Nutrition

Zucchini: The Superfood Growing in Your Garden

This tasty fruit is easily grown in your garden or containers and offers several health benefits
BY Joseph Mercola TIMESeptember 19, 2022 PRINT

The zucchini is an underestimated nutritional treasure.

The peak harvesting season for this delicious member of the gourd family in the Northern Hemisphere is from May to August. When harvested correctly, zucchini (Cucurbita pepo) is dark green and has firm fruit. Although most people think of it as a summer vegetable, it is, indeed, a fruit.

The plant is native to Central America and Mexico. According to the Department of Agriculture (USDA),[1] zucchini may have been one of “The Three Sisters,” which were crops planted within a shared space. This indigenous agricultural practice used three plants—corn, beans, and squash—to nourish and protect each other as they grew.

Zucchini plants can grow in nearly every climate during the warm summer months. It takes only one or two plants to produce enough for one family. In addition to being a good producer throughout the growing season, zucchini is also high in nutrition and has several health benefits. Zucchini are best harvested when they’re 1.5 inches round and no longer than 8 inches.

Zucchini can taste bitter when they become overripe or stressed. That’s because, like other vegetables in the family, zucchini contains toxins the plant uses to defend against predators.[2] Zucchini produces cucurbitacins, which have a bitter taste. Usually, cultivated zucchini has a low level of the toxin, but the level rises when they are overripe or stressed by such things as wide temperature swings, uneven watering, low soil fertility, or low soil pH.

If you’re saving your own seeds, be sure not to save seeds from plants that produced extremely bitter fruit that wasn’t caused by environmental stress, since eating vegetables that are extremely bitter can lead to diarrhea and stomach cramps.

Zucchini Nutrition

In an interview with Everyday Health,[3] Kristin Gillespie, a registered dietitian from Virginia Beach, explained that zucchini is rich in antioxidants and micronutrients, saying, “These benefits include reduced blood sugar levels, improved heart health, improved vision, enhanced weight loss, improved bone health, reduced inflammation, and improved digestion.”

According to the USDA, 1 cup of chopped zucchini is low in calories, high in fiber, and is an excellent source of these nutrients:[4]

Energy 21.1 kcal 
Protein 1.5 grams (g)
Total fat 0.397 g
Total fiber 1.24 g
Sugar 3.1 grams
Calcium  19.8 milligrams (mg)
Iron 0.459 mg
Magnesium 22.3 mg
Phosphorus  47.2 mg 
Potassium 324 mg
Zinc 0.397 mg 
Vitamin C 22.2 mg
Folate 29.8 micrograms (μg)
Choline  11.8 mg
Vitamin A 12.4 μg
Carotene  149 μg
Lutein and Zeaxanthin 2630 μg
Vitamin K 5.33 μg

Zucchini May Help With Weight, Blood Sugar

Because zucchini is high in water and fiber, it may fit well into your weight-loss plan. The water and fiber content help you feel full longer. However, it’s important to note that to make a difference in your weight-loss efforts, zucchini must replace empty calories from junk food or high-carbohydrate foods, as opposed to just adding zucchini to your current diet.

Zucchini noodles, also known as zoodles, are a unique and interesting way of replacing pasta in your diet if you’re seeking to eat gluten-free or low-carb.[5] Zoodles can be made with a julienne peeler for thick, flat slices of zucchini or with a spiralizer for curly zoodles. The zoodles can be sautéed, boiled, baked, or eaten raw.

By replacing pasta with zoodles, you can eat the same volume of food, get full, and feel full longer. This is important since eating foods rich in carbohydrates, such as pasta, can spike your blood sugar level and then cause it to drop within a couple of hours, leaving you feeling hungry all over again.[6]

Although fiber is a type of carbohydrate, it’s the type that your body can’t digest. Instead of being broken down into sugar molecules, it passes through your gut undigested. Another benefit to fiber is helping to regulate how your body uses sugar.

While I recommend that most adults get 50 grams of fiber for every 1,000 calories of food, the USDA’s recommendation for adults up to age 50 is only 25 grams (g) for women and 38 g for men. Women older than 50 should have 21 g and men, 38 g. Unfortunately, according to the Harvard T.H. Chan School of Public Health,[7] most Americans eat only about 15 g per day.

