Acorn squash also called the winter squash, is a species of the Cucurbita family which also includes pumpkins and zucchini. This vegetable reportedly helps prevent spikes in blood sugar and even cancer. The folic acid in acorn squash (and kidney beans and black eyed beans as well) combined with vitamin B12 helps prevent nerve damage and brain shrinkage. According to the National Center for Biotechnology Information, folic acid plays an important part in the development of fetus spinal cord and brain. Deficiency of folic acid can cause birth defects of the brain and spinal cord.