Zucchini

Other Names

Arishi (Rarámuri)AskutasquashAyotliAyotli (Nahuatl)Baby marrowCalabacínCalabazaCalabaza (Nahuatl context)Calam (Huasteco)Cayixam (Seri)Chicsh (Popoluca)CitrouilleCocozelleCourgeCourge péponCourgetteCourgette (French)Cucumis pepo (L.) Dumort.Cucumis zapallo Steud.Cucurbita aurantia Willd.Cucurbita ceratoceras Haberle ex Mart.Cucurbita courgero Ser.Cucurbita elongata Bean ex Schrad.Cucurbita esculenta GrayCucurbita fastuosa Salisb.Cucurbita hybrida Bertol. ex NaudinCucurbita lignosa Mill.Cucurbita mammeata MolinaCucurbita mammosa J.F.Gmel.Cucurbita marsupiiformis Haberle ex M.Roem.Cucurbita melopepo L.Cucurbita oblonga (Duch. ex Lam) LinkCucurbita ovifera L.Cucurbita pepoCucurbita pepo L.Cucurbita pepo subsp. fraternaCucurbita pepo subsp. oviferaCucurbita pepo subsp. pepoCucurbita pepo subsp. pepo Zucchini GroupCucurbita pepo var. cylindricaCucurbita pomiformis M.Roem.Cucurbita pyridaris Duchesne ex Poir.Cucurbita pyxidaris DC.Cucurbita subverrucosa Willd.Cucurbita succedo Arn.Cucurbita tuberculosa Schrad.Cucurbita urnigera Schrad.Cucurbita variegata Steud.Cucurbita venosa Descourt.Cucurbita verrucosa L.Cus (Purépecha)Dynia zwyczajnaFeld-KürbisGartenkürbisGourdGueto-bichi (Zapoteco)Ka (Maya)Ma-she (Chinanteco)MarrowMissa'bîgon (Ojibwe)MogangoMu (Otomí)Ñinc (Mixteco)Noodle squashPaprastasis agurotisPatissonPepo aurantius (Willd.) Peterm.Pepo citrullus SageretPepo clypeiformis Poit.Pepo melopepo (L.) MoenchPepo oblongus Poit.Pepo potiron SageretPepo verrucosus (L.) MoenchPepo vulgaris MoenchPumpaPumpkinSatokurpitsaSierpompoenSpaghetti marrowSpaghetti squashSpaghettikürbisSpaghettipompoenSquashSummer squashSuschi (Tepehuano)Tsi'I (Mixe)Tykev obecnáVegetable marrowVegetable spaghettiXusi-te (Huichol)Zapallo angolaZuccaZucchinaZucchinoГарбуз звичайний (Ukrainian)قرع الكوسة (Arabic)ウリカボチャ (Japanese)美國南瓜 (Chinese traditional)西葫芦 (Chinese simplified)율호박 (Korean)

Synopsis

Zucchini (Cucurbita pepo L.): A Comprehensive Reference

1. Identity and Botanical Classification

Scientific Name and Taxonomy

Cucurbita pepo L., commonly known as zucchini, is a widely grown species in the Cucurbitaceae family. It is a fruit belonging to the Cucurbita genus and the Cucurbitaceae family, which is made up of 22 species, the five most cultivated being C. maxima, C. moschata, C. pepo, C. ficifolia, and C. argyrosperma. The specific zucchini cultivar belongs to the subspecies and variety Cucurbita pepo subsp. pepo, and courgettes are the fruits of a variety of gourd belonging to the species Cucurbita pepo ssp. pepo.

The plant Cucurbita pepo fruit is botanically known as a pepo, a special form of modified berry, which is a feature of the family Cucurbitaceae, described by a rigid outer rind and a fleshy interior. Although often considered a vegetable, zucchini is botanically classified as a fruit, as it grows from a flowering plant and contains seeds. The chromosome number in Cucurbita pepo is 2n=40.

Common Names and Synonyms

Also called courgette or baby marrow, zucchini is easy to grow and prolific in the garden. Because it appeared relatively recently in North America, its name has no English equivalent, and people in the United States, Australia, and Canada use its Italian name; zucchini is called "baby marrow" in South Africa. Its name comes from a plural diminutive of the Italian word for squash — "zucca" — while its other name, "courgette," comes from the French word for this vegetable.

