No category of health benefits from summer squash is better researched than the category of antioxidant benefits. As an excellent source of manganese and a very good source of vitamin C. summer squash provides us with a great combination of conventional antioxidant nutrients. But it also contains an unusual amount of other antioxidant nutrients, including the carotenoids lutein and zexanthin. These antioxidants are especially helpful in antioxidant protection of the eye, including protection against age-related macular degeneration and cataracts. While we often think first about carrots as providing us with antioxidant-related eye health benefits, we also need to start including summer squash in our list of antioxidant-rich foods that can provide us with health benefits in this area.
If properly handled and prepared, summer squash also provides us with special antioxidant advantages in terms of its antioxidant stability. Recent research has confirmed strong retention of antioxidant activity in summer squash after steaming. Research has also confirmed excellent retention of antioxidant activity in summer squash after freezing. These findings mean that the antioxidant benefits of summer squash are available to us under a wide variety of circumstances. We have the option of enjoying raw summer squash, briefly steamed summer squash, and previously frozen summer squash while still coming away with well-documented antioxidant health benefits.
To obtain full antioxidant benefits from summer squash, we need to eat not only the flesh, but also the skin and the seeds. Many valuable antioxidant nutrients are found in those portions of the food, and studies document their importance in the overall antioxidant activity of summer squash. Purchasing organic summer squash is your best way to lower risk of potentially unwanted contaminants (like pesticides) on the skin of this vegetable. While purchasing organic, it's still worthwhile to use a natural bristle brush and gently cleanse the skin of the summer squash under cold running water.
The list of nutrients in summer squash related to healthy blood sugar regulation is a long one. Metabolism of sugar in the body requires ample presence of many B-complex vitamins, and most of these B-complex vitamins are found in valuable amounts in summer squash. Included here are the B-vitamins folate, B6, B1, B2, B3, and choline. Also important in blood sugar metabolism are the minerals zinc and magnesium, as well as omega-3 fatty acids, and all of these nutrients are provided by summer squash.
A mainstay of dietary protection from type 2 diabetes—as well as a key step in food support of diabetes problems—is optimal intake of fiber. Summer squash not only provides a very good amount of dietary fiber at 2.5 grams per cup, but it also provides polysaccharide fibers like pectin that have special benefits for blood sugar regulation. The pectin polysaccharides in summer squash often include chains of D-galacturonic acid called homogalacturonan. An increasing number of animal studies now show that these components in summer squash help keep insulin metabolism and blood sugar levels in balance, and protect against the onset of type 2 diabetes.
While lacking extensive research documentation, there are several other areas of health benefits from summer squash that are definitely worth noting and that may eventually have strong scientific back-up. The first of these areas involves inflammation-related conditions. The presence of omega-3 fats in the seeds of summer squash, the presence of anti-inflammatory carotenoids like lutein, zeaxanthin and beta-carotene, and the presence of anti-inflammatory polysaccharides like homogalacturonan make this vegetable a natural choice for protection against unwanted inflammation. Several preliminary animal studies show potential anti-inflammatory protection from summer squash for the cardiovascular system and also for the GI tract. (Two special areas of digestive tract interest involve anti-inflammatory protection against gastric ulcer and duodenal ulcer.) Insofar as chronic, unwanted inflammation is also a risk factor for development of type 2 diabetes, the anti-inflammatory benefits of summer squash may play an important role in its protection against type 2 diabetes as well.
The seeds of summer squash and oils extracted from its seeds have a long history of use in botanical and folk medicine in two areas. The first area involves the anti-microbial properties of summer squash seeds, and especially their anti-parasitic properties. Interestingly, dried summer squash seeds are still used in some parts of the world for treatment of intestinal tapeworms or other intestinal parasites. We have not seen peer-reviewed studies focusing on the antimicrobial benefits of summer squash seeds, but from our perspective, these benefits are unlikely to come from a food approach to summer squash that includes this vegetable in modest amounts as part of a healthy, whole foods diet. Far more likely these benefits will come from a medicinal approach to summer squash that involves consumption of its dried seeds in non-food amounts or extract of oils from those seeds.
The second area of folk medicine use involves non-cancerous enlargement of the prostate gland known as benign prostatic hyperplasia, or BPH. Seeds of summer squash (and oils from those seeds) have traditionally been used to help lower frequency of urination that is commonly experienced in men diagnosed with BPH. Like the area of anti-microbial benefits, we have not seen peer-reviewed studies focusing on summer squash seeds and their potential benefits in lessening frequency of urination in BPH. But from our perspective, these benefits are also unlikely to come from a food approach to summer squash that includes this vegetable in modest amounts as part of a healthy, whole foods diet. Far more likely these benefits will come from a medicinal approach to summer squash that involves consumption of its dried seeds in non-food amounts or from seed oil extracts.
The combination of antioxidant and anti-inflammatory nutrients in summer squash is a very logical nutrient combination for providing anti-cancer benefits. The development of many cancer types depends on chronic, unwanted oxidative stress that can occur along with poor intake of antioxidant nutrients, and chronic, unwanted inflammation that can occur along with lack of anti-inflammatory nutrients. While we eventually expect to see well-documented anti-cancer benefits from summer squash in large-scale human studies, the anti-cancer research on summer squash is still in a preliminary stage. *As noted in the world’s healthiest foods.