One of these tomato varieties contains lycopene that is more easily absorbed into your bloodstream, and therefore better for you. Can you tell which one?
This research is looking to find the best open-pollinated tomato varieties in the world for human health, particularly those highest in lycopene for cancer prevention.
The research is also seeking to determine whether hybrid tomato varieties (and vegetables in general) are nutritionally deficient in comparison with traditional open-pollinated heirloom varieties.
- Research Papers
- The Secret to Our Health Lies in Older Varieties of Fruit
- Discovery of the Real Tomato (12 April 2013)
- 2013: The Health Potential of the 'Real' Tomato
- Invitation to New Zealand Tomato Growers (April 2013)
- Appendix: Tomato varieties confirmed to contain Tetra-cis-lycopene
A story for children about the very special properties of golden-orange tomatoes, written and illustrated by Janet Bradbury.
We welcome you to download a copy of the book to print or read from your computer for free.
'Jessica and the Golden Orb' was featured by the Wanganui Midweek newspaper in the article 'Tomato stars in new book'.
The Secret to Our Health Lies in Older Varieties of Fruit
Press Release 12th September 2014
A search for the best tomatoes for health has uncovered rare heritage varieties that contain a different form of lycopene that is easily absorbed when eaten raw.
Up to now it was generally understood that you needed to cook your tomatoes in order to improve the absorption of lycopene, the powerful antioxidant that appears to exert positive effects upon human health. But the latest New Zealand research shows that the need to cook your tomatoes only relates to modern varieties and may be due to a fundamental flaw in breeding the first red tomatoes.
Eight years of research by the Whanganui based Heritage Food Crops Research Trust (HFCRT) has culminated in a human trial at Plant & Food Research in Palmerston North to test the lycopene absorption of a golden/orange heritage tomato called ‘Moonglow’ in comparison with a red heritage variety called ‘Rosalita’.
Trial participants were fed one variety of diced raw tomatoes in a simple meal, and then blood samples were taken at 4, 7 and 24 hours to determine how much lycopene had passed through their intestinal walls and was circulating in their blood. This was followed by a 2 week break before the second tomato variety was eaten and further blood tests were taken.
As expected only small amounts of lycopene from the red tomato variety was detected, however the big surprise was the significant amount of lycopene present from the golden/orange variety, especially after 24 hours – when the amount of lycopene was at its highest.
“It is amazing to realise that 24 hours after eating these raw golden/orange tomatoes they are still providing significant health benefits,” said Mark Christensen, research director for the HFCRT. “We have a wonderful opportunity to improve health outcomes for people by eating the right foods, and these particular golden/orange varieties are far superior in that regard compared to tomatoes of other colours (including red).”
The underlying reasons for this significant difference appear to relate to the chemistry and history of tomato.
The original tomatoes that were introduced into Europe in the 1520’s had been cultivated in Mexico. Those original tomatoes were named ‘Pomodoro’, which in Italian means ‘golden fruit’. The HFCRT believes that those original golden tomatoes contained the easily absorbable tetra-cis-lycopene, which has a bent molecular structure and is easily absorbed by the human body when consumed as a raw food – in a salad or picked and eaten straight from the vine. It is believed that the ‘Moonglow’ tomato and other golden/orange varieties that have been chemically analysed and shown to contain tetra-cis-lycopene are strains from those original golden fruit.
Unfortunately when the first Europeans crossed tomatoes to introduce the red colour to improve their consumer appeal, they were not aware that the beneficial easily absorbed form of lycopene was a recessive gene and would be replaced by the dominant red form of lycopene called all-trans-lycopene. This is the form of lycopene in our modern red tomatoes and has a linear molecular structure that cannot pass easily into the bloodstream unless subjected to intense heat. “We would like to think that if this had been known over 450 years ago they may have considered the red tomatoes inappropriate for human consumption and stuck with the golden ones, or at least changed their name to reflect the significant difference that occurred through the breeding process.”
The HFCRT works in partnership with the Whanganui Regional Health Network and as in previous years will be distributing free tomato plants around the Whanganui region – this November all the plants will be golden/orange varieties to meet the joint intention of enabling the community to grow the best tomato varieties for health.
