To make it into this group the items must contain negligible amounts of proteins, fats or carbohydrates, if they contain any at all. Let’s jump right in…


As a group, non-starchy veggies include tender greens like spinach, bitter greens like arugula, cruciferous veggies like broccoli, brussels sprouts and cauliflower, allium veggies like onions and garlic, cultured or fermented veggies like raw sauerkraut and kimchi, and other non-starchy veggies like celery and cucumbers.


Greens like spinach are high in several micronutrients, including folate, vitamin e, vitamin k1, magnesium, potassium and non-heme iron. [1-2]

With spinach, I want to give some special attention to folate here, also known as vitamin B9. Folate plays a significant role in neurological development, and folate deficiency has been linked to certain forms of cancer, as well as Autism Spectrum Disorders and strokes. Therapeutic doses of folate can be found in a single serving of most beans or greens, including spinach.

While synthetic folic acid has been added to enriched cereal grain products in the U.S. since 1998 (in large part as an attempt to prevent neural tube defects in babies of pregnant women), the practice has come under increased scrutiny in recent years. Several studies have expressed concern over the possible health effects of increasing amounts of unmetabolized synthetic folic acid in the blood supply of those who consume these kinds of common foods (and who also may consume synthetic folic acid supplements).

Additionally, other studies, such as a 2018 study from the journal Scientific Reports, have shown that 5-MTHF, the natural, metabolized form of folate found in blood serum, has distinct safety and efficacy advantages over synthetic folic acid.

Bitter greens like arugula and endive are helpful for stimulating the liver and increasing bile production. This action not only assists digestion but also promotes proper detoxification and elimination processes in the body. [9]



Cruciferous vegetables like broccoli, brussels sprouts, cauliflower and cabbage have gained a reputation as being particularly healthy, in part due to their organosulfur and vitamin C content, both of which promote soft tissue health, in addition to having positive immune system and anti-cancer effects. [10]

A 2004 review in the scientific periodical Nutrition Journal highlighted the anti-cancer effects of a regular intake of cruciferous veggies from several studies, including a Chinese study that found that those with the highest intake of cruciferous veggies had only 50% of the cancer risk compared with the lowest intake group.

Results from the Nurse's Health Study were similar, which found a high intake of cruciferous veggies was associated with a 33% lower risk of non-Hodgkin's lymphoma. In the Health Professional Follow Up Study, high intake of cruciferous vegetables was associated with a 51% decrease in bladder cancer. And a Washington State study found that high intake of cruciferous veggies decreased the risk of prostate cancer by 41%. [11]



Allium veggies like onions and garlic contain different organosulfur compounds than cruciferous veggies, but like cruciferous veggies these natural compounds work to promote collagen production, support innate and adaptive immune responses and reduce risk of cardiovascular disease. [12-13]

This 2011 meta-analysis of more than 20 studies from 1966-2010 that included more than 540,000 subjects found that consumption of relatively large amounts of allium veggies (including onion, garlic, leek and scallions) significantly reduced the risk for gastric cancers. Other studies on alliums have found a positive correlation between their regular consumption and reduced risks for several different types of cancer, including breast, prostate, colon and other cancers of the gastrointestinal tract. [14-19]



Other non-starchy veggies include foods like cucumbers and celery, the latter of which is high in dietary nitrates. A plethora of studies published over the last 10-12 years have shown that regular intake of foods high in dietary nitrates (which includes non-starchy veggies like celery, spinach, radishes and cabbages, as well as higher carbohydrate beets) helps promote healthy nitric oxide levels in the body, which in turn has a positive effect on several cardiovascular and immune system markers. [20-28]

A 2014 review from the scientific journal Nutrients highlighted that nitric acid has "demonstrated modest benefits pertaining to cardiovascular health, such as reducing blood pressure, enhancing blood flow and elevating the driving pressure of O2 in the microcirculation to areas of hypoxia or exercising tissue."

