Wednesday, May 20, 2015

Pregnancy Superfood Series - Part 2 - Liver

Check out other posts in my Pregnancy Superfood series!
Eggs / Dark Leafy Greens / Salmon

Wow! If you had told me a couple of years ago that I would be writing any words about liver other than "Blech!" or maybe "Blurgh!" I would have called you a liar and laughed in your face. Yet, here we are. Luckily, I've learned a lot over these past few years and I've opened my eyes to the health benefits of many, many foods I wouldn't touch before. That is why liver is now on my list of top pregnancy superfoods! Read on to find out why...

>> Liver is super for preventing neural tube defects

pregnancy superfood: liver
Folate (also known as vitamin B9) is the number one player in the formation of the neural tube in those first few early weeks of pregnancy, before many women even realize they are pregnant. Defects of the neural tube include spina bifida and anencephaly, very serious conditions that can cause minor or major disabilities and even infant mortality. This is why you will often see recommendations for all women of childbearing age to take a folic acid supplement. Notice I didn't say folate, but folic acid. Folic acid is the synthetic form of folate that is often used in prenatal supplements. Folate is a naturally occurring B vitamin found in many foods, including liver. We'll save that debate for another day, but I ALWAYS recommend real food over synthetic vitamins. Foods are quite complex, carrying not only vitamins and minerals but also the enzymes and cofactors that help our body to absorb and utilize these nutrients.

Folate is necessary for the production of red blood cells, as well as the production, repair and functioning of DNA. During pregnancy, especially in the very early stages, your body is rapidly producing new red blood cells to support the placenta and the little tiny ball of cells that will one day grow into your cuddly little baby. Your body needs folate to keep pumping out those red blood cells. According to the Centers for Disease Control and Prevention (CDC), taking a daily folic acid supplement starting at least one month before pregnancy can reduce the risk of neural tube defects by up to two thirds (1). This study, as noted, was done using folic acid supplements and not folate-rich foods, which would be more difficult to measure, but rest assured that getting your folate from real food is just as good, if not better, for you than popping a vitamin.

The current RDA for folate during pregnancy is 600 mcg (micrograms) per day (2). Just one 3 oz serving of beef liver contains 215 micrograms of folate, over one third of your daily requirement! Paired with other folate-rich foods like dark leafy greens, citrus fruits, squash, bananas and even avocados, you'll be well on your way to meeting your daily needs. Don't fret too much about hitting the RDA on the head every day, either. As long as you are averaging out to somewhere in that range throughout the week you and your baby will be more than covered.

If you aren't quite ready for a heaping plate of liver, I'll give you a few creative ways to work it into your diet at the end of this post.

>> Liver is super for healthy birth weight

Iron supports your increasing blood volume and circulation during pregnancy by rapidly producing new red blood cells. Pregnant women can develop anemia when they don't consume enough dietary iron because the baby will pull from the mother's stores if necessary. The body will always provide for the baby first. That is why it is crucial you eat iron-rich foods during pregnancy. Iron deficiency is often implicated for its role in anemia during pregnancy, which can result in preterm birth and low birth weight. This is especially important during the first trimester, as studies show iron deficiency in the first trimester has a more significant impact on birth weight than in the second and third trimesters (3). We are just beginning to scratch the surface of the implications of nutrition before and during pregnancy, but there is mounting evidence that babies born at a low birth weight are at a greater risk of developing insulin resistance, obesity, hypertension, heart disease and type 2 diabetes later in life (4).

Common nutrition knowledge would have you believe that iron supplements and artificially-forified breads and cereals are the best way to power up your iron stores, but there is a better option and I'm sure you already know what it is...liver. The current RDA for iron during pregnancy is 27 mg and one 3 oz serving of liver contains 5 mg of iron. The type of iron in liver, heme iron, is also more bioavailable than the type of iron from plant foods, non-heme iron, so it is good to get a mix of both. Plant-based sources of iron include spinach, broccoli, pumpkin seeds, molasses and raisins, to name a few. Consuming iron-rich foods with vitamin C-rich foods also aids absorption so try to combine dark leafy greens and citrus fruits into your lovely liver meals to keep your baby belly happy.

