Knowledge

Microgreens are the baby versions of vegetables that you’re likely familiar with. They are typically harvested sometime between when the cotyledon appears to when the first true leaf emerges. Microgreens have vibrant flavors and colors, are tender, and punch way above their weight in terms of nutritional content.

The tender stalks and leaves make excellent food additives that can be used by even the most novice cook to add a nutritional power boost to almost any meal, making it look gourmet and sophisticated.

Many varieties of microgreens have been shown to have anywhere from four to 40 times more vital nutrients than their mature counterpart (1), which is particularly important because mineral deficiencies can lead to serious health problems, like metabolic disorders, organ damage, and in extreme cases, even death (2).

Not only are microgreens significantly more nutrient-dense than adult greens, they can be grown indoors with a fraction of the time and effort of traditional farming, as well as the added benefit that they don’t require pesticides or fertilizer.

In addition, several varieties of microgreens can be grown to maturity in as little as six to eight days, and in general, they are extremely fast-growing. Because of the simplicity and fast turnaround by which high quality nutrient-dense microgreens can be grown, they are a promising alternative for meeting the nutritional needs of urban dwellers, especially for those living in food desserts who are much more likely to have vitamin and mineral deficiencies.

Regardless of whether you live in an urban, suburban, or rural area, it makes sense to start switching from store-bought vegetables to local or home-grown microgreens. The benefits of doing so extend far beyond the individual because of the massive environmental benefits compared to traditional farming methods.

For example, in a study focused on broccoli microgreens, it was found that they require 158–236 times less water than needed to grow a nutritionally equivalent amount of mature vegetable in the fields of California’s Central Valley, in 93–95% less time and without the need for fertilizer, pesticides, or energy-demanding transport from farm to table (3). This is astounding, to say the least.

At CarbonCrowd, we prefer to sell live plant microgreens rather than cut produce. We do not do any processing and would prefer the consumer have control over when the produce is harvested and thus the nutritional quality of the produce. It encourages people to eat greens when they are as fresh as possible — i.e., still living because you just cut it and add it to your meal. Since we do not use fertilizer or pesticides, there is no residue to wash off.

Most of the fresh fruit and vegetables you will see at the grocery store are picked before they are ripened so that they can ripen while they are in transportation. This gives them less time to develop useful phytochemicals, vitamins, and minerals. 

Contrast that with live plants, which preserve the nutritional content until the point of consumption. The 10-14 day period between harvest and consumption for many traditional crops can mean losses ranging between 10-80% of of the total nutritional value, depending on the variety and species (4).  

Here at CarbonCrowd, we have a focus on cruciferous microgreens. Although we do grow other varieties, we have an emphasis on the cruciferous microgreens for several reasons.  Firstly, they’re some of the fastest maturing microgreens that you can grow, with some varieties being ready to harvest in as little as a week, depending on conditions.

In the 2-3 months it takes to grow a crop of tomatoes, you could have grown 8-12 crops of mature microgreens instead. Farming microgreens isn’t the biggest commitment, because you can easily finish a short grow cycle and take a break before starting the next cycle, as opposed to other long term crops that can require a multi-month commitment, which is difficult for many people in today's fast-paced world. Cruciferous varieties give you more flexibility in this sense, since they tend to grow very quickly.

It’s been scientifically established that a diet loaded with cruciferous veggies will lead to a lower risk of mortality generally and reduce the risk of cardiovascular disease specifically (5).

It’s important to keep in mind that these studies often just look at mature vegetables, and the microgreen version of cruciferous vegetables are nutritionally-supercharged versions of the adult plants (6).

Whereas brassica varieties are similar to other microgreens in the sense that they are absolutely loaded with essential vitamins, minerals, and useful phenolic compounds, they are unique in that they contain a class of natural compounds called glucosinolates, which have powerful health benefits. This is one of the major reasons that we focus on the cruciferous varieties.

The following sections provide a breakdown of the various nutrients and health-promoting phytochemicals found in brassica varieties, such as vitamins, carotenoids, fiber, soluble sugars, minerals, glucosinolates, and phenolic compounds (7) (8).

Carotenoids are phytochemicals that are plant-pigment micronutrients. They have been extensively studied for their potential health benefits and protective effects against various illnesses (9).

Some studies have suggested that dietary carotenoids can play a role in reducing risk for several diseases, like cancer (10) (11) and cardiovascular disease (12) (13) (14), as well as eye related conditions, like macular degeneration (15) and cataracts (16) (17).

