With all of the recent talk about the importance of detoxification, did you know that broccoli is actually one of nature’s best detoxifiers? Those little green trees that are known to contain fibre and vitamin C also contain a super antioxidant, glucoraphanin.
But what is it about glucoraphanin or broccoli that makes it so super?
The Discovery Of Glucoraphanin
Many published epidemiological studies show there is a strong correlation between high consumption of cruciferous vegetables (such as broccoli, cauliflower, brussels sprouts, and kale) and a variety of better health outcomes.
In the early 1990s, medical scientists at Johns Hopkins University School of Medicine in Baltimore, Maryland, US, identified glucoraphanin as a naturally-occurring compound in broccoli.
They discovered that when glucoraphanin was converted to sulforaphane, it possessed antioxidant activity and functioned in several ways to modulate factors that lead to many negative health conditions, such as:
- • Prevention of damage to cells caused by oxidants that are released as a normal part of metabolism
- • Removal/elimination of electrophiles that damage DNA and cellular processes
- • Modulation of inflammation
- • Protection against damage from UV radiation
Since this initial work, over the past 20 years, researchers at many medical institutions around the world have been studying the health benefits of glucoraphanin and sulforaphane. By 2014, there were more than 1,700 studies published documenting the health benefits of these phytonutrients.
Most recently, a 12-week long clinical trial involving 291 Chinese men and women residing in Qidong, China–one of its most polluted regions–studied the effects that glucoraphanin and sulforaphane had on the body’s ability to efficiently excrete pollutants.
Published in Cancer Prevention Research in 2014, the study found that the daily consumption of a broccoli beverage containing 260 mg of glucoraphanin and 7 mg of sulforaphane produced higher levels of excretion of certain airborne pollutants.
The researchers found that among participants receiving the broccoli beverage, the rate of excretion of the carcinogen benzene increased 61 percent compared to the placebo group, from the first day and continuing throughout the 12-week period. The rate of excretion of the irritant acrolein, rapidly increased 23 percent during the trial.
It should be noted that, on average, about 10 ounces of broccoli contains 30 mg of glucoraphanin. The participants in the study consumed a significantly higher amount of glucoraphanin than typical servings of broccoli.
Antioxidants In The Body
Antioxidants protect the cells in the body from damage caused by oxidative stress, namely free radicals, which are unstable compounds missing an electron (a negative charge). Free radicals are created as a by-product of normal cellular respiration as well as the result of environmental pollution, UV rays, diesel exhaust, cigarette smoke and alcohol.
Because of their volatility, they ‘steal’ electrons from any source they can find in the body to help stabilise them. Over time, the chronic exposure to free radicals will break down cells, causing a variety of negative effects, both acute and chronic.
Therefore, antioxidants can help to prevent or minimise the build-up of damage over time. Increasing antioxidant activity in the body helps to prevent oxidative damage in the first place. Without antioxidants, our cells could be easily damaged by reactive oxygen species, DNA-damaging electrophiles, inflammation and radiation.
Certain antioxidants contribute electrons to directly neutralise these free radicals, but are consumed in this process. These are known as direct antioxidants, and they last for only a short time in the body as each antioxidant molecule is used up in neutralising free radicals.
By definition, direct antioxidants are electron donors; they can give their electrons to free radicals, neutralising them and thereby preventing them from stealing any more electrons and doing further damage.
Currently, many of the most widely known sources of ingested antioxidants are short-term, direct antioxidants, such as vitamins C and E and polyphenols, including resveratrol (found in grapes and red wine) and EGCG (found in tea); but because each antioxidant molecule is directly used up in the neutralisation process, think of them as ‘one and done’ antioxidants.
However, there is also a set of indirect antioxidants— enzymes that harness the body’s own protective systems to provide persistent and long-lasting protection of cells. These indirect antioxidants induce the natural protective system in the cells, but because they boost the innate protective systems by acting as catalysts to keep this system working, these antioxidants are not used up in the process.
