Cucumber vs. Zucchini — Health Impact and Nutrition Comparison

Summary

Zucchini is slightly richer in calories, almost two times richer in proteins and fats.

Zucchini contains two times more dietary fiber, whereas cucumber contains 1.5 times more net carbs.

Zucchini contains 6.4 times more vitamin C, four times more vitamins E and B6, 3.4 times more folate or vitamin B9, almost three times more vitamin B3.

Cucumber is 3.8 times richer in vitamin K.

Zucchini is relatively richer in most of the minerals as well.

Introduction

Cucumber and zucchini are well-known and widely used foods. These foods belong to the same family, and this article will compare their nutritional values and provide information about the health benefits and potential risks.

Classification

Cucumber (Cucumis sativus) belongs to the Cucumis genus, whereas zucchini (Cucurbita pepo), also known as courgette, or baby marrow, is a summer squash and belongs to the Cucurbita genus.

Both cucumber and zucchini belong to the Cucurbitaceae family, also known as cucurbits or the gourd family. The family includes luffas, squashes, pumpkins, melons, and watermelons.

Appearance

Green cucumbers are the most common; however, cucumbers can be white, yellow, and orange. Regular cucumbers have green stripes on darker green skin.

Ordinary zucchini fruits are striped or uniform-colored and can be any shade of green, whereas the golden zucchini has a deep yellow or orange color.

Taste and Use

Cucumber is best eaten raw. It is used in various salads, sandwiches, burgers, side dishes, and main dishes. Cucumber smoothies are widely known and consumed; they can include lemon, watermelon, spinach, avocado, strawberry, pineapple, mint, tomato, and other fruits and greens.

Cucumber can also be used in alcoholic drinks, such as margarita, gin, martini, collins.

Zucchini is served in a variety of ways. In salads, zucchini is eaten raw, sliced or shredded, or lightly cooked. Depending on the country, it can be cooked, boiled, grilled, baked, fried, barbecued, or incorporated in other recipes.

Zucchini noodles or zoodles are made from zucchini as a substitute for spaghetti. Zucchini can also be used in breadmaking.

Cucumbers can have a mildly sweet or bitter taste. There are different ways of reducing bitterness, for example, removing the skin, cutting the ends, or cutting the cucumber lengthwise, adding salt, and rubbing the parts against each other.

Zucchini has a mild flavor, slightly bitter but also slightly sweet. However, its sweet taste becomes more noticeable when cooked.

Varieties

The two main types of cucumber are slicing and pickling. Pickling cucumbers are shorter, with thinner skins and spines, when compared to slicing cucumbers. Pickling cucumbers often have dark green to light green stripes, whereas most slicing cucumbers have a dark green color.

Some of the common cucumber varieties are English, Armenian, Kirby, Lemon, Persian, Japanese or Kyuri, American, Gherkins, Bush Champion, Ashley, etc.

English or seedless cucumber is long, with thin dark green skin. This cucumber has a very mild flavor and can be found in most supermarkets the whole year.

Armenian or snake cucumber is long and curves at the end. This variety has thin skin and soft seeds.

Kirby cucumber is also known as pickling cucumber. It is short, with bumpy skin and small seeds.

Lemon cucumber looks like a lemon - yellow and round. Yellow cucumber has a sweet taste and soft seeds.

Persian cucumber looks like the English cucumber; however, it has a greater range of lengths. It is also sturdy enough for stir-frying.

Zucchini has a wide range of varieties, such as Black Beauty, Dunja, Gourmet Gold, Cocozelle, Gadzukes, Caserta, Ronde de Nice, Golden Egg, Crookneck, Pattypan, Rampicante, Magda, Zephyr, Raven, Fordhook, Summer Green Tiger, Bush Baby, etc.

Black Beauty is one of the most popular and easy-growing varieties of zucchini. It’s dark green to almost black from the outside and with creamy white flesh inside.

Dunja is straight and has dark green glossy skin. This variety is quick and easy to harvest.

Cocozelle produces darker green streaks and is less watery than the other varieties.

Gadzukes is a dark green zucchini with light green ridges and star-shaped slices.

Caserta color varies from light green to grey, with alternate dark green stripes.

Nutrition

The nutritional values in this article are presented for raw cucumber and raw zucchini.

Macronutrients and Calories

Cucumber and zucchini have similar nutritional contents. Both of them consist of 95% water; zucchini is slightly denser.

One serving size of cucumber is half a cup, sliced, equal to 52g, whereas one serving size of zucchini is one cup, chopped, equal to 124g.

Calories

Both cucumber and zucchini are very low-calorie foods.

A 100g serving of cucumber, with peels, provides 15 calories, while peeled cucumber provides only ten calories. A 100g serving of zucchini provides 17 calories.

Protein and Fats

These cucurbits are not particularly rich in macronutrients; however, zucchini contains more protein compared to cucumber.

Both of the foods have some amounts of all essential amino acids.