Beta carotene is an orange and red pigment in plants, including leafy greens, and as a “pro-vitamin” is one of the most potent carotenoid precursors to Vitamin A. This is a fancy way of saying that it gets your body to produce its own Vitamin A (18).

It also acts as a potent antioxidant with a wide range of reported benefits (19). 

Lutein and zeaxanthin are both xanthophyll carotenoids (yellow pigmentation) that naturally occur in leafy greens, including microgreens. Humans cannot produce zeaxanthin and lutein and require a dietary source for these carotenoids, which are sometimes referred to as macular pigments because of how they accumulate in the eye (20).

Although not all scientists agree, several studies have shown the importance of adequate levels of lutein and zeaxanthin for reducing the risk of Age-Related Macular-Degeneration, the leading cause of blindness in developed countries (21) (22).

Many scientists also believe that lutein and zeaxanthin may play a role in preventing the formation of cataracts (23) (24). 

It’s also reported that lutein and zeaxanthin can help prevent an inflammatory eye condition called Uveitis (25) (26) (27).

Lutein and zeaxanthin help protect your eyes from harmful blue light wavelengths. This occurs because both compounds absorb blue visible light in the 400-500nm range, which prevent damage to the eye by effectively filtering this light from the retina (26).

Besides various benefits for the eyes, lutein and zeaxanthin are also powerful antioxidants with a wide range of reported benefits. They have been shown to help the body recycle glutathione (another powerful antioxidant), and are thought to help prevent low-density lipoprotein, one of the bad types of cholesterol that can contribute to artery plaque build up and, ultimately, cardiovascular diseases (28) (29). Some studies even suggest that dietary intake of these compounds can potentially improve the cognitive functioning of the elderly (30) (31) (32). 

Lycopene is a non-provitamin-A carotenoid that is responsible for the pink and red pigments in some plants. Some cultivars of brassica microgreens have red and pink pigmentations and contain lycopene, which, although it may not be a pro-vitamin, is considered a potent antioxidant. Several studies have indicated that lycopene-rich diets are associated with significant reductions in the risk of prostate cancer (33) (34).

Although it is mostly associated with tomatoes, microgreens, which have pink and red pigmentation, may contain lycopene, with red cabbage being a notable example (35).

Glucosinolates are naturally-occurring organic compounds that brassica microgreens produce on their own. All species of brassica produce these compounds, which are believed to play a role in host defense against microbes and harmful bacteria. When the plant is cut or wounded, the glucosinolates, which are normally stable, make contact with the plant enzyme called myronase which results in a hydrolysis cleavage of the glucosinolate into a variety of products, a significant one being isothiocyanates, which are reported to have a wide range of health benefits. The glucosinolates and the enzyme myronase are contained in different parts of the plant cell, and it is only upon chewing, cutting, or wounding that these compounds will interact and hydrolyze into an isothiocyanate.

Over 200 different glucosinolates have been identified in the literature (36), with 88 being satisfactorily identified with modern spectroscopy methods (37). Most of the research has focused on the health effects of a handful of these important compounds and their hydrolysis byproducts.

Glucoraphanin is one of the most thoroughly studied glucosinolates. It hydrolyzes into sulforaphane, an isothiocyanate that has established health benefits. For example, sulforaphane has been shown to be a promising chemo-preventative agent against a large varieties of cancer, shows benefits for cardiovascular and neurodegenerative diseases, and has also been shown to have benefits for diabetics (38) (39).

In addition to its anti-cancer properties (40), sulforaphane acts as a potent antioxidant (41).

It also has anti-microbial effects (42), anti-inflammatory (43), anti-aging (44), neuroprotective (45), and anti-diabetic effects (46) (47).

Amazingly, sulforaphane can have strong benefits for those with autism, including noticeable behavioral improvements (47). If you have autism or are the caretaker of someone with autism, it might be worth considering giving them fresh brassica microgreens, as it could lead to improvements in one's quality of life.

Sulforaphane even has anti-ulcer activity. It has been shown to have an inhibitory effect for H. pylori (a common bacterial cause of ulcers) by inhibiting urease, an enzyme that H. pylori needs in order to survive inside the stomach (48) (49).

Glucobrassican is a predominant glucosinolate in brassica vegetables and gets hydrolyzed into indole-3-carbinol (I3C). Once in the stomach, a significant portion of the I3C gets metabolized into 3,3’-diindolylmethane, commonly denoted as DIM. I3C has been observed to have anti-tumor properties (50).