The Trust is very grateful to local Whanganui donors as well as the Bay of Plenty branch of the New Zealand Tree Crops Association for providing the funding for this ground-breaking research.
It is generally known that raw food is better for us, so it has always been an anomaly to be told that tomatoes should be cooked in order to improve the health benefits from their lycopene content. Now with this research we are able to get a better understanding of the detrimental effects that commercial breeding can have in changing the inherent health benefits of the original golden tomatoes. Given that commercial breeding practices have changed little over the 450 years since this mistake was made with tomato, this should be a red flag to all those who undertake this practice and even more importantly a clarion call to all those around the world who save old seed varieties. Without those dedicated individuals and small (mainly non-profit) organisations that have recognized the inherent value of this diverse gene pool of material, we would not now have the varieties to find and return to. If we are to learn from Hippocrates, the father of modern medicine, who said “let food be your medicine and medicine be your food”, then we and our future generations will need these seeds to keep us well.
The HFCRT has so far uncovered 16 golden/orange tomato varieties that contain the beneficial tetra-cis-lycopene, and will continue to have more varieties analysed to discover their inherent benefits. They are indebted to Dr Tony McGhie and his colleagues at Plant & Food Research in Palmerston North for their assistance with this research. The golden/orange tomatoes will appeal to many because of their stunning colour (ranging from golden to bright orange), lower acidity and suitability for the home gardener.
Through this research and the world-wide search for heritage tomato varieties conducted by the HFCRT, New Zealanders now have the opportunity to grow these ‘real’ tomatoes with their more available form of lycopene. Seeds of these varieties are available for purchase from www.bristol.co.nz.
Discovery of the Real Tomato (12 April 2013)
We are delighted to announce a break-through in our understanding about the superior health benefits of specific tomato varieties.
Two types of lycopene can be found in tomato. All-trans-lycopene is commonly found in red (and other colour) tomatoes; and tetra-cis-lycopene (also known as prolycopene) is found in some orange heirloom tomatoes.
It has been known for some time that all-trans-lycopene is not well absorbed by the human body: hence the advice to eat cooked tomatoes so the body can better absorb the lycopene. The linear configuration of the all-trans-lycopene molecule seems to hinder its absorption through intestinal walls and into the blood, according to Steven Schwartz from Ohio State's Comprehensive Cancer Centre.
However tetra-cis-lycopene is much better absorbed by the body — in fact two and a half times better! This form was detected in 2011 in "Tangerine", a golden orange heirloom tomato. The structure of this lycopene molecule conforms more closely with the lycopene found circulating in human blood.
Eleven more heirloom tomato varieties that contain this highly beneficial anti-oxidant compound have been identified in the latest research by the Heritage Food Crops Research Trust, assisted by Plant and Food Research in New Zealand.
Top Varieties with Tetra-Cis-Lycopene
|Carotenoids (mg/100g FW)|
|Orange Fleshed Purple Smudge||4.36||0.06||n.d.||0.09|
|Amish Orange Sherbert Heirloom||4.35||0.01||n.d.||0.02|
|Aunt Gertie's Gold||4.21||0.02||n.d.||0.04|
|Amish Yellowish Orange Oxheart||2.67||0.02||n.d.||0.05|
|Earl of Edgecomb||2.63||n.d.||n.d.||0.07|
(n.d. = not detected)
Click on the cultivar names to see photos.
Realising that the common tomato (Solanum lycopersicum) was originally a golden yellow/orange colour is a key piece of the puzzle. This was the colour of the first tomatoes found by the Spanish in Mexico in the early 1500s and taken back to Europe. When they arrived in Italy, they were named pomodoro: "golden fruit".
It is our hypothesis that these golden tomatoes contained the tetra-cis form of lycopene and that they were highly beneficial for human health, as the tetra-cis-lycopene would have been easily absorbed through the intestinal walls into the bloodstream.
Later, when breeding of tomatoes began, they were bred purely for consumer appeal to be red. Unfortunately for 400 years there has been a lack of understanding about the consequences of that breeding approach.
