Beneforte broccoli was developed at the John Innes Centre and the Quadram Institute (formerly the Institute of Food Research), two institutes on the Norwich Research Park. From identifying a high-glucoraphanin broccoli relative in the 1980s, it has taken many years of plant breeding, field trials and studies into potential health benefits to deliver Beneforté broccoli to your supermarket shelves.
This long term publicly-funded scientific research is supported by the Biotechnology and Biological Sciences Research Council (BBSRC), a public body that invests in world-class bioscience to generate new knowledge, products, services and to inform policy. BBSRC actively supports the researchers it invests in to deliver impact from their work to promote economic growth and wellbeing in the UK and beyond.
Keeping healthy involves eating a balanced diet and taking plenty of exercise. Our diets include fruit and vegetables, as lots of studies have suggested that eating plenty of fruit and vegetables helps to keep us healthy. There are many reasons why fruit and veg may keep us healthy – they are high in fibre, minerals and vitamins, but low in calories. We also think that many of the natural chemical compounds they contain, which give them their distinctive flavours, aromas and colours, may also help our bodies to stay healthy.
Broccoli contains one of these natural compounds, called glucoraphanin. Beneforte is even more of a good thing as it contains 2-3 times more glucoraphanin than other broccoli varieties.
Broccoli is one of a group of vegetables called crucifers. Cruciferous vegetables are good at switching on our own defences and there is a body of scientific evidence that diets high in these vegetables help to reduce risk of cancer and maybe also heart disease.
Most of the evidence that broccoli and other crucifers keep us healthy comes from large studies of people’s diets, some of which have looked at hundreds of thousands of people. Many of these studies suggest that people who eat several portions of these vegetables every week have a lower risk of cancer and a lower risk of heart disease.
We think this is because these vegetables contain compounds known as glucosinolates. The dietary studies suggest that having regular intake of the glucosinolates contained in crucifers may help our bodies to keep functioning well, especially as we get older. When we eat glucosinolates they are converted into chemicals known as isothiocyanates.
Glucoraphanin is the very special glucosinolate in broccoli, which is found at even higher levels in Beneforte. In our digestive system, this is converted to an isothiocyanate called sulphoraphane. Sulphoraphane enters our bodies’ cells and switches on our ‘antioxidant’ genes. These genes are part of our natural defence system which helps to protect us from environmental toxins but are also important in ensuring that we can combat a wide range of common diseases and keep us healthy as we get older.
A healthy metabolism is important to maintaining health, and glucoraphanin in broccoli can help to ‘re-tune’ the metabolism, through activating our bodies natural defences that help ensure our metabolic machinery functions well.
This may help to protect against chronic diseases such as obesity, Type II diabetes, cardiovascular diseases and some forms of cancer.
How much broccoli or glucoraphanin we need to eat to help us to keep healthy? We can’t say for sure because the levels of glucoraphanin in ordinary broccoli can vary, and sometimes broccoli can have very little. We have developed Beneforte broccoli to have a very stable, rich and reliable level of glucoraphanin to ensure that you will get your dose of glucoraphanin.
Broccoli and other Crucifers
Broccoli is a member of a group of vegetables called the crucifers. Broccoli is thought to be derived from a cabbage-like relative in pre-Roman times by selective breeding. Broccoli comes from the Mediterranean region (its name derives from ‘little sprouts’ in Italian) and was eaten by the Romans.
The same common ancestor is behind cabbages, cauliflowers, Brussels sprouts and Kohlrabi, and botanically all of these cruciferous vegetables are the same – they were just selectively bred hundreds of years ago to accentuate different characteristics. In the case of broccoli, the flower stalks don’t develop fully, but instead produce a proliferation of flower buds that group onto ‘spears.’ Cauliflowers are believed to have been bred from broccoli. Unlike broccoli their flower stops developing even before any flower buds are produced resulting in the characteristic white head, or ‘curd’, made up of immature flowering tissue.
So despite being the same species, the crucifers look remarkably different, in size and shape. They do, however, still share some characteristics. They have similar flowers, consisting of petals arranged in a cross shape, (the name “crucifer” is derived from the word cruciform, meaning cross-shaped). They also have characteristically strong aroma and taste, which has been behind their popularity in use in Mediterranean cuisine and subsequent spread around the world. And now we think that the compounds that are behind these tastes are what might be responsible for the observations from dietary studies that diets high in crucifers reduce risk of developing chronic disease.