They have a very low-fat content as well. Even though zucchini contains three times more fats, 100g of each of the two foods covers only 3% of the daily fat need.

Cucurbits are absent in cholesterol and trans fats.

Carbohydrates

Cucumber is slightly richer in carbs compared to zucchini and peeled cucumber.

While zucchini contains two times more dietary fiber, cucumber contains 1.5 times more net carbs.

Peeling the skin off of cucumber doesn’t negatively affect the dietary fat content.

Vitamins

Zucchini is richer in most vitamins.

Zucchini contains 6.4 times more vitamin C, four times more vitamins E and B6, 3.4 times more folate or vitamin B9, almost three times more vitamin B3. Zucchini is richer in vitamins A and B1 as well.

Cucumber contains 3.8 times more vitamin K. It is also richer in vitamin B5.

Both of the cucurbits are absent in vitamin D and vitamin B12.

Minerals

Cucumber contains 1.5 times more selenium and four times less sodium.

On the other hand, zucchini is richer in iron, potassium, magnesium, copper, zinc, and phosphorus.

Cucumber and zucchini are equal in calcium.

One serving of these foods covers less than 7% of the daily mineral need.

Glycemic Index

Both cucumber and zucchini are low glycemic index, diabetes-friendly foods.

Low glycemic index diets reduce fasting blood glucose levels, therefore positively affecting glycemic control and may lead to weight loss in people with diabetes or prediabetes (1).

Acidity

Both cucurbits are acidic foods.

The pH value of cucumber falls from 5.12 to 5.78. The pH value of pickled cucumber is 4.20 - 4.60.

The pH value of zucchini is calculated for the cooked food, ranging from 5.69 - 6.10 (2).

The PRAL or potential renal acid load value of cucumber is -2.4, and the PRAL value of zucchini is -4.2, making it more alkaline. The negative PRAL values of these foods mean that they are base-producing.

Weight Loss & Diets

• The Atkins diet is a low-carbohydrate diet, and both of these products are advised throughout all phases of the diet, including phases 1 and 2.
• The Dukan diet is a four-phase, low-carb, high-protein weight loss plan comparable to the Atkins diet. Cucumbers and zucchini are non-starchy veggies that are also low in calories, making them an excellent addition to this diet. In addition, cucumbers and zucchini are allowed during the second (cruise) PV (protein and vegetables) phase, the third (consolidation), and the fourth (stabilization) phases of the Dukan Diet. Gherkin (a variety of pickled cucumber) is allowed in moderation during the first (attack) and second (pure protein) phases too.
• The Mediterranean diet is a diet centered on traditional foods from Greece, Italy, and other Mediterranean Sea countries, so cucumber and zucchini are recommended during this diet.
• Cucumber and zucchini are recommended on the paleo diet because they are vegetables that people may have consumed during the Paleolithic Era.
• Intermittent fasting is more like an eating habit than a diet because it regulates when you eat rather than what you consume. Thus, either of these products may be consumed while following this diet.
• Both cucumber and zucchini are great for weight-loss diets.
• They can be consumed during the DASH (Dietary Approaches to Stop Hypertension) diet as well.

Health impact

Health Benefits

Cardiovascular health

One study has concluded that cucumber lowers systolic and diastolic blood pressure in older people. The potential mechanism is due to its diuretic effect, which decreases circulating fluid in the bloodstream, reducing the heart’s workload (3). In terms of zucchini, its high potassium and low sodium content may decrease arterial blood pressure. (4-2).

According to this rat study, zucchini consumption may decrease "bad" cholesterol (low-density lipoprotein), triglycerides, and consequently total cholesterol levels; in addition, it may increase "good" cholesterol (high-density lipoprotein) levels in the blood (4). Information about increasing ‘’good’’ cholesterol levels in the blood is unknown for cucumber, but its consumption may also decrease ‘’bad’’ cholesterol and triglyceride levels (5). 

From all this, it follows that zucchini and cucumber consumption may prevent or slow down the process of atherosclerosis, which is the main cause of the development of myocardial infarction, stroke, and other life-threatening diseases (6.7).

In addition, both of these products have cucurbitacin I and B, which potentially protect the heart against cardiac hypertrophy and oxidative stress (the disturbed balance between production and accumulation of reactive oxygen species); however, one study suggests that cucurbitacin I may lead to cardiac hypertrophy and cardiac cell death (8.9.10.11).

Diabetes

Both cucumber and zucchini are low glycemic index foods. They are low in sugar but rich in dietary fiber. They are used in weight loss diets and have low glycemic index values, reducing the risk of developing type 2 diabetes or medication (12).

According to these studies, cucumber has active components with anti-diabetic, anti-hyperglycemic, and hypoglycemic effects (blood sugar-lowering activities) and may be used to treat and manage diabetes mellitus (13.14.15). Zucchini may also help with the treatment of type 2 diabetes by increasing insulin levels, reducing glucose levels, and improving glucose tolerance (16.17).

