Winter squashes provide good source of fiber and vitamin C

Q. Do the various kinds of winter squash differ in nutrients or recommended preparation?

A. Winter squash come in many sizes and shapes, but nutrient content probably varies as much within any given variety as between varieties. Almost all winter squash is an all-star source of beta-carotene and its antioxidant carotenoid "cousins." It's also a good source of vitamin C, potassium and dietary fiber, all with about 75 calories in a cup of cooked squash cubes.

Spaghetti squash, however, is a little lower in calories, fiber and the nutrients noted above. Its preparation is unique, too, since after cooking it can be pulled out with a fork to form strands similar to spaghetti. It's often served like pasta.

The other squash each have a slightly distinctive flavor and texture, but all make savory additions to soups, stir-fries, stews, curries and mixed oven-roasted vegetables. On their own, they can be baked, steamed or microwaved to serve stuffed, in chunks or pureed, often accompanied with sweet spices (cinnamon, ginger), fruits (such as apples or cranberries) or nuts.

Acorn squash are small with a very hard rind, so they are often best cut in half and baked without peeling. Butternut squash is sweet and moist with a slight nutty flavor, and the skin is easy to peel, so they are great when you want chunks to roast or add to stews. Buttercup squash has a delicious sweet flavor, but because it can be a bit dry, use it especially in moist dishes so you won't feel the need to drown it in butter.

Don't be afraid of delicious large squash like Hubbard, because amounts beyond what you can use at one time can be frozen, either in raw slices or (ideally) after cooking, in cubes or pureed.

Q. Are frozen berries as high in antioxidant phytochemicals as fresh ones?

A. Frozen berries are generally somewhat lower than their fresh counterparts in the antioxidant compounds called flavonoids, but they are still good sources. USDA data shows vitamin C content also modestly lower in frozen compared to fresh berries, yet raspberries and strawberries in both forms are extremely high in this nutrient.

Research providing direct comparisons of the overall antioxidant power of fresh versus frozen berries is quite limited. When fresh berries are not readily available, frozen options are an excellent choice, especially since the fresh berries in the research comparisons probably do not reflect values found in out-of-season berries transported long distances.

Q. Are CoQ10 supplements recommended for cancer patients?

A. Coenzyme Q10 (CoQ10, also known as ubiquinone) is a naturally occurring antioxidant supplied mainly by production within our bodies, but also found in trace amounts in meat, poultry, fish, and some oils and nuts. Supplements are often promoted as a way to prevent heart disease and cancer, but research-established benefits are not nearly as clear as some claims suggest.

Certain highly effective chemotherapy medications face limited use because of heart-damaging effects. Some researchers suggest that CoQ10 supplements could help prevent this damage and allow more effective treatment doses, but studies show inconsistent results. Other studies, which used the supplements along with tamoxifen in breast cancer treatment, demonstrated increased signs of DNA repair enzymes and decreased signs of cancer cells spreading throughout the body.

However, larger clinical trials to test these possibilities are needed; some animal research suggests boosting CoQ10 antioxidant levels could work against chemotherapy and radiation therapy. CoQ10 could also work against blood thinner medications like warfarin. On the other hand, statin medications that lower blood cholesterol may decrease body production of CoQ10, so doctors may advise supplements for some people.

Bottom line: We need more research, and anyone considering CoQ10 supplements should discuss benefits and risks carefully with their doctor.

• Provided by the American Institute for Cancer Research. Learn more about the group and its New American Plate program at aicr.org.