The beneficial tetra-cis-lycopene is a recessive gene, and as systematic breeding took place, this recessive gene was replaced by the more dominant all-trans-lycopene gene.
In order to correct this mistake, we must go back to the past to re-discover the old original tomatoes that still contain the correct composition of beneficial compounds for human health. This is the focus of our research. After seven years, we believe we have found the indicator that we have been searching for: tetra-cis lycopene. We believe that the varieties that still contain this compound have retained sufficient elements of their original genetic makeup to be the correct platform from which to take tomatoes into the future.
One of the great challenges for people at this time is the lack of understanding of the consequences of our actions. We have a vast amount of knowledge and many technical skills, but we appear to lack the wisdom to know when to apply them and when not to. Tomato is one of the most widely eaten fruits in the world and as such could play a major role in reducing heart disease and cancer — but only if we eat the varieties with high levels of beneficial compounds. However the unrestrained commercial breeding of tomatoes has led to a disturbing reduction in their actual medicinal benefit.
We are now beginning the second phase of our tomato research, concentrating on growing those varieties that are high in tetra-cis-lycopene and distributing them throughout New Zealand communities.
Based on what we have learnt from years of research into apples and tomatoes — that commercially bred varieties contain reduced levels of beneficial compounds — we will not "breed" these orange tomatoes, cross them or in any other way artificially manipulate them.
However we will encourage members of our community to become part of this next phase of the research – to actively participate by growing these plants with love. This is the most important ingredient that we can share, along with our intention to be open to these plants further evolving, so that their fruits will contain the very best qualities for human health and wellbeing. In this way we wish to create through our positive intention, and to allow the consequences to freely manifest.
Moonglow tomatoes also make a terrific centrepiece!
2013: The Health Potential of the 'Real' Tomato
The Heritage Food Crops Research Trust is a very small charitable Trust in New Zealand that investigates the health properties of fruit and vegetables in order to find the very best medicinal foods for human health. To date, we have concentrated on apples, tomatoes and beans.
We wish to find the truth about what foods are best for our health. The data we have gathered on tomatoes clearly shows some of the old heirloom varieties have substantially higher levels of beneficial compounds than modern hybrid varieties.
Our direction has been influenced by our earlier work on apples, which indicated that there must be a flaw in modern breeding programmes whereby breeding criteria (and possibly other factors) led to lower levels of beneficial compounds in modern bred apples. Accordingly we have striven to find the oldest tomato varieties available anywhere in the world. Our work highlights the accelerated contamination of the gene pool that has happened in the past hundred years.
Tomatoes: the 'golden fruit'
We are seven years into our tomato study. Our research on apples and tomatoes has shown the importance of heirloom (heritage) and old seedling varieties that contain much higher levels of beneficial compounds compared to modern, commercially bred varieties. For instance, within the wonderful diversity of colours, shapes and sizes of heirloom tomatoes, are a rich assortment of carotenoids and polyphenolic compounds. This includes varieties with good levels of specific medicinal compounds such as lycopene, recognised in a number of reputable studies to reduce the incidence of heart disease and certain cancers.
In our search for the best medicinal tomato, we are trying to find a tomato that has retained the purity of its genetic blueprint over a considerable period of time; a variety that has not been changed through human manipulation. We believe that we have found just that in some heirloom orange tomatoes, varieties we think are closely linked to the 'golden fruits' or pomodoro that appear in the 1544 herbal of Matioli. They were the first tomatoes introduced to Europe following Hernan Cortes's conquest of Mexico (and tomatoes are still known by that name today in Italy). Our hypothesis is that these tomatoes will provide superior health benefits.
Because the health benefits of lycopene are widely recognized in scientific literature, it is one of the key compounds we looked for in the chemical analysis of our heirloom tomato samples. However the all-trans-lycopene present in today's red tomatoes is a molecule whose linear structure seems to hinder its absorption within the body. This is why we hear recommendations to cook tomatoes and combine them with fat, in order to improve our absorption of lycopene. This has always seemed to me to be unusual, given that natural food in its raw state is typically better for us, and each stage of processing of food does diminish the medicinal quality of that food.
