Lycopene's Role In Reducing The Risk Of Prostate Cancer
Who would have thought that one of a man?s best sources of
protection against prostate cancer is a tomato? The substance that
gives the tomato its deep red color may also reduce a man?s risk of
developing prostate cancer by 35%.
The tomato?s newfound miracle nutrient is called lycopene, and it
belongs to a family of natural pigments (carotenoids) found in plants
and animals. Beta carotene, the orange-colored precursor to vitamin A,
is probably the best known of the approximately 500 carotenoids found
in nature.
According to the most current research, lycopene is a top-flight
antioxidant, obtained through the diet from tomatoes (or, now, from
lycopene supplements) and capable of protecting the body against many
degenerative diseases, including cancer.
Researchers from Harvard University Medical School studied 47,894
men, age 40 to 75 and free of any diagnosed cancer, over a six-year
period. Their dietary preferences and consumption frequency for 131
foods and beverages were assessed, providing researchers a detailed
picture of the yearly nutrient intake of each man.
Of the 46 foods, tomato sauce, tomatoes, pizza, and strawberries
were associated with a reduced risk of prostate cancer. The researchers
learned that the first three of these foods were the primary dietary
sources of lycopene, accounting for 82% of the lycopene intake for the
men. (While strawberries were associated with a reduced prostate cancer
risk, they are not a significant source of lycopene.) Those who
consumed ten or more servings of these three tomato-based foods per
week had a 35% reduced chance of developing prostate cancer.
The lycopene in these foods is one of five groups of carotenoids: No
measurable protective effect against prostate cancer was noted among
the four other primary carotenoids: alpha carotene (found in carrots),
beta carotene (in yams, sweet potatoes, yellow squash), lutein (found
in dark green, leafy vegetables), and beta-cryptoxanthin (in oranges).
It?s important to know that lycopene is the predominant carotenoid
found in the blood, in various tissues (such as liver, kidney, adrenal
glands, testes, and ovaries), and in the prostate gland itself.
Research suggests that lycopene is an essential part of the body?s
natural defense against harmful oxidizing agents such as free radicals.
Lycopene is now being touted as a highly capable antioxidant; Dr.
Giovannucci pointed out that copene is the most efficient scavenger of
singlet oxygen [free radicals] among the common carotenoids.?
If tomatoes are a key factor in natural prostate protection, it?s
logical that food scientists would seek a lycopene-rich strain.
Scientists in Israel, working for Lyco-Red Natural Products Industries
in Beer-Sheva, used traditional cross-breeding methods to produce a
tomato with up to four times more lycopene than is found in regular
tomatoes.
The extract from these hybridized tomatoes (grown by organic
methods) is called Lyc-O-Mato? and it takes two metric tons of the
lycopene-enriched tomatoes to produce one gram of the lycopene extract,
which is mixed with tomato oil, beta carotene, and vitamin E for better
absorption and additional antioxidant benefits. The Lyc-O-Mato? extract
is now used in at least 13 nutritional supplements.
A diet rich in carotenoid-containing foods is associated with a
number of health benefits. Lycopene provides the familiar red color to
tomato products and is one of the major carotenoids in the diet of
North Americans and Europeans. Interest in lycopene is growing rapidly
following the recent publication of epidemiologic studies implicating
lycopene in the prevention of cardiovascular disease and cancers of the
prostate or gastrointestinal tract. Lycopene has unique structural and
chemical features that may contribute to specific biological
properties. Data concerning lycopene bioavailability, tissue
distribution, metabolism, excretion, and biological actions in
experimental animals and humans are beginning to accumulate although
much additional research is necessary.
Increasing clinical evidence supports the role of lycopene as a
micronutrient with important health benefits, because it appears to
provide protection against a broad range of epithelial cancers.