Indirect antioxidants boost the body’s Phase 2 Enzyme System–enzymes that act to increase the body’s own detoxification pathways. The Phase 2 Enzyme System is activated by Nrf2, a transcription factor that, when induced, triggers an increase in production of specific antioxidant enzymes, hence protecting the cells.
From Glucoraphanin To Sulforaphane
Glucoraphanin is one such indirect antioxidant that makes broccoli a superfood. It belongs to a category of compounds called glucosinolates, which are naturally found in cruciferous vegetables.
These are enzymatically converted into isothiocyanates, which are active in the body. This enzymatic conversion is performed by an enzyme called myrosinase, also found naturally in cruciferous vegetables.
When we chew raw broccoli, the glucoraphanin and myrosinase interact to create sulforaphane, also releasing the sulfur-like flavor some report tasting when eating raw broccoli.
Sulforaphane is what is responsible for activating a rechargeable and sustainable antioxidant system within the body. In fact, sulforaphane has long-lasting antioxidant effects—up to 72 hours—compared to vitamin C that only lasts up to three hours in the body.
Myrosinase-like activity can also be provided by the body’s own intestinal microflora. If glucoraphanin is consumed by itself—as in glucoraphanin-fortified foods, beverages and supplements—the human gut microflora will convert a portion of it to sulforaphane.
This is important because if broccoli is cooked at high temperatures for an extended period of time, the endogenous plant myrosinase enzyme becomes deactivated and thus conversion becomes dependent upon the gut microflora. As in many types of metabolism modulated by the microbiome, this conversion rate varies from individual to individual.
Delivering Glucoraphanin To Consumers
Even though broccoli is healthy, people may not want to eat it, especially at levels high enough to have a meaningful effect. While the Asia Pacific region accounts for 75 percent of the global vegetable consumption, according to Euromonitor International, there are other regions in the world where vegetable consumption is dismal, at best.
In fact, in the US, an online omnibus survey of 1,012 nationally representative adults conducted this year showed that nearly one in three (32 percent) Americans found a reason to avoid eating more broccoli.
Furthermore, nearly two in five (39 percent) wish they could get the nutritional benefits from broccoli without actually having to eat it—demonstrating that consumers are looking for an easier way to get the antioxidant boosting benefits of broccoli.
Even for those who do eat the vegetable, the amount of glucoraphanin a broccoli contains varies tremendously from one plant to another, with no signal for consumers to tell how much glucoraphanin is in what they buy.
High-quality glucoraphanin extracts from broccoli seeds can deliver concentrations of glucoraphanin upwards of 13 percent. If consumers do not like broccoli or cannot eat it every day, there are glucoraphanin-fortified foods, beverages and supplements available with ingredients like the truebroc brand, which delivers high quality and consistent levels of glucoraphanin.
Besides food applications, glucoraphanin has also been successfully added to a variety beverage applications, including hot and cold tea, coffee, smoothies, fruit and ice popsicles, as well as meal replacement drinks for adults, such as the Vietnam-based Vinamilk Sure Prevent product.
Glucoraphanin can be especially valuable in beverages, because it is water-soluble, heat-stable, pH stable from 3.0-9.0, and has a very neutral and acceptable sensory profile.
High quality glucoraphanin powders go through a filtering process so that the colour is white to tan and therefore does not add any unsightly discolouring. Also, during the filtration process, flavour that is characteristic of broccoli is stripped away leaving a neutral tasting and smelling powder. This makes it ideal for teas and other beverages that do not inherently have a rich flavour profile.
Glucoraphanin is an important phytonutrient found in broccoli that naturally works with the body’s own protective enzyme systems to provide significant health benefits.
Many consumers may want the health benefits of broccoli, so for those who would like to do without eating the vegetable, beverages are a great way to introduce this powerful antioxidant into their diets. From stick packs to tea bags to single serve coffee cups, beverage manufacturers can make a big impact by providing good-for-you products while maintaining a healthy margin.