We became aware of studies at Ohio State University and the Agricultural Research Service in California on an heirloom tomato variety, "Tangerine". These found an alternative form of lycopene they call tetra-cis-lycopene. (It is also known as prolycopene.) Its structure is more like the lycopene that circulates in human blood. Tomato sauces made from red and Tangerine tomatoes were tested on volunteers. They found that the tetra-cis-lycopene from the Tangerine variety was more efficiently absorbed by the body. Further, oxidative damage decreased after eating either of the sauces, but the effect was greater after eating the Tangerine tomato sauce.
This clearly indicates the superior benefit of consuming these orange tomatoes containing tetra-cis-lycopene in a cooked form. But what about raw? The research has not yet been done to find out how tetra-cis-lycopene behaves and is absorbed when eaten as a raw fruit. Nevertheless, based on the indicators, we are confident that it will be very well absorbed by the body when eaten raw. We will endeavour to obtain funding so that this research can be done.
We now have data on over 300 tomato varieties. We found 12 varieties with tetra-cis-lycopene ranging from 1.01 to 5.36 mg/100g FW: all are heirlooms and distinctively orange in colour. We used a modern commercially bred hybrid tomato called "Daniella" as a control. This is one of the most popular commercial hybrid tomatoes in New Zealand and is an attractive red, regular sized, firm and prolific tomato. Its levels of medicinal compounds are very low!
Our research leads us to the hypothesis that traditional Solanum lycopersicon tomatoes were originally golden-orange in colour and contained tetra-cis-lycopene that is more easily absorbed in the human body and therefore of great benefit for human health.
We further hypothesise that tomatoes containing tetra-cis-lycopene have greater potential to improve human health, in particular by reducing the incidence of heart disease and certain cancers.
Extensive breeding of tomatoes over hundreds of years has led to the recessive gene in tetra-cis-lycopene being progressively bred out, replaced by the more dominant all-trans-lycopene we now find in tomatoes and red tomatoes in particular. This inadvertent consequence of tomato breeding has significantly diminished the modern tomato's medical value. It is quite probable that there is no modern commercially bred hybrid tomato with this valuable tetra-cis-lycopene.
We consider the identification of tetra-cis-lycopene and its connection to the original pomodoro tomatoes a breakthrough in our understanding. From now on we will only grow these high-health golden-orange varieties.
The challenge we now face is how to maintain or even enhance the medicinal qualities of these varieties, without falling into the commercial (or perhaps ego-driven) trap of manipulation for the wrong reasons.
Our Trust contracts a scientist at a major New Zealand plant research organization to carry out the chemical analysis of our tomato samples. His attempts to generate some interest within his organisation in further research on tomatoes have been unsuccessful. He was told there were major commercial barriers to the establishment of a 'new' tomato, one being the yield: if a variety can't produce 16 trusses of fruit, commercial growers are not interested. And even though the research on heirloom tomatoes clearly shows that they are superior for human health, they are perceived to be less productive and hence not worth growing. This of course ignores the quite different requirements of the many gardeners growing their own tomatoes in their backyard.
In the modern world we have given responsibility for growing food over to commercial interests, especially as we have become more time-constrained with work pressures, travel times and the complexities of modern day living. However as many are now realising, modern commercial growers use seeds and methods that conform to their specific criteria and needs. Maximising profit for business through increasing yields has come at the cost of nutritional and medicinal quality.
In my view, those breeding tomatoes over the centuries have been completely unaware of the long-term implications of what they were doing. Only on examination of the results do we see the foolhardiness of the approach taken. It is impossible to quantify the adverse health outcomes arising from tampering with a healthy medicinal fruit for spurious commercial reasons. If this is representative of the widespread breeding and manipulation of our food supply that has taken place, then we only have to look around us at the level of ill health in society today to see the consequences.
