Eat Your (Leafy) Greens

By Emily Hahn APD

While dark green leafy vegetables may not always be a favourite at the dinner table, there is no denying the ‘eat your greens’ mealtime mantra is spoken as a gesture of love and good intention, founded in the wisdom that dark green and leafy vegetables are a rich source of body-loving nutrients. Let’s look at the humble vegetable group we call ‘dark green & leafy’ to see what all the fuss is about.
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Dark Green and Leafy Vegetables

This group of vegetables includes arugula (rocket), Bok choy (Chinese chard), collard greens (a variety of cabbage that produces long leaves instead of a head), dandelion greens, kale, mustard greens, rapini (broccoli raab), Swiss chard, turnip greens and spinach.

It also includes the brassica vegetables since there are many nutritional overlaps. Brassicas (also called cruciferous vegetables) are broccoli, cauliflower, broccolini, turnip, Brussels sprouts, and cabbage. This short list is limited to those most cultivated in the West, but Mother Nature’s generosity in producing edible green plants the globe over means that many cultures have leafy greens native to their geographical location, and thus include them in their dietary pattern.
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Nutritionally, dark green and leafy vegetables are rich in:

• dietary fibre for lowering serum cholesterol, improving blood sugar control, lowering blood pressure, improving stool regularity, feeding healthy gut bugs

 

• folate for cell growth and repair, preventing neural tube defects in developing fetuses

 

• vitamin C contributes to antioxidant defense system and immune function, used to make collagen and neurotransmitters such as serotonin

 

•  vitamin E contributes to antioxidant defence system and immune function, provides cell protection

 

• vitamin K for blood clotting, bone health, and blood vessel health

 

• vitamin A for eye health, reproductive health in men and women, immune function, cell growth and development

 

• iron for healthy red blood cells to transport oxygen around the body, immune function, and supporting the antioxidant defense system

 

• magnesium for bone and teeth health, nerve health, muscle health, and takes part in hundreds of essential cellular reactions

 

• calcium for bone and teeth health, nerve health, muscle health, healthy blood pressure, balancing blood pH

 

• potassium for fluid balance, nerve health, muscle health, blood pressure health

 

• flavonoids which contribute to antioxidant defenses       (1)(2)

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Preparing for Pregnancy

While dark green and leafy vegetable consumption and fertility has not been heavily studied, research is consistent when it comes to the protective effects of dark green and leafy vegetables for positive birth outcomes and all-round health.

Zerfu and colleagues (3) found that poor or inconsistent consumption of dark green leafy vegetables was associated with a 92% higher risk of experiencing an adverse pregnancy outcome compared to those with a higher or more consistent intake. Low or no green leafy vegetables consumption has also been identified as a risk factor for small for gestational age (4; 5), spontaneous preterm birth (4; 6), and gestational diabetes mellitus (4; 7).
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Low dark green and leafy vegetable intake has also been positively associated with anaemia during pregnancy, particularly in those with a low red meat consumption (8; 9). Finally, as rich sources of magnesium, dark green and leafy vegetables are important for preventing hypomagnesemia during pregnancy, which is associated with pre-eclampsia and pre-term birth (6).
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Adding Dark Green Leafy Vegetables to Your Week

Some nutrients in dark green leafy vegetables cannot be absorbed by the body in the absence of fat, so pairing these vegetables with a source of fat is a great way to ensure you’re getting all the nutritional benefits.
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Stuetz and colleagues (10) write about this beautifully in discussion of their findings that women in Tanzania who cooked their leafy vegetables with peanuts (a source of fat) were found to have higher levels of fat-soluble vitamin A in their blood.

Here are some ideas for including dark green and leafy vegetables in your week:

• Crush up black peppercorns and mustard seeds in a mortar and pestle, and sprinkle over broccoli or broccolini with a generous splash of extra virgin olive oil (mustard seeds also enhance the potency of an anti-inflammatory compound called sulforaphane found in broccoli)

• Chop fresh or frozen green leaves or dark green veg finely and add to soups, stews, chilli, or pasta sauce (e.g. Bolognese)

• Use spinach or arugula to make a pesto with nuts (pine or other) and olive oil, and use on pasta, white fish, chicken, or salad.

• Add chopped greens to a stir-fry near the end of the cooking time.

• Cook green leaves (e.g. chard, spinach, Bok choy) until they are wilted but still bright green. Serve drizzled in extra virgin olive, citrus juice and pepper, or a splash of sesame oil, soy sauce and sesame seeds.

• Fold cooked greens into an omelette or frittata (include the egg yolks for a fat source).