Researchers found that cucumber extracts may protect the liver and pancreas from the damaging effects of diabetes (18). In the case of zucchini, these effects are unknown.

Digestive Health

Dietary fibers from cucumber and zucchini are known to have protective effects against certain gastrointestinal diseases such as constipation, gastroesophageal reflux disease, inflammatory bowel disease, irritable bowel syndrome, hemorrhoids, colon cancer, duodenal ulcer, diverticulitis (19). A number of factors contribute to these effects:

• dietary fiber increases mechanical stimulation or irritation of the colonic mucosa with increased secretion and peristalsis, which leads to increased fecal mass (20)
• the gut microbes may interact directly with dietary fiber, resulting in the production of key metabolites like short-chain fatty acids. These molecules have anti-cancer (they may inhibit the growth and proliferation of cancer cells) and anti-inflammatory effects on colon cells, making them important for colon health (21.22). 

Both cucumber and zucchini are great sources of water, which is important in this case to prevent constipation (23.24.25.26.27). In spite of this, fluid intake does not affect the treatment of constipation caused by other factors.

Cancer

Cucumbers and zucchini have anticancer effects that are useful in both preventing and treating cancer.

Cucurbitacins in cucumber may block tumor cell development and signaling pathways, causing cancer cells to die. Different groups of cucurbitacins have antitumor activity against lung, pancreatic, colon, breast, liver, and cervical cancers (28.29.30.31.32). 

Zucchini, on the other hand, shows anticancer action due to its direct cytotoxic effect, which is further increased by its antioxidant characteristics (33).

Hydration

Adequate fluid intake maintains homeostasis, bodily functions, and health.

Skin health - increased water consumption may improve the hydration of the epidermis layer, playing a key role in skin barrier function. Increased water intake hydrates the skin and reduces dryness as well.

Cognition - dehydration (when water deficits exceed 2% of body mass loss) impairs cognitive performance (attention, executive function, and motor coordination).

Mood and fatigue - dehydration is associated with increased negative emotions (anger, hostility, confusion, and depression), tension, fatigue, and tiredness.

Kidney stones - high fluid intake is associated with a lower risk of kidney stone formation.

Bodyweight - increased fluid consumption contributes to the reduction in body fat and weight (34).

Despite this, it should be noted that in the case of heart valve disease, water intake should be limited.

Downsides and Risks

Cucumbers and zucchini may cause allergic reactions.

Cucurbits may cause oral allergy syndrome (itching, burning, redness, and swelling of the lips, mouth, tongue, and soft palate), nausea, diarrhea, asthma, rhinitis, watery eyes, or contact urticaria (35.36.37).

Both cucumber and Aspirin contain salicylate, and people allergic to Aspirin may need to avoid cucumbers, apples, almonds, oranges, berries, tomatoes, and some other foods as well (38). This effect is unknown for zucchini.

References

1. https://academic.oup.com/ajcn/article/110/4/891/5543221?login=false
2. https://www.clemson.edu/extension/food/food2market/documents/ph_of_common_foods.pdf
3. http://perpustakaan.poltekkes-malang.ac.id/assets/file/karyadosen/5._Jurnal_Effec_Cocom_Budi_.pdf
4. https://www.scirp.org/html/1-2702747_98189.htm
5. https://www.banglajol.info/index.php/JSR/article/view/10252
6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4441156/
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16. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/cucurbita-pepo
17. https://pdfs.semanticscholar.org/6cbf/3a7850edbd4a9e85e38bf41aa1d2f0db6e3c.pdf
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21. https://pubmed.ncbi.nlm.nih.gov/27113407/
22. https://pubmed.ncbi.nlm.nih.gov/3144695/
23. https://fdc.nal.usda.gov/fdc-app.html#/food-details/168409/nutrients
24. https://fdc.nal.usda.gov/fdc-app.html#/food-details/169291/nutrients
25. https://www.nature.com/articles/1601907
26. https://pubmed.ncbi.nlm.nih.gov/28450053/
27. https://pubmed.ncbi.nlm.nih.gov/15654804/
28. https://cancerres.aacrjournals.org/content/69/14/5876
29. https://www.nature.com/articles/srep36594
30. https://www.sciencedirect.com/science/article/abs/pii/S000927971400163X
31. https://www.researchgate.net/publication/303121869_Anti-cancer_activity_of_Cucumis_sativus_cucumber_flowers_against_human_liver_cancer
32. https://www.frontiersin.org/articles/10.3389/fphar.2019.01287/full
33. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537869/
34. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6356561/
35. https://www.sciencedirect.com/sdfe/pdf/download/eid/1-s2.0-S2213219821011053/first-page-pdf
36. https://www.sciencedirect.com/science/article/abs/pii/S0091674900886935
37. https://www.jstage.jst.go.jp/article/allergolint/64/1/64_S1323-8930-14-00013-6/_article/-char/ja/
38. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1805260/pdf/bullnyacadmed00102-0098.pdf