Purple Tomatoes Increased Lifespan of Cancer-Prone Mice

A new study suggests that tomatoes genetically altered to be rich in antioxidants may increase the life span in mice that are predisposed to cancer. 

Using genes from the snapdragon flower, researchers in Europe modified tomatoes so they would contain high amounts of anthocyanins, which are powerful antioxidants commonly found in dark berries like blackberries and blueberries. The new genes also caused the tomatoes to become purple in the process.

Anthocyanins have been linked to a reduced risk of cancer, heart disease, diabetes, obesity, and age-related degenerative diseases. However, many of the most commonly eaten fruits and vegetables may not contain enough anthocyanins to gain health benefits. 

Mice genetically altered to be prone to cancer ate diets rich in the purple tomatoes or a standard diet with or without normal tomatoes. Those that ate the purple tomatoes lived significantly longer (182 days on average) than mice that ate standard diets (142 days on average). 

Although the findings, published in the journal Nature Biotechnology, are promising, more studies are needed to confirm these results. 

Tomatoes naturally contain high levels of other antioxidants called lycopene and flavonoids. Lycopene is most abundant in highly processed tomatoes. Also, cooking tomatoes in oil helps the fruit release more lycopene. Flavonoids can be water soluble and fat soluble, so eating foods with water or fat is thought to increase the beneficial effects of these antioxidants. 

For more information about tomatoes and their antioxidants, please visit Natural Standard's Foods, Foods, Herbs & Supplements database. For more information about genetically modified foods, please visit Natural Standard's Genomics & Proteomics database.

Comments

[James]

Which antioxidants (anthocyanins, lycopene or flavonoids) have the greatest effect on reducing cancer? If it is the anthocyanins, why did the researchers choose tomatoes and not a fruit that already has anthocyanins, like blue berries? Also, what kind of cancer did the mice get? The type of cancer may play a role in the effectiveness of antioxidants. Not all cancers are the same.

[Gabrielle]

I always knew that antioxidants are associated with reduced risk of cancer but did not know some antioxidants are more potent than others in regards to risk reduction. If more of these antioxidants are discovered, I wonder if I can expect to see most of our foods be modified with these antioxidants. Organic foods are popularly consumed because they are natural and are not tampered with substances. If foods become modified to contain antioxidants in the hopes of reducing cancer, what will happen to the popularity of organic foods?

[mark]

OK, purple tomatoes? I don’t think I would want to eat purple tomatoes even if they are found to be beneficial. Maybe the researchers should find a way to modify the tomatoes in a way that makes them more appealing to the consumers so that they would think these tomatoes are safe rather than rotten, purple tomatoes.

[Jenni D.]

I recently saw on my local news station that purple tomatoes helped with cancer. Before I saw this show I didn’t even know about purple tomatoes. There are antioxidants in tea, beans, berries, spices and potatoes. Could these foods be used in a similar study, or is the purple tomato a “stronger” type of antioxidant?

It’s nice to see foods that heal instead of pills that heal. I am not against medication, yet I think it’s a lot easier for our bodies and healthier if we could heal our bodies through the foods we already consume.

[Mark]

There still are safety concerns regarding genetically altered foods. We still do not know if they are completely safe and if they have any unseen adverse effects. Long-term effects are also unknown. Although it seems promising to alter our foods to have more antioxidants to reduce cancer, there may be other undiscovered implications, and we should be cautious moving forward. So organic foods may still be around for a while.

[nina]

I would love to grow the purple tomatoes. Where can I get the seeds?

[Tamara.S]

Prostate cancer and its prevention has been the focus of much lycopene research.

UV exposure results in a reduction in antioxidants in the skin and blood. Research has shown that antioxidant supplements in conjunction with sunscreen can help to lower the risk of sunburn. Antioxidants, including lycopene, may be obtained from a healthy diet.

At an international forum in Washington, a number of international scientists discussed new and ongoing studies of lycopene in relation to male fertility, osteoporosis, skin cancer, ocular disease, lung function, as well as prostate, breast and endometrial cancers.

Acknowledgement: www.jarrahbark.com/cancercentral/cancer_tomato_lycopene.html

[Becca]

Food that is rich in antioxidants are beneficial for our overall health. Anthocyanins are flavanoids that provide color to most flowers and fruits. They are a class of pigments associated with the protection against a wide range of human diseases. Most fruits and vegetables (other than blueberries and blackberries) do not contain amounts high enough to see health benefits. The studies were done in cancer-prone mice and showed that intake of these purple tomatoes showed significant extension of their life span. I do have to add though that purple tomatoes just don't seem natural -- like green peanut butter -- not very appealing.

[Anna H.]

I hope that the studies are taken seriously and people (instead of mice) can benefit from the genetically altered tomatoes! It is incredible to think about all the benefits that natural products can offer to mankind and just imagine how many have not been discovered as of yet. I only hope that these investigations will be successful and that soon we can buy purple tomatoes with their high level of antioxidants at any neighborhood grocery store.

[Kevin]

I was thinking along the same lines as Mark. Although these purple tomatoes contain high amounts of these beneficial antioxidants, would the unknown effects of genetic engineering cancel out the health advantages? I would rather stick to eating regular tomatoes for now.

[Marie G]

I had no idea that cooking tomatoes in oil would be better! In regards to certain nutrients being water- and fat-soluble, is there a standard way to prepare fruits and vegetables to keep all the nutrients? I try to include more vegetables in my meals, but I would like to know what is the best way to cook them to keep my diet healthy.