• Try arugula, baby spinach, mesclun mix, watercress, or baby mustard greens in your salad and dress with an oil-based salad dressing, such as this easy recipe: 3Tbsp extra virgin olive oil; 4Tbsp apple cider vinegar; juice one lemon; 1Tbsp dijon mustard; 1 Tbsp honey/maple syrup.

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• Chuck some dark green leaves into your morning smoothie and add some coconut milk or full fat yoghurt/kefir.

Preparing for conception is a wonderful time to care for your body with the health-protective powers of dark green and leafy vegetables. If you’re looking for some further guidance on your fertility journey, we’d love to support you in clinic or via telehealth.

You can book a complimentary phone call with us here or check out our science backed approach to get pregnant sooner in Create a Fertile Gut!

References

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1. Randhawa, MA Khan, AA Javed, MS & Sajid, MW (2015) Chapter 18 - Green Leafy Vegetables: A Health Promoting Source, in Ronald Ross Watson (ed) Handbook of Fertility, Academic Press, pp 205-220, doi: 10.1016/B978-0-12-800872-0.00018-4.
2. Babu, PVA & Liu, D (2009) Chapter 18 - Flavonoids and Cardiovascular Health, in Ronald Ross Watson (eds), Complementary and Alternative Therapies and the Aging Population, Academic Press, pp. 371-392, doi:10.1016/B978-0-12-374228-5.00018.
3. Zerfu, TA Pinto, E & Baye, K (2018) Consumption of dairy, fruits and dark green leafy vegetables is associated with lower risk of adverse pregnancy outcomes (APO): a prospective cohort study in rural Ethiopia, Nutrition and Diabetes, 8:52, doi: 10.1038/s41387-018-0060-y.
4. Jankovic-Karasoulos T, Furness DL, Leemaqz SY, Dekker GA, Grzeskowiak LE, Grieger JA, Andraweera PH, McCullough D, McAninch D, McCowan LM, Bianco-Miotto T, Roberts CT. Maternal folate, one-carbon metabolism and pregnancy outcomes. Matern Child Nutr. 2021 Jan;17(1):e13064. doi: 10.1111/mcn.13064. Epub 2020 Jul 28. PMID: 32720760; PMCID: PMC7729528.
5. McCowan L, Horgan RP. Risk factors for small for gestational age infants. Best Pract Res Clin Obstet Gynaecol. 2009 Dec;23(6):779-93. doi: 10.1016/j.bpobgyn.2009.06.003. Epub 2009 Jul 14. PMID: 19604726.
6. Enaruna NO, Ande A, Okpere EE. Clinical significance of low serum magnesium in pregnant women attending the University of Benin Teaching Hospital. Niger J Clin Pract. 2013 Oct-Dec;16(4):448-53. doi: 10.4103/1119-3077.116887. PMID: 23974737.
7. Chen Q, Wu W, Yang H, Zhang P, Feng Y, Wang K, Wang Y, Wang S, Zhang Y. A Vegetable Dietary Pattern Is Associated with Lowered Risk of Gestational Diabetes Mellitus in Chinese Women. Diabetes Metab J. 2020 Dec;44(6):887-896. doi: 10.4093/dmj.2019.0138. Epub 2020 Sep 11. PMID: 33081427; PMCID: PMC7801758.
8. Tadesse SE, Seid O, G/Mariam Y, Fekadu A, Wasihun Y, Endris K, Bitew A. Determinants of anemia among pregnant mothers attending antenatal care in Dessie town health facilities, northern central Ethiopia, unmatched case -control study. PLoS One. 2017 Mar 13;12(3):e0173173. doi: 10.1371/journal.pone.0173173. PMID: 28288159; PMCID: PMC5348124.
9. Diamond-Smith NG, Gupta M, Kaur M, Kumar R. Determinants of Persistent Anemia in Poor, Urban Pregnant Women of Chandigarh City, North India: A Mixed Method Approach. Food Nutr Bull. 2016 Jun;37(2):132-43. doi: 10.1177/0379572116637721. Epub 2016 Mar 23. PMID: 27009090.
10. Stuetz W, Gowele V, Kinabo J, Bundala N, Mbwana H, Rybak C, Eleraky L, Lambert C, Biesalski HK. Consumption of Dark Green Leafy Vegetables Predicts Vitamin A and Iron Intake and Status among Female Small-Scale Farmers in Tanzania. Nutrients. 2019 May 7;11(5):1025. doi: 10.3390/nu11051025. PMID: 31067775; PMCID: PMC6567817.