Both I3C and DIM stimulate the anti-tumor genes p21, p27, and p53, and can therefore have a preventative effect against both herpes and HPV virus (51) (52).

I3C has specifically been shown to have chemopreventive activity for all stages of breast cancer carcinogenesis (53) (54). Many studies have looked at the anticancer effect of I3C (55) (56) (57).

Both I3C and DIM work to stimulate the production of liver enzymes that can neutralize and degrade harmful metabolites taken up as pollutants (58).

DIM’s anti-cancer effect works through multiple different mechanisms; in addition to its antiproliferative action, apoptosis and cell-cycle arrest, it also has anti-metastatic activity (54) (59).

 Gluconasturtiin is another well studied glucosinolate found in brassica microgreens. It gets hydrolyzed into phenethyl isothiocyanate (PEITC).

PEITC is believed to act as an anti-cancer agent. It targets multiple proteins that affect cancer-promoting mechanisms, like cell proliferation, progression, and metastasis (60).

PEITC is a well-studied ITC, and research on this organic compound has entered the human-trial clinical stage. For example, in a 2016 study, PEITC was shown to reduce NNK metabolic activation ratios for smokers by 7.7%, suggesting potential as an inhibitor of lung carcinogenesis (NNK is one of the most harmful carcinogens in tobacco smoke) (61).

Sinigrin is another glucosinolate found in Brassica species. An important hydrolysis byproduct of sinigrin is allyl isothiocyanate (AITC). AITC is reported to have a wide variety of health benefits, ranging from anticancer (62) (63) (64), anti-inflammatory (65) (66) (67), antibacterial (68) (69) (70) (71), antifungal (72), to wound-healing effects (73) (74).

Interestingly, AITC has also been shown to work synergistically with PEITC to fight certain cancers (75) (76). AITC has also been shown to act as an antioxidant (77).

Like other GSL’s, glucoiberin hydrolizes into an isothiocyanate called iberin. Although not as widely known as glucorphanin and it’s ITC sulforaphane, it’s known to have an anti-cancer effect in cells (78) (79).

Part of the reason that iberin is effective against cancer is its phase 2 induction activity.  It has an additional anti-cancer effect through cyclin-mediated cell cycle arrest and epigenetic modulation by inhibition of histone deacetylase activity (79).

Iberin has also been shown to have anti-inflammatory properties because it down-regulates NF-κB activity (79).

Glucoerucin is another important glucosinolate found in many brassica varieties. While glucoerucin is structurally very similar to glucoraphanin, it’s a bit different from it and other glucosinolates in the sense that it’s been shown to act as an antioxidant before it hydrolizes into its isothiocyanate known as erucin (80).

Erucin is thought to be a potent anti-inflammatory that acts by inhibiting pro-inflammatory cytokines and enzymes (81). It’s been theorized that erucin may be helpful for those suffering from diabetic nerve pain due to its anti-hyperalgesic effect (82).

Erucin is believed to be a powerful anti-cancer agent and has been studied extensively with in vitro and in vivo studies. It’s been shown to operate with a range of beneficial mechanisms, such as modulating phase 1 enzymes, inducting phase 2 enzymes, up-regulating phase 3 enzymes, and modulating cell proliferation (83) (84) (85) (86) (87) (88) (89) (90) (91) (92) (93) (94) (95) (94) (96) (97).

Glucotropaeolin is another glucosinolate that breaks down into an isothyocyanate named benzyl isothiocyanate (BITC), and can be found in many varieties of microgreens. This glucosinolate was found to exhibit protective mechanisms against pancreatic carcinogenesis in vitro (98) and helped reduce factors leading to obesity (99).

Several studies have shown that BITC has the potential to reduce inflammation and could help prevent skin cancer.

Phenolic compounds are naturally occurring phytochemicals found in plant species like brassica.

Microgreens are loaded with antioxidants, but brassica microgreens have particularly high levels of antioxidants because of their unique phenolic profile and content, since phenolic compounds have been shown to have higher antioxidant activity than both carotenoids and vitamins (100) (101) (102) (flavonoid content of several vegetables and their antioxidant activity) (103).

In addition to their affect as antioxidants, phenolic compounds are reported to have a wide variety of useful properties, including anti-tumor activity (104), anti-inflammatory and anti-microbial (105), antiallergic (104), and enzyme inhibition (106), among other benefits.