Tomatoes and related tomato products are the major source of lycopene
compounds, and are also considered an important source of carotenoids
in the human diet. Undesirable degradation of lycopene not only affects
the sensory quality of the final products, but also the health benefit
of tomato-based foods for the human body. Lycopene in fresh tomato
fruits occurs essentially in the all-trans configuration. The main
causes of tomato lycopene degradation during processing are
isomerization and oxidation. Isomerization converts all-trans isomers
to cis-isomers due to additional energy input and results in an
unstable, energy-rich station. Determination of the degree of lycopene
isomerization during processing would provide a measure of the
potential health benefits of tomato-based foods. Frozen foods and
heat-sterilized foods exhibit excellent lycopene stability throughout
their normal temperature storage shelf life. Lycopene bioavailability
(absorption) can be influenced by many factors. The bioavailability of
cis-isomers in food is higher than that of all-trans isomers. Lycopene
bioavailability in processed tomato products is higher than in
unprocessed fresh tomatoes. The composition and structure of the food
also have an impact on the bioavailability of lycopene and may affect
the release of lycopene from the tomato tissue matrix. Food processing
may improve lycopene bioavailability by breaking down cell walls, which
weakens the bonding forces between lycopene and tissue matrix, thus
making lycopene more accessible and enhancing the cis-isomerization.
More information on lycopene bioavailability, however, is needed.
The pharmacokinetic properties of lycopene remain particularly poorly
understood. Further research on the bioavalability, pharmacology,
biochemistry, and physiology must be done to reveal the mechanism of
lycopene in human diet, and the in vivo metabolism of lycopene.
Consumer demand for healthy food products provides an opportunity to
develop lycopene-rich food as new functional foods, as well as
food-grade and pharmaceutical-grade lycopene as new nutraceutical
products. An industrial scale, environmentally friendly lycopene
extraction and purification procedure with minimal loss of
bioactivities is highly desirable for the foods, feed, cosmetic, and
pharmaceutical industries. High-quality lycopene products that meet
food safety regulations will offer potential benefits to the food
industry.
Lycopene has been identified as a phytochemical with potentially protective health
benefits. The cellular content of lycopene and other tomato-related carotenoids with
proposed beneficial health effects can be increased through prolonged supplementation.
Lycopene, the main carotenoid in tomato, has been shown to be a potent antioxidant in
vitro. However, there is no significant evidence of its antioxidant action in vivo. We
evaluated the effect of tomato intake on plasma carotenoid concentrations and lymphocyte
resistance to oxidative stress... Tomato consumption also had an effect on cellular
antioxidant capacity: lymphocyte DNA damage after ex vivo treatment with hydrogen peroxide
decreased by 42% in the groups of subjects after consumption of the tomato diet.
CONCLUSION: The consumption of tomato products may reduce the
susceptibility of lymphocyte DNA to oxidative damage.
Dietary consumption of the carotenoid lycopene (mostly from tomato
products) has been associated with a lower risk of prostate cancer.
Evidence relating other carotenoids, tocopherols, and retinol to
prostate cancer risk has been equivocal. This prospective study was
designed to examine the relationship between plasma concentrations of
several major antioxidants and risk of prostate cancer... In the
placebo group, plasma lycopene was very strongly related to lower
prostate cancer risk (5th quintile OR = 0.40; P, trend = 0.006 for
aggressive cancer), whereas there was no evidence for a trend among
those assigned to beta-carotene supplements. However, in the
beta-carotene group, prostate cancer risk was reduced in each lycopene
quintile relative to men with low lycopene and placebo. The only other
notable association was a reduced risk of aggressive cancer with higher
alpha-tocopherol levels that was not statistically significant. None of
the associations for lycopene were confounded by age, smoking, body
mass index, exercise, alcohol, multivitamin use, or plasma total
cholesterol level. These results concur with a recent prospective
dietary analysis, which identified lycopene as the carotenoid with the
clearest inverse relation to the development of prostate cancer. The
inverse association was particularly apparent for aggressive cancer and
for men not consuming beta-carotene supplements. For men with low
lycopene, beta-carotene supplements were associated with risk
reductions comparable to those observed with high lycopene. These data
provide further evidence that increased consumption of tomato products
and other lycopene-containing foods might reduce the occurrence or
progression of prostate cancer.
