How Other Kinds of Processing Affect This Food
Canning and freezing. Canned spinach, which is processed at high heat, is olive or bronze
rather than green. Like cooked spinach, canned spinach and frozen spinach have only 50
percent of the vitamin C in fresh spinach.
Medical Uses and/or Benefits
Reduced risk of cardiovascular disease, cancer, decline of brain function, and other diseases of
aging. Antioxidants prevent free radicals, fragments of molecules, from hooking up with
other fragments to produce compounds that damage body cells, thus lowering your risk of
heart disease, cancer, memory loss, and other conditions associated with aging or damaged
cells. In 1996, researchers at the USDA Jean Mayer Human Nutrition Research Center on
Aging at Tufts University (Boston) showed that, ounce for ounce, strawberries, blueberries,
and spinach were the most potentially potent antioxidants of 40 foods tested. While blue-
berries scored number one in the Tufts study, antioxidant ranking of these foods may vary
depending on growing conditions, season, and other variables.
Lower risk of some birth defects. As many as two of every 1,000 babies born in the United
States each year may have cleft palate or a neural tube (spinal cord) defect due to their moth-
er’s not having gotten adequate amounts of folate during pregnancy. The current RDA for
folate is 180 mcg for a woman and 200 mcg for a man, but the FDA now recommends 400 mcg
for a woman who is or may become pregnant. Taking folate supplements before becoming
pregnant and continuing through the first two months of pregnancy reduces the risk of cleft
palate; taking folate through the entire pregnancy reduces the risk of neural tube defects.
Possible lower risk of heart attack. In the spring of 1998, an analysis of data from the records
for more than 80,000 women enrolled in the long-running Nurses’ Health Study at Harvard
School of Public Health/Brigham and Women’s Hospital, in Boston, demonstrated that a diet
providing more than 400 mcg folate and 3 mg vitamin B 6 daily, either from food or supple-
ments, might reduce a woman’s risk of heart attack by almost 50 percent. Although men
were not included in the study, the results were assumed to apply to them as well.
However, data from a meta-analysis published in the Journal of the American Medical
Association in December 2006 called this theory into question. Researchers at Tulane Univer-
sity examined the results of 12 controlled studies in which 16,958 patients with preexisting
cardiovascular disease were given either folic acid supplements or placebos (“look-alike” pills
with no folic acid) for at least six months. The scientists, who found no reduction in the risk
of further heart disease or overall death rates among those taking folic acid, concluded that
further studies will be required to ascertain whether taking folic acid supplements reduces
the risk of cardiovascular disease.
Lower risk of stroke. Various nutrition studies have attested to the power of adequate
potassium to keep blood pressure within safe levels. For example, in the 1990s, data from
the long-running Harvard School of Public Health/Health Professionals Follow-Up Study of
male doctors showed that a diet rich in high-potassium foods such as bananas, oranges, and
Spinach