The following section dives into some of the well-studied phenolic compounds that can be found in various microgreens.

Ferulic acid is naturally present in many species of brassica. It’s a compound that is the derivative of a non-flavonoid phenolic hydroxycinnamic acid, and is often found in anti-aging skin formulas (107).

Interestingly, it’s been shown to increase sperm viability. It’s also been shown to have a wide variety of benefits, such as antioxidant effects, anti-inflammatory effects (108), anti-microbial/virus effects, anti-carcinogenic, anti-thrombotic, modulation of enzyme activity, and antiallergic effects (109).

Additional research shows that ferulic acid also has a wide range of therapeutic effects like antiatherogenic, antidiabetic, anti-aging, neuroprotective, radioprotective, and hepatoprotective effects (110).

Sinapic acid is a well-studied hydroxycinnamic acid that, along with its derivatives, are seen as some of the most important phenolic compounds in the brassica species (111). It’s believed to be a potent antioxidant superior to ferulic acid (112) and more akin to caffeic acid (113). Several studies have established sinapic acid’s antimicrobial properties (114) (115) (116) (117) (118) (113). It also has additional benefits as an anti-inflammatory (119), has been shown to act as an anti-cancer agent (120), and, amazingly, it has been shown to have an anti-anxiety effect (121) (122). One of sinapic acid’s derivatives, 4-Vinylsyringol, has been shown to be a potent anti-mutagenic agent (123). Another derivative, called sinapine, is thought to have therapeutic benefits for Alzheimer's, dementia, ataxia, myasthenia gravis, and Parkinson's because of its ability to inhibit acetylcholinesterase, a neurotransmitter enzyme (124) (125). Syringaldehyde is another derivative of sinapic acid and has been shown to be a potent antioxidant (126) (127) (122).

Quercetin is a plant pigment flavonoid with strong antioxidant effects, among other benefits. It’s been the subject of many scientific studies and has been shown to have several health-promoting properties. Quercetin has an anti-bacterial effect against practically every strain of bacteria, including many that are harmful for human health and can be found naturally in the body (128). It helps to prevent infection and replication, which is also why it is believed to have an antiviral effect, including on viruses like herpes simplex virus, Japanese encephalitis virus, and certain respiratory viruses (129) (130) (131). It should therefore not come as a surprise that quercetin is being evaluated as a potentially effective prophylactic against the novel coronavirus. Several studies suggest it may provide a therapeutic benefit (132) (133) and clinical trials are currently ongoing (134). If you are currently a smoker, you may benefit from quercetin, which has been shown to reduce the free radicals associated with smoking (135). Quercetin acts as a powerful anti-inflammatory by inhibiting enzymes associated with inflammation, specifically cyclooxygenase (COX) and lipoxygenase (136) (137) (128). Scientists found that diets high in dietary flavonoids such as quercetin were associated with a decrease in Serum C-reactive protein concentrations (CRP), which is an important biomarker of inflammation (138) and is associated with many diseases like heart disease, lupus, and obesity. It’s also believed that quercetin could be helpful for some types of arthritis (139) (140). In a study on Greek men with coronary heart disease, it was found that quercetin likely improved endothelial health by improving flow-mediated dilation of major arteries (141). It’s also been shown to inhibit platelet aggregation to improve the health of the endothelium (128) and was shown in a double-blinded, placebo controlled study to protect against clogged arteries by working to reduce systolic blood pressure and plasma-oxidized low-density lipoprotein (sometimes referred to as bad cholesterol) (142). Several studies have shown the beneficial effect of quercetin for blood pressure (143) (144). Quercetin has been shown to have neuroprotective effects and is known to protect the brain from oxidative stress that can lead to alzheimers and other neurological conditions (145). It’s also believed to protect against injury by various neurotoxins and has also been shown to suppress neuroinflammation and has a preventative effect for degenerative and cerebrovascular diseases associated with stroke and dementia (146). Quercetin is believed to have anti-cancer properties, including anti-proliferation, growth factor suppression, as well as antioxidant activity (128) (147). Several studies have examined quercetin’s ability to inhibit the growth of tumors and malignant cells (148) (149), with several studies showing it could specifically be helpful against colon and prostate cancer (150) (151). Quercetin is thought to have anti-ulcer activity and has been shown to inhibit H. pylori infections, the cause of most stomach ulcers. It’s believed that quercetin increases gastric mucous production, which, in conjunction with its antioxidant activity, could explain this effect (152) (153). Additionally, researchers believe that quercetin has great potential to help with issues like allergies, asthma, and bronchitis because it exerts anti-allergy effects by inhibiting the release of histamine (154). One clinical trial for quercetin showed that it reduced upper respiratory tract infections for older subjects (155). Many believe that the anti-allergic effect of quercetin is significant and can play a major role in preventing various types of allergies (156). Some doctors have claimed that if you suffer from leaky gut, you may benefit from dietary quercetin (156), although it’s unclear if this has been proven in a clinical study.

