Sometimes when admiring the small army of broccoli plants growing in our garden standing at attention as if they're guarding their patch of soil from various animal and insect marauders they look to me like beings from another planet what with their large green bushy head and slender torso. And in spite of the 41st President's famous aversion of the vegetable these plant aliens are one of the healthiest and most nutritious power foods available.
While broccoli was originally a native of the Asia Minor and the Mediterranean region it wasn't until the 20th century that it finally became popular in the US and even then for the most part broccoli consumption was limited to Italian immigrants living here.
The understanding of broccoli's health benefits has brought about a significant interest in and subsequent research on the plant in recent years. The family of compounds that have really grabbed the imagination of scientists is called the glucosinolates. This group of substances once consumed will with the assistance of an enzyme called myrosinase convert to a new biologically active group of compounds called isothiocyanates. One of them sulforaphane is the primary member of this group and has received a significant amount of scientific attention.
Phase II detoxification
Perhaps the most clinically valuable role isothiocyanates and specifically sulforaphane play in the human body is their ability to stimulate phase II detoxification pathways in addition to cytochrome P450 enzymes. The P450 enzyme family acts among other things as catalysts for reactions involving the metabolism of many drugs precancerous chemicals such as PCBs and hormones including 17-beta estradiol. This mechanism of action the activation of P450 enzymes in addition to activating Nrf2 may perhaps be where sulforaphane displays its cancer-protective properties. Nrf2 is a transcription factor that when activated stimulates the body's primary antioxidatve response pathway. This pathway is essential in reducing damage and protecting cells as well as DNA from toxin-generated reactive oxygen species which can lay the groundwork for the genesis of cancer.
One property that many clinicians may not be aware of is sulforaphane's ability to heal gastrointestinal mucosa damaged by H. pylori. H. pylori infections can generate a high amount of localized oxidative stress. This effect can be very damaging greatly compromising the integrity of the GI tract's epithelial lining. It is again sulforaphane's antioxidative properties that act as tissue-protective agents minimizing GI damage in those suffering with H. pylori. Additionally broccoli sprouts high in sulforaphane were shown to help control and minimize H. pylori colonization as well.
Another application that was investigated through sulforaphane's induction of the Nrf2 pathway was its ability to act as a neuroprotective agent. Spinal cord injuries can obviously be very traumatic with high post-injury levels of tissue-damaging inflammation oxidation and antioxidant depletion being key factors in the resultant pathophysiology of the injury's cascade. Researchers found that in animal models of contusive spinal cord injury sulforaphane use holds potential as a therapeutic tool as it was shown to help mitigate tissue damage through the activation of the Nrf2 pathway.
In one final reference to Nrf2 sulforaphane use was shown to suppress the accumulation of mercury in the brain (a major issue for individuals suffering with autism and ADHD for instance) in study animals exposed to methylmercury.
Exposure to excessive amounts of UV radiation is a continued health concern for many people including clinicians. It can inflict its detrimental effects through lipid peroxidation suppression of the immune response and direct damage to vulnerable DNA among others effects. Sulforaphane was shown to reduce damage to skin tissue indicating its usefulness as a possible skin-protective compound.
Broccoli and its potent constituent sulforaphane can be powerful allies in helping to prevent disease. For those who have an aversion to the vegetable perhaps broccoli sprouts or a daily dose of a sulforaphane-containing supplement can help protect us from some of the daily chemical toxic insults we all unfortunately encounter.
Michael Fuhrman D.C.