

Review

N/(-)

↓ disease risk

Chronic Disease Risk

Fairfield KM

Vitamins for chronic disease prevention in adults: scientific review.

Fairfield KM, Fletcher RH.

JAMA. 2002 Jun 19;287(23):3116-26. 

2002

CONTEXT: Although vitamin deficiency is encountered infrequently in developed countries, inadequate intake of several vitamins is associated with chronic disease.

OBJECTIVE: To review the clinically important vitamins with regard to their biological effects, food sources, deficiency syndromes, potential for toxicity, and relationship to chronic disease.

DATA SOURCES AND STUDY SELECTION: We searched MEDLINE for English-language articles about vitamins in relation to chronic diseases and their references published from 1966 through January 11, 2002.

DATA EXTRACTION: We reviewed articles jointly for the most clinically important information, emphasizing randomized trials where available.

DATA SYNTHESIS: Our review of 9 vitamins showed that elderly people, vegans, alcohol-dependent individuals, and patients with malabsorption are at higher risk of inadequate intake or absorption of several vitamins. Excessive doses of vitamin A during early pregnancy and fat-soluble vitamins taken anytime may result in adverse outcomes. Inadequate folate status is associated with neural tube defect and some cancers. Folate and vitamins B(6) and B(12) are required for homocysteine metabolism and are associated with coronary heart disease risk. Vitamin E and lycopene may decrease the risk of prostate cancer. Vitamin D is associated with decreased occurrence of fractures when taken with calcium.

CONCLUSIONS: Some groups of patients are at higher risk for vitamin deficiency and suboptimal vitamin status. Many physicians may be unaware of common food sources of vitamins or unsure which vitamins they should recommend for their patients. Vitamin excess is possible with supplementation, particularly for fat-soluble vitamins. Inadequate intake of several vitamins has been linked to chronic diseases, including coronary heart disease, cancer, and osteoporosis.

Review of RCT studies

(-)

↓ risk prostate cancer

Chronic Disease Risk

Weisburger JH

Lycopene and tomato products in health promotion.

Weisburger JH.

Exp Biol Med (Maywood). 2002 Nov;227(10):924-7.

2002

International research through epidemiological techniques has provided information on risk factors and preventive approaches in chronic disease. Causation complementing this base of knowledge with laboratory research on associated markers for each disease has outlined the possible mechanisms whereby risk factors and preventive conditions operate. Furthermore, laboratory research in animal models and cell cultures has expanded the appropriate elements associated with each condition. Individuals in the Mediterranean area present with a lower risk of several important chronic diseases, including coronary heart disease and a number of types of cancer associated with nutritional traditions, such as breast, colon, and prostate cancer. Vegetables and fruits in general and cooked tomatoes, together with olive oil, appear to be the nutritional traditions that account for this lower risk. These results lead to public health recommendations to consume more vegetables and, especially, cooked tomatoes with olive oil.

Review

(-)
↓ cancer risk by having ↑ intake

Chronic Disease Risk

Rao AV

Lycopene.

Rao AV, Ray MR, Rao LG.

Adv Food Nutr Res. 2006;51:99-164.

2006

Oxidative stress is now recognized as an important etiological factor in the causation of several chronic diseases including cancer, cardiovascular diseases, osteoporosis, and diabetes. Antioxidants play an important role in mitigating the damaging effects of oxidative stress on cells. Lycopene, a carotenoid antioxidant, has received considerable scientific interest in recent years. Epidemiological, tissue culture, and animal studies provide convincing evidence supporting the role of lycopene in the prevention of chronic diseases. Human intervention studies are now being conducted to validate epidemiological observations and to understand the mechanisms of action of lycopene in disease prevention. To obtain a better understanding of the role of lycopene in human health, this chapter reviews the most recent information pertaining to its chemistry, bioavailability, metabolism, role in the prevention of prostate cancer and cancer of other target organs, its role in cardiovascular diseases, osteoporosis, hypertension, and male infertility. A discussion of the most relevant molecular markers of cancer is also included as a guide to future researchers in this area. The chapter concludes by reviewing global intake levels of lycopene, suggested levels of intake, and future research directions.

