The Latest News About Summer Squash
Summer squashes belong to the Cucurbitaceae family of plants and are relatives of winter squashes (including pumpkins), melons (including watermelon), and even cucumbers. But summer squashes are typically much more delicate than their fellow Cucurbitaceae, and are more often eaten fresh and shortly after harvest. In the United States, you'll generally find three types of summer squash: zucchini; crookneck and straightneck squashes; and scallop squashes, which are also called pattypan squashes.
What's New and Beneficial About Summer Squash
- Although summer squash has long been recognized as an important food source of carotenoids, only recently have research studies documented just how fantastic summer squash can be when it comes to these key antioxidants. For some groups of study participants, summer squash turns out to be the primary food source of alpha-carotene and beta-carotene in the entire diet! For lutein, zeaxanthin, and beta-cryptoxanthin (three other health-supportive carotenoids) summer squash also comes out among the top three food sources in several studies.
- When we think about food and antioxidants, what first comes to mind might be fresh fruit and vitamin C, or bright orange carrots and beta-carotene. Yet several recent studies have underscored the unique contribution made by summer squash to our antioxidant requirements. While not as rich in some of the more widely-publicized antioxidants like beta-carotene, summer squash is a very strong source of other key antioxidant nutrients, including the carotenoids lutein and zeaxanthin. Since the skin of this food is particularly antioxidant-rich, it's worth leaving the skin intact and purchasing organic summer squash to help avoid potential unwanted contaminants.
- If you usually microwave or boil your summer squash, you'll be interested to know this: steaming is much better than either of these two methods in terms of nutrient retention. New evidence shows that summer squash can retain a large amount of its antioxidant activity after steaming. Using zucchini as their summer squash, researchers found that steaming was a better way to preserve zucchini's antioxidant activity than boiling or microwaving. Interestingly, even previously frozen zucchini held on to its antioxidant activity fairly well after steaming. These findings are great news for anyone enjoys steamed vegetables and who sometimes needs to freeze surplus vegetables for later use.
- We tend to think about squashes - both summer and winter - as starchy vegetables. This thinking is correct, since about 85-90% of the total calories in squashes (as a group) come from carbohydrate, and about half of this carbohydrate is starch-like in composition and composed of polysaccharides. But we also tend to think about polysaccharides as stagnant storage forms for starch that cannot do much for us in terms of unique health benefits. Here our thinking is way off target! Recent research has shown that the polysaccharides in summer squash include an unusual amount of pectin - a specially structured polysaccharide that often include special chains of D-galacturonic acid called homogalacturonan. It's this unique polysaccharide composition in summer squash that is being linked in repeated animal studies to protection against diabetes and better regulation of insulin. We expect to see future studies on humans confirming these same types of benefits from consumption of summer squash.
Of all of the cooking methods we tried when cooking summer squash, our favorite is Healthy Sauté. We think that it provides the greatest flavor and is also a method that allows for concentrated nutrient retention. To Healthy Sauté summer squash, heat 3 TBS of broth (vegetable or chicken) or water in a stainless steel skillet. Once bubbles begin to form add sliced squash, cover, and Healthy Sauté for 3 minutes (1-1/2 minutes on one side, and then 1-1/2 minutes on the other side) on medium heat. Transfer to a bowl and toss with our Mediterranean Dressing. (See our 3-Minute Healthy Sautéed Summer Squash recipe for details on how to prepare this dish.)
Summer squash provide numerous health benefits including:
- Antiloxidant benefits
- Blood sugar benefits
- Anti-inflammatory benefits
- Anti-microbial protection
- Prostate health support
For more details on summer squash's health benefits, see this section of our summer squash write-up.
While not often considered as a premiere food source of antioxidants, summer squash can provide you with unique amounts of antioxidant nutrients, including the carotenoids lutein and zeaxanthin. While summer squash contains very little overall fat (only 1/2 gram per cup), the fat in summer squash (mostly stored in its edible seeds) is unique in composition and includes omega-3s (in the form of alpha-linolenic acid), monounsaturates (in the form of oleic acid), and also medium chain fats (in the form of lauric and myristic acids). Summer squash is an excellent source of copper and manganese. It is a very good source of vitamin C, magnesium, dietary fiber, phosphorus, potassium, folate, vitamin B6, and vitamin K. Additionally, it is a good source of vitamin B1, zinc, omega-3 fatty acids, niacin, vitamin B2, pantothenic acid, calcium, iron, choline, and protein.
For more on this nutrient-rich food, including references related to this Latest News, see our write-up on summer squash.