High blood pressure and possible ethnic differences

On page 66 of a new book Plagues and the Paradox of Progress: Why the World is Getting Healthier in Worrisome Ways, by Thomas Bollyky, it is mentioned that early Western medical personal working in Africa in the 1920s were surprised to find no cases of hypertension/high blood pressure among the native African people. Only one native woman was known to be overweight and it was noted that she worked in a brewery which led the medical person in the document to speculate whether beer drinking could be fattening (yes it can). The first case of hypertension in a native African person wasn’t noted until the 1940s.

Question: Does the Western style of living or working or export of Western products cause hypertension in native Africans? If native Africans living in their traditional environment using their traditional diet have no risk for hypertension then what changed that caused an increased risk? This topic is also important for prenatal health as preeclampsia can include hypertension/high blood pressure and it does tend to be an increased risk for women with African American ancestry. The DASH diet may be helpful, for more on preeclampsia risk factors and possible tips for prevention or management, see Preeclampsia & TRP Channelseffectivecare.info

Dr. Agbai’s discovery that helps protect against symptoms of Sickle Cell Anemia – Thiocyanate.

Yes per Dr Agbai who has worked with patients in Africa and in the U.S., the standard diets are different. There is a difference in type of starch and amount of starch in typical African or Jamaican diet and western U.S. style diet, and there is a difference in amounts of foods that contain thiocyanate. The yams commonly grown in Africa are larger and woodier/less sweet than sweet potatoes and they are also a good source of thiocyanate.

Thiocyanate is a phytonutrient that helps protect against Sickle cell anemia by preventing the red blood cells from forming the sickle shape instead of the normal round indented shape (like a tire or doughnut shape that has a filled in shallower center). It is important to eat adequate iodine and protein rich foods that contain methionine (found more in animal product protein sources than in a vegan diet) in order to protect thyroid health.

Listen to interviews with Dr. Agbai by the radio show Your Own Health and Fitness: http://www.yourownhealthandfitness.org/?page_id=509

Agbai O. Anti-sickling effect of dietary thiocyanate in prophylactic control of sickle cell anemia. J Natl Med Assoc. 1986;78(11):1053-6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2571427/

There may be a slight difference in retention of calcium and loss of magnesium that would be protective with a diet low in calcium might may increase risk of metabolic syndrome type conditions when excess calcium.

I’ve discussed this topic of potential differences between western style diet and traditional African culture and possible differences in health in my early days of blogging when I found a research article from ~ 1970s that noted ethnic differences in health outcomes but did not take into account possible differences in average ethnic diet at the time. (I haven’t found that article in my files yet. I will update this post if I do find it.) To get to the point directly – people with native African ancestry may have kidney differences that conserve calcium better, and possibly not conserve as much magnesium, as other ethnic groups. This would be protective when calcium was not very available in the diet but then would be an increased negative health risk if the diet contained a lot of calcium or phosphorus.

There is known problems in medical research in the U.S. with bias in research studies towards use of white males as study participants with less information gathered about minority groups and females.

Before discussing calcium and magnesium and kidney health in more detail – briefly – there is bias in medical research towards white males. Research studies over the years have often had more limited numbers of minorities and females among the experimental and control groups or as a focus of research. A summary of the issue was included in a recent article in the New York Times that is focused on the potential benefits and risk of bias in the use of Artificial Intelligence (AI) in medical diagnostic processes or other medical roles.

” Medicine has long struggled to include enough women and minorities in research, despite knowing they have different risk factors for and manifestations of disease. Many genetic studies suffer from a dearth of black patients, leading to erroneous conclusions. Women often experience different symptoms when having a heart attack, causing delays in treatment. Perhaps the most widely used cardiovascular risk score, developed using data from mostly white patients, can be less precise for minorities. ” – Dhruv Khullar

“A.I. Could Worsen Health Disparities,” by Dhruv Khullar, The New York Times, Opinion, Jan. 31, 2019

It is not racist or sexist to discuss differences in physiology and the potential effects those differences might have on health. It is discriminatory to only study one group of people primarily and then try to treat everyone else as if they weren’t individuals but were all instead exactly like the group that had been studied. It is discrimination to not treat individuals as individuals or to pretend that differences don’t exist.

Adequate magnesium is needed for preventing high blood pressure, cardiovascular disease, and many other chronic conditions including dementia.

