Pumpkins are part of the winter squash group. Also included in the group are acorn, butternut, and spaghetti squash. Winter squash, like other richly colored vegetables, provide excellent sources of carotenes. Generally, the richer the color, the richer the concentration. They also offer a very good source of vitamins B1 and C, folic acid, pantothenic acid, fiber, and potassium. Winter squash is also a good source of vitamin B6 and Niacin.
Studies have shown that, due to their carotene properties, winter squash exert a protective effect against many cancers (particularly lung cancer). Diets that are rich in carotenes (especially pumpkins) offer protection against cancer, heart disease, and type 2 diabetes. Studies have also shown that pumpkin seeds are helpful in reducing symptoms of benign prostatic hyperplasia (BPH).
Since summer squash have a high water content, they are not as nutrient-dense as the winter varieties. Summer squash still provide several nutritional benefits. They are low in calories and provide a decent amount of vitamin C, potassium, and carotenes.
Studies have shown that juice made from summer squash is equal to juice made from pumpkins, leeks, and radishes in their ability to prevent cell mutations. Summer squash are especially beneficial during the summer months due to their higher water content. They protect against dehydration and the carotenes help to protect against the damaging effects of the sun.