What’s New and Beneficial About Spinach

Recent studies continue to underscore the amazing versatility of spinach. Because this leafy vegetable is rich in water-soluble vitamins, fat-soluble vitamins, minerals, and a wide variety of phytonutrients, there are many different ways to incorporate spinach into your meal plan and enjoy a variety of nutritional benefits. For example, we’ve seen a recent study in which the sautéing of spinach was best able to retain its total carotenoid content (in comparison with steaming or boiling or frying). Alternatively, we’ve seen an equally recent study showing far less loss of vitamin C from spinach when this vegetable was steamed for 5 minutes (instead of being microwaved or boiled for that same amount of time). Yet numerous studies also point to the nutrient benefits of raw spinach. For example, about 25% of the folate in spinach can be lost from cooking, and spinach can be thought of as a special nutritional contributor in terms of folate, since it ranks as our Number 3 source of this nutrient at WHFoods. So as you can see, there are important nutritional benefits to be had from many different ways of incorporating spinach into your meal plan. In our 7-Day Meal Plan, for example, we include spinach in its raw form in smoothies, and we also have recipes in which we boil and sauté this amazing vegetable.
New research is underway involving the nitrate content of spinach. You’ve probably heard about nitrate (and nitrite) in the context of food additives, since both of these nitrogen-containing substances have often been used as preservatives for bacon and deli meats. However, when nitrate is used as a food additive, it is usually in a concentrated (10 or more milligrams per 8 ounces) when compared with its naturally-occurring amount in certain foods. For example, even though spinach is a rich source of nitrate, its nitrate content usually totals far less than 1 milligram per 8 ounces. And at this lower, naturally-occurring level, the nitrate in spinach may actually provide us with health benefits. For example, bacteria in our saliva and in our lower intestine can convert nitrate (NO3) into nitrite (NO2) and nitrite into nitric oxide (NO), and this nitric oxide might in turn help to protect proper function of the intestinal lining. While we do not have definitive studies about this potential role of nitrate in spinach, this area of research is one of active interest.
Chlorophyll is the pigment that gives spinach its renowned green color. Inside the cells of the spinach plant, the places where chlorophyll gets stored are called chloroplasts, and their membranes play an active role in converting sunlight into energy (through a process called photosynthesis). These chloroplast-associated membranes are called thylakoid membranes, or simply thylakoids. Because fresh spinach is such a rich source of chlorophyll (and actually our Number 1 source of chlorophyll at WHFoods, containing about 24 milligrams of chlorophyll per cup), it has often been used in research studies as a source for thylakoids and their potential health benefits. Several recent studies in this area have shown thylakoid-rich extracts from spinach to delay stomach emptying, decrease levels of hunger-related hormones like ghrelin, and increase levels of satiety-related hormones like glucagon-like peptide 1 (GLP-1). Exactly what these changes mean is not yet clear, but researchers hope to eventually determine whether routine intake of spinach can help lower risk of obesity partly because of these thylakoid-related processes. It is also worth noting in this context that several prescription drugs currently used to help treat type 2 diabetes (for example, albiglutide, exanatide, dulaglutide, and liraglutide) work by imitating the activity of GLP-1. For this reason, future studies may find a relationship not only between risk of obesity and spinach intake but risk of type 2 diabetes as well.
It is important to underscore the amazing versatility of spinach! Consider these results from our WHFoods rating system: spinach ranks as our Number 1 source of magnesium and iron (both minerals); our Number 2 source of vitamins B2 and B6 (both water-soluble vitamins), our Number 3 source of folate (another water-soluble vitamin), and our Number 2 source of vitamin K (a fat-soluble vitamin). Spinach is also our Number 2 source of vitamin E, our Number 3 source of calcium, potassium, and vitamin A, our Number 5 source of manganese, and our Number 8 source of copper.