Morphological Description

C. pepo L. is a monoecious, herbaceous, annual plant with a high growth rate of vegetation and adaptability. Zucchini fruits are morphologically cylindrical or slightly club-shaped, but may vary due to differences in cultivar and genotype; they are dark green, light green, yellow, or striped in external coloration depending on varying chlorophyll and carotenoid concentrations. Zucchini is harvested at an immature stage for its tender, elongated fruit that typically measures 6 to 8 inches in length.

The fruit wall (pericarp) is structurally differentiated into three different layers: the exocarp, which is the outer layer that is thin but protective; the mesocarp, a juicy fleshy tissue; and the endocarp, which is the innermost layer. Seeds contain high lipids (30–50%), proteins, and phytosterols. The plant grows a well-branched taproot system with many lateral roots; the roots are fibrous and shallow, with the major concentration found in the upper 30–40 cm of soil, which helps in effective uptake of nutrients but exposes the plant to drought stress.

Common Forms and Preparations

Zucchini is consumed and prepared in numerous forms across culinary and health traditions. Sliced zucchini can be grilled, steamed, sautéed, or battered and fried; it can be stuffed with meats, cheeses, or grains and then baked; it can be an excellent low-carb substitute for traditional noodles in pasta preparations; and while usually served cooked, zucchini works well in salads with dips or as a wrap. The zucchini flowers have a soft, delicate texture and can be stuffed with soft cheeses and herbs, then battered and fried. In terms of supplement or nutraceutical forms, the medicinal systems practiced in traditional medicine have utilized different parts of plants such as fruit, seeds, flowers, and leaves in the treatment of digestive ailments, urinary inflammation, anti-inflammatories, wound healing, and general nutritional value.

2. Historical and Traditional Use

Pre-Columbian Mesoamerica

The zucchini, known botanically as a variety of Cucurbita pepo, traces its origins to the domestication of wild gourds native to southern Mexico; indigenous Mesoamerican peoples initiated the cultivation of C. pepo approximately 10,000 years ago, marking one of the earliest instances of plant domestication in the Americas. This process involved selective breeding of wild squash species, transitioning from small, bitter fruits to larger, more palatable varieties suitable for human use; archaeological evidence from Guilá Naquitz cave in Oaxaca, Mexico, provides the earliest direct proof of this domestication, with excavations uncovering squash rinds and seeds identified as C. pepo.

Cucurbita pepo played a central role in the diet of pre-Columbian populations, providing essential calories, vitamins, and minerals; the fruits and seeds were often stored for winter, and some varieties were incorporated into local rituals and traditions. The indigenous people not only consumed zucchini but also utilized its flowers and young leaves in their traditional cuisine. During this time, indigenous people of the region cultivated and bred various types of squash, including zucchini, for food, medicine, and ceremonial purposes.

Introduction to Europe and Development of the Modern Cultivar

After the discovery of the Americas by Europeans in the 15th century, Cucurbita pepo was introduced to Europe, Africa, and Asia; explorers and traders quickly recognized its nutritional qualities and ease of cultivation. While squashes generally originated from the Americas, the specific courgette variety was developed for the first time in the early 1800s in northern Italy. Only a century after the first voyage of Columbus, elongate C. pepo had become established in Italy.

Domenico Romoli (1560, Venice) presented numerous recipes specifying zucca marina; in the 1570 Opera of Bartolomeo Scappi, the Vatican chef and personal cook to Pope Pius V, recipes distinguish between the zucche and cocuzze nostrali. Zucchini were developed in Milan in northern Italy. Zucchini appeared in North America in the early 20th century, more precisely in the 1920s, probably brought back by Italian immigrants; it is likely that its first place of cultivation in North America was California.

Traditional Folk Medicine Uses

Zucchini has been used in traditional folk medicine to treat colds and alleviate aches, due to its antioxidant, anti-carcinogenic, anti-inflammatory, antiviral, antimicrobial, and analgesic activities. Traditionally, this plant is used in Africa and Asia for the treatment of different diseases including fever, whooping cough, urinary problems, anti-scorbutic properties, hyperplasia, rheumatism, hemorrhoids, miscarriage complications, prostate concerns, constipation, and blindness.

Some of the traditional methods used were poultices made by crushing leaves and applying them to the external parts of the skin to relieve minor skin burns and inflammations; the cooling and moisturizing effect of the plant made it a popular food prescription in hot seasons to avoid dehydration and intestinal pain. Zucchini preparations have often been prescribed by traditional healers for mild constipation, attributed to the presence of fiber as well as a relaxing effect on the gastrointestinal tract; seed decoctions were used in rural systems of herbal medicine, especially in Asian and Latin American regions, to aid the prostate and urinary bladder.