These compounds are called glucosinolates and are used by the plants as a form of natural defence. The plant stockpiles glucosinolates inside its cells. When these cells are damaged, for example by insects biting into them, the glucosinolates mix with special enzymes kept separately within in the cell, breaking them down into other compounds called isothiocyanates. These deter the insects, but give broccoli and other crucifers their distinctive taste.
In broccoli, the predominant glucosinolate is called glucoraphanin, and the isothiocyanate is called sulphoraphane. In fact, broccoli is the only crucifer to have any significant quantity of glucoraphanin. Beneforté has been bred, using traditional techniques, to be 2-3 times higher in the amount of glucoraphanin compared to standard broccoli varieties. Whilst this was done primarily because studies on glucoraphanin have shown it may reduce risks of chronic diseases, we have made sure that it hasn’t drastically altered the taste of broccoli. In fact many people prefer the taste of Beneforté.
As well as the increased levels of glucoraphanin, Beneforté also contains all of the nutrients found in standard broccoli varieties. Broccoli is high in fibre and a good source of vitamins A, C K, as well as folate and calcium.
Dietary studies that look at differences in peoples’ diets and how these appear to affect their health are known as epidemiological studies. Many epidemiological studies have shown that diets rich in cruciferous vegetables reduce the risk of developing chronic diseases including some forms of cancer and heart disease.
Researchers carrying out these studies publish their findings in scientific journals. These papers are peer-reviewed, by expert scientists unconnected with the study to independently verify the study design, the data and the conclusions drawn from it. We have collected together many of the papers relating to the effects of cruciferous vegetables.
Epidemiological studies don’t, on their own, show that lifestyle factors such as cruciferous vegetables in the diet cause a reduction in chronic disease. Instead they highlight general trends in the population. Scientists can follow up trends identified in epidemiological studies with experiments that uncover exactly how, in the human body, different foods can have beneficial effects. A plausible mechanism, coupled with strong epidemiological data, provides the best evidence for health effects related to diet. This quality of evidence is needed to support health claims and policies underlying governmental health, diet and nutritional advice.
There are different general types of epidemiological study. One type looks at a group of people with a certain health condition, for example cancer. The diets of these people are then compared with a carefully selected ‘control’ group of people who haven’t developed cancer. The studies, known as retrospective case-controlled studies, can associate dietary differences with the risk of getting health conditions, but they suffer from a number of problems. Firstly, they rely on people accurately recalling their dietary habits, usually through filling in questionnaires, which can be a challenge. Also, selecting the healthy ‘control’ group of people is incredibly hard. Ideally the groups should be very similar, but a problem with measuring the effects of a healthy diet is that eating plenty of fruit and vegetables is often part of a generally healthier lifestyle, and is affected by socioeconomic factors. The design of the study and the interpretation of the data can overcome some of these problems.
Some studies have shown that cruciferous vegetables may reduce the risk of prostate cancer[i], bladder cancer[ii], breast cancer[iii] and other conditions, a list of which is available. Some of these studies have tried to improve the study design by measuring compounds in urine instead of reported diet to assess cruciferous vegetable intake.
More recently, ‘cohort studies’ have also been reporting their findings. Cohort studies follow very large groups of people over a period of time, and correlate their diet and lifestyle with the development of diseases and conditions. These studies involve tens of thousands of people and follow them over decades.
Cohort studies have shown some protection against cardiovascular disease from cruciferous vegetables [iv] as well as prostate cancer[v] [vi] and others detailed in the table.
In addition, a number of ‘meta-analyses’ have attempted to combine many of the different studies undertaken by different research groups around the world to give an overview.
Meta-analyses have provided evidence that cruciferous vegetables reduce the risk of colon cancer[vii], prostate cancer[viii]and breast cancer[ix]
The strongest evidence for health-protecting effects of eating certain foods comes from Human Intervention Trials, where a group of human volunteers have their diet supplemented with the food being tested and the effects compared with a similar group who do not receive the supplementation. With good study design, neither the volunteers nor the researchers should be able to tell which diets are being supplemented, avoiding any bias in the study.