Hypoxia and hypoxemia are both common symptoms seen in more severe COVID cases, and it's no surprise that inhaled nitric oxide has been used successfully to improve respiration, CV functioning and blood oxygen levels in these cases. [29-30]

Part of what makes the topic of dietary nitrates and nitric oxide so relevant is the fact that cardiovascular disease is the top annual killer of adults, both in America and worldwide. As a matter of fact, in the U.S., cardiovascular disease has been the top cause of adult death for each of the last 100 years. [31-33]

The discovery of nitric oxide as a signaling molecule in the cardiovascular system was so ground breaking that the 1998 Nobel Prize in Medicine was awarded to 3 Americans for their work in the area- biochemist Robert Furchgott PhD, pharmacologist Louis Ignarro PhD and physician Ferid Murad MD, PhD. [34]



And then there are pickled veggies (like these pickles), as well as fermented veggies like sauerkraut and kimchi. Fermented foods like these naturally contain gut-supporting probiotics, and several studies have shown that regularly consuming these foods lowers the risk & severity of gastrointestinal conditions like IBS, diarrhea & constipation, as well as conditions like cancer, obesity, respiratory conditions, skin conditions, blood sugar problems, type 2 diabetes, neurological disorders, heart disease and hypertension. [35-39]


As a group, there’s a decent amount of clinical data on the health benefits of non-starchy veggies in general, such as this 2016 study from the official journal of the London Cardiovascular Society, which highlighted the positive effects regular consumption of non-starchy veggies have against several common conditions, including cardiovascular disease, cancer, diabetes and obesity. [40]

For most people I recommend at least one serving of non-starchy veggies with each meal. Most veggies are digested best when properly cooked but eating certain veggies raw (ex. cucumbers, radishes, etc.) can confer additional benefits (although over-consumption of certain veggies such as broccoli can lead to gastric upset).



One important possible exception to this “eat an abundance of non-starchy veggies” advice is for those battling SIBO, or small intestinal bacterial overgrowth. This is a condition that involves an over-abundance of bacteria and yeast, some pathogenic but some beneficial, being present in the small intestines.

Several studies, such as one published in the March 2017 edition of the journal Gut & Liver, have found that consuming moderate to high amounts of fermentable carbohydrates, even from otherwise healthy non-starchy veggies, can sometimes aggravate SIBO and IBS conditions where SIBO may be present. Many researchers and health professionals have found that a low FODMAP diet, which looks to restrict intake of any fermentable carbohydrate, helps alleviate SIBO symptoms and, when combined with other healthy lifestyle habits and therapies, allows the gut to move out of dysbiosis (i.e. imbalance). [41-48]


Non-starchy veggies include tender greens like spinach, bitter greens like arugula, cruciferous veggies like broccoli, brussels sprouts and cauliflower, allium veggies like onions and garlic, cultured or fermented veggies like raw sauerkraut and kimchi, and other non-starchy veggies like cucumbers and celery, the latter of which is high in heart-healthy dietary nitrates.

Spinach, as well as other non-starchy veggies like asparagus and broccoli, are high in vitamin B9 (i.e. folate), which helps promote neurological health and reduces the risk of certain types of cancer.

Bitter greens like arugula and endive have been shown to improve digestion, in part by stimulating bile production in the liver.

Cruciferous veggies like broccoli, Brussels sprouts, cauliflower and cabbage are high in vitamin C and organosulfur compounds, both of which have been shown to promote soft tissue and immune system health, in addition to having anti-cancer effects.

Allium veggies like onions and garlic also contain organosulfur compounds and have similar health effects as cruciferous veggies. Studies have also shown that intake of allium veggies is linked to a reduced risk of heart disease.

Celery, as well as non-starchy veggies like spinach, radishes and cabbage, are high in dietary nitrates, which help increase nitric oxide levels in the cardiovascular system. Nitric oxide is an important signaling molecule that dilates blood vessels, helps improve circulation and blood flow, reduces hypertension, inhibits platelet aggregation, improves mitochondrial efficiency and protects the heart against cell injury and death.

Raw, fermented veggies like kimchi and sauerkraut contain high levels of beneficial bacteria (probiotics), and studies have shown that consumption of these foods lowers the risk and severity of several common conditions, including gastrointestinal disorders, cardiovascular disease, cancer, respiratory conditions, neurological conditions (like Alzheimer’s) and diabetes.

For most people I recommend consuming an abundance of non-starchy veggies, more often than not properly cooked (for example- roasted, steamed, sautéed, etc.) but sometimes raw as well.

For those battling SIBO and certain types of IBS, a low FODMAP diet may prove therapeutic. Non starchy veggies that are often allowed on the low FODMAP diet include celery, cucumbers, pickles and most greens (including lettuce, spinach, kale and endive).


1 (USDA food composition database)

2 (Linus Pauling Institute at Oregon State Univ.)