The seeds are widely recognized in traditional remedies for their anti-parasitic properties and are often used in traditional medicine to expel intestinal worms. Cucurbita species have been traditionally employed to address a range of ailments such as cardiovascular disease, atherosclerosis, diabetes, muscle pain, and inflammation, in addition to their use in food (ripe fruit and seeds) and dyes.

The presence of mucilage gives zucchini emollient properties on the digestive system, and as an easy-to-digest food, it is suitable for those with digestive problems. In the Mediterranean region, zucchini became a key component of traditional dishes such as ratatouille in France and pisto manchego in Spain, with ratatouille originating from the need to use garden vegetables so they would not spoil, and zucchini featured among those garden vegetables.

3. Key Constituents and Active Compounds

Overview of Phytochemical Profile

Phytochemical studies indicate that zucchini contains carotenoids (β-carotene, lutein, zeaxanthin), phenolic acids (chlorogenic and caffeic acids), flavonoids (quercetin, kaempferol), phytosterols (β-sitosterol), tocopherols, essential fatty acids, and polysaccharides, which collectively contribute to its overall biological effects. Zucchini is thus an important source of health-promoting phytochemicals, such as phenolic acids, flavonoids, vitamin C, and carotenoids.

Carotenoids

Carotenoids — such as lutein, zeaxanthin, and beta-carotene — are particularly plentiful in zucchini. Substantial amounts of lutein and zeaxanthin (30–50% of total dietary carotenoid content) are present in zucchini (or vegetable marrow), and different kinds of squash. These carotenoids are fat-soluble pigments with potent antioxidant properties. The protective effects of carotenoids are mainly related to their defense against oxidative stress and their ability to scavenge free radicals. Current evidence suggests lutein and its isomers play important roles in ocular development, vision performance, and lowering risk for common age-related eye diseases; these xanthophyll carotenoids include lutein, its structural isomer zeaxanthin, and meso-zeaxanthin, a lutein metabolite.

Phenolic Compounds

The daily intake of polyphenols has received much attention due to the health benefits from their antioxidant/anti-radical, anti-carcinogenic, anti-inflammatory, antiviral, and antimicrobial activities. Among the more known flavonoids identified specifically in zucchini are quercetin-3-O-rutinoside (rutin), isorhamnetin 3-O-rutinoside (narcissin), and other flavonoid glycosides, with all these metabolites being found together in the extract from zucchini. The largest amount of compounds from the group of fatty acids was detected in the most diverse phytochemical profile of zucchini, including γ-linolenic acid (all-cis-6,9,12-octadecatrienoic acid) derivative and linoleic acid (9Z, 12Z)-octadeca-9,12-dienoic acid derivatives.

Vitamins and Minerals

On the nutritional front, zucchini is defined as a low-calorie product with a high moisture content (approximately 95% w/v), containing significant dietary fiber, vitamins C and K, potassium, and other vital micronutrients. One cup (113 grams) of raw zucchini contains approximately 18 calories, 1.37 grams of protein, 0.2 grams of lipid fat, 1.2 grams of dietary fiber, and 2.49 grams of total sugars; the same amount offers about 21.33% of the daily value for vitamin C, 18.92% for vitamin B6, and 12.31% for vitamin B2. Zucchini is an excellent source of potassium, an important intra-cellular electrolyte; potassium is a heart-friendly electrolyte and helps bring about reduction in blood pressure and heart rates by countering the pressure effects of sodium.

Phytosterols and Seeds

Cucurbita pepo seeds are particularly nutritious, high in protein and unsaturated fatty acids including omega-3 and omega-6, and also contain essential minerals such as zinc, iron, and magnesium, as well as phytosterols known for their overall health benefits. β-Sitosterol is the principal phytosterol identified in the plant. These activities of C. pepo might be due to the existence of certain classes of compounds including flavonoids, terpenoids, cardiac glycosides, and cucurbitacin glycosides.