Fortunately there is a growing awareness of the need to take back responsibility and exercise control over our food supply once more. To this end we are very pleased to be members of various seed saving organisations and part of this wonderful, worldwide reawakening of understanding regarding food. It is indeed fortunate that there are dedicated individuals and groups who keep the remnants of our heirloom seeds alive, jewels we can turn to when these breeding mistakes are eventually detected.
Our emphasis on medicinal quality is not new. It is an ancient understanding, epitomised by the teachings of Hippocrates: that food is mankind's medicine and contains within it all that is needed to keep people well.
Invitation to New Zealand Tomato Growers (April 2013)
We invite keen tomato growers to join us and be part of our ongoing tomato research.
The Heritage Food Crops Research Trust has completed 7 years of research into heirloom tomatoes. This has culminated with the finding of 12 varieties that contain a better form of lycopene (known as tetra-cis-lycopene) that has been shown in studies in the United States to be 2.5 times more efficiently absorbed by the body than the all-trans-lycopene found in red tomatoes. The tetra-cis-lycopene is found in certain golden orange heirloom tomatoes and the Trust had imported seed of these varieties for its research.
Lycopene that can be absorbed, finds its way into the blood where because it is a powerful antioxidant, it protects cells and essential fatty acids ("the good fats") against oxidation.
To date the US studies have only compared tomato sauces made from red and orange tomatoes and found in the blood samples taken from their volunteers that the lycopene from the orange tomato sauce was much better absorbed into the body and correspondingly better able to decrease oxidative damage.
Lycopene in fresh red tomatoes is not well absorbed by the body because it has a linear molecular structure, which has difficulty passing through the intestinal wall into the blood.
However the tetra-cis lycopene found in these orange heritage tomatoes has a bent molecular form that corresponds more closely with the lycopene found naturally within the body.
This is one reason why our researchers believe that the lycopene from these orange tomatoes picked straight from the vine or tossed into a salad (especially with an oil-based dressing) will be also well absorbed and able to exert its health-giving properties. We are currently looking for funding from New Zealand philanthropists so that we can initiate this study. Another reason we are so excited about this find is the historical background – it's been like putting the pieces of a puzzle together.
In the early 1500's Hernan Cortes and his conquistadores conquered Mexico and discovered the tomatoes that were being grown there. They sent them back to Europe and when they arrived in Italy they were named "Pomodoro", which is still their name in Italy today – it means golden fruits. We believe these original golden tomatoes would have all contained the tetra-cis lycopene and that this would be naturally well-absorbed by the body. At some stage after this introduction into Europe, breeding began to take place and the tomatoes were bred to be red to appeal to consumers' love of red coloured fruit. At that stage we hypothesise that the recessive tetra-cis lycopene gene was inadvertently replaced with the more dominant all-trans-lycopene form found in red tomatoes. Hence at a very early stage in the breeding of tomatoes an error occurred that has been repeated for hundreds of years, and it is only now that we think we can see what has happened.
We believe that there is a wonderful opportunity to improve human health by replacing red tomatoes with these orange tomatoes. Tomato is the primary source of lycopene for human consumption. We know that it is a powerful biological antioxidant and scientific studies have shown that high lycopene intake is associated with decreased risk of heart disease and cancer, especially prostate cancer.
Our Trust together with the Whanganui Regional Primary Health Organisation will be getting Bristol Plants and Seeds to grow 5,000 of these orange tomato plants for free distribution around the Whanganui region this November. We will also be asking keen tomato growers to give us a few seeds back so that we can have enough seeds for future wider distributions. We will also asking growers to keep an eye out for any possible changes as the varieties may potentially evolve naturally over time. We wish to avoid the mistakes made by commercial breeders in the past who have diminished the levels of beneficial compounds in today's modern tomatoes. Rather than try and control the breeding process, as commercial breeders do, we would like to try an alternative approach.
Our objective is to have the best tomatoes in the world for human health and we would like individuals who share this intent to join us, to grow these tomatoes with this intention and with love. It is an open-source project in that people will be free to grow and sell their produce or plants or give them away to others. We just ask that you don't physically manipulate the varieties to try and cross them. Just allow this to happen naturally, if that is what is meant to happen, and if you notice that a change has occurred in the variety, then please share a few seeds back with us, so that we can analyze and monitor the ongoing development of these fruits.
