Please Pass the Ketchup: Cooked Tomatoes May Do More to Prevent Cancer than Fresh
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Food Science Education Research Please Pass the Ketchup: Cooked Tomatoes May Do More to Prevent Cancer than Fresh Judy Smith ABSTRACT: One of the core competencies in the IFT Education standards is for students to achieve competency in communications skills (that is, oral and written communication, listening, interviewing, and so on). According to the IFT guidelines, by the time students graduate, they should not only be able to search for and condense information but also be able to “communicate technical information to a non-technical audience.” The Education Division of IFT sponsors an annual writing competition for undergraduate students to bring attention to and promote the development of communication skills. The short essays can be on any technical subject or latest development in the food science and technology field that may be important to the consumer. The article must be written in nontechnical language such that someone reading a local newspaper could understand it. Due date for submissions is typically the first week in June. More information on eligibility, rules, submission, and judging criteria will be posted on IFT’s Education Division website. Monetary prizes are awarded to the authors of the top 3 papers, and the winning entry is published in the Journal of Food Science Education (JFSE) each year. JFSE is pleased to publish this year’s winning entry submitted by Judy Smith from the Univ. of Maine. MS 20080632 Submitted 8/19/2008, Accepted 10/7/2008. Author Smith is with Univ. of Maine, Education Division Undergraduate Technical Writing Competition, 1st Place, 2008. Direct inquiries to author Smith (E-mail: [email protected] ). O ne can hardly avoid hearing about how important antioxidants are. Ads for diet supplements and skin lotions stress the usefulness of antioxidants in preventing disease and even postponing the inevitable aging process. Although common sense suggests that these guardians of good health should come from eating plenty of fresh fruits and vegetables, in some cases cooking them may make them even better for us. Studies comparing the tumor-fighting abilities of cooked and fresh tomatoes have yielded surprising results. While it is true that the high temperatures exceeding 190 ◦ F that are needed to safely preserve tomatoes results in lower values for vitamin C, the total antioxidant benefits in cooked tomatoes are actually higher than in the fresh variety (Dewanto and others 2002). The term oxidation describes the damage done to our cells by light, oxygen, and certain metals, often referred to as “free radicals.” These disruptive thieves steal a speck of hydrogen and start a domino effect of damage. Much like that last card on a house of cards, this action causes the whole structure to fall down. This collapse undermines the way our immune system works. Our body’s natural defenses against diseases such as cancer no longer work. Antioxidants work in one of the 2 ways: some slow the chain reaction, while others donate hydrogen and stop the damage before it starts. Studies of lycopene, an antioxidant that occurs naturally in red or orange plant foods, from Cornell Univ., Taiwan, and Germany, have found that lycopene content is much greater in the tomatoes that have been cooked. Lycopene works by pairing with single oxygen atoms, which are unstable alone and usually occur in pairs, and therefore can stop the oxidation process. Lycopene is recognized as a valuable fat-soluble component that supports the immune system and slows the damage caused by free radicals. The higher concentrations of tomato pulp in such products as tomato paste in relation to fresh tomatoes give one possible explanation for the increase in lycopene. However, the data support that the process of cooking the tomatoes releases the normally tightly bound lycopene from the plant cell walls, making it easier for our bodies to use. Studies have also shown that other chemical compounds in tomatoes called phenolics help to protect and work with the lycopene to make the antioxidant effects even stronger (Shen and others 2007). Many of the possible chemical reactions in our bodies do not hurt us because they happen much too slowly. Sometimes catalysts, called enzymes, help these reactions along. Scientists have identified an enzyme referred to as COX-2, which causes tumors to form when cells are exposed to cancer-causing compounds. The antioxidant cocktail provided by processed tomatoes has been shown to suppress this enzyme and to help prevent the growth of cancerous tumors in laboratory experiments (Shen and others 2008). Results show much greater antioxidant and tumor suppression ability in the heat-treated tomatoes. It 6 Journal of Food Science Education—Vol. 8, 2009 C 2008 Institute of Food Technologists ®
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Transcript of Please Pass the Ketchup: Cooked Tomatoes May Do More to Prevent Cancer than Fresh
Food Science Education Research
Please Pass the Ketchup: CookedTomatoes May Do More to Prevent
Cancer than FreshJudy Smith
ABSTRACT: One of the core competencies inthe IFT Education standards is for students toachieve competency in communications skills(that is, oral and written communication,listening, interviewing, and so on). According tothe IFT guidelines, by the time studentsgraduate, they should not only be able to searchfor and condense information but also be able to“communicate technical information to anon-technical audience.” The Education Divisionof IFT sponsors an annual writing competition forundergraduate students to bring attention to andpromote the development of communicationskills. The short essays can be on any technicalsubject or latest development in the food scienceand technology field that may be important to theconsumer. The article must be written innontechnical language such that someonereading a local newspaper could understand it.Due date for submissions is typically the firstweek in June. More information on eligibility,rules, submission, and judging criteria will beposted on IFT’s Education Division website.Monetary prizes are awarded to the authors ofthe top 3 papers, and the winning entry ispublished in the Journal of Food ScienceEducation (JFSE) each year. JFSE is pleased topublish this year’s winning entry submitted byJudy Smith from the Univ. of Maine.