There are two types of fiber found in fruits and vegetables, and both are beneficial. Soluble fiber[8] dissolves in water and can help slow digestion. That also helps you to stay full longer. Soluble fiber can be found in nuts, seeds, avocados, Brussels sprouts, and apples. As soluble fiber dissolves with water, it turns into a gel.

Insoluble fiber adds bulk to the stool and encourages the food to pass more quickly through the digestive tract. While soluble fiber has demonstrated the ability to help to lower your glucose levels, insoluble fiber can help to prevent constipation. Both types of fiber are beneficial and necessary in your diet. Zucchini has nearly equal amounts of soluble and insoluble fiber.[9]

Take Care of Your Heart and Gut Health

Researchers have found a bidirectional association between your gut microbiome and your cardiovascular health. Scientific interest in gut health has revealed evidence that it plays an important role in cardiovascular diseases. Gut dysbiosis is linked to obesity, Type 2 diabetes, hypertension, atherosclerosis, and heart failure.[10]

In 2018, San Francisco State University released a study[11] in which they recruited 20 men and 17 women to test their cardiovascular fitness and their gut microbiome. An analysis of the bacterial composition revealed participants with the best fitness had a higher ratio of firmicutes to bacteroides.

Firmicutes bacteria are associated with a reduction in leaky gut. According to one of the researchers, this shows that exercise has a crucial impact on your gut microbiome and may lead to the creation of individualized “exercise prescriptions” to improve gut health.[12] An animal study[13] at Johns Hopkins University School of Medicine demonstrated that when food is eaten, gut bacteria produce chemicals that are absorbed and may activate receptors that lower blood pressure.

In other words, the relationship between your gut health and your cardiovascular health is complex and bidirectional. Zucchini can help contribute to a gut-friendly microbiome, since high-fiber foods help to improve gut health. By supporting regular bowel movements, it can help to reduce the symptoms of irritable bowel syndrome and relieve constipation.[14]

One animal study[15] specifically evaluated the effect that zucchini has on the prevention of cardiovascular disease. The rats receiving the intervention were fed a high-fat diet plus 10 percent zucchini, 15 percent zucchini, and 20 percent zucchini. The data showed that those getting 15 percent and 20 percent of their diet from zucchini had morphological changes in the heart, spleen, and kidney that demonstrated a preventive effect against cardiovascular disease.

The data also demonstrated that the animals lost weight after eight weeks of intervention on a high-fat diet plus zucchini. It also was found to increase HDL-C levels and lower triglycerides and LDL-C. They hypothesize that the cholesterol-lowering ability was likely related to the fiber found in zucchini.

While 15 percent to 20 percent may sound like a high percentage of zucchini in the diet, the beneficial effects may have been related to the fiber and nutrition found not only in zucchini, but in other vegetables.

Zucchini May Reduce Your Risk of Cancer

A research study looking at the effects of fruits and vegetables published in 1991 concluded that “major public health benefits could be achieved by substantially increasing consumption of these foods.”[16] Many other studies[17] [18][19] have demonstrated the powerful effect that fruits and vegetables have on cancer prevention.

A lab and animal study[20] published in 2020 in Scientific Reports analyzed the effects of cucurbitacin B and I against colon cancer cell growth. The study demonstrated that both inhibited tumor growth in the lab and in an animal study, which suggested that these compounds found in zucchini could inhibit colon cancer.

More research is necessary to determine if zucchini holds a key to preventing other types of cancer or reducing the overall risk of cancer outside the role it plays in the family of fruits and vegetables.

Grow Zucchini in Your Garden or Pots

When you care for it correctly, zucchini can grow in your garden or containers. In either case, you will want to use organic fertilizer to ensure a good harvest. You don’t have to purchase organic fertilizer at the store or rely on fertilizer from agrichemical businesses. You can use compost to provide a base for your garden and make a fertilizing liquid by soaking mashed comfrey leaves in water when your plants need an extra boost. (Filter out the leaves and just use the liquid.)