The Institute of Food Research has conducted a small-scale human intervention trial to fill in gap between observational studies in men at risk of developing prostate cancer and showed there were more positive changes in gene expression amongst men who were on the broccoli-rich diet, and these changes may be associated with the reduction in the risk of developing prostate cancer. The Institute of Food Resarch is now carrying out a much larger study, funded by the Prostate Cancer Foundation looking at the protective effects of broccoli consumption against prostate cancer.
The development of Beneforté broccoli is giving researchers the ability to give volunteers dietary interventions containing different levels of glucoraphanin. The first of these trials[ix] showed that high glucoraphanin broccoli (Beneforté) was able to ‘re-tune’ metabolic processes in our cells linked to health outcomes. In further studies, published in 2015, we have shown that a diet rich in high glucoraphanin broccoli reduced blood LDL cholesterol levels. Two independent dietary intervention trials showed that people eating 400g of high glucoraphanin broccoli saw an average reduction of 6% in the LDL cholesterol after 12 weeks[x].
List of References
[i] Joseph, M. A., K. B. Moysich, J. L. Freudenheim, P. G. Shields, E. D. Bowman, Y. Zhang, J. R. Marshall, and C. B. Ambrosone. “Cruciferous Vegetables, Genetic Polymorphisms in Glutathione S-Transferases M1 and T1, and Prostate Cancer Risk.” Nutr Cancer 50, no. 2 (2004): 206-13. http://dx.doi.org/10.1207/s15327914nc5002_11[ii] Lin, J., A. Kamat, J. Gu, M. Chen, C. P. Dinney, M. R. Forman, and X. Wu. “Dietary Intake of Vegetables and Fruits and the Modification Effects of Gstm1 and Nat2 Genotypes on Bladder Cancer Risk.” Cancer Epidemiol Biomarkers Prev 18, no. 7 (Jul 2009): 2090-7. http://dx.doi.org/10.1158/1055-9965.EPI-08-1174
[iii] Fowke, J. H., Chung, F. L., Jin, F., Qi, D., Cai, Q., Conaway, C., Cheng, J. R., Shu, X. O., Gao, Y. T. and Zheng, W. (2003) “Urinary Isothiocyanate Levels, Brassica, and Human Breast Cancer ” http://cancerres.aacrjournals.org/content/63/14/3980.full
[iv] Joshipura, K. J., A. Ascherio, J. E. Manson, M. J. Stampfer, E. B. Rimm, F. E. Speizer, C. H. Hennekens, D. Spiegelman, and W. C. Willett. “Fruit and Vegetable Intake in Relation to Risk of Ischemic Stroke.” JAMA 282, no. 13 (Oct 6 1999): 1233-9. http://dx.doi.org/10.1001/jama.282.13.1233
[v] Kirsh, V. A., U. Peters, S. T. Mayne, A. F. Subar, N. Chatterjee, C. C. Johnson, R. B. Hayes, Lung Colorectal Prostate, and Trial Ovarian Cancer Screening. “Prospective Study of Fruit and Vegetable Intake and Risk of Prostate Cancer.” J Natl Cancer Inst 99, no. 15 (Aug 1 2007): 1200-9. http://dx.doi.org/10.1093/jnci/djm065
[vi] Richman, E. L., P. R. Carroll, and J. M. Chan. “Vegetable and Fruit Intake after Diagnosis and Risk of Prostate Cancer Progression.” Int J Cancer 131, no. 1 (Jul 1 2012): 201-10. http://dx.doi.org/10.1002/ijc.26348
[vii] Wu, Q. J., Y. Yang, E. Vogtmann, J. Wang, L. H. Han, H. L. Li, and Y. B. Xiang. “Cruciferous Vegetables Intake and the Risk of Colorectal Cancer: A Meta-Analysis of Observational Studies.” Ann Oncol 24, no. 4 (Apr 2013): 1079-87. http://dx.doi.org/10.1093/annonc/mds601
[viii] Liu, B., Q. Mao, M. Cao, and L. Xie. “Cruciferous Vegetables Intake and Risk of Prostate Cancer: A Meta-Analysis.” Int J Urol 19, no. 2 (Feb 2012): 134-41. http://dx.doi.org/10.1111/j.1442-2042.2011.02906.x
[ix] Liu, X., and K. Lv. “Cruciferous Vegetables Intake Is Inversely Associated with Risk of Breast Cancer: A Meta-Analysis.” Breast 22, no. 3 (Jun 2013): 309-13. http://dx.doi.org/10.1016/j.breast.2012.07.013
[ix] Armah, C. N., Traka, M.H., Dainty, J.R., Defernez, M., Astrid Janssens, Leung, W., Doleman, J., Potter, J.F., and Mithen, R.F. A diet rich in high glucoraphanin broccoli interacts with genotype to reduce discordance in plasma metabolite profiles through modulating mitochondrial disfunction, Am J Clin Nutr 2013 98: 712-722 doi: 10.3945/ajcn.113.065235
[x] Armah, C.N. et al A diet rich in high glucoraphanin broccoli reduces plasma LDL cholesterol: evidence from randomised controlled trials”, Molecular Nutrition and Food Research
Glucoraphanin is a naturally occurring compound found almost exclusively in broccoli. Many studies around the world have associated broccoli with reducing the risks of developing certain chronic diseases such as cancer and heart disease, and on-going research is pointing towards glucoraphanin being the compound responsible for these health benefits. Beneforté broccoli contains 2-3 times the amount of glucoraphanin than other broccoli varieties.