Low magnesium levels, particularly when there is also plenty of phosphorus may increase cardiovascular risks. Adequate magnesium levels are protective and elevated magnesium is unusual and may be increase cardiovascular risks. In good health the body maintains magnesium and other electrolyte levels within specific ranges. (5) Higher magnesium levels have also been associated with higher levels of potassium and of albumin, a blood plasma protein, (6), which is important for fluid balance and transport of a variety of chemicals in addition to magnesium (such as steroids, fatty acids, and thyroid hormones (wikipedia/serum albumin), about 30% of serum magnesium is carried in a non-electrically active form on proteins, primarily albumin (Clinical Biochemistry/serum magnesium) (9).

Alzheimer’s dementia and other types of dementia are more common in blacks than whites in the U.S. and may be a risk earlier in life too, early onset Alzheimer’s can occur in the forties and fifties instead of the more frequent age of diagnosis after age 60. See: African Americans Face Greater Risk of Alzheimer’s Disease than Whites, usatoday.. The reason is not known but the increased frequency on high blood pressure in blacks is thought to be a risk factor.

There may be differences in rate of urinary loss of albumin in different ethnic groups. With the presence of excess abdominal weight participants in a renal study of Hindustani-Surinamese, or African-Surinamese ancestry had an increased likelihood of albuminuria than participants of Dutch ancestry with the greatest risk found in the Hindustani-Surinamese group. (7) Asian Americans and African Americans were found to have better blood albumin levels in a renal study and the Asian Americans had better renal biomarkers compared to other ethnic groups in the study. (8)

When looking at hypertension and high blood pressure risk with the same diet in modern research there is a significant increased risk for African Americans to have high blood pressure and to have it occur earlier in life than in whites. (prevalence in the U.S. of hypertension in adults was “42 % for blacks and 28 % for whites,” (2011-2012)). (2)

So it is a good question – how did hypertension frequency in Africans in the 1920s change from zero to 42% for African Americans in the United States, in 2011-2012? Diet differences that were noted in 2009-2010 between white groups and African American groups were more cholesterol and sugar and less fiber, whole grains, nuts/beans/seeds, fruits and vegetables for the African Americans on average. Dairy intake was not mentioned as being significantly difference. In another research comparison calcium intake was lower on average in African Americans but so was magnesium (Table 1). (2)

Within the introduction and Diet and Blood Pressure sections of the article it is mentioned that ethnic differences in cardiovascular metabolism has been noted in African American groups and that their reduction in blood pressure when following the DASH diet was even better than the reduction in people of other ethnic background who followed the diet (it includes a magnesium rich Beans/Nuts/Seeds group as a daily/weekly recommendation). The INTERMAP study found an increased Sodium to Potassium ratio in urinary excretion and less total Potassium urinary excretion for the African American participants than white participants. (2)

Other research has also supported the idea that high blood pressure may have more to do with excess sodium (salt) intake in relation to low potassium intake than just having to do with the amount of sodium in the diet. Potassium is found in all vegetables and fruits in varying amounts, beans/nuts/seeds, and in liquid milk and yogurt. (Kidney dialysis and other patients with Chronic Kidney Disease have to avoid excess potassium so this article includes a list of potassium rich foods for the purpose of educating regarding what needs to be limited but for people of average kidney health it is a list of good sources to include in the diet: Potassium and Your CKD Diet, National Kidney Foundation.

Learning is an ongoing process, in the meantime some possible health tips for people of any ancestry:

