The Many Functions of the Liver

As we continue to learn about the digestive system in class, I continue to be amazed at how important each of our organs actually is. But nothing amazes me more than the liver. I know I talk about the liver all the time, but I came across this list of the liver’s functions in my Anatomy & Physiology textbook and I thought it was worth sharing. Use this as a reminder of how important it is to put healthy, real foods into our bodies so that our liver doesn’t have to work too hard. When the liver is overworked, we are more susceptible to weight gain, sickness, and many other health issues.

Carbohydrate Metabolism: The liver works to maintain a healthy blood sugar level. When blood sugar is low, the liver breaks down glycogen to glucose and releases the glucose into our bloodstream. When blood sugar is high (such as right after we eat a meal), the liver converts glucose to glycogen and triglycerides and helps us store these.

Lipid (Fat) Metabolism: Liver cells store some triglycerides. They also work to break down fatty acids to create energy (ATP). The liver creates lipoproteins, which are responsible for transporting fatty acids, triglycerides and cholesterol to and from body cells. The liver also creates cholesterol (remember, over 80% of our cholesterol is made within the body and only 15-20% actually comes from diet).

Protein Metabolism: Liver cells prepare amino acids (proteins) to be used for energy production.

Processing of Drugs & Hormones: The liver can detoxify certain substances such as alcohol, and it excretes drugs. It also chemically alters or excretes thyroid hormones, estrogens and aldosterone. Any over-the-counter or prescription medications we take must be processed by the liver, as they are foreign to our body.

Synthesis of Bile Salts: The liver creates bile salts, which are transported to the small intestine. Bile salts are necessary for the emulsification and absorption of fats.

Storage: The liver is the primary storage site for vitamins A, B12, D, E, and K, and for the minerals iron and copper. The liver stores these nutrients until they are needed elsewhere in the body.

Phagocytosis: The liver is responsible for killing off aged red blood cells and white blood cells, as well as some bad bacteria in the body.

Activation of Vitamin D: The liver, along with the skin and kidneys, is crucial in the activation of vitamin D. The vitamin D absorbed from the sunshine through one’s skin is inactive, and the liver must be involved in the activation process in order for someone to receive the vitamin D’s benefits.

Are you as impressed as I am with the liver? It’s the second biggest organ we have (the skin is the first), so let’s try to take care of it by reducing things like alcohol, smoking, and medications, and by increasing our intake of fresh, whole foods and plenty of water!

Chromium

Chromium has come up a few times in my classes recently, so I thought I’d do a quick overview of what it is, why it is important, and which foods contain high levels of chromium.

What is chromium?

Chromium is an essential trace mineral. Our bodies absorb about 10-25% of chromium from a particular food.

Why is chromium so important?

One of the main functions of chromium is to help control blood sugar. Chromium is used to produce glucose tolerance factor, which is a compound that helps insulin function properly. When insulin is functioning properly, we are less likely to experience dramatic highs and lows in our blood sugar. I talked about blood sugar last week here – if you are someone who has ever had trouble stabilizing your blood sugar, you know what I’m talking about when I say “highs and lows”. Not everyone experiences these dramatic shifts, but many do (I know I do!).

One of the results of balancing blood sugar through chromium’s ability to produce glucose tolerance factor could be a clearing up of someone’s acne. Often times acne is directly related to blood glucose levels, and when they become balanced, the skin will also clear up.

Another function of chromium is fat and cholesterol metabolism. One study has found that chromium works with niacin (vitamin B3). You may remember when I talked about niacin back in March. It is a key nutrient used for metabolism of all of our food.

Chromium intake has also been linked to an increase in lean body mass.

Since our country eats so much processed foods, it is very realistic to think that one may have a chromium deficiency if they have certain symptoms. Symptoms can include high triglyceride levels, high blood sugar, low HDL cholesterol and high blood pressure.

Which foods contain chromium?

The most chromium-packed food I could find is (big surprise) calf’s liver. I blogged a great liver recipe here, but remember that it is extremely important to get your liver from a grass-fed calf to ensure its liver is healthy.

Other great food sources of chromium include potatoes (and I don’t mean french fries, unless of course you make them yourself at home); oysters; chicken; bran; whole grain bread; raw onions; green peppers; romaine lettuce; carrots; apples; bananas; cooked spinach; and cooked cabbage.

