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Eating broccoli retunes metabolism

Researchers at the Institute of Food Research have obtained the first evidence from human studies of how diets rich in glucosinolates, such as glucoraphanin found in broccoli, can ‘re-tune’ cellular processes that get disrupted as we age.

_DSC0270Retuning these processes to normal may contribute to the reduced risk of cancer seen in people who eat diets rich in broccoli and similar vegetables. A high glucoraphanin broccoli variety, called Beneforté, is now available in UK supermarkets.

Inside each of our cells are specialised structures called mitochondria, which act as the engines of the cell. Mitochondria either burn up dietary fats and sugars to make energy or export them to be used by the cell as the building blocks to make other compounds needed for health. Mitochondria can also convert fats and sugars into forms for storage, which is how we can put on weight if we eat too much. For good health, we need to balance all these different metabolic activities.

Excessive fat or sugar in the diet can overload the mitochondrial machinery. Also, as we age, this machinery works less efficiently, especially if we do not have sufficient exercise. This is because of the build-up of Reactive Oxygen Species (ROS) in the mitochondria that inhibit some of the metabolic processes. The mitochondria may also begin to produce other compounds that can cause chronic inflammation. Disturbed metabolism and badly functioning mitochondria are associated with the development of chronic diseases such as obesity, Type II diabetes, cardiovascular disease and some forms of cancer.

To study what effects glucosinolate consumption has on metabolism, the researchers at the IFR carried out human dietary intervention trials. These involve making controlled and very specific changes to people’s diets over a period of time, and provide the best possible evidence for the effects specific foods have on our bodies and metabolism.

_DSC025248 volunteers were randomly split into three groups. Over a period of 12 weeks, one group ate high glucoraphanin broccoli, one group ate standard broccoli, and the third ate no broccoli. The researchers measured 346 metabolites in the blood before and after the 12 week period. They found that people who ate the high glucoraphanin broccoli had improved metabolism, and most of them had reduced levels of fatty acids in the blood and other lipid compounds that are associated with inflammation. They concluded that this was because of a bioactive compound called sulforaphane that is derived from glucoraphanin. This switched on ‘antioxidant’ genes which reduced the excessive ROS in the cells enabling their metabolic machinery to work better.

A number of studies have shown that diets rich in cruciferous vegetables may reduce the risk of cancer, type II diabetes and other chronic diseases of ageing through the actions of glucosinolates. This new study, published in the American Journal of Clinical Nutrition, provides the first evidence from human intervention trials of the mechanism behind this protective effect. This is being followed up by another study with a larger number of volunteers that is also looking at metabolism and biomarkers of cardiovascular health.

Beneforte broccoli growing in the field

Beneforte broccoli growing in the field

In 2011, a high glucoraphanin variety of broccoli was launched in UK supermarkets following significant investment in research from the Biotechnology and Biological Sciences Research Council (BBSRC).  Beneforté ‘super broccoli’ represents a special achievement for UK bioscience: a consumer-focused, nutritionally-enhanced product. Beneforté broccoli was developed through traditional breeding techniques by the Institute of Food Research and the John Innes Centre on the Norwich Research Park, both of which receive strategic funding from BBSRC.

Reference: A diet rich in high glucoraphanin broccoli interacts with genotype to reduce discordance in plasma metabolite profiles through modulating mitochondrial disfunction, Charlotte N. Armah et al was published in the American Journal of Clinical Nutrition Am J Clin Nutr 2013 98: 712-722

doi: 10.3945/ajcn.113.065235

Contacts:

Andrew Chapple, andrew.chapple@ifr.ac.uk, 01603 251490

 

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11 Responses to Eating broccoli retunes metabolism

  1. Laura 31 July, 2013 at 10:28 am #

    Thank you for this interesting summary. I’d like to hear more about your findings; what did you find with the group who ate normal broccoli and how did this compare with the other groups? Did participants experience changes that they perceived were a result of the increased consumption of broccoli?