  1. Adequate magnesium is essential for kidney and heart health and high blood pressure is an early symptom of low magnesium levels. Dietary sources may not be sufficient if intestinal absorption is poor or if renal losses are excessive. Epsom salt baths or footsoaks or magnesium chloride are topical forms. Adequate protein and phospholipids in the diet are also important to provide the albumin and other specialized transport molecules that carry magnesium and other chemicals within the vascular or other fluids of body tissue. More information about magnesium sources and symptoms of deficiency are available in a previous post: To have optimal Magnesium needs Protein and Phospholipids too.
  2. Adequate calcium and vitamin D are needed for health however excess may cause an imbalance between calcium and magnesium levels as magnesium is excreted along with excess calcium by the kidneys and less magnesium may be absorbed by the intestines as vitamin D causes increased absorption of calcium and magnesium but calcium may be more available in a modern processed food diet. For more information about vitamin D sources see: Light up your life with Vitamin D, peace-is-happy.org. Deficiency of calcium or of vitamin D can cause secondary hyperparathyroidism which can also be more common in renal failure due to excess phosphorus buildup and deficiency of active vitamin D. The healthy kidney is involved in activating vitamin D. (Secondary hyperparathyroidism, National Kidney Foundation) Calcium is plentiful in most dairy products and is also found in almonds, sesame seeds, beans, dark green leafy vegetables and other produce. Variations of a 2000 calorie menu plan shows that even a vegan diet can provide 1000 milligrams of calcium per day and a menu with dairy products can provide an excess with over 1600 milligrams of calcium, see: Healthy Hair is the Proof-of a healing diet.
  3. The DASH diet (Dietary Approach to Stop Hypertension) may help because it encourages potassium and magnesium rich vegetables, fruits, beans, nuts and seeds. Calcium is provided without being over recommended with two to three servings of dairy group foods. See example daily/weekly diet plan recommendations here: What is the DASH diet?, dashdiet.org.
  4. Adequate without excess protein helps protect the kidneys from having to overwork excreting nitrogen from excess protein breakdown. Adequate water is essential for kidney and vascular health as it helps with excretion of toxins and transport of nutrients and oxygen in the vascular system. More information about protein and water recommendations are available in a previous post: Make every day Kidney Appreciation Day.

/Disclaimer: This information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes./

  1. Thomas Bollyky, Plagues and the Paradox of Progress: Why the World is Getting Healthier in Worrisome Ways, 2018, MIT Press, https://mitpress.mit.edu/books/plagues-and-paradox-progress
  2. Chan Q, Stamler J, Elliott P. Dietary factors and higher blood pressure in African-Americans. Curr Hypertens Rep. 2015;17(2):10. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4315875/“Marked ethnic differences exist in bone metabolism and development of calcified atherosclerotic plaque (CP). Relative to European-Americans, African-Americans have lower rates of osteoporosis (despite ingesting less dietary calcium), form fewer calcium-containing kidney stones and manifest skeletal resistance to PTH (1,2,3). Systemic differences in regulation of calcium and phosphorus appear to be involved (4). Related phenomena may include the markedly lower amounts of calcified CP in African-Americans, despite the presence of more severe conventional cardiovascular disease risk factors (5,6,7,8,9). Together these observations suggest biologically mediated ethnic differences in the regulation of bone and vascular health.” […]  “The DASH/DASH-Na diet BP reduction was more pronounced for blacks compared to whites [313637]. Although the DASH dietary approach has been incorporated into lifestyle changes recommended for patients with HTN [3], data show that few hypertensive Americans consume diets even modestly concordant with the DASH diet and less so for blacks [38]. Only about 19 % of individuals with known HTN from NHANES 1999–2004 had DASH-concordant diets.”
  3. Barry I. Freedman, et al, Vitamin D, Adiposity, and Calcified Atherosclerotic Plaque in African-Americans,J Clin Endocrinol Metab. 2010 March; 95(3): 1076–1083. [ncbi.nlm.nih.gov/pmc/articles/PMC2841532/?tool=pubmed]  
  4. Potassium and Your CKD Diet, National Kidney Foundation, https://www.kidney.org/atoz/content/potassium
  5. Ryota Ikee, Cardiovascular disease, mortality, and magnesium in chronic kidney disease: growing interest in magnesium-related interventions, Renal Replacement Therapy2018 4:1,   https://rrtjournal.biomedcentral.com/articles/10.1186/s41100-017-0142-7
  6. Noriaki Kurita, Tadao Akizawa, Masafumi Fukagawa, Yoshihiro Onishi, Kiyoshi Kurokawa, Shunichi Fukuhara; Contribution of dysregulated serum magnesium to mortality in hemodialysis patients with secondary hyperparathyroidism: a 3-year cohort study, Clinical Kidney Journal, Volume 8, Issue 6, 1 December 2015, Pages 744–752, https://doi.org/10.1093/ckj/sfv097
  7. van Valkengoed IG, Agyemang C, Krediet RT, Stronks K. Ethnic differences in the association between waist-to-height ratio and albumin-creatinine ratio: the observational SUNSET study. BMC Nephrol. 2012;13:26. Published 2012 May 7. doi:10.1186/1471-2369-13-26. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3492102/
  8. Frankenfield DL, et al., Differences in intermediate outcomes for Asian and non-Asian adult hemodialysis patients in the United States, Kidney International, Vol 64, Issue 2, Aug. 2003, pp 623-631 https://www.sciencedirect.com/science/article/pii/S0085253815493706
  9. M H Kroll, R J Elin, Relationships between magnesium and protein concentrations in serum. Clinical Chemistry Feb 1985, 31 (2) 244-246; http://clinchem.aaccjnls.org/content/31/2/244.long

Pre-eclampsia means pre convulsions; a life threatening prenatal condition.