[Emma]

I think James brings up some good points. I didn’t know that blueberries had anthocyanins, but I guess they used tomatoes and not blueberries maybe because it was easier to modify tomatoes than blueberries? I’d also like to know if the efficacy of the antioxidants would vary depending on the type of cancer.

[liz]

I would think that you would need to consume a large of these tomatoes if they're going to be used as a medicinal food. I share Mark’s concern regarding the long-term effects and safety of genetically modified food.

[PB Atkins]

If these are related to the anthocyanins found in lignonberries and raspberries, we have yet another antioxidant that may decrease blood pressure and protect against oxidation! Purple vegetables usually scare me, but if the color is from amazing antioxidants, bring on the violet!!

Although this is fascinating, this is tooooo new to feed to humans, I say. The article lists the color purple as a separate feature of the antioxidant properties. I would like to know what other "hidden features" come along with this amazing new product, like maybe pancreatic cancer sudden cardiac death. Let’s find out more over time and before humans get too close.

[Metu]

I think we are all in agreement: no one wants to eat Frankenfood. Plus, there is the taste consideration, not to mention the obvious: cost. The tomato is a marvelous fruit (yes -- I too, used to think it was a vegetable) with proven health benefits. Don't mess with it.

[claire]

Why genetically alter a nutrient when you can just increase its intake? Genetically changing a substance should not be the answer. Once a nutrient is genetically altered, it is no longer considered natural; it is now a synthetic substance. Synthetic substances also tend to be more expensive.

[K.K.]

Purple tomatoes would certainly look good on gourmet plates, but you don’t need purple tomatoes to eat a diet rich in antioxidants. It may well be the anthocyanin antioxidant itself that is providing the positive effect. Do we know what level of anthocyanin was in the purple tomatoes and what the fresh berry equivalent would be?

[JC]

I think if the researchers can make the tomatoes contain higher amounts of antioxidants, they should also be able to make them not purple and extremely tasty. If they went as far as to make them healthier, why not make them a normal color with a great taste and perfect juiciness. Soon everything we eat will be able to cure cancer and save the world.

[Phil Mav.]

Very true Claire! I mean why turn to genetic engineering when the easiest and safest option is to just consume more tomatoes in your diet? This is an instance where I see genetically engineered foods as totally unnecessary. I would see it differently if genetic engineering was used to grow tomatoes in an area where they couldn’t grow, but increasing its antioxidant content through genetic engineering defeats the purpose of natural and healthy eating.

[Kay]

As mentioned before, it's important to remember that this study was done on mice and not humans. Studies on animals are limited in the sense that you can't check on these subjects and find out if there were any long-term effects to eating the purple tomatoes. I say stick with the natural fruits and vegetables until we are sure this is safe in the long run.

[Pam C.]

The study says that natural tomatoes contain inadequate levels of anthocyanins to produce any health benefits. Maybe eating more tomatoes won't do enough. Genetically engineered purple tomatoes may be the only way to get these health benefits in a more direct and effective manner. I think genetically engineered foods could be beneficial for our future, and we should take advantage of them, especially in areas where people are malnourished.

[SUMA]

I agree with Claire -- why alter the tomato? Multiple foods contain anthocyanins, why not increase their intake? According to a study in the Cancer Letter, Oct 8, 2008, the daily intake of anthocyanins in residents of the United States is estimated to be about 200 milligrams or about nine times higher than that of other dietary flavonoids.

Another study {Cooke, 2005} states that “studies of the pharmocokinetics of anthocyanins after their consumption as single agents, anthocyanin mixtures or berry extracts, suggest that anthocyanins reach levels of 10(-8)-10(-7) M in human blood. It is not clear whether such concentrations are sufficient to explain anticarcinogenic effects and whether anthocyanins exert chemo preventative efficacy themselves, or if they need to undergo hydrolysis to their aglyconic counterparts.” The authors further state that anthocyanidins have been shown to inhibit malignant cell survival and confound many oncogenic signaling events in the 10(-6)-10 (-4) M concentration range.

Further studies aimed at enhancing the absorption of anthocyanins and/or their metabolites are necessary to determine their effectiveness as a chemo preventative. Meanwhile, bring on the blueberries!

[Van]

I agree with PB Atkins. I feel like there is still much to research about foods that are genetically engineered, and we do not know enough to begin eating purple tomatoes. If the color is behind the antioxidant power, then let us start off by eating more fruits and vegetables that are naturally purple.

[MHD]

The one line in this blog that caught my eye was "cooking tomatoes in oil may release more lycopene." Immediately I thought of the Meditteranean diet and how the ingenious combination of olive oil, a heart protectant, and lycopene-rich tomatoes could be the perfect combination for creating a healthy, long life. It has been long known that, generally, the more color a vegetable has, the more anticancer effects it may also have. For instance, most highly cruciferous vegetables are a dark green. Tomatoes with lycopene are a bright red, and acai and blackberries are dark purple. It is interesting to note that the purple tomatoes may have more impact than normal red ones. I wonder if this may be due to the darker color.

[John Smith]

Antioxidants must be our chance at the “fountain of youth.” There are so many health benefits from them -- the list is almost endless. Unfortunately, most Americans do not get the amount required to truly reap the potential benefits. I am curious as to the availability of antioxidant supplements and the composition of them. Most nuts and berries seem to contain the highest quantities of antioxidants. This seems appropriate to coincide with the idea that living naturally with the environment is the most health-efficient method. Most foragers in ancient cultures lived primarily off of nuts and berries, other fruits/vegetables and perhaps the occasional wild animal. It seems this diet may have more uses for today’s current health problems than we have yet to grasp. As for the purple tomatoes, they are genetically altered, so they probably give you cancer.