Science now recognises that scientists can influence the outcomes of their experiments just by wanting a particular outcome and hence the modern advent and use of double-blind trials. We believe that a person's intention when they plant a seed can influence the growth and development of that plant. We would like to couple that with research into whether outcomes are not as random as has previously been thought. Einstein used to say that "God does not play dice" (allowing for each person's individual interpretation for the term "God"), perhaps life has more meaning than we may have previously attributed to it. Perhaps there are external factors and natural laws that affect man. Perhaps we have a creative ability through our intention that can influence the outcome of events. Our research intends to explore these possibilities through the medium of "tomatoes".
Mark Christensen inspects some of the Trust's golden/orange tomatoes.
- Turning up the heat on tomatoes boosts absorption of lycopene
- "Tangerine Tomatoes top reds in preliminary lycopene study": Agricultural Research, February 2011
Appendix: Tomato varieties confirmed to contain Tetra-cis-lycopene
Tetra-cis-lycopene is a highly beneficial bioavailable form of lycopene, and exhibits a golden-orange or tangerine tomato colour. But not all tomatoes with this colour contain tetra-cis-lycopene, as this colour can also be expressed by beta-carotene. Hence it is necessary to chemically analyse each tomato variety to verify whether or not it contains tetra-cis-lycopene.
We provide here a list of all the varieties that we have had analysed and confirmed to have tetra-cis-lycopene to assist health conscious gardeners, healthy food advocates and researchers worldwide. Data has been obtained from the 2015 season.
|Concentration (mg/100g FW)|
|Amish Yellowish Orange Oxheart||n.d.||8.21||n.d.||n.d.|
|Alice Brewer (orange)||0.02||3.82||n.d.||n.d.|
|Alice Brewer (orange)||0.02||1.55||n.d.||n.d.|
|Amish Orange Sherbert Heirloom||n.d.||5.36||n.d.||n.d.|
|Aunt Gerties Gold||0.06||5.73||n.d.||n.d.|
|Barnes Mountain Orange||n.d.||6.54||n.d.||n.d.|
|Brown's Yellow Giant||n.d.||3.57||n.d.||n.d.|
|Djena Lees Golden Girl||0.04||5.23||n.d.||0.04|
|Earl of Edgecomb||0.11||2.52||n.d.||n.d.|
|Gary Ibsen's Gold||0.03||4||n.d.||n.d.|
|Gary's Golden Bear||0.08||1.64||n.d.||0.01|
|Homer Fike's Yellow Oxheart||0.05||1.74||n.d.||0.01|
|Ilse's Orange Latvian||n.d.||6.73||n.d.||n.d.|
|King's Gold (Koanga)||0.04||3.02||n.d.||n.d.|
|Large Yellow Amish||0.04||4.28||n.d.||n.d.|
|Olga's Round Golden Chicken||0.05||7.27||n.d.||n.d.|
|Orange Fleshed Purple Smudge||0.03||6.99||n.d.||0.04|
|Pegs Round Orange||0.02||1.08||n.d.||n.d.|
|Roughwood Golden Plum||0.14||3.82||n.d.||n.d.|
|Small Sweet Orange||0.12||1.63||0.66||0.12|
|Summer Cider Apricot||n.d.||6.15||n.d.||n.d.|
|Tangella (cherry type)||0.03||6.13||n.d.||n.d.|
|Yellow Brandywine Platfoot Strain||0.13||4.15||n.d.||n.d.|
|Yoders Yellow German||0.03||2.65||n.d.||0.01|
|Yoder's Yellow German||0.02||3.4||n.d.||n.d.|
Notes on tetra-cis-lycopene levels
* The level of tetra-cis-lycopene is very dependent upon the ripening state of the tomato, with maximum levels appearing to be at the optimum full ripeness stage for picking and immediate eating. Our 'Moonglow' tomatoes were picked early and therefore their level of 5.38 for tetra-cis-lycopene will be greater if left to ripen further.