If you’re growing zucchini in a pot, make sure it has a diameter of at least 24 inches and a depth of 12 inches. The pot should have at least one good drainage hole at the bottom. You can even use a large plastic storage container when you drill drainage holes. Avoid using regular garden soil that can contain pests or weed seeds. Fill the container with lightweight, well-draining soil, and plant the zucchini after the last frost in your area.[21]

You can also start the plants indoors four to six weeks before the last frost. Plant two or three seeds about 1 inch into the soil with a couple of inches of space between each seed. As the seedlings become established, add mulch to maintain a stable ground temperature and retain water. Zucchini does well when they are planted on a raised mound. Two or three plants close together to allow the flowers to easily pollinate can provide you with a good crop.[22]

If you’re using containers, you can move the containers close to each other for pollination. Each flower opens for approximately one day. If it isn’t pollinated on that day, you don’t get zucchini. When plants are close to each other, you’ll have flowers opening consistently, which improves your chances of pollination.

Female flowers have a tiny fruit behind the base of the flower. You can manually pollinate by removing the male flowers and dusting pollen into the female flowers. Zucchini enjoy at least 2 inches of water a week. If there isn’t enough rainfall, you will need to supplement. If possible, water the plants below the leaves, which reduces the chance of powdery mildew.[23]

The plants grow quickly, so you may be harvesting 40 days after planting. The fruit also grows quickly, so check your plant every day for new zucchini. Harvest with a sharp knife or pruning shears. If you miss a zucchini, remove any overripe or large squash as soon as possible. This reduces the nutrient demand on the plant. Zucchini can be stored in the refrigerator unwashed, dry, and whole.

Multiple Ways to Include Zucchini in Menu Plan

There are multiple ways to enjoy zucchini in your menu plan. I like to dry zucchini chips in my dehydrator with seasonings. You can cut them to a thickness of your liking to enjoy as low-carb, crispy treats or with a meal.

Slice up your fresh zucchini in a salad, create zoodles topped with parmesan cheese with a meal or try these delicious crunchy fritters with avocado dill dip, courtesy of Healthy Holistic Living.[24] They’re an organic and healthy approach to fritters.

References

[1]

US Department of Agriculture, The Three Sisters of Indigenous American Agriculture

[2]

Nebraska Extension in Lancaster County, July 13, 2021

[3]

Everyday Health, July 22, 2022

[4]

U.S. Department of Agriculture, Squash, Summer, Zucchini, Includes Skin, Raw

[5]

Downshiftology, Dec. 30, 2019

[6]

South China Morning Post, June 1, 2021

[7]

Harvard TH Chan School of Public Health, Fiber

[8]

MedlinePlus, Soluble Versus Insoluble Fiber

[9]

Common Sense Health, Soluble Fiber and Insoluble Fiber Foods List Vegetable table

[10]

Circulation Research, 2017; 120(7)

[11]

Science Daily, July 11, 2018

[12]

Science Daily, July 11, 2018

[13]

Johns Hopkins Medicine, The Power of Gut Bacteria and Probiotics for Heart Health

[14]

Harvard TH Chan School of Public Health, Vegetables and Fruit, Gastrointestinal Health

[15]

Food and Nutrition Science, 2020; 11(2)

[16]

Nutrition and Cancer, 1991; doi.org/10.1080/01635589209514201

[17]

Journal of the American Dietetic Association, 1996;96(10)

[18]

Nutrition and Cancer, 2006; 54(1)

[19]

Journal of Clinical Oncology, 2009; 27(16)

[20]

Scientific Reports, 2020; 10(1290)

[21]

Gardening Know How, Zucchini Plant Care

[22]

The Spruce, Sept. 29, 2020, No. 2 Monitor Pollination

[23]

HGTV, May 25, 2021, Growing Zucchini

[24]

Healthy Holistic Living

 

Dr. Joseph Mercola is the founder of Mercola.com. An osteopathic physician, best-selling author, and recipient of multiple awards in the field of natural health, his primary vision is to change the modern health paradigm by providing people with a valuable resource to help them take control of their health.
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