Eclampsia is an old medical term for convulsions and has been a known risk with pregnancy for many centuries. (G5.1) In more recent centuries the earlier warning signs of pre-eclampsia have been recognized and include high blood pressure, protein in the urine, and edema – increased swelling in the legs, arms and face. Many women may experience increased puffiness or swelling in the lower legs during later stages of pregnancy and it can be painful to walk with swollen feet. In the more severe condition fluid is also collecting in other areas of the body on the exterior of cells instead of being collected by lymphatic or blood vessels and excreted as urine as in normal health.

Why the condition occurs is not known although some risk factors are known. It is more of a risk for very young women, (G5.3); very young women who are also overweight, (G5.4); overweight women; or women over age 40; women who are pregnant with twins, triplets, or more; women of African ethnicity;  women with a history or currently have high blood pressure; and any women who already had pre-eclampsia during previous pregnancies, or who have a family history of other women in their family (such as the pregnant woman’s sisters or her mother) having had pre-eclampsia. (G5.2) Very low calcium intake may increase risk. (G5.1)

What is known is that the condition or related high blood pressure conditions during pregnancy are a significant cause of maternal deaths, 18% of all maternal deaths in the U.S., and of neonatal/infant deaths, over 10,000 each year in the U.S.. It is also more frequently associated with preterm delivery of infants which can leave the infant more at risk for many other chronic health or development complications. (G5.1)

My health is not great, but it has been worse – I prefer better than worse. On my bucket list is to continue working on collating available research regarding the simple question – Why did simply adding raw shelled pumpkin seeds help my previous prenatal clients prevent the risk of having pre-eclampsia during their later pregnancies.

Possible answers: genetic variations in the TREK 1 potassium ion channels may leave women in some families more at risk for developing preeclampsia due to their membranes being less responsive as normal to changes in acidity or stretch – swelling. (G5.5) The preventative health solution might be too eat a more alkaline promoting diet, a more vegetable based diet rather than excess meats and dairy foods.

Very young women and women of African ethnicity may be more at risk due to less space within the abdomen and pelvic cavity. Young women may be smaller framed than more fully mature women in their twenties and the pelvic shape of women of African ethnicity is slightly narrower than that of other ethnic groups (may be a better shape for running fast though.) A hypothesis suggests a preventative health strategy that includes spending a half hour or so daily or periodically during the day in a position where the head is rested on the arms on a pillow while kneeling so the abdomen is inverted slightly and is above the heart – to help fluid movement and relieve pressure in the area around the baby. (G5.6)

The position that is recommended in the hypothesis article (G5.6) can be seen in this article, see Figure 3, Knee-Chest Position: (G5.7). It would likely help women with a family history of preeclampsia too if TREK 1 variations were involved, to relieve intra-abdominal pressure, or for any prenatal woman in the third trimester. The position can also help promote the infant remaining or moving to a head down position which is safer for delivery (preventing a breech birth delivery).

Pumpkin seeds may be particularly helpful due to being a good source of many nutrients including magnesium, (G5.13), zinc, (G5.11), and phospholipids. (G.26) Cocoa/chocolate is also a good source of magnesium and phospholipids (G.26) and women who report eating chocolate several times per week prenatally has been associated with less risk for preeclampsia. (G5.8)(G5.9) Zinc levels have been found to be significantly lower in women with preeclampsia than in pregnant women not experiencing preeclampsia. (G5.12)  Pumpkin seeds may also help due to omega 3 fatty acid content (G5.11) which has also been found to help reduce risk of preeclampsia. (G5.10Pumpkin seeds  or pumpkin seed oil may help prevent preeclampsia due to increased detoxification and removal of toxins from the body as they may cause a diuretic effect. (G5.11)

Pumpkin seeds are a good source of many minerals. Just two tablespoons provides about 25% of the daily recommendation for magnesium. (G5.13) They are also a source of manganese and other trace minerals including selenium. A larger serving of 100 grams (1/3-1/2 cup) would provide 17% of the daily recommendation for selenium and almost 200% of the recommendation for manganese. (G5.14) Supplements of 100 micrograms of selenium per day  for 6-8 weeks during later pregnancy were found beneficial for preventing pregnancy induced hypertension – high blood pressure in the later part of pregnancy is an early sign of preeclampsia. (G5.15)

Balance of nutrients is important and loss of nutrients due to increased oxidative stress may be the underlying problem rather than deficiency. Selenium, magnesium, and manganese levels were found to be comparable in women who did and did not develop preeclampsia in later pregnancy however the women who did develop the condition had elevated copper levels in early pregnancy. (G5.16) Copper and zinc levels need to be in balance with each other for optimal health.

