Broccoli sprouts are a firm reminder that size does not equate to stature. These minute and youthful versions of the familiar broccoli plant are represented by an impressively large body of scientific literature that suggests this food source may combat certain cancers, detoxify the body from environmental pollutants, and possibly hold a key to the treatment of autism.
Packing health enhancing nutrients such as vitamin C, iron, and calcium, one serving (84 grams) of broccoli sprouts contains 5 grams of carbohydrates and 2 grams of protein. However the secret weapon concealed within these youngsters is a glucosinolate compound called glucoraphanin, which is converted by enzymes during digestive processes into a potent anti-oxidant and possible anti-inflammatory called sulforaphane.
Although fully matured broccoli offers a certain amount of sulforaphane, the amount found within the sprouts is far more concentrated. A paper published in the Journal of Agricultural And Food Chemistry details the difference in sulforaphane content between the two. It states:
- Mature broccoli contained 44-171 mg of sulforaphane per 100 g dry weight.
- Broccoli sprouts contained 1153 mg of sulforaphane per 100 g dry weight.
The authors concluded that the yield of sulforaphane in sprouts is “about 10 times higher than that of mature broccoli.” They also note that, “sulforaphane could not be detected in most of broccoli products,” suggesting present commercial broccoli products are of “low quality.”
So what’s the big deal with sulforaphane? How does it work? And what does it do?
An article on “The Stem Cell Theory of Cancer,” published by the Ludwig Center for Cancer Stem Cell Research and Medicine, states that: “[A]mong all cancerous cells, a few act as stem cells that reproduce themselves and sustain the cancer, much like normal stem cells normally renew and sustain our organs and tissues.” A paper, authored by researchers from the University of Michigan and Ohio State University, documents a series of studies that evaluated sulforaphane for its ability to inhibit breast cancer stem cells. The results showed great promise. Sulforaphane was found to inhibit the proliferation of breast cancer cell lines and induce the cancer killing process of apoptosis.
According to the Encyclopedia of Cancer, “One of the hallmark characteristics of stem cells is the ability of sphere formation. A sphere is a collection of cells that arise from a single cell through clonal growth. Upon seeding a single stem cell of mammary origin in culture, the first mammosphere to be formed is known as the primary mammosphere.” In one of the studies conduced by the researchers from the universities of Ohio and Michigan, sulforaphane was shown to inhibit the formation of primary spheres. Indeed, the numbers of spheres declined by 45 to 75 percent and the actual size of the spheres were reduced by between 8 and 125-fold.
The researchers exposed tumor-initiating ALDH-positive cells to differing levels of sulforaphane. As the authors explain, these cells are “capable of self-renewal and generating tumors resembling the parental tumor.” The team found small (1 μM) doses of sulforaphane decreased the population of ALDH-positive cells by over 65 percent, whilst a larger dose (5 μM) achieved a reduction of over 80 percent. The authors note that sulforaphane was able to “inhibit stem/progenitor cells” at concentrations which “hardly affected the bulk population of cancer cells,” implying that, “sulforaphane is likely to preferentially target stem/progenitor cells compared to the differentiated cancer cells.”
Further research from the Tokyo University of Science in Japan showed broccoli sprouts reduced a type of bacteria linked to gastric cancer, Helicobacter pylori , both in mice and in humans. The authors explain, “SF [sulforaphane] is powerfully bactericidal against Helicobacter pylori infections, which are strongly associated with the worldwide pandemic of gastric cancer.” The team concluded that, “Daily intake of sulforaphane-rich broccoli sprouts for 2 months reduces H. pylori colonization in mice and improves the sequelae of infection in infected mice and in humans. This treatment seems to enhance chemoprotection of the gastric mucosa against H. pylori-induced oxidative stress.”
Air pollution is becoming an increasing cause for concern as our world becomes more and more industrialized — so much so that in 2013 a branch of the World Health Organization, The International Agency for Research on Cancer (IARC), officially classified outdoor air pollution as a carcinogen. Two of the most notorious chemicals that contribute to this toxic mix are benzene and acrolein.
