Spinach

Health Benefits

Outstanding Broad-Based Nourishment

                         Spinach is already widely-enjoyed as a food, and its commonplace appearance in salad bars as well as many different types of cuisine may lead us to forget just how impressive this leafy is in terms of nourishment. It's also worth noting in this context that spinach also serves as a very good source of 6 additional nutrients, including fiber, phosphorus, vitamin B1, zinc, protein, and choline, and as a good source of omega-3 fatty acids, vitamin B3, pantothenic acid, and selenium.

Anti-Inflammatory Support

                            In research studies on spinach, it is not difficult to trace an ongoing interest in the anti-inflammatory benefits of this green leafy vegetable, especially with respect to events inside our digestive tract. We suspect that much of this interest is due to the multi-faceted nature of spinach in terms of anti-inflammatory nutrients. In the phytonutrient category, spinach flavonoids are important in this regard, since spinach is known to contain a glucuronide and glucopyranonside forms of the flavonoids spinacetin, patuletin, and jaceidin. Also well-studied in spinach are a subgroup of flavonoids known as methylenedioxyflavones. All of the flavonoids listed above have been shown to have anti-inflammatory properties, and some have been investigated for their ability to decrease cancer risk as well.



               Carotenoids are a second category of anti-inflammatory phytonutrients that you will find in plentiful supply from spinach. Spinach is our Number 2 source of the carotenoids lutein and zeaxanthin at Worldwide veg Foods. It is also a rich source of neoxanthin and violaxanthin. These carotenoids fall into the subdivision of carotenoids known as epoxyxanthophylls. Like all of the flavonoids listed earlier, each of these carotenoids has been shown to provide us with anti-inflammatory benefits.

  
              As mentioned earlier, improved control of inflammation—especially within the digestive tract—has been linked to the unusual nitrate content of spinach, and the role of digestive tract bacteria in converting nitrate into nitric oxide.



                         Spinach is by no means a high-fat food, but it does contain omega-3 fatty acids as well as diacylglycerols (which are molecules that contain fatty acids within them). Omega-3s play a critical role in regulation of inflammation throughout our body, since many anti-inflammatory messaging molecules are made directly from omega-3s. Spinach is a good source of the omega-3 fatty acid known as alpha-linolenic acid (ALA), and its diacylglycerols can also contain stearidonic acid (SDA) and eicosapentaenoic acid (EPA) —two additional omega-3s. Of these three omega-3s, however, ALA appears to be the most consistently present and is present in the most readily measurable amounts. By contrast, in some nutrient databases, you will not find either SDA or EPA listed as components of spinach, with only ALA showing a measurable amount. From our perspective, however, the varying amounts of these different omega-3 fatty acids is less important than their very presence in spinach which many people would not expect to be a source of any omega-3 fats. When all of these different nutrient groups are combined together—flavonoids, carotenoids, nitrates, and omega-3s—what emerges is a vegetable profile with broad-based anti-inflammatory benefits.

Other Health Benefits

                             As mentioned earlier in this profile, studies on the chlorophyll and thylakoid content of spinach have raised interesting possibilities for this food as one that can help regulate hunger, satiety, and also blood sugar levels. Since spinach serves as Number 1 source of chlorophyll with about 24 milligrams per cup. The hunger and satiety research on spinach involves the ability of 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). The blood sugar research is an offshoot of this GLP-1 research, since prescription drugs that mimic the activity of GLP-1 (called GLP-1 agonists) are currently used to help treat type 2 diabetes. While it would not be accurate to equate routine intake of fresh spinach with use of a prescription drug or with the use of a food extract (like a thylakoid extract), it would also be wrong to ignore the potential connections here between the nutrient composition of spinach and our experience of hunger and satiety, as well as our body's blood sugar regulation. Future studies should help us piece together the exact nature of these relationships.



