Can broccoli sprouts prevent cancer? Help you live longer? What are the health benefits of sulphoraphane?
Sulforaphane is a phytochemical found in certain plants. It is particularly common to cruciferous vegetables including broccoli, cauliflower, and kale. It’s well known that eating cruciferous vegetables is linked to a lower risk of cancer.
Research shows that sulforaphane has potential health benefits in cancer, mortality, aging, heart disease, and more.
This article will provide an overview of the current state of understanding regarding sulfuraphane’s benefits.
Sulforaphane is an isothiocyanate (an organic sulfur-rich compound). The chemical structure of sulforaphane is below:
Sulforaphane is interesting in that it primarily exists in a deactivated form as glucoraphanin. When the plant containing sulforaphane is damaged, it releases an enzyme called myrosinase. This enzyme then activates sulforaphane – leading to its potential health benefits when consumed.
Briefly steaming may be a good way to prepare vegetables for the most sulforaphane content. Although, raw vegetables appear to have up to ten times the amount present.
Hundreds of studies have investigated the potential health benefits of sulforaphane in animals and humans. These indicate that sulforaphane may have several positive effects.
There are more than a dozen active clinical trials investigating sulforaphanes potential benefits.
- Several “test tube” (in vitro) studies have shown that sulforaphane slows down colon, cervical, pancreatic, prostate, lung, breast, skin, and leukemic cancer cell growth.
- Sulforaphane may improve chemotherapy by acting as an adjuvant (helper) for the medication cisplatin.
- In animals, intake of broccoli sprouts is linked to decreased cancer occurrence and growth.
- Clinical trials are currently underway investigating sulforaphane for use as an adjuvant therapy in prostate cancer.
- Sulforaphane appears to improve the cell-protective and antioxidant response in old cells, suggesting that it may have an anti-aging effect.
- Sulforaphane reduces senescence (aging-related dysfunction) in cell lines in vitro (in test-tubes).
- Sulforaphane may have protective effects in skin aging following UV exposure.
- Sulforaphane and its inactive form glucoraphanin have several antioxidant and anti-inflammatory properties.
- Eating 100g of broccoli sprouts a day resulted in marked reduction of LDL-cholesterol (low-density lipoprotein; the “bad” kind) and oxidative stress markers (proteins which signify inflammation).
- Sulforaphane (as concentrated broccoli sprout extract) reduced fasting blood glucose (how much sugar is in the blood when fasting) and improved other markers of blood sugar control in Type 2 Diabetics.
- Sulforaphane appears to have antimicrobial activity, especially against Helicobacter pylori – the causative agent of many stomach infections.
- Sulforaphane appears to have antiarthritic effects in mice. It is unclear whether this is true for humans. Interestingly, a major reason for this appears to be that it regulates the immune system, meaning that sulforaphane may be useful in other immune-related dysfunctions as well (allergies, for example).
- Sulforaphane may protect against the type of brain injury which causes Parkinson’s and Alzheimer’s Diseases.
Important side note
It is important to remember that much of the above is preliminary scientific results. Though there have been several successful clinical trials in humans, these too require further validation. Though, it seems undisputed at this point that at worst sulforaphane is an excellent nutrient, and that cruciferous vegetables should be consumed regularly.
Side effects, possible toxicity
As with any chemical (natural or not), consuming too much may carry unwanted side effects.
Various clinical trials have investigated the safety of sulforaphane at various concentrations. Below are some of the results of these clinical trials:
- Consuming 25 or 100 micromol of glucoraphanin for seven days had no significant side effects.
- 200 adults ate broccoli sprout infusions containing 175 mg glucoraphanin with no adverse side effects.
- Topical application of 340 micromol sulforaphane three times had no adverse side effects on the skin. However, a dose of 681 micromol caused a 3 millimeter erythema (a type of rash).
- In a study investigating the oral consumption of 60 mg sulforaphane for 6 months, most reported adverse events were non-serious and consisted largely of bloating and bowel discomfort.
- Long-term safety has not been investigated past 8 months.
- Sourcing sulforaphane from natural sources (i.e. broccoli sprouts) appears to have little or no safety concerns.
In summary, sulforaphane at a dosage found in cruciferous vegetables is safe to consume. Eating a lot of these vegetables may cause an upset stomach.
How does it work – the basics
Antioxidation and detox
Sulforaphane is an antioxidant, meaning it neutralizes toxic chemicals known as free radicals. Free radicals are caused naturally and unnaturally and can cause damage to cells because they are so reactive. Sulforaphane can help to reduce them, improving cell health.
Inflammation is a leading cause of illness in the world, and often linked to other diseases (including cancer, diabetes, cardiovascular diseases, etc.). By reducing free radicals in your body, sulforaphane helps to reduce inflammation.
Sulforaphane is linked to several epigenetic pathways (turning genes on or off) which protect your DNA from mutations that can lead to cancer.
How does it work – the nitty gritty
Sulforaphane is an incredibly active biomolecule. It is a part of several pathways in the body, and is known to interact and activate several other molecules.
NRF2 (Nuclear factor erythroid 2-related factor 2)
The NRF2 pathway is the most well-known. Sulforaphane makes NRF2, a gene involved in anti-oxidation, uptick its downstream genes.
NRF2 is a regulatory gene – it functions by turning other genes on or off. When NRF2 activates its downstream genes, it increases cell health and antioxidant properties.
NF𝛋B (Nuclear factor kappa B)
Sulforaphane also appears to have an effect on NF𝛋B, one of the most well-studied pro-cancer and inflammatory pathways.
Sulforaphane treatment results in a reduction in several inflammatory molecules (e.g., IL-6, TNF-ɑ, IL-2, IL-4, IFN-ᵞ). This suggests that sulforaphane is directly inhibiting NF𝛋B, reducing inflammation in the body.
There are several proposed epigenetic pathways by which sulforaphane appears to act.
Dosage and how to get more sulforaphane
The best dosage may be between 50 and 100 mg taken daily in two or more doses.
The best source of sulforaphane is broccoli sprouts. Other vegetables known to contain sulforaphane are:
- Brussel sprouts
- Bok Choy
To activate sulforaphane, it is important to chew the vegetables. Either eat them raw or after very brief steaming.
Combining these vegetables with mustard seeds or powder can also increase the sulforaphane content due to the presence of myrosinase in these foods.
Sulforaphane is a naturally-sourced nutrient most common in cruciferous vegetables.
Sulforaphane may have several health benefits – including in aging, heart health, cancer, skin health, arthritis, and neurodegenerative disorders. More high-quality studies are required to confirm these benefits in humans.
Broccoli sprouts are the best source of sulforaphane.
Eating sulforaphane-rich foods is a sure-fire way to boost your health.