The epidemiologic literature in the English language regarding
intake of tomatoes and tomato-based products and blood lycopene (a
compound derived predominantly from tomatoes) level in relation to the
risk of various cancers was reviewed. Among 72 studies identified, 57
reported inverse associations between tomato intake or blood lycopene
level and the risk of cancer at a defined anatomic site; 35 of these
inverse associations were statistically significant. No study indicated
that higher tomato consumption or blood lycopene level statistically
significantly increased the risk of cancer at any of the investigated
sites. About half of the relative risks for comparisons of high with
low intakes or levels for tomatoes or lycopene were approximately 0.6
or lower. The evidence for a benefit was strongest for cancers of the
prostate, lung, and stomach. Data were also suggestive of a benefit for
cancers of the pancreas, colon and rectum, esophagus, oral cavity,
breast, and cervix. Because the data are from observational studies, a
cause-effect relationship cannot be established definitively. However,
the consistency of the results across numerous studies in diverse
populations, for case-control and prospective studies, and for
dietary-based and blood-based investigations argues against bias or
confounding as the explanation for these findings. Lycopene may account
for or contribute to these benefits, but this possibility is not yet
proven and requires further study. Numerous other potentially
beneficial compounds are present in tomatoes, and, conceivably, complex
interactions among multiple components may contribute to the anticancer
properties of tomatoes. The consistently lower risk of cancer for a
variety of anatomic sites that is associated with higher consumption of
tomatoes and tomato-based products adds further support for current
dietary recommendations to increase fruit and vegetable consumption.
Known hazards:
People with arthritis who are allergic to tomatoes and other members of
the nightshade family should consult their physician first before
taking lycopene.
Who would have thought that one of a man?s best sources of
protection against prostate cancer is a tomato? The substance that
gives the tomato its deep red color may also reduce a man?s risk of
developing prostate cancer by 35%.
The tomato?s newfound miracle nutrient is called lycopene, and it
belongs to a family of natural pigments (carotenoids) found in plants
and animals. Beta carotene, the orange-colored precursor to vitamin A,
is probably the best known of the approximately 500 carotenoids found
in nature.
According to the most current research, lycopene is a top-flight
antioxidant, obtained through the diet from tomatoes (or, now, from
lycopene supplements) and capable of protecting the body against many
degenerative diseases, including cancer.
Researchers from Harvard University Medical School studied 47,894
men, age 40 to 75 and free of any diagnosed cancer, over a six-year
period. Their dietary preferences and consumption frequency for 131
foods and beverages were assessed, providing researchers a detailed
picture of the yearly nutrient intake of each man.
Of the 46 foods, tomato sauce, tomatoes, pizza, and strawberries
were associated with a reduced risk of prostate cancer. The researchers
learned that the first three of these foods were the primary dietary
sources of lycopene, accounting for 82% of the lycopene intake for the
men. (While strawberries were associated with a reduced prostate cancer
risk, they are not a significant source of lycopene.) Those who
consumed ten or more servings of these three tomato-based foods per
week had a 35% reduced chance of developing prostate cancer.
The lycopene in these foods is one of five groups of carotenoids: No
measurable protective effect against prostate cancer was noted among
the four other primary carotenoids: alpha carotene (found in carrots),
beta carotene (in yams, sweet potatoes, yellow squash), lutein (found
in dark green, leafy vegetables), and beta-cryptoxanthin (in oranges).
It?s important to know that lycopene is the predominant carotenoid
found in the blood, in various tissues (such as liver, kidney, adrenal
glands, testes, and ovaries), and in the prostate gland itself.
Research suggests that lycopene is an essential part of the body?s
natural defense against harmful oxidizing agents such as free radicals.
Lycopene is now being touted as a highly capable antioxidant; Dr.
Giovannucci pointed out that copene is the most efficient scavenger of
singlet oxygen [free radicals] among the common carotenoids.?
If tomatoes are a key factor in natural prostate protection, it?s
logical that food scientists would seek a lycopene-rich strain.
Scientists in Israel, working for Lyco-Red Natural Products Industries
in Beer-Sheva, used traditional cross-breeding methods to produce a
tomato with up to four times more lycopene than is found in regular
tomatoes.
The extract from these hybridized tomatoes (grown by organic
methods) is called Lyc-O-Mato? and it takes two metric tons of the
lycopene-enriched tomatoes to produce one gram of the lycopene extract,
which is mixed with tomato oil, beta carotene, and vitamin E for better
absorption and additional antioxidant benefits. The Lyc-O-Mato? extract
is now used in at least 13 nutritional supplements.
