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Sulforaphane and its effects on Cancer, Mortality, Aging, Brain and Behavior, Heart Disease, and More
The following vegetables contain a compound called glucoraphanin that is converted, in the body, into a substance called sulforaphane. This compound has a vast array of health benefits, many of which are discussed below.
- Broccoli spout
- Brussels sprouts
- Collard greens
- Bok choi
- Pak choi
Key facts on Sulforaphane:
- This compound is the most powerful known activator of the NRF2 metabolic pathway
- This pathway influences the expression of over 200 genes
Some of the genes that sulforaphane influences have antioxidant and anti-inflammatory effects, and others help to inactivate harmful compounds.
Sulforaphane has been shown to help prevent and fight cancer, and may help to treat cardiovascular disease.
Sulforaphane can help the body excrete carcinogens.
Dr. Patrick consumes 40-60 milligrams of sulforaphane every day.
- She does so by eating broccoli sprouts, which contain large amounts of the compound.
A 2011 study, published in the American Journal of Clinical Nutrition, showed that high rates of vegetable consumption was linked with significant reductions in all caused mortality. Which isn’t all that surprising, but:
- The study also showed that those who consumed the largest quantities of cruciferous vegetables enjoyed the most significant reductions in all cause mortality.
There has been extensive research that suggests the consumption of cruciferous vegetables reduces cancer risk.
One study found that men who consumed 3-5 servings of cruciferous vegetables per week enjoyed over a 40% decrease in the risk of developing prostate cancer, compared to men who consumed less than one serving per week.
- Another study found that men who ate two or more servings of a half cup of broccoli per week were 44% less likely to develop bladder cancer, relative to men who consumed less than one serving per week.
Another study found that smokers who consumed at least four and a half servings of cruciferous vegetables per month were 55% less likely to develop lung cancer (relative to those who consumed less than two and a half servings per month)
Studies have shown that the consumption of cruciferous vegetables reduces the risk of developing breast cancer.
Freezing affects the bioavailability of sulforaphane. Fresh, unfrozen foods, will contain the highest concentrations of sulforaphane.
In addition to reducing the risk of developing cancer, cruciferous vegetable consumption seems to help those who are fighting cancer.
- The consumption of four servings of broccoli per month was linked with a 57% reduction in cancer-caused mortality in patients with bladder cancer, relative to those who only had one serving per month.
The most likely causal agents responsible for these incredible disease fighting properties are a class of compounds called isothiocyanates.
- These substances are formed from a compounds called glucosinolates
- The enzyme responsible for the formation of isothiocyanates is called myrosinase.
Myrosinase is activated when cruciferous plant tissue undergoes chewing, crushing, or chopping.
- However, it can be inactivated by periods of prolonged boiling and other forms of heat.
Sulforaphane is an isothiocyanate.
- It is very well researched, and very potent.
Sulforaphane is formed from a glucosinolate called glucoraphanin (also commonly referred to as sulforaphane glucosinolate)
The best source of glucoraphanin (which the body transforms into sulforaphane) is probably broccoli sprouts, which contain up to 100 times more of the compound than adult broccoli.
Sulforaphane can both reduce cancer risk, and kill active cancer cells. At this point, the biological mechanisms behind these effects are fairly well understood.
In one study, several groups of rats were given a compound known to trigger the development of cancer.
- 96% of the control group developed cancer after exposure.
- Another group was given high dose of isothiocyanates at the outset of the study. Only 38% of this group developed bladder cancer following exposure. The tumors that did develop in isothiocyanate-treated group were smaller in size.
The administration of large amounts of sulforaphane to men with prostate resulted in an 86% reduction in rate of doubling of their PSA levels. (PSA, or prostate specific antigen, is used as an indicator of prostate cancer activity)
- In other words, the sulforaphane seemed to significantly deactivate these mens’ tumors.
- In another nearly identical study, a smaller dose of sulforaphane was administered. In this, the doubling of PSA was again reduced, but to a lesser degree than it was in the initial study. This result indicates that sulforaphane’s effects are dose dependent.
Sulforaphane seems to bioaccumulate in breast tissue, which may have protective effects.
In mice, sulforaphane was shown to inhibit the growth of breast cancer cells.
Cato the Elder, a prominent roman soldier, senator, and historian, wrote about cabbage’s efficacy for treating a wide variety of conditions. (Cabbage is a cruciferous vegetable).
Sulforaphane can deactivate carcinogens, and help the body excrete them.
The consumption of Brussels sprouts had been shown to reduce oxidative DNA damage in humans.
The consumption of both sulforaphane and glucoraphinin have been shown increase the rate at which benzene is excreted from the body by 61%. (Benzene is a known carcinogen in both humans and animals)
- Primary sources of benzene exposure include automobile exhaust and cigarette smoke (both firsthand and secondhand)
- Sulforaphane and glucoraphinin have similar effects on acrolein, another chemical carcinogen, which can form when carbohydrates, protein, and fats are heated.
An isothiocyanate present in the edible aquatic plant watercress can detoxify a common carcinogen found in tobacco called “NNK.”
Repeat key point: The consumption of cruciferous vegetables can lead to the deactivation and excretion of harmful compounds.
In addition to their potent anti-cancer properties, there is good evidence to suggest that cruciferous vegetables can improve cardiovascular health.
