Spinach can reduce the risk of skin and breast cancer. In 1997 study, decreased breast cancer risk from regular spinach intake was noted. (Cancer Epidemiol Biomarkers Prev. 1997 Nov;6(11):887-92.) This study believed that the beta-carotene found in spinach was the reason. Spinach contains multiple factors that are chemoprotective against breast cancer and other cancers.
Animal studies presented to the Federation of American Societies for Experimental Biology 1999 annual meeting have shown that lutein also plays a preventative role and also slows the growth of existing mammary gland tumors. If these results are equally representative of human subjects, spinach may serve as a valuable preventative and suppressor of mammary tumors and breast cancer. The study concluded that lutein normalises immune response (commonly compromised in tumor & cancer patients), enabling the immune system to better fight the tumors.
Spinach also reduces the risk of skin cancer. Science is currently aware of thirteen nutrients that improve the Sun Protection Factor (SPF) of human skin. Of these, ten are found in spinach.
A 2001 study published in the Proceedings of the National Academy of Sciences shows that chlorophyllin, a derivative of chlorophyll that is abundant in spinach, greatly reduces the risk of aflatoxin related liver cancer. Aflatoxin is a fungus commonly found in grains, soybeans and peanuts and is a known carcinogen that damages human DNA. Ongoing research is seeking to ascertain whether chlorophyllin may also be protective against colon cancer and smoking-related lung cancer.
Chlorophyllin aside, spinach is already protective against colon cancer due to its high antioxidant carotenoid levels, specifically of lutein and zeaxanthin. (Am J Clin Nutr 2000;71:575-82)
Spinach has also been proven to reduce the risk of stomach cancer. (International Journal of Epidemiology, 2001)
Other studies attribute lutein and zeaxanthin found in spinach to the reduced risk of ovarian cancer. (Cancer Causes and Control, 2001)
In 2004, research was published by The University of Texas M. D. Anderson Cancer Center shows that spinach is protective against bladder cancer. High dietary intake of the alpha-tocopherol form of Vitamin E found in spinach was associated with a 42 percent reduced risk of bladder cancer in their five year study. Another form of Vitamin E also abundant in spinach, gamma-tocopherol, serves to reduce the risk of prostate.
In regards to human cancer generally, a 2005 Japanese study looked at the fruits and vegetables most commonly claimed to have cancer protection benefits. It studied human cancer cells under laboratory conditions and concluded that spinach was the most cancer protective of all. In additon to a preventative role, spinach had the strongest inhibitory effect on human cancer cell proliferation. (The Journal of Nutritional Biochemistry Volume 16, Issue 10, October 2005, Pages 594-601.)
One new category of health-supportive nutrients found in spinach is called “glycoglycerolipids.” Glycoclycerolipids are the main fat-related molecules in the membranes of light-sensitive organs in most plants. They’re indispensable for the process of photosynthesis carried out by plants. However, recent lab research in laboratory animals has shown that glycoglycerolipids from spinach can help protect the lining of the digestive tract from damage-especially damage related to unwanted inflammation. You can expect to see more studies about this exciting new category of molecules in spinach and its potential health benefits.
In a recent study on the relationship between risk of prostate cancer and vegetable intake-including the vegetables spinach, broccoli, cauliflower, cabbage, Brussels sprouts, mustard greens, turnip greens, collards, and kale-only spinach showed evidence of significant protection against the occurrence of aggressive prostate cancer. (“Aggressive prostate cancer” was defined as stage III or IV prostate cancer with a Gleason score of at least 7. Gleason scores are based on lab studies of prostate tissue and common tumor-related patterns.) The study authors did not speculate about specific substances in spinach that may have been involved in decreased prostate cancer risk. However, we know that certain unique anti-cancer carotenoids-called epoxyxanthophylls-are plentiful in spinach, even though they may not be as effectively absorbed as other carotenoids like beta-carotene and lutein. You can count on seeing future research on neoxanthin and violaxanthin-two anti-cancer epoxyxanthophylls that are found in plentiful amounts in the leaves of spinach.
Spinach Recommended for Breast Cancer in Moderation
Spinach components have been shown to inhibit growth and proliferation of cervical cancer cells in the laboratory and carcinogen-induced colon cancer in mice. Dietary intake of spinach has been found to be associated with lower risks of head and neck, lung, gallbladder, stomach, liver, bladder, prostate and ovarian cancer in population studies.
