I. Vegetables and root vegetables

I. 20 Arugula

The Mediterranean leafy green – a high nitrate-NO axis and a Brassica-glucosinolate matrix in a single leaf.

Latin: Eruca sativa (or Diplotaxis tenuifolia – FODMAP: 🟢 low (75 g green zone)Evidence: ★ ★Microbiota: Nitrate-NO oral axis + Brassica-glucosinolate-sulforaphane secondary matrix

Arugula in 1 minute

What does it provide? High nitrate content (250–500 mg/100 g – a range similar to beetroot), Brassica-family glucosinolate (glucoerucin, glucoraphanin), quercetin and kaempferol, vitamin K, folate, magnesium.

How much? 50–75 g fresh leaves/day (a small bowl) – Bondonno 2016 J Nutr nitrate-rich vegetable RCTs used this dose [2748].

When to avoid? Warfarin (high vitamin K, constant intake required). Hashimoto / Graves' disease with high-dose raw consumption (glucosinolate goitrogenic potential). Infants under 6 months: nitrate-methemoglobinemia risk.

📜 Historical Overview

Arugula was the Mediterranean salad green of the ancient Roman Empire – in Historia Naturalis Pliny attributed aphrodisiac properties to it, and Roman monasteries banned its cultivation through the Middle Ages (due to its overly "spicy" character). At the end of the 20th century, the Italian "cucina povera" (peasant cuisine) brought it back to the table, and the Mediterranean trend of the 1990s made it popular worldwide.

Scientific Background

Arugula's nitrate content is outstanding within the Brassica family – 250–500 mg/100 g fresh weight [2752] [912]. Bondonno 2016 J Nutr studied "nitrate-rich vegetables" (including arugula, spinach, beetroot, watercress) in a comprehensive portfolio in human RCTs: daily 80–100 mg nitrate intake produced significant flow-mediated dilation (FMD) improvement and blood pressure reduction [2751]. The mechanism is the oral microbiota – Veillonella, Rothia – nitrate reduction → nitrite → systemic NO pathway [2749].

The Brassica-glucosinolate matrix (glucoerucin being the main component) hydrolyzes to erucin-sulforaphane during chewing (myrosinase enzyme) – Akkermansia-supporting and NRF2-activating secondary effects, but the concentration in arugula is moderate compared to broccoli [2750].

At the microbiome level, alongside the classic oral-NO pathway, the Brassica-sulforaphane-mediated Akkermansia muciniphila support is indirect. The quercetin and kaempferol fraction provides a polyphenol matrix.

✅ Combine with

+ Extra-virgin olive oil + lemon: classic Mediterranean salad – fat enhances vitamin K absorption.
+ Beetroot + walnut: dual nitrate matrix + omega-3 – a sport-microbiota protocol.
+ Grated Parmesan: classic Italian "rucola pesto" – calcium-fat matrix.
+ Trout or salmon: fatty fish + nitrate-NO synergy.
+ Peanut sauce (or hazelnut): an Italian "pesto di rucola" alternative.

🚫 Avoid combining with

Tannin-rich beverages (black tea, red wine) in high doses: impaired iron absorption.
Thyroid hormone (L-thyroxine) at the same time: separate by ≥ 2 hours.
Heat treatment > 5 min of boiling: partial loss of nitrate + vitamin K; raw preferred.
In large amounts on an empty stomach in acid-sensitive individuals: GI irritation.

⚠️ When to avoid – condition-specific

Warfarin therapy: high vitamin K (≈ 110 µg/100 g) – CONSTANT intake required, not abrupt change.
Active Hashimoto / Graves' disease + high raw dose (≥ 200 g/day): glucosinolate goitrogenic potential.
Infant under 6 months: methemoglobinemia (nitrate) risk.
Hyperoxaluric kidney stones + high oxalate intake: moderate oxalate content (manage).
Pregnancy (dietary amount is safe): wash thoroughly before fresh salad consumption (Listeria, Toxoplasma risk).

❌ Myths and their refutation

"Arugula can only be consumed as a spice in small amounts."False. As a salad base, 50–100 g/day is safe and has documented clinical effects [2753].

"Raw Brassica is dangerous."A serious exaggeration. A dietary portion (≤ 200 g fresh / day) is safe alongside thyroid hormone replacement. The classic "cabbage goitrogen" myth originates from the iodine-deficient context of the 19th century.

References

[912] EFSA Panel on Contaminants. Nitrate in vegetables — scientific opinion. EFSA Journal 2008;689:1–79. EFSA Journal. 2008. Link

At the request of the European Commission, the EFSA Panel on Contaminants in the Food Chain (CONTAM) performed a scientific risk assessment of nitrate in vegetables. The opinion reviews the sources of nitrate exposure and its possible health consequences, weighing the risks associated with nitrate intake against the beneficial effects of vegetable consumption. The document was published in the EFSA Journal (2008; 689:1-79).

[2748] Bondonno CP, Croft KD, Hodgson JM. Dietary nitrate, nitric oxide, and cardiovascular health. Journal of Nutrition. 2016.

Review of human studies on the cardiovascular effects of nitrate-rich vegetables (including arugula, spinach, beetroot, watercress). Daily nitrate intake is converted via oral-microbiota nitrate reduction into systemic nitric oxide, improving vascular function and reducing blood pressure.

[2749] Hord NG, Tang Y, Bryan NS. Food sources of nitrates and nitrites: the physiologic context for potential health benefits. American Journal of Clinical Nutrition. 2009. Link

Review of dietary sources of nitrates and nitrites and their physiologic role. It describes the oral-microbiota nitrate→nitrite→nitric-oxide pathway and the potential cardiovascular benefit of leafy-green vegetables.

[2750] Bell L, Wagstaff C. Glucosinolates, myrosinase hydrolysis products, and flavonols found in rocket (Eruca sativa and Diplotaxis tenuifolia). Plants. 2020.

Review of the nutritional value, glucosinolate and flavonol content of Eruca sativa and Diplotaxis tenuifolia (arugula). It describes the myrosinase-mediated hydrolysis of glucoerucin to erucin-sulforaphane during chewing.

[2751] Velmurugan S, Gan JM, Rathod KS, Khambata RS, Ghosh SM, Hartley A et al. Dietary nitrate improves vascular function in patients with hypercholesterolemia: a randomized, double-blind, placebo-controlled study. American Journal of Clinical Nutrition. 2016. Link

Randomized, double-blind, placebo-controlled study in hypercholesterolemic patients demonstrating that dietary nitrate improves vascular function. It supports the flow-mediated-dilation-improving effect of nitrate-rich vegetables such as arugula.

[2752] . Rocket (arugula), raw (NDB 11959). USDA FoodData Central. 2019. Link

Entry from the USDA FoodData Central nutrition database for raw arugula, documenting macro- and micronutrient composition (including vitamin K, folate, magnesium). A reference source for the nutrient values reported in the chapter.

[2753] . Rocket (arugula) — low FODMAP serving guidelines. Monash University FODMAP. 2023. Link

Classification from the Monash University FODMAP database placing arugula in the low-FODMAP category (green up to a 75 g serving). It provides a practical basis for the safety of consuming 50—100 g daily as a salad base.