Courgette Benefits & Nutrition: Organic vs Conventional
Courgette, also known as zucchini, is a mild-tasting summer squash with a nutrient and bioactive-compound profile that is more interesting than its subtle flavour suggests. This article looks at courgette nutrition and courgette benefits through a research-informed lens, with a particular focus on one question that is rarely covered in depth: what does the growing method — organic versus conventional — actually change about its antioxidant content? Alongside this, we look at courgette’s core nutritional value, its studied bioactive compounds, and the Ayurvedic perspective on how it is traditionally prepared and consumed.
What Is Courgette? Cucurbita Pepo
Courgette (zucchini, baby marrow) is a type of summer squash with the botanical name Cucurbita pepo, part of the wider Cucurbitaceae (gourd and marrow) family. It is a warm-season crop that grows best in well-drained soil with a pH range of roughly 6.0 to 6.8. The plant produces large, lobed leaves and yellow, trumpet-shaped flowers, both of which are edible and used in cooking.
Fruit colour is not purely aesthetic. Yellow and deeper green courgette varieties carry higher concentrations of carotenoids — including beta-carotene, lutein, and zeaxanthin — than lighter green varieties, a pattern confirmed by direct compound analysis of “Yellow” and “Light Green” cultivars (Martínez-Valdivieso et al., 2017).
Courgette Nutritional Value
Per the U.S. Department of Agriculture’s FoodData Central entry for raw zucchini including skin (FDC ID 169291), 100 g of raw courgette provides approximately 17–21 kcal, 94–95 g water, 1.2 g protein, around 3.1 g carbohydrate, 1.0 g fibre, and roughly 18–22 mg vitamin C, alongside potassium, folate, and small amounts of magnesium and calcium. Figures vary slightly between data releases and reporting sources, so for precise current values it is worth cross-checking the live FoodData Central entry directly rather than relying on any single secondary source, including this one.
| Nutrient (per 100 g raw, with skin) | Approximate value |
|---|---|
| Energy | ~17–21 kcal (71–88 kJ) |
| Water | ~94–95 g |
| Protein | ~1.2 g |
| Carbohydrate | ~3.1 g |
| Fibre | ~1.0 g |
| Vitamin C | ~18–22 mg |
| Potassium | ~260–325 mg |
| Folate | ~20–24 µg |
| Lutein + zeaxanthin | ~2,100 µg |
Glycemic Index: A Figure Worth Considering
A glycemic index of around 15 for courgette is widely repeated across nutrition and diabetes-focused resources— it circulates as a commonly cited estimate rather than a directly measured and published research value. What is better established is the underlying reason courgette has minimal blood glucose impact regardless of the exact GI figure used: its very low available carbohydrate content (around 2–3 g net carbs per 100 g) keeps its glycemic load low by definition, since glycemic load accounts for both the glycemic index and the actual carbohydrate quantity in a typical serving.
Organic Versus Conventional Courgette: What the Evidence Shows
Published research directly comparing organic and conventional courgette is limited, which makes the three-year field trial by Kopczyńska et al. (2020) — published in Antioxidants — one of the more useful reference points available. The study followed two courgette varieties (Astra Polka and Nimba) grown in parallel organic and conventional systems in Poland across the 2016, 2017, and 2018 growing seasons, analysing dry matter, vitamin C, polyphenols, carotenoids, and chlorophylls by HPLC.
The organically grown fruits were observed to carry significantly higher concentrations of several bioactive compound groups than the conventionally grown fruits from the same trial:
| Compound group | Conventional | Organic | Statistical significance |
|---|---|---|---|
| Dry matter (g/100 g f.w.) | 4.83 | 5.37 | p = 0.003 |
| Total polyphenols (µg/g f.w.) | 23.51 | 42.63 | p < 0.001 |
| Phenolic acids, sum (µg/g f.w.) | 21.44 | 38.40 | p < 0.001 |
| Flavonoids, sum (µg/g f.w.) | 2.07 | 4.22 | p < 0.001 |
| Carotenoids, sum (mg/100 g f.w.) | 0.76 | 0.99 | p < 0.001 |
| β-carotene (mg/100 g f.w.) | 0.65 | 0.87 | p < 0.001 |
| Lutein (mg/100 g f.w.) | 0.095 | 0.103 | p = 0.015 |
| Zeaxanthin (mg/100 g f.w.) | 0.030 | 0.032 | not significant |
| Chlorophylls, sum (mg/100 g f.w.) | 2.06 | 2.57 | p < 0.001 |
| Total vitamin C (mg/100 g f.w.) | 6.34 | 5.99 | not significant |
| Dehydroascorbic acid (mg/100 g f.w.) | 3.12 | 2.77 | p = 0.020 (higher in conventional) |
Source: Kopczyńska et al. (2020), Tables 2 and 6. f.w. = fresh weight.