Kaempferol, named after the German scientist Engelbert Kaempfer who discovered it, is another flavonoid that has been shown to have strong anti-cancer effects, among other benefits. It’s a well-studied drug that has been shown to exhibit  antiproliferative and proapoptotic effects against a variety of cancers, including bladder cancer (157), breast cancer (158) (159) (160), colon cancer (161), esophageal cancer (162), kidney cancer (163), lung cancer (164), ovarian cancer (165), pancreatic cancer (166), prostate cancer  (167), and stomach cancer (168) (169). Kaempferol is believed to additionally act to prevent cancer through anti-angiogenic action (170) (171) (172) (169) or, in other words, by preventing tumors from forming new blood vessels. Kaempferol is believed to have an additional anti-cancer effect by downregulating certain proteins and molecules that play a role in cancer metastization (173) (174) (175) (176). Kaempforal has been shown to have a strong anti-inflammatory effect by reducing the levels of pro-inflammatory molecules (169). For example, it has been shown to reduce the expression of CRP, COX-2, and iNOS via alterations in NF-κB pathway (177) as well as inhibiting the activation of STAT-1(177). Some studies have shown that Kaempferol may be able to downregulate the matricellular protein osteopontin, a Reactive-Oxygen-Species-dependent cytokine, where elevated plasma levels are associated with chronic inflammatory diseases like cancer (178) (179), Crohn's disease (180), atherosclerosis, aortic abdominal aneurysms (181), and a range of autoimmune diseases like lupus (182), multiple sclerosis (183), and rheumatoid arthritis (184).

Luteloin is a beneficial compound found within many varieties of microgreens. In addition to its action as an antioxidant, it has anti-tumor, anti-inflammatory, and anti-apoptotic effects (185) (186). It also has strong cardiovascular benefits; specifically, it reduces inflammation and oxidative stress and a healthy intake will reduce the risk of heart attacks, coronary heart disease, atherosclerosis, and heart failure (187) (188). It’s also been shown by several studies to have beneficial neuroprotective effects (189). In a fascinating and eye-opening study on children with autism, luteolin was shown to have negative symptoms related to the disorder (190).

Caffeic acid is a beneficial phenolic compound found in certain vegetables, including brassica species, amongst others. Experiments have revealed innumerable physiological effects of CA, which include: antibacterial activity (191) (192), antiviral activity (193) (194) (195) (196), immunostimulatory activity (191) (197), anti-inflammatory activity (193) (192) (194) (195) (196), anti-atherosclerotic activity (191)(192), cardioprotective activity (194) (198), antidiabetic activity (194) (196), antiproliferative activity (191) (199) (200), anticancer activity (193) (192) (194) (195) (196), hepatoprotective activity (201) (202), and anti-hepatocellular carcinoma activity (203) (204). This important compound prevents the production of ROS (reactive oxygen species), which is associated with many diseases, including cancer. Additionally, recent studies have specifically shown that the anti-cancer effect works through specific mechanisms that help to regulate gene expression, reduce transition metals, and form covalent adducts and direct toxicity (205). This compound has been shown to have promise against hepatocarcinoma (HCC), a deadly type of cancer (206).

P-coumaric is a phytochemical and nutraceutical found in various edible plants. It is both a good antioxidant and a good antimicrobial (207). It has been shown to reduce low-density lipoprotein (LDL) peroxidation, which is another way of saying that it can reduce "bad" cholesterol (208). This can help prevent atherosclerosis (209).

Anthocyanins are a group of plant pigments that are colored flavonoids. They are often associated with red, blue, and purple colors in plants. They have strong antioxidant properties in addition to other health benefits. Some examples of anthocyanins which can be found in cruciferous crops are: “cyanidin 3-O-(sinapoyl)(feruloyl)diglucoside-5-O-glucoside and cyanidin 3-O-(sinapoyl)(sinapoyl)diglucoside-5-O-glucoside” (210).