According to the Centers for Disease Control and Prevention and the Environmental Protection Agency, exposure to both benzene and acrolein can be caused by tobacco smoke, and by oil and gasoline emissions. Exposure to benzene can cause headaches, confusion, and vomiting. Very high levels can be fatal, with long-term exposure causing anemia, irregular menstrual periods, leukemia, and other forms of cancer. Exposure to acrolein may result in eye irritation and general respiratory congestion. Thankfully, research has shown that broccoli sprouts can help our bodies eliminate these nasty substances.
An international team of researchers from several institutions based in the U.S. and China, including the prestigious John Hopkins University, tested broccoli sprouts as a means of protecting humans from air pollution. The study involved 291 participants from the rural He-He Township, Qidong, in the Yangtze River delta region of China, a location exposed to large levels of air pollutants. During a 12-week randomized clinical trail subjects drank a broccoli sprout-based beverage. Urine measurements were taken before and during the study period. When these were analyzed, it was found that “rapid and sustained, statistically significant” increases in the excretion of benzene and acrolein occurred in those receiving the broccoli sprout drink in comparison to placebo.
The researchers stated, “Measures of sulforaphane metabolites in urine indicated that bioavailability did not decline over the 12-week daily dosing period. Thus, intervention with broccoli sprouts enhances the detoxification of some airborne pollutants and may provide a frugal means to attenuate their associated long-term health risks.”
Research conducted by scientists from Massachusetts General Hospital for Children and the John Hopkins University of Medicine suggests that sulforaphane may ease some of the behavioral symptoms in those diagnosed with autism spectrum disorders (ASDs).
The authors of the paper documenting the research sum up autism spectrum disorders as “encompassing impaired communication and social interaction, and repetitive stereotypic behavior and language, affects 1-2% of predominantly male individuals and is an enormous medical and economic problem for which there is no documented, mechanism-based treatment.”
In the placebo-controlled, randomized, double-blind clinical trail, 29 young men with ASD received daily oral doses of sulforaphane derived from broccoli sprouts over an 18 week period, followed by a four week period without treatment. The participants behavior was measured by three behavioral measures provided by parents, caregivers, and physicians. These included the Aberrant Behavior Checklist, Social Responsiveness Scale, and Clinical Global Impression Improvement Scale. After an 18 week treatment period, it was observed that those receiving sulforaphane showed substantial improvements in behavior compared to placebo in areas such as social interaction, abnormal behavior, and verbal communication. Interestingly, after treatment with sulforaphane was ceased, total scores on all scales started to return to pretreatment levels.
The authors of the paper explained sulforaphane was chosen for this research due to its effectiveness against conditions that arise in ASD: “Dietary sulforaphane, of recognized low toxicity, was selected for its capacity to reverse abnormalities that have been associated with ASD, including oxidative stress and lower antioxidant capacity, depressed glutathione synthesis, reduced mitochondrial function and oxidative phosphorylation, increased lipid peroxidation, and neuroinflammation.”
An article, published by John Hopkins Medicine, quotes two of the researches involved in the study:
“‘We believe that this may be preliminary evidence for the first treatment for autism that improves symptoms by apparently correcting some of the underlying cellular problems,’ says Paul Talalay, M.D., a professor of pharmacology and molecular sciences, who has researched these vegetable compounds for the past 25 years.
“‘We are far from being able to declare a victory over autism, but this gives us important insights into what might help,’ says co-investigator Andrew Zimmerman, M.D., now a professor of pediatric neurology at UMass Memorial Medical Center.”
How To Grow Your Own Broccoli Sprouts At Home
Since sulforaphane is far more concentrated in broccoli sprouts than in the mature vegetable, an adequate amount of this beneficial compound can be obtained by sprinkling a portion of sprouts (a quarter cup) on the top of a salad or in a sandwich, or adding them to a smoothie. In the video below, Tom Malterre of Whole Life Nutrition offers detailed guidance on how to cultivate your own supply of these easy to grow and health enhancing sprouts — all that’s required is some seeds, a little water, and a mason jar with a perforated lid!