What are the health benefits of turnip greens?

Turnip greens are part of the cruciferous vegetable family, which also includes kale, broccoli, Brussels sprouts, cabbage and rutabaga. These nutrition powerhouses pack in loads of nutrients for little calories and should be top of the list for your weekly grocery run. The bulbous root of the turnip is also edible and provides a bevy of health benefits, however this article will focus on the stem, or leafy green part of the turnip.

Turnip greens rank among the top foods in regards to ANDI score (Aggregate Nutrient Density Index), which measures vitamin, mineral and phytonutrient content in relation to caloric content. Turnip, mustard and collard greens as well as kale and Swiss chard all earn the highest possible score of 1,000 points.

This article provides a nutritional breakdown of turnip greens and an in-depth look at its possible health benefits, how to incorporate more turnip greens into your diet and any potential health risks of consuming turnip greens.

Contents of this article:

1.  Nutritional breakdown of turnip greens
2.  Possible health benefits of consuming turnip greens
3.  How to incorporate more turnip greens into your diet
4.  Potential health risks of consuming turnip greens

Nutritional breakdown of turnip greens

One cup of boiled turnip greens contain 29 calories, 2 grams of protein, 0 gram of fat, 6 grams of carbohydrate, 5 grams of fiber and 1 gram of sugar, 660% of your daily needs for vitamin K, 220% of vitamin A, 66% of vitamin C, 42% of folate, 20% of calcium needs, 14% of vitamin E and 6% of iron.

Along with other leafy greens, turnip greens contain very high nitrate levels (more than 250 mg/100 g). High intakes of dietary nitrate have been shown to lower blood pressure, reduce the amount of oxygen needed during exercise and enhance athletic performance.

Possible health benefits of consuming turnip greens

Healthy skin and hair

Turnip greens are part of the cruciferous vegetable family, which also includes kale, broccoli, Brussels sprouts, cabbage and rutabaga.

When you think of ways to maintain healthy skin and hair, eating turnip greens may not come to mind, but it should! Turnip greens are great for your skin because they are packed full of vitamin A, a nutrient required for sebum production that keeps hair moisturized. Vitamin A is also necessary for the growth of all bodily tissues, including skin and hair.

Adequate intake of vitamin C (one cup of boiled turnip greens provides over 50% of daily needs) is needed for the building and maintenance of collagen, which provides structure to skin and hair.

Iron deficiency is a common cause of hair loss, which can be prevented by an adequate intake of iron-containing foods like collard greens. Not getting enough iron in your diet can also affect how efficiently your body uses energy. Turnip greens are a great non-heme source of iron, along with spinach, lentils and collard greens.

Increasing iron absorption

Iron deficiency is one of the most common nutrient deficiencies in developed countries and a leading cause of anemia. Eating foods that are high in vitamin C with foods that are iron-rich maximizes the body's ability to absorb iron. Turnip greens alone are an excellent source of vitamin C and a good source of iron.

Osteoporosis prevention

Low intakes of vitamin K have been associated with a higher risk for bone fracture. Adequate vitamin K consumption can improve bone health by improving calcium absorption, reducing urinary excretion of calcium and acting as a modifier of bone matrix proteins.⁵ Just one cup of cooked turnip greens provides a whopping 529 micrograms of vitamin K, well above your daily need. Turnip greens are also calcium kings, providing one of the highest calcium contents per gram of any fruit or vegetable.

Cancer prevention and treatment

There are many nutrients in turnip greens that make them great cancer fighters.

For the past 30 years, consuming cruciferous vegetables has been associated with a lower risk of cancer; namely lung and colon cancer. Recently, studies have suggested that the sulfur-containing compounds (namely sulforaphane) that give cruciferous vegetables their bitter bite are also what give them their cancer-fighting power.

Sulforaphane is now being studied for its ability to delay or impede cancer with early promising results associated with melanoma, esophageal, prostate and pancreatic cancers. Researchers have found that the sulforaphane compound can inhibit the enzyme histone deacetylase (HDAC), known to be involved in the progression of cancer cells. The ability to stop HDAC enzymes could make sulforaphane-containing foods a potentially powerful part of cancer treatment in the future.

Turnip greens and other green vegetables that contain high amounts of chlorophyll have been shown to be effective at blocking the carcinogenic effects of heterocyclic amines, which are generated when grilling foods at a high temperature.⁴ If you tend to like your grilled foods charred, make sure to pair them with green vegetables to help negate these effects.