3 (June 2020)

4 (2018; found physiological advantages of using 5-MTHF vs folic acid for minimizing the risk of birth defects)

5 (2018; 12 wk randomized placebo controlled trial found 5-MTHF increases blood folate concentrations to a greater extent than folic acid)

6 (2017 study found that unmetabolized synthetic folic acid may impair uptake of 5-MTHF, the dominant bioactive form of folate, in human umbilical endothelial cells)

7 (2014 review of differences between folic acid, food folate & 5-MTHF, which found that natural 5-MTHF has important advantages over synthetic folic acid)

8 (2008; effects of increased circulating unmetabolized synthetic folic acid due to 1998 fortification efforts)


10 (2008; data from 64k women found consumption of green veggies associated w/ lower rate of diabetes)

11 (2004 study; cruciferous vegetables (broccoli, cauliflower, cabbage, Brussels sprouts) contain sulforophane, which has anti-cancer properties; Chinese study found that those w/ the highest intake had 50% of the risk of the lowest intake group; In the Nurses' Health Study a high intake of cruciferous vegetables was associated with a 33% lower risk of non-Hodgkin's lymphoma; In the Health Professionals Follow-Up Study, high intake of cruciferous vegetables was associated with a statistically significant 51% decrease in bladder cancer; In a Washington state study, high intake resulted in a statistically significant 41% decrease in prostate cancer risk)

12 (2018 Australian study; many large observational follow-up studies have reported the inverse associations of leafy green, cruciferous & allium veggies with CVD outcomes.

13 (2017; >1200 Australian women >70 yrs old; higher cruciferous and allium vegetable intakes were associated with a lower risk of ASVD mortality)

14 (2011; meta-analysis of >20 studies from 1966-2010 that included >540,000 subjects found that consumption of relatively large amounts of allium veggies (onion, garlic, leek, scallions) reduced the risk for gastric cancer)

15 (2019; Chinese study of >800 people with colon cancer + matching controls; “A decreased colorectal cancer risk was observed for the consumption of total & individual allium vegetables including garlic, leeks & onion”)

16 (2016; “high consumption of certain Allium vegetables, in particular garlic and leek, may reduce the risk of breast cancer”)

17 (2015; “Epidemiological studies indicate some protective associations of Allium vegetable consumption against cancers, particularly cancers of the gastrointestinal tract”)

18 (2004; “higher intake of allium products is associated with reduced risk of several types of cancers. Organosulfur compounds present in Allium vegetables, are considered to be responsible for the beneficial effects of these herbs. Several mechanisms have been proposed to explain the cancer-preventive effects of Allium vegetables and related organosulfur compounds. These include inhibition of mutagenesis, modulation of enzyme activities, inhibition of DNA adduct formation, free-radical scavenging, and effects on cell proliferation and tumor growth.”)

19 (2002; 238 prostate cancer subjects & 471 control subjects; those with highest intake of total allium vegetables (including garlic & scallions) had a statistically significantly lower risk of prostate cancer than those in the lowest category.)

20 (2019; “recent research suggests that diets consisting of foods high in nitrate, such as green leafy vegetables and dietary nitrate-based supplements, can provide added support to the NOS system and enhance the cardiovascular health benefits assigned to NO.”)

21 (2018; “a 2013 meta-analysis of 16 eligible randomized crossover trials evaluated the relationship between inorganic nitrate or beetroot juice supplementation and blood pressure verified the strong association of dietary nitrate consumption and blood pressure reduction”…”nitrate-rich green leafy vegetables have shown promising blood pressure-lowering effects and improved endothelial function in healthy adults. Vegetables particularly rich in nitrates include green leafy vegetables such as spinach and lettuce as well as fennel, rocket, radishes, Chinese cabbage”)

22 (2018; “There is a growing body of evidence suggesting that dietary nitrate may have a protective role in health, in particular vascular health. This is linked to the enterosalivary nitrate-nitrite-nitric oxide pathway, in which dietary nitrate can be metabolized in the human body to produce nitric oxide (NO). NO is an important chemical messenger, responsible for a variety of physiological functions including maintaining vascular health, gastrointestinal function, and regulation of immune and inflammatory cells.”

23 (2017; “Dietary nitrate confers several cardiovascular beneficial effects on blood pressure, platelets, endothelial function, mitochondrial efficiency and exercise.”

24 (2016; “inorganic nitrate has proven time and again to be effective in reducing blood pressure in healthy individuals, and largely successful in reducing blood pressure in hypertensive patients.”…”dietary nitrate could also potentially offer options to improve cardiovascular outcome in other patient groups such as dialysis and heart failure patients, particularly since, in addition to blood pressure lowering, nitrate has been shown to be beneficial in improving exercise performance, tolerance and mitochondrial function.”)