Two things can be true at once here, and both are worth holding in view rather than simplifying into a single headline. First, organic cultivation was associated with meaningfully higher concentrations of phenolic acids, flavonoids, carotenoids, and chlorophylls across this trial — differences the authors attribute in part to the stress-response and secondary-metabolism effects associated with organic growing conditions and reduced nitrogen availability. Second, total vitamin C content was not significantly different between the two systems; only its oxidised form, dehydroascorbic acid, was found at higher levels in the conventional fruit. Zeaxanthin, similarly, showed no significant difference by growing system.
A further observation from the same trial deserves more attention than it typically receives: the year of cultivation had a stronger overall effect on bioactive compound levels than the growing system did. Across nearly every compound measured, 2017 — a season with more typical rainfall and temperature — produced the highest concentrations, while the driest year (2016) produced the lowest, regardless of whether the crop was organic or conventional. This suggests that, at least in this trial, seasonal growing conditions modulated courgette’s antioxidant density as much as or more than the organic/conventional distinction alone.
Treated as an early, well-controlled dataset rather than a definitive verdict, it offers a genuinely useful — if still developing — picture of what organic courgette cultivation may contribute nutritionally.
Bioactive Compounds: Lutein and Zeaxanthin: Eye and Cognitive Health Observations
Lutein and zeaxanthin, the xanthophyll carotenoids present in courgette skin in particular, are established as the only dietary carotenoids that accumulate in the retina’s macula — hence their designation as macular pigments. A 2022 review in Nutrients by Mrowicka et al. summarises their role in supporting macular health and their associations with broader antioxidant and neuroprotective activity in the eye, skin, heart, and intestines. It is worth noting that this review’s own list of key dietary sources for lutein and zeaxanthin centres on kale, spinach, broccoli, peas, and corn rather than courgette specifically — so courgette is reasonably positioned as one contributor to lutein and zeaxanthin intake within a varied diet, rather than as a standout source.
On cognitive function, a randomised, double-blind, placebo-controlled trial by Lopresti et al. (2022) in Frontiers in Nutrition gave adults with self-reported mild cognitive complaints either a placebo or a daily supplement of 10 mg lutein and 2 mg zeaxanthin for six months. The supplemented group showed significant improvements in visual episodic memory and visual learning compared to placebo, though no significant differences emerged on the other cognitive measures tested. Two caveats are relevant here: the doses used were concentrated supplement amounts, well above what a serving of courgette would realistically provide, and the trial measured supplementation rather than whole-food intake. It is a genuinely useful data point on lutein and zeaxanthin as nutrients, but it is not a direct estimate that eating courgette produces the same cognitive effect.
Vitamin C in Courgette
Vitamin C (ascorbic acid) plays a well-established role in collagen synthesis, supporting skin, bone, and joint structure. USDA data puts raw courgette’s vitamin C content at roughly 18–22 mg per 100 g, a moderate but useful contribution when courgette is eaten as part of a varied vegetable intake. As the organic-versus-conventional comparison above shows, the more consistent differences observed relate to polyphenols, carotenoids, and chlorophylls rather than vitamin C itself.
Bioavailability: Raw and Cooked, and the Ayurvedic View
Courgette is reported to contain approximately 93.5–95% water (Kopczyńska et al., 2020), which contributes to its light, easily digestible character. How it is prepared can influence how its nutrients are absorbed and used — a concept broadly described as the food matrix effect, referring to how the physical and chemical structure of a food interacts with digestion and nutrient release.
Raw courgette retains water-soluble and heat-sensitive nutrients such as vitamin C more fully, since ascorbic acid is known to degrade with heat exposure, extended cooking time, and cut-surface oxidation. Gentle cooking methods such as steaming, on the other hand, are understood to break down plant cell walls, which can improve the digestibility and accessibility of certain nutrients, at some cost to heat-sensitive compounds. Neither approach is inherently superior across the board; the better choice depends on which nutrients and which digestive considerations matter most in a given context.