A study of diabetics showed that the consumption of cruciferous vegetables drove down biomarkers associated with heart disease, such as serum triglycerides.
They also had a near 25% drop in fasting blood sugar.
Sulforaphane consumption also seems to be able to combat neurodegenerative diseases.
A study on beetles showed that the consumption of broccoli can significantly boost beetle lifespan (in some cases, by up to 32.7%).
- These benefits also seem to results from sulforaphane’s effects on a biochemical pathway known as NRF2. As previously mentioned, this biological pathway is also present in humans, suggesting that sulforaphane consumption may be able to increase human lifespan as well.
Side note: There is an important gene in humans called FOXO3. People with a certain variant of the FOXO3 gene are 2.7 times more likely to live to be a centenarian.
A person’s chances of living to be a centenarian seem to be strongly influenced by the the degree to which they are able to keep inflammation at bay.
- Excerpt from a study on super centenarians: “Our results suggest that suppression of inflammation is the most important driver of successful longevity that increases in importance with advancing age.”
Inflammation is also an important predictor of cognitive ability.
The activation of an inflammation promoting pathway in mice has been shown to accelerate their aging by up to 30%.
- Sulforaphane has been shown, in mouse models, to down regulate this pathway, and have the opposite effect.
Key point: The evidence suggests that sulforaphane consumption drives reductions in inflammation, likely due to its effects on the NRF2 pathway.
NRF2 regulates approximately 200 genes, many of which have salubrious effects. (I want more people to know this word)
A dose of sulforaphane has been shown in mouse models to boost the functioning of the adaptive immune system. Sulforaphane consumption seems to be able to help mitigate the natural decline that the adaptive immune system undergoes as we age.
- Note: We have two types immune response, adaptive and innate. The adaptive immune response is based off of a form of cellular memory, whereby previously encountered foreign agents are recognized and attacked. (This is why you can develop immunity to some pathogens after exposure)
Sulforaphane can lower inflammation in the brain.
Key fact: According to Dr. Patrick, “The NRF2 pathway is the body’s strongest defense against oxidative stress.”
Oxidative stress has strong negative effects on the brain.
Research has shown that when people with autism spectrum disorder receive doses of sulforaphane, they show very significant reduction in their exhibition of autistic behaviors (such as difficulty with verbal interaction). For more on this, click here.
- Similar reductions in symptom prevalence have been shown following the consumption of glucoraphanin, (the precursor of sulforaphane) in patients suffering from schizophrenia. Both diseases are believe to have oxidative stress components.
According to the NIH, 10% of U.S adults are on some form of selective serotonin uptake inhibitor to combat depression.
- Evidence strongly suggests that nutrition plays a huge role in depression. These effects of a person’s diet on the production and function of their neurotransmitters, and their overall level of inflammation.
When scientists inject healthy individuals with pro-inflammatory cytokines (which cause inflammation), these individuals often begin to experience depressive symptoms.
- These symptoms can be alleviated through the administration of EPA, which is known for its anti-inflammatory properties.
Seeing as the consumption of cruciferous vegetables can lower levels of inflammation markers in humans, it stands to reason that cruciferous vegetable consumption may also be able to help combat depression.
Key excerpt: “In ten different models of stress induced depression, sulforaphane alleviated depressive symptoms and anxiety as well as the antidepressant prozac, in mice. Sulforaphane also decreased stress hormones and the inflammatory response to various social stressors.”
Mice that suffer social defeat often begin to exhibit symptoms of depression, such as avoiding social contact. The administration of sulforaphane prevented this avoidance behavior.
Brain inflammation and the presence of reactive oxygen species is typical in patients suffering from Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease.
When mice are triggered to develop diseases similar to those mentioned above, the injection sulforaphane lead to improvements in both spatial memory and working short term memory.
- Sulforaphane has also been shown to reduce tremors and balance dopamine levels in mice with artificially induced Parkinson’s disease.
Sulforaphane seems to be able to protect against traumatic brain injury in animals.
- It appears to help heal the blood-brain barrier in animals, following TBI.
- It is likely that such effects would also hold for humans suffering from TBI.
Excerpt from a study of muscular dystrophy in mice: “Sulforaphane (administration) significantly increased skeletal muscle mass, muscle force, running distance, and morphology of dystrophic muscle.”
If a person wants to get a good dose of sulforaphane in their diet, how many broccoli sprouts (one of the most concentrated sources of sulforaphane) would they have to eat?
- 1 gram of broccoli sprouts contains about 2.4 micro moles of sulforaphane (.425 mg)
- Some human studies showing promising results (reduction in PSA, inflammation, etc) used a daily dose of between 40 – 60mg of sulforaphane. This is also the amount that Dr. Patrick usually eats every day.
- One jar of broccoli sprouts will contain approximately 120mg of sulforaphane.
Prolonged heating and boiling of cruciferous vegetables can cause the sulforaphane the contain to become biologically useless.
- Light steaming (3-4 minutes) is just fine.
Dr. Patrick is not a huge fan of most sulforaphane / glucoraphanin supplements on the market.
- She usually just eats raw broccoli sprouts.
After watching this lecture, I can honestly say that if someone asked the best way to improve their life, I might just tell them to eat more cruciferous vegetables.
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