Mechanisms of Action

The pharmacological activities of Cucurbita pepo are multifactorial and synergistic; rather than acting through a single bioactive compound, zucchini exerts therapeutic effects via combined antioxidant, anti-inflammatory, metabolic, and immunomodulatory mechanisms; the interplay between phenolics, carotenoids, fiber, phytosterols, and micronutrients enhances its preventive potential against chronic non-communicable diseases. A range of pharmacological effects — such as antioxidant, anti-inflammatory, antidiabetic, cardioprotective, hepatoprotective, antimicrobial, neuroprotective, and possible anticancer effects — are shown by experimental studies, greatly related to the modulation of oxidative-stress pathways, inflammatory mediators, and metabolic enzymes.

4. Scientific Evidence by Area of Use

4.1 Antioxidant Activity

Zucchini fruits (both "Yellow" and "Light Green" varieties) and four distinctive components — lutein, β-carotene, zeaxanthin, and dehydroascorbic acid — have been studied; summer squash (Cucurbita pepo subsp. pepo) is a seasonal vegetable that contains a number of beneficial micronutrients including minerals, carotenoids, vitamin C, and phenolic compounds, and has been used in traditional folk medicine to treat colds and alleviate aches, due to its antioxidant/anti-radical, anti-carcinogenic, anti-inflammatory, antiviral, antimicrobial, and analgesic activities. Total phenolic contents of zucchini fruits have been quantified; one set of studies showed phenolic content ranged between 96.2 and 117.3 mg GAE/100 g of fresh weight as affected by biostimulant treatments, while other studies recorded an average phenolic content of 8.67 mg GAE/g FW.

Evidence strength: Antioxidant activity has been well-characterized in vitro across multiple laboratory studies using methods such as DPPH, ABTS, and FRAP assays. There was an important decrease in antioxidant activity and phenolic compounds when zucchini was frozen, while antioxidant activity was much greater in stir-fried produce compared to steamed and raw. Direct human clinical trials specifically testing zucchini's antioxidant effects are lacking; the evidence base is predominantly laboratory and observational.

4.2 Ocular Health: Lutein, Zeaxanthin, and Age-Related Macular Degeneration

Zucchini is a recognized dietary source of lutein and zeaxanthin, two xanthophyll carotenoids that accumulate in the human retina. From the many carotenoids in the diet, the human retina selectively accumulates only two — zeaxanthin and lutein; their concentration is so high in the macula that the carotenoids are visible as a dark yellow spot called the macular pigment; because these carotenoids absorb blue light and are powerful antioxidants, scientists have hypothesized that they protect the retina.

In the original Age-Related Eye Disease Study (AREDS1), researchers found that supplementation with vitamins C (500 mg) and E (400 IU), β-carotene (15 mg), zinc (80 mg), and copper (2 mg) reduced the risk of progression to a more advanced age-related macular degeneration (AMD) by about 25%; AREDS2 later incorporated lutein (10 mg) and zeaxanthin (2 mg) into the formulation; in secondary analysis, L/Z supplements on top of the AREDS formulation lowered the progression to advanced AMD, though this only occurred in persons with low dietary L/Z.

Lutein and zeaxanthin have been hypothesized to protect against visual disorders including AMD, age-related cataracts, ischemic/hypoxia-induced retinopathy, light damage of the retina, retinitis pigmentosa, retinal detachment, uveitis, and diabetic retinopathy; the mechanism may be due to physical blue light filtration properties and local antioxidant activity; surveys about supplementation have indicated that moderate intakes of lutein and zeaxanthin are associated with decreased AMD risk and less visual impairment.

Evidence strength: Importantly, the FDA concluded that no credible evidence exists for a health claim about the intake of lutein or zeaxanthin (or both) and the risk of age-related macular degeneration or cataracts, based on its evidence-based review. Some clinical studies have found evidence that people with higher dietary or serum levels of zeaxanthin and lutein had reduced risk for advanced stages of AMD, but others have found no association. The evidence for lutein and zeaxanthin supplementation improving macular pigment optical density (MPOD) is more consistent: a meta-analysis of 20 randomised controlled trials found that lutein, zeaxanthin, and meso-zeaxanthin supplementation improves MPOD in both healthy subjects and in AMD patients in a dose-response manner. Overall, the ocular benefits attributed to zucchini's carotenoids are derived from the broader evidence on lutein and zeaxanthin compounds, not from clinical trials of zucchini consumption specifically.