In Ayurveda, courgette is considered to have a balancing effect on the Vata and Pitta doshas, attributed to its cooling and easily digestible qualities, and is traditionally associated with gut-friendly, mildly diuretic, and gentle anti-inflammatory properties when used in liver- and digestion-supportive preparations. Ayurvedic principles generally favour courgette steamed or gently cooked until just tender, with raw preparations reserved more for hot weather, and caution against excessive raw intake overall as potentially depleting rather than nourishing when it dominates the diet. This traditional framing sits alongside the modern nutritional picture rather than replacing it — each offers a different, complementary lens on the same food.
Three Ways to Consume Courgette
- Steamed courgette topped with a pinch of pink Himalayan salt and a spoonful of coconut oil
- A room-temperature salad of raw, thinly sliced courgette with lemon juice, natural salt, and black pepper
- Courgette and green mung bean soup, gently spiced with turmeric, and finished with sunflower or pumpkin seeds
Suitability and Precautions
Courgette is generally easy to digest and well suited to frequent inclusion in a balanced diet. As with any dietary change, seek individual professional guidance — particularly during pregnancy, in the presence of known allergies, or alongside chronic health conditions — before adjusting intake. This article is intended as an informational overview and does not constitute personalised dietary or medical advice.
Summary
Courgette’s nutritional and observational profile spans a low-calorie, high-water base alongside meaningful concentrations of vitamin C, potassium, folate, and the carotenoids lutein, zeaxanthin, and β-carotene, concentrated particularly in the skin. The organic-versus-conventional research available so far, led by Kopczyńska et al. (2020), points to organically grown courgette carrying higher levels of phenolic acids, flavonoids, carotenoids, and chlorophylls than conventionally grown fruit from the same trial — though not higher total vitamin C, and with the growing season itself shown to be an equally significant variable. Separate cell- and organism-model research from Martínez-Valdivieso et al. (2017) supports the safety of courgette’s key compounds and describes anti-proliferative activity against one cancer cell line in vitro, without constituting evidence of a cancer-prevention effect in humans from dietary intake. Considered together with its traditional standing in Ayurveda as a light, digestible, Vata- and Pitta-balancing food, courgette holds up as a well-rounded, versatile vegetable worth a regular place on the plate — understood through both its modern research profile and its longer traditional use.
References
- Kopczyńska, K., Kazimierczak, R., Średnicka-Tober, D., Barański, M., Wyszyński, Z., Kucińska, K., Perzanowska, A., Szacki, P., Rembiałkowska, E., & Hallmann, E. (2020). The Profile of Selected Antioxidants in Two Courgette Varieties from Organic and Conventional Production. Antioxidants, 9(5), 404. https://doi.org/10.3390/antiox9050404
- Martínez-Valdivieso, D., Font, R., Fernández-Bedmar, Z., Merinas-Amo, T., Gómez, P., Alonso-Moraga, Á., & Del Río-Celestino, M. (2017). Role of Zucchini and Its Distinctive Components in the Modulation of Degenerative Processes: Genotoxicity, Anti-Genotoxicity, Cytotoxicity and Apoptotic Effects. Nutrients, 9(7), 755. https://doi.org/10.3390/nu9070755
- Mrowicka, M., Mrowicki, J., Kucharska, E., & Majsterek, I. (2022). Lutein and Zeaxanthin and Their Roles in Age-Related Macular Degeneration—Neurodegenerative Disease. Nutrients, 14(4), 827. https://doi.org/10.3390/nu14040827
- Lopresti, A. L., Smith, S. J., & Drummond, P. D. (2022). The Effects of Lutein and Zeaxanthin Supplementation on Cognitive Function in Adults With Self-Reported Mild Cognitive Complaints: A Randomized, Double-Blind, Placebo-Controlled Study. Frontiers in Nutrition, 9, 843512. https://doi.org/10.3389/fnut.2022.843512
- United States Department of Agriculture, Agricultural Research Service. FoodData Central, FDC ID 169291. https://fdc.nal.usda.gov/fdc-app.html#/food-details/169291/nutrients