Why should we care? The risk of complications or death for mothers and infants due to pre-eclampsia is significant and is worse in undeveloped nations. The rate of maternal death has been increasing in the U.S. and now is worse than that of other developed nations. Other developed nations range from four to nine maternal deaths per 100,000 live births while in the U.S. the rate has worsened to 26.4 maternal deaths per 100,000 live births. (G5.17) If 18% of those deaths are due to preeclampsia, (G5.1), then in 2015 when there were 3,978,497 births, (G5.18), approximately 189 families lost a mother due to the dangers of preeclampsia.

This is an introduction to the topic, a longer draft is available here: G5: Preeclampsia & TRP Channels, which does not contain some of the information in this post – yet.

Traveling is fun, I took pictures, but traveling the internet saves gasoline. Bucket list – before I kick the bucket I hope to continue working on ways to help women identify their individual risk factors that may be involved in preeclampsia and identify ways to reduce those risks. Like many problems a similar set of symptoms can have a variety of underlying causes, not just one cause, one set of symptoms. Health requires many things, not just one simple solution.

This may seem melodramatic however my health has been bad enough over the years and more recently to make me very appreciative of health and mental health. Dementia is a very real problem and one that is growing in number of people effected either as patients or as caregivers. I have improved my health but it required many changes in diet and lifestyle habits that  are ongoing, missing a day or two can send me back into negative health symptoms.

Magnesium is an important part of preeclampsia care that may also be needed for dementia. I will also post my initial draft on a magnesium  article I began working on after reading a textbook: Magnesium and the Central Nervous System, (free Magnesium ebook, adelaide.edu.au).  The short message that overlaps with this post is that to have adequate magnesium stores within the cells where it is needed for optimal health then it is likely also essential to have adequate protein intake and phospholipid intake. Something that I have found important that is not included in the text or other current medical articles on the topic is that for some people topical sources of magnesium such as Epsom salt/magnesium sulfate baths or footsoaks or magnesium chloride hand lotions or topical liquid solutions may be needed to bypass problems with intestinal absorption of magnesium.

  • Disclaimer: Opinions are my own and the information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes.

G.26: Arlen Frank, Chemistry of Plant Phosphorus Compounds, Elsevier, Jun 3, 2013, https://books.google.com/books/about/Chemistry_of_Plant_Phosphorus_Compounds.html?id=6btpFSV1T2YC (G.26)  

Robert Vink, Mihai Nechifor, editors, Magnesium in the Central Nervous System, University of Adelaide Press, 2011, adelaide.edu.au, free ebook pdf, https://www.adelaide.edu.au/press/titles/magnesium/magnesium-ebook.pdf 