4.3 Cardiovascular Health

Zucchini supports cardiovascular health by providing potassium, magnesium, and antioxidants that regulate blood pressure and improve circulation; its soluble fiber binds to cholesterol in the gut, helping lower LDL cholesterol. Researchers agree that eating foods high in fiber decreases the risks of cardiovascular illnesses such as heart diseases and strokes, as it decreases high blood pressure. The soluble fiber (pectin) found in zucchini has been shown to help lower "bad" LDL cholesterol levels.

Zucchini genotypes showed the highest concentrations of total minerals (24,338–62,136 mg kg⁻¹ dry weight) among Cucurbita pepo varieties, with traditional zucchini showing the highest concentrations for K, Ca, Mg, Fe, Mn, Zn, and Na. Preclinical (animal) studies have investigated the effects of zucchini on cardiovascular biomarkers in high-fat diet models. The presence of certain components in summer squash, including zucchini, has indicated lipid-lowering effects in animal studies.

Evidence strength: Although most evidence is derived from in vitro and animal studies, dietary epidemiology supports its inclusion in balanced diets for metabolic and cardiovascular health. There are no dedicated randomized controlled trials testing zucchini specifically for cardiovascular outcomes in humans. The cardiovascular benefits are inferred from the established nutritional properties of its constituent compounds (potassium, fiber, polyphenols) in the broader dietary literature.

4.4 Glycemic Control and Metabolic Health

Zucchini is a non-starchy vegetable with a low glycemic index, meaning it is less likely to cause rapid spikes in blood sugar levels; for individuals managing type 2 diabetes, consuming zucchini can help maintain steadier blood glucose levels. The high-fiber content in zucchini is essential for diabetic diets; fiber aids in slowing down the digestion process, resulting in a more gradual release of glucose into the bloodstream.

Therapeutically, C. pepo is identified as effective in hypoglycemic (antidiabetic) and hypolipidemic activities. Cucurbita species have been traditionally employed to address ailments such as diabetes and inflammation; their medicinal derivatives, such as hydroethanolic extracts, have demonstrated a wide spectrum of biological activities, including anticancer, antimicrobial, and antiparasitic effects.

Evidence strength: Evidence for antidiabetic activity of Cucurbita pepo extracts is primarily preclinical (in vitro enzyme inhibition studies and animal models). Human clinical trial data specific to zucchini consumption and blood sugar control are limited. The low glycemic index of zucchini as a whole food is well-documented and generally accepted within nutritional science, but controlled intervention studies are needed.

4.5 Digestive Health

Zucchini is a great source of dietary fiber, which has been positively linked to maintaining a healthy gut; insoluble fiber acts as a bulking agent in stools, easing passage through the gut; soluble fiber supports gut bacteria; these bacteria create short-chain fatty acids (SCFAs) that provide nutrients mainly in the colon, and SCFAs also have anti-inflammatory properties and reduce the risks of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease. Zucchini is a good source of fiber, with 2 grams per medium fruit.

The presence of mucilage gives zucchini emollient properties on the digestive system, making it an easy-to-digest food suitable for those with digestive problems.

Evidence strength: The digestive benefits are supported by its fiber content, consistent with well-established evidence in the dietary fiber literature. No controlled clinical trials specific to zucchini and gastrointestinal disease outcomes have been identified in the peer-reviewed literature.

4.6 Anti-inflammatory Activity

Rather than acting through a single bioactive compound, zucchini exerts its effects via combined antioxidant, anti-inflammatory, metabolic, and immunomodulatory mechanisms. Quercetin and kaempferol, flavonoids found in zucchini, are established anti-inflammatory compounds in the pharmacological literature, operating through inhibition of pro-inflammatory enzymes and cytokines. The anti-inflammatory properties of zucchini come from its vitamin C, beta-carotene, and the presence of other antioxidants.

Evidence strength: Anti-inflammatory activity for zucchini and its constituents is supported primarily by in vitro and animal experimental data. Dedicated human clinical trials evaluating zucchini's anti-inflammatory properties as an isolated intervention are not available in the published peer-reviewed literature.

4.7 Genotoxicity, Cytotoxicity, and Potential Anticancer Properties

One study aimed to assess the added value of the nutritional components of zucchini — specifically the carotenoids (lutein, β-carotene, and zeaxanthin) and vitamin C — with respect to DNA integrity and possible in vivo genotoxic and in vitro cytotoxic effects; to measure these properties, different assays were carried out including genotoxicity and anti-genotoxicity (in vivo analysis using the Drosophila melanogaster model), and cytotoxicity and pro-apoptotic activity (in vitro assays using the promyelocytic leukemia HL60 cell line). Lutein and zeaxanthin, naturally occurring carotenoids, have shown to reduce the risk of cataracts and age-related macular degeneration; zeaxanthin is related to the reduction of melanoma cells' viability.