                        Excessive inflammation, of course, typically emerges as a risk factor for increased cancer risk. (That's why many anti-inflammatory nutrients can also be shown to have anti-cancer properties.) But even when unrelated to cancer, excessive inflammation has been shown to be less likely following consumption of spinach. Particularly in the digestive tract, reduced inflammation has been associated not only with the flavonoids found in spinach, but also with its carotenoids. Neoxanthin and violaxanthin are two anti-inflammatory epoxyxanthophylls that are found in plentiful amounts in the leaves of spinach. While these unique carotenoids may not be as readily absorbed as carotenoids like beta-carotene or lutein, they still play an important role in regulation of inflammation and are present in unusual amounts in spinach.

Description

                          While clearly visible as a green leafy vegetable, spinach actually falls into a different food family than many other well-known green leafy vegetables. In the cruciferous vegetable family you will find collard greens, kale, mustard and turnip greens, bok choy and arugula. Spinach, however, is not a cruciferous vegetable but belongs to a food family known as the chenopod or amaranth family. (The science names here are Chenopodiaceae and Amaranthaceae.) Among other green leafy vegetables in this chenopod group, beet greens and Swiss chard are perhaps the best-known (and of course beets themselves are also members of this food family). Yet foods in the chenopod family also extend outside of the vegetable group. The grains amaranth and quinoa are also members of this same food family that contains spinach and Swiss chard.



                   The genus/species name for spinach is Spinacia oleracea, and within this genus/species can be found many different varieties of spinach. Most popular descriptions of spinach varieties include three groups: savoy, semi-savoy, and flat-leafed. Savoy varieties of spinach typically feature leaves that are more curly and crinkly, and "springy" to the touch. Flat-leafed varieties are much more flat just like their name suggests, as well as smoother and often more broad. Some of the flat-leafed varieties of spinach are quite famous for their spade-shaped leaves. Semi-savoy varieties fall somewhere in the middle of this curly versus flat spectrum. Some people consider the flat-leafed varieties of spinach as easier to clean, but we have not found spinach cleaning to be difficult in the case of any varieties. It's worth noting here that you will often hear flat-leafed spinach also being referred to as smooth-leafed spinach.



                        Alongside of these distinctions between savoy, semi-savoy and flat-leafed, you will also hear spinach varieties being referred to by color. For example, purple passion spinach and red mountain spinach are terms that you might hear in this context. While these varieties still belong to the chenopod family of foods, but they do not belong to the same genus/species of spinach as has been included at WHFoods (Spinacia oleraceae. Purple passion spinach and red mountain spinach actually belong to the genus/species Atriplex hortensis and are often described as being members of the orach subgroup within the chenopod family.



                                      You may also hear spinach being referred to as Malabar or New Zealand spinach. In this case, we have left the chenopod family entirely, and we have shifted over into a different family of foods known as the Basellaceaefamily. While the leaves of Malabar/New Zealand spinach may appear similar to the spinach leaves that we are familiar with in the supermarket, these leaves actually grown on a vine and they have their own unique nutrient composition.


                   In general, spinach is a cool season crop and sensitive to excessive heat. It is also fairly fast-growing. Given its fast growth rage and susceptibility to heat, spinach can quickly form flowers and seeds and put more energy into this flower/seed development than into leaf growth. The emergence of flowering and seed development in plants is called bolting. Because spinach can be quick to bolt (thus producing fewer large-sized leaves), spinach growers often talk about spinach varieties as either "slow-bolting" or "fast-bolting." Slow-bolting spinach is more heat resistant and thus slower to form flowers/seeds. Slow-bolting is not necessary the same as highly productive, however, and growers often look for trade-offs between rate of bolting and rate of growth/leaf formation.
                      

                                   Some popular varieties of savoy spinach include Bloomsdale, Harmony, and Avon. Popular flat-leafed varieties include Red Kitten, Corvair, Bordeaux, and Space. Semi-savoy varieties include Indian Summer, Tyee, and Melody.