    • Comms247 1 August, 2013 at 10:33 am #

      Hi Laura, thanks for your comment. We didn’t see the same ‘metabolic retuning’ effect with normal broccoli as we did with the high glucosinolate broccoli. It is possible we may have seen a similar effect if we had run the trial over a longer period of time, or had included more people.
      The participants who were given broccoli weren’t told whether or not they were receiving high glucosinolate broccoli or normal broccoli, as they look identical. In addition, this wasn’t known by the investigators until after the data had been collected. All the diets were well received and no adverse effects were reported. The metabolic changes we reported on were based on independent measurements of hundreds of different metabolites in the volunteers blood ”

      Andrew Chapple, IFR Communications

      • Desmond 1 August, 2013 at 10:26 pm #

        Hello, thanks for taking the time to publish this study. I went to a sams club here in the united states and purchased 6 bags. I have a chemistry question about the study.. Since the mitochondria works more efficiently it is a stretch to assume part of the benefit from this broccoli cultivar is due to its ability to chelate labile iron ions and which halted the ROS hydroxyl radical? Thanks!

        • Comms247 2 August, 2013 at 3:55 pm #

          Hello Desmond,

          Glucoraphanin, present at 2-3X higher levels in Beneforté, is converted to sulforphane in the gut, which then is taken into the blood stream. Sulforaphane activates a protein in our cells called Nrf2, which then turns on a number of genes behind our cellular antioxidant defence mechanisms. However, we’re not aware of any evidence of a link to iron chelation.

  2. Keith 10 August, 2013 at 1:25 pm #

    Thanks for the very interesting article. I dont like the taste of broccoli unfortunately, would taking a high quality sulforane supplement not be equivalent?

    • Comms247 12 August, 2013 at 1:00 pm #

      The Beneforté broccoli has been described by some to have a “milder” flavour than standard broccoli and so it may well appeal to those who have previously not been so keen on standard broccoli.

      As for taking sulforaphane supplements. The compound that has enhanced levels in Beneforté broccoli, glucoraphanin, is broken down by myrosinase type enzymes deep in the gut to produce sulforaphane which is then utilised by the body. Taking a supplement of sulforaphane may not deliver the same quantity or even reach the same site of action as it would if one had eaten the vegetable.

  3. Bonnie 22 August, 2013 at 11:54 am #

    Hello, thank you very much for the study. is Beneforté broccoli available in Hong Kong?

    • Comms247 4 September, 2013 at 10:42 am #

      Dear Bonnie, unfortunately Beneforté is not yet available in Hong Kong

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    […] 31 July 2013, Institute of Food Research (UK) — "Researchers at the Institute of Food Research have obtained the first evidence from human studies of how diets rich in glucosinolates, such as glucoraphanin found in broccoli, can ‘re-tune’ cellular processes that get disrupted as we age. Retuning these processes to normal may contribute to the reduced risk of cancer seen in people who eat diets rich in broccoli and similar vegetables. A high glucoraphanin broccoli variety, called Beneforté, is now available in UK supermarkets. Inside each of our cells are specialised structures called mitochondria, which act as the engines of the cell. Mitochondria either burn up dietary fats and sugars to make energy or export them to be used by the cell as the building blocks to make other compounds needed for health. Mitochondria can also convert fats and sugars into forms for storage, which is how we can put on weight if we eat too much. For good health, we need to balance all these different metabolic activities. Excessive fat or sugar in the diet can overload the mitochondrial machinery. Also, as we age, this machinery works less efficiently, especially if we do not have sufficient exercise. This is because of the build-up of Reactive Oxygen Species (ROS) in the mitochondria that inhibit some of the metabolic processes. The mitochondria may also begin to produce other compounds that can cause chronic inflammation. Disturbed metabolism and badly functioning mitochondria are associated with the development of chronic diseases such as obesity, Type II diabetes, cardiovascular disease and some forms of cancer. …"  […]

  3. Eating broccoli retunes metabolism | GR2 Food, Nutrition and Health - 13 August, 2013

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