MS 20080632 Submitted 8/19/2008, Accepted 10/7/2008. Author Smith is with Univ. of Maine,Education Division Undergraduate Technical Writing Competition, 1st Place, 2008. Direct inquiriesto author Smith (E-mail: [email protected]).
One can hardly avoid hearing about how important antioxidantsare. Ads for diet supplements and skin lotions stress the usefulnessof antioxidants in preventing disease and even postponing the inevitable
aging process. Although common sense suggests that these guardians of goodhealth should come from eating plenty of fresh fruits and vegetables, in somecases cooking them may make them even better for us. Studies comparing thetumor-fighting abilities of cooked and fresh tomatoes have yielded surprisingresults. While it is true that the high temperatures exceeding 190 ◦F that areneeded to safely preserve tomatoes results in lower values for vitamin C, thetotal antioxidant benefits in cooked tomatoes are actually higher than in thefresh variety (Dewanto and others 2002).
The term oxidation describes the damage done to our cells by light, oxygen,and certain metals, often referred to as “free radicals.” These disruptive thievessteal a speck of hydrogen and start a domino effect of damage. Much like thatlast card on a house of cards, this action causes the whole structure to fall down.This collapse undermines the way our immune system works. Our body’s naturaldefenses against diseases such as cancer no longer work. Antioxidants work inone of the 2 ways: some slow the chain reaction, while others donate hydrogenand stop the damage before it starts.
Studies of lycopene, an antioxidant that occurs naturally in red or orangeplant foods, from Cornell Univ., Taiwan, and Germany, have found thatlycopene content is much greater in the tomatoes that have been cooked.Lycopene works by pairing with single oxygen atoms, which are unstable aloneand usually occur in pairs, and therefore can stop the oxidation process.Lycopene is recognized as a valuable fat-soluble component that supports theimmune system and slows the damage caused by free radicals. The higherconcentrations of tomato pulp in such products as tomato paste in relation tofresh tomatoes give one possible explanation for the increase in lycopene.However, the data support that the process of cooking the tomatoes releases thenormally tightly bound lycopene from the plant cell walls, making it easier forour bodies to use. Studies have also shown that other chemical compounds intomatoes called phenolics help to protect and work with the lycopene to makethe antioxidant effects even stronger (Shen and others 2007).
Many of the possible chemical reactions in our bodies do not hurt us becausethey happen much too slowly. Sometimes catalysts, called enzymes, help thesereactions along. Scientists have identified an enzyme referred to as COX-2,which causes tumors to form when cells are exposed to cancer-causingcompounds. The antioxidant cocktail provided by processed tomatoes has beenshown to suppress this enzyme and to help prevent the growth of canceroustumors in laboratory experiments (Shen and others 2008). Results show muchgreater antioxidant and tumor suppression ability in the heat-treated tomatoes. It
6 Journal of Food Science Education—Vol. 8, 2009 C© 2008 Institute of Food Technologists®
Please pass the ketchup . . .
is believed that the heat process releases these antioxidants fromthe plant tissue and makes them more available for us to use.
This is good news for gardeners who, faced with moretomatoes than they can possibly eat, resort to making andfreezing sauce as well as canning their tomatoes. The cookingprocess may actually improve the overall nutritive value byreleasing the lycopene from the plant’s cell walls. Thisinformation also bodes well for people who do not like freshtomatoes. When ketchup first arrived on the scene, dietitians,who feared that it would provide empty calories, eyed itsuspiciously. Although ketchup also contains a fair amount ofsugar, it does contain concentrated processed tomatoes, so itmay have some antioxidant effect. Many people who may notwant to eat a fresh tomato do enjoy eating pizza. Pizza saucewould also contain a significant amount of concentrated
tomatoes as well. Fresh fruits and vegetables undoubtedlyprovide us with the best Mother Nature has to offer, but it isgood to know that the process used to preserve these beautiesmay actually enhance their nutritive value.
ReferencesDewanto V, Wu X, Adom KK, Liu RH. 2002. Thermal processing enhances the
nutritional value of tomatoes by increasing total antioxidant activity. J AgricFood Chem 50:3010–4.
Shen YC, Chen SL, Wang CK. 2007. Contribution of tomato phenolics toantioxidation and down-regulation of blood lipids. J Agric Food Chem55(16):6475–81.
Shen YC, Chen SL, Zhuang SR, Wang CK. 2008. Contribution of tomatophenolics to suppression of COX-2 expression in KB cells. J Food Sci73(1):C1–10.
Available on-line through ift.org Vol. 8, 2009—Journal of Food Science Education 7