When we eat broccoli, the glucoraphanin is converted into another compound called sulphoraphane, which turns on our antioxidant defences. These help to rebalance our metabolic machinery and remove some of the potentially damaging effects of an imbalanced metabolism. These metabolic imbalances contribute to an increased risk of getting chronic diseases such as heart disease and some cancers. We think the reduced risks of contracting these diseases in people who eat diets rich in broccoli and other crucifers is down to the ‘retuning’ of our metabolic machinery through the antioxidant defences that are turned on after we eat glucoraphanin.
We are now investigating the links between glucoraphanin, antioxidants, metabolism and disease. Glucoraphanin is converted into sulphoraphane by the beneficial bacteria that live in our digestive systems. A few hours after eating broccoli, sulphoraphane is seen in our blood stream. From here, it enters the cells of our liver and other tissues, where it can activate our bodies’ antioxidant defences.
In our cells there is a protein called Nrf2. Nrf2 is usually tethered to another protein called KEAP1, which drags Nrf2 off to be degraded for natural recycling. When sulphoraphane enters our cells, it breaks the link between Nrf2 and KEAP1. Nrf2 is now free to enter the nucleus of the cell, which is where the DNA is kept. DNA contains all of the instructions, in the form of genes, for making us and all of the proteins and enzymes that keep alive and healthy. But it is important that the correct genes are only switched on at the right time. Genes have a special bit of code that tells them whether to be on or off, and Nrf2 binds to this piece of code for the genes that make antioxidant enzymes and activates them. Sulphoraphane is among the most potent inducers of antioxidant genes known, which is why we believe the higher levels you get from eating Beneforté broccoli are so beneficial.
Beneforté broccoli is the best way of ensuring that you get a sizeable portion of glucoraphanin in your diet. We are still carrying out research to work out how much we need to eat to get the health benefits. Some studies suggest we need to eat the equivalent of one portion of ordinary broccoli every day, while other studies suggest we can eat less. This may be because the levels of glucoraphanin in broccoli can be quite variable. This is why we developed Beneforté broccoli, to guarantee that you get your glucoraphanin.
Three years of field trials at over 50 different sites in Europe and North America have shown that Beneforté broccoli consistently produces 2-3 times the amount of glucoraphanin than other leading varieties of broccoli, without affecting yield, quality or the levels of other nutrients. Sulphur is an essential component of glucoraphanin and Beneforté broccoli is better at absorbing sulphur from the soil, and also better at channelling this sulphur into producing glucoraphanin than other broccoli varieties, which in poor soils can struggle to produce much glucoraphanin. This explains how Beneforté consistently and reliably delivers more glucoraphanin than ordinary broccoli.
A Healthy Metabolism
Each cell in our body contains the central metabolic machinery which converts the carbohydrates and fats in our food to energy and other useful compounds needed to function healthily. As we age or when our cells become stressed, our metabolic machinery starts to work less well and begins to make what are known as reactive oxygen species (ROS). While a healthy cell needs a small amount of ROS, too much can be damaging. By having regular doses of glucoraphanin, we can keep our ROS within safe limits, which helps our metabolism to function normally. One consequence of keeping ROS in balance is that we can burn up fat effectively, rather than storing it in our bodies.