In one investigation, the cytotoxicity of specific concentrations of hydro-alcoholic extracts of C. pepo and S. nigrum was studied on normal and cancer (HepG2 and CT26) cell lines; the cytotoxic effects and IC50 of the extracts on the selected cell lines were studied; however, the IC50 of S. nigrum extract was significantly lower than that of the C. pepo extract.

Evidence strength: Anticancer activity for zucchini constituents is strictly preliminary, based on in vitro cell-line studies and in vivo invertebrate models (e.g., Drosophila). No human clinical data support anticancer claims for zucchini.

4.8 Antimicrobial and Antiviral Activity

Cucurbita pepo has been used in traditional folk medicine to treat cold and alleviate ache; previous pharmacological tests have shown that it possesses antiviral, anti-inflammatory, and analgesic effects. Medicinal derivatives of Cucurbita species, such as hydroethanolic extracts, have demonstrated a wide spectrum of biological activities, including anticancer, antimicrobial, and antiparasitic effects.

Evidence strength: Antimicrobial and antiviral data for zucchini are preliminary, derived from extract-based in vitro studies. No randomized controlled trials in humans have assessed zucchini's antimicrobial or antiviral efficacy.

5. Body Systems and Health Areas of Association

Visual/Ocular System: Zucchini is a good source of lutein and zeaxanthin, types of carotenoids that fight cell damage and disease; studies show this pair can improve or potentially prevent eye conditions like age-related macular degeneration (AMD).
Cardiovascular System: Potassium, fiber, and antioxidants in zucchini are associated in the dietary literature with blood pressure regulation, LDL cholesterol management, and reduced cardiovascular risk.
Gastrointestinal System: High in both water and fiber, zucchini is considered a powerhouse for digestive health; its soluble fiber acts as a prebiotic feeding beneficial gut bacteria, while insoluble fiber adds bulk to stool.
Metabolic/Endocrine System: Relevant to blood glucose management via its low glycemic index and fiber content; preclinical evidence exists for antidiabetic enzyme inhibition.
Immune System: Zucchini may help the immune system in a few ways; first, its fiber content feeds the gut microbiome, which plays a key role in fighting off unwanted invaders.
Musculoskeletal System: Traditional uses include treatment of rheumatism and aches; mechanistically attributed to anti-inflammatory compounds.
Urinary/Prostate: Seed decoctions were used in rural systems of herbal medicine, especially in Asian and Latin American regions, to aid the prostate and urinary bladder.
Skin and Integument: Traditional methods included poultices made by crushing leaves and applying them to the skin to relieve minor burns and inflammations.

6. Dosage Forms and Dosages Reported in Studies

Zucchini is not a standardized supplement with prescribed dosing in the same manner as a pharmaceutical compound. As a whole food, its nutritional contributions depend on quantity and preparation. From the scientific literature, the following dosage-related data points have been reported:

Zucchini is one of the lowest caloric content vegetables at 14 kcal/100 g and has the highest water content of 96.5%.
One cup of 113 grams of raw zucchini contains 18 calories, 1.37 grams of protein, 0.2 grams of lipid fat, 1.2 grams of dietary fiber, and 2.49 grams of total sugars.
Regarding lutein and zeaxanthin from dietary sources: the recommended daily intake of lutein is approximately 10.0 mg and that of zeaxanthin is 2 mg; lutein intake in adults varies, with average intakes being 1–2 mg/day.
In the AREDS2 clinical trial on eye health: lutein (10 mg) and zeaxanthin (2 mg) were incorporated into the supplement formulation used in the study among people with early AMD.
Future research should focus on clinical trials, bioavailability studies, nanoformulation of extracts, and molecular mechanism elucidation before standardized dosing for specific conditions can be established.

No standardized therapeutic dosage for zucchini as a supplement has been established in official pharmacopoeial monographs or by regulatory bodies such as the NIH Office of Dietary Supplements, EMA, or EFSA. The absence of standardized extract preparations or dosing recommendations reflects the current state of the evidence, which is primarily preclinical.