>> Liver is super for baby's brain and nervous system development

Liver is also a good source of vitamin B6. Vitamin Bplays many important roles during pregnancy, but, most importantly, it is vital for your baby's brain and nervous system development due to its role in red blood cell production. You don't need much, the RDA is only 1.9 mg and 3 oz of beef liver contains almost half that, coming in at .9 mg. Because you don't need much, you should easily be able to get enough through diet alone as long as you are aware of the foods highest in vitamin B6 like liver and other meats, tuna, potatoes and sweet potatoes, sunflower seeds, spinach and bananas.

Bonus! Vitamin B6 may also help to relieve morning sickness. Known in my book as "all day sickness", studies on vitamin B6 supplementation have shown a significant reduction in morning sickness symptoms (I'm talking about vomit) after just three days of therapy (5). I'll be honest and admit the only thing that seemed to help me was ginger on all the things, but every woman is different and nausea and vomiting of pregnancy (the technical term) is a complex symptom so it is well worth increasing your intake of B6 foods to see if you can get a little relief.

>> Is it safe to eat liver during pregnancy?

I've seen this question come up time and time again so I feel I should address it here. Women are often warned to avoid liver during pregnancy because of the risk of vitamin A toxicity. It is true that liver has high levels of vitamin A, but the studies that have been done on vitamin A toxicity and its link to birth defects showed only an increased risk of birth defects in women who obtained synthetic vitamin A in the form of supplements (6). Other studies have found no correlation. To drive it home even more, a 2000 study in the American Journal of Clinical Nutrition showed that, of all the reported studies, there is simply not enough evidence to attribute these birth defects to vitamin A toxicity because the study sizes have not been large enough and the classification methods have not been precise enough to reach a level of statistical significance (7).  That is my fancy way of saying there is no harm in eating liver during pregnancy. There is not a single study I have found that shows any correlation between liver consumption during pregnancy and an increased risk of birth defects. Do you want to eat it every day? Probably not. But isn't that true of all foods? A healthy, whole foods diet is all about balance and variety to get maximum nutrition. Plus, it would get pretty darn boring.

We have already touched on the differences between whole foods and synthetic vitamins and the history of ancestral cultures is rich with stories of liver and other organ meats being fed to men and women during the preconception period and pregnancy. I fully believe that traditional cultures, throughout history and the few that remain today, are more in tune with what their bodies need than we are and they know that liver is the bee's knees. Heck, less than a century ago liver and cod liver oil were advertised to pregnant women and babies.

All of that being said, you do want to source liver carefully in order to obtain only the highest quality meat. Look for organ meats from humanely raised, pastured animals; raised without hormones, antibiotics or GMO feed. Different animals have different nutrient compositions, as well. This article from the Weston A. Price foundation includes a Liver Comparison Chart if you are curious.

love your baby...eat liver

>> Learning to love liver!

So, maybe I've convinced you of the importance of liver, but convincing you to eat it may be a more difficult task. Liver is know for its, um, strong flavor, but there are a bunch of awesome recipes and cooking techniques that I am sure there is one you will love. Chicken liver does seem to be the most mild in flavor so it may be a good gateway liver (haha). Here are a few ideas to get you started (I will add recipes for these as I add them to the site):
  • Chicken liver pâté 
  • Chicken liver mousse
  • Pan-fried liver with bacon and onions
  • Grind up liver with beef to make meatballs, burgers or ground taco meat

If you still aren't quite ready to take the plunge you can try these Liver + Beef Bars from Epic Bar, available through Barefoot Provisions. You can also find desiccated liver supplements, like these grass-fed beef liver powder capsules from Perfect Supplements, available on Amazon. Just swallow it down...all of the health benefits and none of the taste. I do hope you'll try to cook liver, though and find a way that you enjoy eating it. 

Next week in this series we will be discussing dark, leafy greens!

So, be honest...have I talked you into giving it a try? What are you going to try first? Or, if you already have a favorite liver recipe, let me know in the comments what it is so others can try it, too!

Image courtesy of Mister GC at FreeDigitalPhotos.net