Some people also take a chromium supplement if they are experience signs of a deficiency. Before supplementing with chromium, talk to your doctor or nutritionist about any potential interactions chromium could have with other drugs.

Calf's Liver

Many of you have heard the phrase “Don’t eat anything your grandmother wouldn’t recognize.” Michael Pollan has said this, but so have countless other health and nutrition enthusiasts. It’s simple advice and it makes sense: most processed foods, like Doritos or Hostess cupcakes or flavored yogurt, were not around when our grandparents were young. They may have cooked with more butter and used heavy cream in more of their recipes, but let’s face it: they still ate much healthier than people do now. They ate whole foods, and were more likely to eat locally grown and produced foods because that was what was available to them. More meals were cooked at home, and kids were not eating fast food.

Last night Ed and I ate a dinner that our grandparents would definitely recognize: calf’s liver. My Nutrients teacher talks a lot about liver in class. She eats it often, and a few weeks ago she sent us her liver recipe. When Ed and I were at Denver’s indoor farmer’s market, we purchased a bag of frozen calf livers from a Colorado, grass-fed beef farm. Liver from a grass-fed calf is free from toxins and the best type of liver to consume. It provides more nutrients per gram than any other food that exists!

Liver is extremely nutrient-dense. One serving contains almost 700% of your daily vitamin B12; 600% of your vitamin A; over 200% of daily folate; 130% of vitamin B2 (riboflavin); and very high amounts of copper, selenium, zinc, tryptophan, protein, vitamin C, vitamin B3 (niacin), phosphorous, iron, and vitamins B5 and B6. And all of these nutrients are packed into a mere 180 calories. Can you see what this is such a powerful food!? It is a great way to replenish if you haven’t gotten sufficient vitamins due to illness or travel. The B-vitamins are crucial for all of your body’s metabolic processes, and are associated with lower cancer risk. The folate is great for women before, during and after pregnancy. The iron in calf’s liver is a very usable source, meaning our body will recognize it and utilize it properly.

So, even though I’ve never tried calf’s liver and the thought of it was a little scary, I was completely convinced and even excited to try it after I learned all of these health benefits. The recipe is fairly easy but still full of flavor and it makes a great meal.

Recipe

1 lb pastured beef or bison liver, sliced or cubed

1 large onion, chopped

1 large red pepper, seeded and sliced

1 slice pastured bacon, chopped (optional)

Handful of dried figs (about 10-15), stem removed, cut in quarters

½ juicy orange (or one whole lime – orange for a sweet taste, lime for a tart taste)

2-3 cloves garlic, finely chopped

Handful of pine nuts (optional – We used almonds because we didn’t have pine nuts)

½ tsp Celtic sea salt

Freshly ground black pepper

Dash of balsamic vinegar

2-3 tbs stable cooking oil – ghee, coconut oil, butter, etc.

Heat large sauté pan over medium heat. When hot add bacon and cook until tender (not crispy). Add ½ of the cooking oil – heat just to melt. Add onions and sauté until soft and translucent. Add red pepper, figs and pine nuts. Sauté until peppers are soft (not mushy), 5-6 minutes. Push vegetables to outside of pan leaving an empty hole in center.

Add the remaining oil. Melt and add liver. Cook until just browned through, maybe 3-4 minutes (it goes pretty fast, don’t over cook or it will become tough). Incorporate cooked liver with the vegetable/fig mixture. Squeeze orange or lime juice (catching the seeds) over the mixture. Sprinkle with salt and pepper and a dash of balsamic vinegar. Adjust seasoning to taste if needed. Stir another brief minute to incorporate flavors. Serve immediately.

We forgot a few ingredients but followed this recipe for the most part. Ed was already a liver-lover, so I was the wild card this time… and I loved it! I even went back for more. I definitely want to try to make this every few weeks so we can replenish our stores of all the important nutrients. Plus, it’s an easy dinner. I recommend trying it at least once. It’s so good for you, how could you not? Find a place in your city where you can buy calf’s liver from a grass-fed cow or buffalo – most likely a farmer’s market or health food store. Let me know what you think!

We’d love to try a liver mousse at some point too… not quite as healthy but would make a great appetizer if we’re entertaining!