A diet rich in carotenoid-containing foods is associated with a
number of health benefits. Lycopene provides the familiar red color to
tomato products and is one of the major carotenoids in the diet of
North Americans and Europeans. Interest in lycopene is growing rapidly
following the recent publication of epidemiologic studies implicating
lycopene in the prevention of cardiovascular disease and cancers of the
prostate or gastrointestinal tract. Lycopene has unique structural and
chemical features that may contribute to specific biological
properties. Data concerning lycopene bioavailability, tissue
distribution, metabolism, excretion, and biological actions in
experimental animals and humans are beginning to accumulate although
much additional research is necessary.
Increasing clinical evidence supports the role of lycopene as a
micronutrient with important health benefits, because it appears to
provide protection against a broad range of epithelial cancers.
Tomatoes and related tomato products are the major source of lycopene
compounds, and are also considered an important source of carotenoids
in the human diet. Undesirable degradation of lycopene not only affects
the sensory quality of the final products, but also the health benefit
of tomato-based foods for the human body. Lycopene in fresh tomato
fruits occurs essentially in the all-trans configuration. The main
causes of tomato lycopene degradation during processing are
isomerization and oxidation. Isomerization converts all-trans isomers
to cis-isomers due to additional energy input and results in an
unstable, energy-rich station. Determination of the degree of lycopene
isomerization during processing would provide a measure of the
potential health benefits of tomato-based foods. Frozen foods and
heat-sterilized foods exhibit excellent lycopene stability throughout
their normal temperature storage shelf life. Lycopene bioavailability
(absorption) can be influenced by many factors. The bioavailability of
cis-isomers in food is higher than that of all-trans isomers. Lycopene
bioavailability in processed tomato products is higher than in
unprocessed fresh tomatoes. The composition and structure of the food
also have an impact on the bioavailability of lycopene and may affect
the release of lycopene from the tomato tissue matrix. Food processing
may improve lycopene bioavailability by breaking down cell walls, which
weakens the bonding forces between lycopene and tissue matrix, thus
making lycopene more accessible and enhancing the cis-isomerization.
More information on lycopene bioavailability, however, is needed.
The pharmacokinetic properties of lycopene remain particularly poorly
understood. Further research on the bioavalability, pharmacology,
biochemistry, and physiology must be done to reveal the mechanism of
lycopene in human diet, and the in vivo metabolism of lycopene.
Consumer demand for healthy food products provides an opportunity to
develop lycopene-rich food as new functional foods, as well as
food-grade and pharmaceutical-grade lycopene as new nutraceutical
products. An industrial scale, environmentally friendly lycopene
extraction and purification procedure with minimal loss of
bioactivities is highly desirable for the foods, feed, cosmetic, and
pharmaceutical industries. High-quality lycopene products that meet
food safety regulations will offer potential benefits to the food
industry.
Lycopene has been identified as a phytochemical with potentially protective health
benefits. The cellular content of lycopene and other tomato-related carotenoids with
proposed beneficial health effects can be increased through prolonged supplementation.
Lycopene, the main carotenoid in tomato, has been shown to be a potent antioxidant in
vitro. However, there is no significant evidence of its antioxidant action in vivo. We
evaluated the effect of tomato intake on plasma carotenoid concentrations and lymphocyte
resistance to oxidative stress... Tomato consumption also had an effect on cellular
antioxidant capacity: lymphocyte DNA damage after ex vivo treatment with hydrogen peroxide
decreased by 42% in the groups of subjects after consumption of the tomato diet.
CONCLUSION: The consumption of tomato products may reduce the
susceptibility of lymphocyte DNA to oxidative damage.
Dietary consumption of the carotenoid lycopene (mostly from tomato
products) has been associated with a lower risk of prostate cancer.