  1. John D. MacArthur, Placental Fluorosis: Fluoride and Preeclampsia, Townsend Letter, May 2015; 382:74-79. http://www.townsendletter.com/May2015/placental0515.html (G5.1)
  2. Who is at risk of Preeclampsia?, NICHD, Eunice Kennedy Shriver National Institute of Child Health and Human Development,  https://www.nichd.nih.gov/health/topics/preeclampsia/conditioninfo/Pages/risk.aspx (G5.2)
  3. Priscila E Parra-Pingel, Luis A Quisiguiña-Avellán, Luis Hidalgo, Peter Chedraui, Faustino R Pérez-López, Pregnancy outcomes in younger and older adolescent mothers with severe preeclampsia, Adolesc Health Med Ther. 2017; 8: 81–86. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5476435/ (G5.3)
  4. Mulualem Endeshaw, Fantu Abebe, Solomon Worku, Lalem Menber, Muluken Assress, Muluken Assefa, Obesity in young age is a risk factor for preeclampsia: a facility based case-control study, northwest Ethiopia. BMC Pregnancy Childbirth. 2016; 16: 237. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4992278/ (G5.4)
  5. Chad L. Cowles, Yi-Ying Wu, Scott D. Barnett, Michael T. Lee, Heather R. Burkin, Iain L.O. Buxton, Alternatively Spliced Human TREK-1 Variants Alter TREK-1 Channel Function and Localization. Biol Reprod. 2015 Nov; 93(5): 122. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4712007/ (G5.5)
  6. Diane J.Sawchuck, Bernd K.Wittmann, Pre-eclampsia renamed and reframed: Intra-abdominal hypertension in pregnancy, Medical Hypotheses, Vol 83, Iss 5, Nov 2014, pp 619-632 
    http://www.sciencedirect.com/science/article/pii/S0306987714002722  (G5.6)
  7. Marybeth Lore, MD, Umbilical Cord Prolapse and Other Cord Emergencies, Citation Lore, M, Glob. libr. women’s med., (ISSN: 1756-2228) 2017; DOI 10.3843/GLOWM.10136 https://www.glowm.com/section_view/heading/Umbilical%20Cord%20Prolapse%20and%20Other%20Cord%20Emergencies/item/136 (G5.7)
  8. Elizabeth W Triche, Laura M Grosso, Kathleen Belanger, Amy S Darefsky, Neal L Benowitz, Michael B Bracken. Chocolate consumption in pregnancy and reduced likelihood of preeclampsia. Epidemiology. 2008 May;19(3):459-64. PMID: 18379424 http://www.greenmedinfo.com/article/chocolate-consumption-during-pregnancy-may-reduce-likelihood-preeclampsia (G5.8)
  9. Audrey F Saftlas, Elizabeth W Triche, Hind Beydoun, Michael B Bracken. Does chocolate intake during pregnancy reduce the risks of preeclampsia and gestational hypertension? Ann Epidemiol. 2010 Aug;20(8):584-91. PMID: 20609337  http://www.greenmedinfo.com/article/chocolate-intake-during-pregnancy-may-reduce-risks-preeclampsia-and-gestationa (G5.9)
  10. M A Williams, R W Zingheim, I B King, A M Zebelman. Omega-3 fatty acids in maternal erythrocytes and risk of preeclampsia. Epidemiology. 1995 May;6(3):232-7. PMID: 7619928 http://www.greenmedinfo.com/article/omega-3-fatty-acid-consumption-may-contribute-reduction-risk-preeclampsia (G5.10)
  11. Pumpkin Seeds versus Pumpkin Seed Oil, Activation Products Blog, https://www.activationproducts.com/blog/pumpkin-seeds-vs-pumpkin-seed-oil/ (G5.11)
  12. Yue Ma, Xiaoli Shen, Dongfeng Zhang, The Relationship between Serum Zinc Level and Preeclampsia: A Meta-Analysis. Nutrients. 2015 Sep; 7(9): 7806–7820. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4586561/ (G5.12)
  13. Megan Ware, RDN, LD, What are the Health Benefits of Pumpkin Seeds?  Jan. 18, 2017, MedicalNewsToday.com, https://www.medicalnewstoday.com/articles/303864.php (G5.13)
  14. Pumpkin Seeds: Nutrition Facts, nutrition-and-you.com, https://www.nutrition-and-you.com/pumpkin-seeds.html (G5.14)
  15. L Han, S M Zhou. Selenium supplement in the prevention of pregnancy induced hypertension. Chin Med J (Engl). 1994 Nov;107(11):870-1. PMID: 7867399 http://www.greenmedinfo.com/article/selenium-supplementation-may-contribute-reduction-risk-pregnancy-induced-hyper (G5.15)
  16. Hiten D. Mistry, Carolyn A. Gill, Lesia O. Kurlak, Paul T. Seed, John E. Hesketh, Catherine Méplan, Lutz Schomburg, Lucy C. Chappell, Linda Morgan, Lucilla Poston, Association between maternal micronutrient status, oxidative stress, and common genetic variants in antioxidant enzymes at 15 weeks׳ gestation in nulliparous women who subsequently develop preeclampsia. Free Radic Biol Med. 2015 Jan; 78: 147–155. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4291148/ (G5.16)
  17. Nina Martin, Renee Montagne, U.S. has the Worst Rate of Maternal Deaths in the Developed World, May 12, 2017, NPR, https://www.npr.org/2017/05/12/528098789/u-s-has-the-worst-rate-of-maternal-deaths-in-the-developed-world (G5.17)
  18. Birth Data, National Vital Statistics System, CDC, https://www.cdc.gov/nchs/nvss/births.htm (G5.18)