25 (2016; nitrate enters the human diet mainly through the consumption of vegetables whereas nitrite (NO2 −) enters the diet through consumption of processed foodstuffs, particularly resulting from use in meat preservation; Nitric oxide was identified as an important biologically active molecule in the late 1980s as the elusive “endothelium‐derived relaxation factor.” Soon thereafter, nitric oxide was recognized as a signaling molecule involved in a vast number of physiologic processes, including regulation of blood flow and blood pressure. Nitric oxide–mediated signaling is also used to protect the heart against cellular injury or death; 80% to 85% of nitrate is derived from vegetables)

26 (2016; “there is no evidence that nitrate intake is carcinogenic in humans. Instead, epidemiological evidence indicates that consumption of vegetables reduces risk of cancer”)

27 (2013; Dietary nitrate has been demonstrated to have a range of beneficial vascular effects, including reducing blood pressure, inhibiting platelet aggregation, preserving or improving endothelial dysfunction, enhancing exercise performance in healthy individuals and patients with peripheral arterial disease.”…Typically, around 85% of dietary nitrate (the inorganic nitrate anion, NO3−) is derived from vegetables”)

28 (2012; “Consumption of vegetables accounts for ~ 80–85 % of daily nitrate exposure in humans, therefore establishing inorganic nitrate as a promising factor in cardiovascular health benefits of vegetables.”)

29 (2014; “Evidence suggests that NO3− is the viable active component within beetroot juice (BRJ) and other vegetables, responsible for health-promoting and ergogenic effects. NO3− supplementation has also demonstrated modest benefits pertaining to cardiovascular health, such as reducing blood pressure (BP), enhancing blood flow, and elevating the driving pressure of O2 in the microcirculation to areas of hypoxia or exercising tissue. Nitrate is found primarily in the diet (>80%) as an inorganic component of vegetables. Predominate sources of nitrates are beets, celery, lettuce, radishes, and spinach”)






35 (2018; sauerkraut & IBS study; 34 Norwegian patients)

36 (2018; review of data on fermented foods & health effects)

37 (2018; review of data on fermented foods & health effects)

38 (2017; benefits of consuming fermented foods)

39 (2014; kimchi’s health benefits)

40 (2016; in meta analysis of 8 studies and >540,000 participants found consumption of green leafy & cruciferous veggies led to 15.8% reduced incidence of cardiovascular disease; mechanism of action include bile acid binding capacity, dietary nitrates, magnesium, antioxidants like vitamin C)

41 (2019; “there may be a role for low FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) diets in decreasing fermentable substrates in the context of SIBO. Low FODMAP diets aim to greatly deplete or entirely eliminate the highly fermentable simple carbohydrates which are commonly found in certain dairy products, fruits, vegetables, nuts and legumes, with the ultimate aim of graded reintroduction of specific FODMAPs”)

42 (2019; A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols has been shown to be beneficial in IBS)

43 (2017; “many studies and randomized controlled trials have reported a good control of IBS symptoms after a diet low in FODMAPs, with improvement in overall gastrointestinal symptoms in as high as 68-86% of IBS patients. However, there is also evidence that intensive restriction of FODMAPs could potentially have long-term negative consequences, both from a nutritional point of view, and the impact on the intestinal microbiota. Thus, identifying the most offending FODMAPs in specific patients could mitigate dietary restrictions”)

44 (2017; “In patients with SIBO, bacteria in the small bowel may ferment carbohydrates such as lactose, fructose and also the dietary fermentable oligo-, di-, monosaccharides and polyols (FODMAPs), which forms gas resulting in flatulence, abdominal bloating and pain. Hence, restriction of these dietary components may improve these symptoms.”)

45 (2017; “IBS is a common condition affecting 10% to 15% Americans. It accounts for 25% to 50% of visits to gastroenterologists, many primary care physician visits, and is the second largest medical reason for missing work (after the common cold)”…”82% of patients reported improvement in bloating, 85% reported improvement in abdominal pain, and 87% noted improvement in flatulence on a low-FODMAP diet, which appears to be more effective than standard dietary advice for symptom control in IBS”)

46 (2013; “the prevalence of SIBO in IBS varies from 30 to 85% depending on the source used. The prevalence of SIBO in liver cirrhosis is 50% and in celiac disease, the prevalence of SIBO in some studies is also estimated to be 50%”)

47 (2012; “A low-FODMAP diet appears to be effective for treatment of at least a subset of patients with IBS”)

48 (2010; “The hydrogen breath test is considered to be more accurate for the diagnosis of SIBO compared to the methane breath test according to most authors”…hydrogen and methane breath tests have some drawbacks with possible false results and difficulties in their interpretation”)