Review

(-)

↓general disease risk

Chronic Disease Risk

Rao AV

Carotenoids and human health.

Rao AV, Rao LG.

Pharmacol Res. 2007 Mar;55(3):207-16. Epub 2007 Jan 25.

2007

Dietary guidelines recommend increased consumption of fruits and vegetables to combat the incidence of human diseases such as cancer, cardiovascular disease, osteoporosis and diabetes. Fruits and vegetables are good sources of antioxidant phytochemicals that mitigate the damaging effect of oxidative stress. Carotenoids are a group of phytochemicals that are responsible for different colors of the foods. They are recognized as playing an important role in the prevention of human diseases and maintaining good health. In addition to being potent antioxidants some carotenoids also contribute to dietary vitamin A. There is scientific evidence in support of the beneficial role of phytochemicals in the prevention of several chronic diseases. Although the chemistry of carotenoids has been studied extensively, their bioavailability, metabolism and biological functions are only now beginning to be investigated. Recent interest in carotenoids has focused on the role of lycopene in human health. Unlike some other carotenoids, lycopene does not have pro-vitamin A properties. Because of the unsaturated nature of lycopene it is considered to be a potent antioxidant and a singlet oxygen quencher. This article will review carotenoids in general and lycopene in particular for their role in human health.

Review

(-)

↓ CVD risk
↓ cancer risk
↓ disease risk
↓ Ox stress

Chronic Disease Risk

Erdman JW Jr

Are the health attributes of lycopene related to its antioxidant function?

Erdman JW Jr, Ford NA, Lindshield BL.

Arch Biochem Biophys. 2009 Mar 15;483(2):229-35. Epub 2008 Nov 1.

2009

A variety of epidemiological trials have suggested that higher intake of lycopene-containing foods (primarily tomato products) or blood lycopene concentrations are associated with decreased cardiovascular disease and prostate cancer risk. Of the carotenoids tested, lycopene has been demonstrated to be the most potent in vitro antioxidant leading many researchers to conclude that the antioxidant properties of lycopene are responsible for disease prevention. In our review of human and animal trials with lycopene, or lycopene-containing extracts, there is limited support for the in vivo antioxidant function for lycopene. Moreover, tissue levels of lycopene appear to be too low to play a meaningful antioxidant role. We conclude that there is an overall shortage of supportive evidence for the "antioxidant hypothesis" as lycopene's major in vivo mechanism of action. Our laboratory has postulated that metabolic products of lycopene, the lycopenoids, may be responsible for some of lycopene's reported bioactivity.

Review

N

limited evidence for role as anti-ox

Chronic Disease Risk

Arab L

Lycopene and cardiovascular disease.

Arab L, Steck S.

Am J Clin Nutr. 2000 Jun;71(6 Suppl):1691S-5S; discussion 1696S-7S. 

2000

Considerable evidence suggests that lycopene, a carotenoid without provitamin A activity found in high concentrations in a small set of plant foods, has significant antioxidant potential in vitro and may play a role in preventing prostate cancer and cardiovascular disease in humans. Tomato products, including ketchup, tomato juice, and pizza sauce, are the richest sources of lycopene in the US diet, accounting for >80% of the total lycopene intake of Americans. Unlike other carotenoids, lycopene is not consistently lower among smokers than among nonsmokers, suggesting that any possible preventive activity is not as an antioxidant. Instead, lycopene may have a cholesterol synthesis-inhibiting effect and may enhance LDL degradation. Available evidence suggests that intimal wall thickness and risk of myocardial infarction are reduced in persons with higher adipose tissue concentrations of lycopene. The question of whether lycopene helps to prevent cardiovascular disease can only be answered by a trial specifically evaluating its effectiveness in this area.

Review

(-)

↑ [lyco] in adipose:
↓ MI risk & ↓ intimal wall thickness