Carotenoids and glycolipids isolated from spinach have been demonstrated to cause dose-dependent growth inhibition in breast cancer cells. Several population studies have found that spinach consumption is associated with lower risk of breast cancer. Spinach consumption may help counteract the cancer-promoting effects of the heme iron in red meat.
Baby spinach has higher flavonoid concentration than mature spinach. Red spinach (Amaranthus gangeticus) is a plant used in South Asian cooking that is closely related to common spinach. Based on the few studies that have been performed, red spinach appears to have anti-cancer activities similar to that of common spinach.
Spinach contains oxalic acid and purines; intake of spinach has been shown to increase the risk of kidney stone and gallstone formation, as well as gout. Individuals prone to stones or gout may want to limit or avoid spinach. Oxalates interfere with calcium absorption, and therefore spinach should not be eaten at the same time as calcium-rich foods by breast cancer patients and others to whom calcium levels are important. Boiling reduces the oxalic acid content of spinach and increases iron availability.
Spinach can interfere with Warfarin (coumadin) and other blood-thinning therapy.
Spinach Nutritional Profile
Spinach is an excellent source of bone-healthy vitamin K, magnesium, manganese, and calcium; heart-healthy folate, potassium, and vitamin B6; energy-producing iron and vitamin B2; and free radical-scavenging vitamin A (through its concentration of beta-carotene) and vitamin C.
It is a very good source of digestion-supportive dietary fiber, muscle-building protein, energy-producing phosphorus, and the antioxidants copper, zinc and vitamin E.
In addition, it is a good source of anti-inflammatory omega-3 fatty acids, and heart-healthy niacin and selenium. While this mixture of conventional nutrients gives spinach a unique status in the antioxidant and anti-inflammatory department, it is the unusual mixture of phytonutrients in spinach that “seals the deal” in terms of its antioxidant and anti-inflammatory components.
In terms of flavonoids, spinach is a unique source of methylenedioxyflavonol glucuronides, and in terms of carotenoids, its difficult to find a more helpful source of lutein and zeaxanthin. The epoxyxanthophyll carotenoids neoxanthin and violaxanthin are also welcomed constituents of spinach leaves.
Spinach Health Benefits
Spinach Phytonutrients Anti-Inflammatory & Anti-Cancer
Even though virtually all vegetables contain a wide variety of phytonutrients- including flavonoids and carotenoids-spinach can claim a special place among vegetables in terms of its phytonutrient content. Researchers have identified more than a dozen different flavonoid compounds in spinach that function as anti-inflammatory and anti-cancer agents. (Some of these substances fall into a technical category of flavonoids known as methylenedioxyflavonol glucuronides.) The anticancer properties of these spinach flavonoids have been sufficiently impressive to prompt researchers to create specialized spinach extracts that could be used in controlled laboratory studies. These spinach extracts have been shown to slow down cell division in human stomach cancer cells (gastric adenocarcinomas), and in studies on laboratory animals, to reduce skin cancers (skin papillomas). A study on adult women living in New England in the late 1980s also showed intake of spinach to be inversely related to incidence of breast cancer.
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.
Decreased risk of aggressive prostate cancer is one health benefit of spinach consumption that should not be overlooked when talking about the anti-cancer properties of spinach. “Aggressive prostate cancer” is defined as stage III or IV prostate cancer which carries with it a Gleason score of at least 7. (Gleason scores are prostate cancer rating measurements that require lab studies of prostate tissue and evaluation of common tumor-related patterns.) Interestingly, in a recent study that evaluated possible prostate cancer-prevention benefits from a variety of vegetables including spinach, broccoli, cauliflower, cabbage, Brussels sprouts, mustard and turnip greens, collards, and kale – only spinach showed evidence of significant protection against the occurrence of aggressive prostate cancer.
Two of the carotenoids that are especially plentiful in spinach-lutein and zeaxanthin-are primary antioxidants in several regions of the eye, including the retina and the macula. Although we haven’t seen specific studies on spinach intake and prevention of eye-related problems like macular degeneration, we have seen studies showing that human blood levels of lutein can be increased by consumption of spinach in everyday amounts. We’ve also seen at least one group of researchers suggesting that spinach has a likely role to play in prevention of eye problems, including age-related macular degeneration.