7. Safety Considerations and Interactions

General Safety

The risk of allergic sensitization and elicitation reactions upon dietary exposure to zucchini-derived food enzymes cannot be excluded, but is not expected to exceed the likelihood of allergic reactions following consumption of pumpkin or zucchini per se, which is low. For most people, Cucurbita pepo is safe and beneficial to consume.

Cucurbitacin Toxicity ("Toxic Squash Syndrome")

The most significant and well-documented safety concern specific to zucchini relates to cucurbitacins — a class of naturally occurring triterpenoid compounds that can accumulate under certain conditions. Cucurbitacin poisoning, often referred to as "toxic squash syndrome," can manifest through a variety of symptoms ranging from mild to severe, depending on the level of toxin ingested; cucurbitacins are naturally occurring compounds found in zucchini, pumpkins, and squash; although generally bred out of cultivated varieties, stress on the plant or cross-pollination can occasionally lead to elevated levels, posing a health risk.

Cucurbitacins are plant-produced, bitter chemical compounds that occur naturally in this plant family; these compounds occur in a subset of species in the cucurbit family and are usually found at highest concentrations in the roots of plants; over the years that humans have been developing cucurbit varieties, cucumbers, melons, squash, and pumpkin lines have been selected to be free of high levels of these extremely bitter compounds.

Humans in the US exposed to small amounts of zucchini containing cucurbitacins (0.1 ounce of zucchini) experienced irritation of their intestines, greatly increased intestinal motility (diarrhea), headaches, severe stomach cramps, and collapsed within 1 to 2 hours of ingesting the intoxicating summer squash. Another study reported a fatal case of food poisoning due to cucurbitacin in a zucchini; Dutch researchers presented the case at the International Congress of Therapeutic Drug Monitoring and Clinical Toxicology; the incident involved an older, formerly healthy couple, with both patients having consumed a maximum of two bites of a dish containing zucchini grown from their home garden.

Cucurbitacins are a diverse family of organic compounds found in edible plants such as zucchini, pumpkin, cucumber, and others; these plants produce cucurbitacins in response to environmental stress such as poor growing conditions, and levels of these compounds decrease during maturation. Garden vegetables can develop dangerous levels of cucurbitacins for several reasons; cross-pollination poses the greatest risk, as wild species with high cucurbitacin levels may pollinate cultivated cucurbits, resulting in the production of seeds that develop into plants with bitter, toxic fruit; environmental stress can also raise cucurbitacin levels, as plants produce more of these compounds during drought conditions as a survival strategy.

The lungs, pancreas, liver, and kidney can also be affected, along with a reduction in red blood cell levels; the reported cases of human poisonings are relatively small, so information on the effects in humans is limited.

Practical Safety Guidance Based on Published Data

Do not eat squash or other cucurbit fruit if there is a noticeable bitterness.
Modern cultivated varieties have very low amounts of cucurbitacin compounds because farmers have bred them to be less bitter.
Only consume edible cultivars of cucurbits purchased from reputable suppliers.

Potential Drug Interactions

No well-documented drug interactions exist for zucchini under normal consumption conditions; however, cucurbitacins can worsen hypotension and dehydration, which may be dangerous if a person is taking antihypertensives, diuretics, or chemotherapy drugs. This interaction risk applies specifically to zucchini with elevated cucurbitacin content, not to commercially grown zucchini consumed in ordinary dietary amounts.

Effect of Cooking and Preparation on Nutrient Profile

Raw zucchini offers a similar nutrition profile as cooked zucchini, but with less vitamin A and more vitamin C, a nutrient which tends to be reduced by cooking. There is an important decrease in antioxidant activity and phenolic compounds when zucchini is frozen. Zucchini skin contains a large amount of its vitamin C and B6, so it is advisable not to peel it.

8. Nutraceutical and Industrial Status

The industrial and nutraceutical utilization of Cucurbita pepo L. has expanded significantly in recent years due to its rich phytochemical profile and functional food attributes. In general, zucchini is a promising nutraceutical and therapeutic agent that requires additional clinical support, extract standardization, and mechanistic research to support health assertions and enable its conversion to evidence-based pharmaceutical and nutraceutical products.

Although most evidence is derived from in vitro and animal studies, dietary epidemiology supports its inclusion in balanced diets for metabolic and cardiovascular health; future research should focus on clinical trials, bioavailability studies, nanoformulation of extracts, and molecular mechanism elucidation.

References

Health Conditions

Health conditions that Zucchini may help support.

No conditions available.

Body Systems

Body systems that Zucchini may help support.

No body systems available.