History

                         Spinach is generally regarded as being native to the Middle East, and appears to have been cultivated there for well over a thousand years. Trading between the Middle East and Asia is believed to have been responsible for the migration of spinach to several Asian countries, and today there are few places in the world where spinach is not found as a cultivated food.



                     Within the United States, the average adult consumed 3.9 pounds of spinach in 2017, and California served as the largest spinach-producing state with about 45,000 harvested acres. Arizona, New Jersey, and Texas combined with California to account for 98% of all commercially grown spinach in the U.S.
On a global level, China currently produces the greatest amount of commercially grown spinach, with the United States, Japan, and Turkey also falling into the Top 10 countries for spinach production.

How to Select and Store

                        Choose spinach that has vibrant deep green leaves and stems with no signs of yellowing. The leaves should look fresh and tender, and not be wilted or bruised. Avoid those that have a slimy coating as this is an indication of decay.



                              We encourage the purchase of certified organically grown foods, and spinach no exception. Repeated research studies on organic foods as a group show that your likelihood of exposure to contaminants such as pesticides and heavy metals can be greatly reduced through the purchased of certified organic foods, including spinach. In many cases, you may be able to find a local organic grower who sells spinach but has not applied for formal organic certification either through the U.S. Department of Agriculture (USDA) or through a state agency. (Examples of states offering state-certified organic foods include California, New York, Oregon, Vermont, and Washington.) However, if you are shopping in a large supermarket, your most reliable source of organically grown spinach is very likely to be spinach that displays the USDA organic logo.



                  Do not wash spinach before storing as the exposure to water encourages spoilage. Place spinach in a plastic storage bag and wrap the bag tightly around the spinach, squeezing out as much of the air as possible. Place in refrigerator where it will keep fresh for up to 5 days.



                              Here is some background on why we recommend refrigerating spinach. Whenever food is stored, four basic factors affect its nutrient composition: exposure to air, exposure to light, exposure to heat, and length of time in storage. Vitamin C, vitamin B6, and carotenoids are good examples of nutrients highly susceptible to heat, and for this reason, their loss from food is very likely to be slowed down through refrigeration.

Avoid storing cooked spinach as it will not keep very well.

Individual Concerns

Oxalate Content

                    Spinach has consistently been determined to have high oxalate content. Oxalates are naturally occurring organic acids found in a wide variety of foods, and in the case of certain medical conditions, they must be greatly restricted in a meal plan to prevent over-accumulation inside the body.

Nutritional Profile

                        Spinach is an excellent source of vitamin K, vitamin A (in the form of carotenoids), manganese, folate, magnesium, iron, copper, vitamin B2, vitamin B6, vitamin E, calcium, potassium and vitamin C. It is a very good source of dietary fiber, phosphorus, vitamin B1, zinc, protein and choline. Additionally, spinach is a good source of omega-3 fatty acids, niacin, pantothenic acid and selenium. In addition to the nutrient richness of spinach in terms of these conventional nutrients, spinach also provides the carotenoids lutein, neoxanthin, and violaxanthin; the flavonoids spinacetin, patuletin, and jaceidin; and naturally-occurring nitrates.

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 Worldwide veg Foods. So as you can see, there are important nutritional benefits to be had from many different ways of incorporating spinach into your meal plan.

•  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 Worldwide veg food 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.

Recommendations

                            The many different types of green vegetables available to provide you with exceptional nourishment are nothing short of astonishing! Not only can you choose from dark green leafy vegetables from the cruciferous group (for example, mustard greens, turnip greens, kale, or collards), but also from the leguminous vegetable group (like green beans or green peas), the squash/gourd group (including zucchini and cucumber) the parsley/umbelliferous group (like fennel and celery), green allium vegetables like leeks, green lettuces like romaine, and finally, of course the chenopod/amaranth group that includes spinach as well as beet greens. Rather than relying exclusively on any one of these green vegetable subgroups, we recommend that you consider including green vegetables across all of these subgroups when putting together your weekly meal plan.