Spinach Helping You Bone Up
The vitamin K provided by spinach-almost 200% of the Daily Value in one cup of fresh spinach leaves and over 1000% of the Daily Value in one cup of boiled spinach (which contains about 6 times as much spinach)-is important for maintaining bone health. Vitamin K1 helps prevent excessive activation of osteoclasts, the cells that break down bone. Additionally, friendly bacteria in our intestines convert vitamin K1 into vitamin K2, which activates osteocalcin, the major non-collagen protein in bone. Osteocalcin anchors calcium molecules inside of the bone. All of these vitamin K-related mechanisms point to the importance of vitamin K-rich foods for bone health, and it is difficult to find vegetables that are richer in vitamin K than spinach. (On our World’s Healthiest Foods list, only kale provides more micrograms of vitamin K per cup.) Spinach is also an excellent source of other bone-supportive nutrients including calcium and magnesium.
Spinach Selection & Storage
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.
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.
Avoid storing cooked spinach as it will not keep very well.
Spinach Preparation
Spinach should be washed very well since the leaves and stems tend to collect sand and soil. Before washing, trim off the roots and separate the leaves. Place the spinach in a large bowl of tepid water and swish the leaves around with your hands as this will allow any dirt to become dislodged. Remove the leaves from the water, empty the bowl, refill with clean water and repeat this process until no dirt remains in the water (usually two to three times will do the trick). Do not leave spinach soaking in the water as water-soluble nutrients will leach into the water.
Spinach sold in bags has been pre-washed and only needs to be rinsed. If you are going to use it in a salad, dry it using a salad spinner or by shaking it in a colander.
Non-organic spinach must be washed very thoroughly to remove pesticide residue as much as possible.
The Healthiest Way of Cooking Spinach
Spinach is only one of three vegetables we recommend boiling to free up acids and allow them to leach into the boiling water; this brings out a sweeter taste from the spinach. Discard the boiling water after cooking; do not drink it or use it for stock because of its acid content.
Use a large pot (3 quart) with lots of water and bring to a rapid boil. Add spinach to the boiling water and boil for 1 minute. Begin timing as soon as you place the spinach in the pot if you are using 1 pound or less of spinach. If you are cooking larger quantities of spinach bring the water back to a boil before beginning timing the 1 minute. Do not cover the pot when cooking spinach. Leaving the pot uncovered helps to release more of the acids with the rising steam. Research has shown that the boiling of spinach in large amounts of water helps decrease the oxalic acid content by as much as 50%.
Remove spinach from pot, press out liquid with a fork, place in a bowl, toss with our Mediterranean Dressing, and top with your favorite optional ingredients.
Spinach Juice
Spinach juice is the most powerful way to use spinach as part of a cancer treatment. Spinach is best juiced with other vegetables such as carrot, beet root and lemon or apple. In post-treatment, adding spinach to a salad is both tasty and healthy.
Spinach Research Links
One form of vitamin E appears beneficial in reducing bladder cancer risk.
http://www.spinachwords.com/research/mar2004-vitamin-e-bladder-cancer.shtml
Supplement reduces risk of aflatoxin-related liver cancer.
http://www.spinachwords.com/research/nov2001-aflatoxin-chlorophyllin.shtml
Dietary Lutein Inhibits Mammary Tumor Growth And Normalizes Immune Balance In Tumor-Bearing Mice.
http://www.spinachwords.com/research/apr1999-lutein-mammary-tumor.shtml
Spinach for Sun Protection
http://www.spinachwords.com/sun_protection.shtml
An epoxide-furanoid rearrangement of spinach neoxanthin occurs in the gastrointestinal tract of mice and in vitro: formation and cytostatic activity of neochrome stereoisomers.
http://www.ncbi.nlm.nih.gov/pubmed/15333710
Lutein bioavailability is higher from lutein-enriched eggs than from supplements and spinach in men.
http://www.ncbi.nlm.nih.gov/pubmed/15284371
Isolation and characterization of structurally novel antimutagenic flavonoids from spinach (Spinacia oleracea).
http://www.ncbi.nlm.nih.gov/pubmed/11409964
Oxalic acid does not influence nonhaem iron absorption in humans: a comparison of kale and spinach meals.
http://www.ncbi.nlm.nih.gov/pubmed/17440529
Vitamin D acts as an agent that prevents and cures diseases such as rickets and osteomalacia. Rickets is a popular bone disease which occurs commonly in children due to poor vitamin D IU levels. When the same deficiency occurs in adults, the problem is known as osteomalacia. This ailment is very much prevalent among women after age 40. The cause are closely related to a diet that’s deficient in Vitamin D, associated with poor exposure to the sun.