Evidence relating other carotenoids, tocopherols, and retinol to
prostate cancer risk has been equivocal. This prospective study was
designed to examine the relationship between plasma concentrations of
several major antioxidants and risk of prostate cancer... In the
placebo group, plasma lycopene was very strongly related to lower
prostate cancer risk (5th quintile OR = 0.40; P, trend = 0.006 for
aggressive cancer), whereas there was no evidence for a trend among
those assigned to beta-carotene supplements. However, in the
beta-carotene group, prostate cancer risk was reduced in each lycopene
quintile relative to men with low lycopene and placebo. The only other
notable association was a reduced risk of aggressive cancer with higher
alpha-tocopherol levels that was not statistically significant. None of
the associations for lycopene were confounded by age, smoking, body
mass index, exercise, alcohol, multivitamin use, or plasma total
cholesterol level. These results concur with a recent prospective
dietary analysis, which identified lycopene as the carotenoid with the
clearest inverse relation to the development of prostate cancer. The
inverse association was particularly apparent for aggressive cancer and
for men not consuming beta-carotene supplements. For men with low
lycopene, beta-carotene supplements were associated with risk
reductions comparable to those observed with high lycopene. These data
provide further evidence that increased consumption of tomato products
and other lycopene-containing foods might reduce the occurrence or
progression of prostate cancer.
The epidemiologic literature in the English language regarding
intake of tomatoes and tomato-based products and blood lycopene (a
compound derived predominantly from tomatoes) level in relation to the
risk of various cancers was reviewed. Among 72 studies identified, 57
reported inverse associations between tomato intake or blood lycopene
level and the risk of cancer at a defined anatomic site; 35 of these
inverse associations were statistically significant. No study indicated
that higher tomato consumption or blood lycopene level statistically
significantly increased the risk of cancer at any of the investigated
sites. About half of the relative risks for comparisons of high with
low intakes or levels for tomatoes or lycopene were approximately 0.6
or lower. The evidence for a benefit was strongest for cancers of the
prostate, lung, and stomach. Data were also suggestive of a benefit for
cancers of the pancreas, colon and rectum, esophagus, oral cavity,
breast, and cervix. Because the data are from observational studies, a
cause-effect relationship cannot be established definitively. However,
the consistency of the results across numerous studies in diverse
populations, for case-control and prospective studies, and for
dietary-based and blood-based investigations argues against bias or
confounding as the explanation for these findings. Lycopene may account
for or contribute to these benefits, but this possibility is not yet
proven and requires further study. Numerous other potentially
beneficial compounds are present in tomatoes, and, conceivably, complex
interactions among multiple components may contribute to the anticancer
properties of tomatoes. The consistently lower risk of cancer for a
variety of anatomic sites that is associated with higher consumption of
tomatoes and tomato-based products adds further support for current
dietary recommendations to increase fruit and vegetable consumption.
Known hazards:
People with arthritis who are allergic to tomatoes and other members of
the nightshade family should consult their physician first before
taking lycopene.
- JOHN ANDERSON. Natural Pharmacy. LYCOPENE in Tomatoes Reduces Prostate Cancer Risk by 35%
- Clinton SK. Lycopene: chemistry, biology, and implications for human health and disease. Nutr Rev; 56(2 Pt 1):35-51 1998
- Shi
J, Le Maguer M. Lycopene in tomatoes: chemical and physical properties
affected by food processing. Crit Rev Food Sci Nutr; 40(1):1-42 2000 - Paetau
I, Rao D, Wiley ER, Brown ED, Clevidence BA. Carotenoids in human
buccal mucosa cells after 4 wk of supplementation with tomato juice or
lycopene supplements. Am J Clin Nutr; 70(4):490-4 1999 - Riso
P, Pinder A, Santangelo A, Porrini M. Does tomato consumption
effectively increase the resistance of lymphocyte DNA to oxidative
damage? Am J Clin Nutr; 69(4):712-8 1999 - Gann PH, Ma J,
Giovannucci E, Willett W, Sacks FM, Hennekens CH, Stampfer MJ. Lower
prostate cancer risk in men with elevated plasma lycopene levels:
results of a prospective analysis. Cancer Res; 59(6):1225-30 1999 - Giovannucci
E. Tomatoes, tomato-based products, lycopene, and cancer: review of the
epidemiologic literature. J Natl Cancer Inst; 91(4):317-31 1999
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