And, as an excellent source of the powerful antioxidant vitamin C, turnip greens can help fight the formation of free radicals known to cause cancer.

Diabetes

Studies have shown that type 1 diabetics who consume high-fiber diets have lower blood glucose levels and type 2 diabetics may have improved blood sugar, lipids and insulin levels. One cup of boiled turnip greens provides about 5 grams of fiber.

The Dietary Guidelines for Americans recommends 21-25 g/day for women and 30-38 g/day for men.

Turnip greens also contain an antioxidant known as alpha-lipoic acid, which has been shown to lower glucose levels, increase insulin sensitivity and prevent oxidative stress-induced changes in patients with diabetes. Studies on alpha-lipoic acid have also shown decreases in peripheral neuropathy or autonomic neuropathy in diabetics.³

Of note, most studies have used intravenous alpha-lipoic acid and it is unsure whether oral supplementation would elicit the same benefits.³

Digestion

Turnip greens are high in both fiber and water content, which help to prevent constipation, promote regularity and maintain a healthy digestive tract.

Fertility

For women of child-bearing age, consuming more iron from plant sources such as spinach, beans, pumpkin and green beans appears to promote fertility, according Harvard Medical School's Harvard Health Publications. 

Adequate folic acid intake is also needed for pregnant women in order to protect their infants against neural tube defects. One cup of turnip greens provides approximately 42% of daily folic acid needs and 6% of iron.

Sleep and mood

The choline in turnip greens is an important nutrient that helps with sleep, muscle movement, learning and memory. Choline also helps to maintain the structure of cellular membranes, aids in the transmission of nerve impulses, assists in the absorption of fat and reduces chronic inflammation.⁶

Folate, also found in collard greens, may help with depression by preventing an excess of homocysteine from forming in the body, which can prevent blood and other nutrients from reaching the brain. Excess homocysteine interferes with the production of the feel-good hormones serotonin, dopamine, and norepinephrine, which regulate not only mood, but also sleep and appetite as well.⁷

Exercise and athletic performance

Dietary nitrate has been shown to improve muscle oxygenation during exercise and has the potential to enhance tolerance during long-term endurance exercise and possibly improve quality of life for those with cardiovascular, respiratory, or metabolic diseases who find activities of daily living difficult because of lack of oxygenation.

Beetroot juice (high nitrate food) improved performance by 2.8% (11 seconds) in a 4-km bicycle time trial and by 2.7% (45 seconds) in a 16.1-km time trial. Beetroot is just one of many vegetables that are high in nitrate. Leafy green vegetables like turnip greens and arugula are among the top sources.⁸

More benefits

Consumption of fruits and vegetables of all kinds has long been associated with a reduced risk of many adverse health conditions. Many studies have suggested that increasing consumption of plant foods like turnip greens decreases the risk of obesity, diabetes, heart disease and overall mortality while promoting a healthy complexion, increased energy, and overall lower weight.

It is important to remember that it is not the individual vitamins, minerals or antioxidants alone that make vegetables like turnip greens such an important part of our diet. It has been proven time and again that isolating these healthful nutrients in supplement form will not provide the same outcomes.

How to incorporate more turnip greens into your diet

Look for turnip greens that have firm, deep green leaves. Smaller leaves will be tenderer and have a milder flavor. Store turnip greens in the refrigerator to keep fresh.

Serve turnip greens with pastas such as orecchiette.

Turnip greens can be enjoyed raw in salads or on sandwiches or wraps, braised, boiled, sautéed or added to soups and casseroles.

Try sautéing fresh garlic and onions in extra-virgin olive oil until soft then add greens and continue to sauté until desired tenderness. 

Avoid frying in bacon fat or lard and make sure to not overcook your greens, which will cause them to have a more potent and bitter sulfur taste. Add black-eyed peas and brown rice for a healthier version of a southern favorite.

Quick tips to incorporate more turnip greens into your daily routine:

• Add a handful of fresh turnip greens to an omelet or scramble
• Throw a handful of turnip greens and blend into a fresh juice or smoothie
• Sauté greens in a small amount of extra-virgin olive oil and season with freshly ground black pepper and freshly grated Parmesan cheese. Eat as a side dish or top your baked potato.

Potential health risks of consuming turnip greens

If you are taking blood-thinners such as Coumadin (warfarin) it is important that you do not suddenly begin to eat more or less foods containing vitamin K, which plays a large role in blood clotting.

If improperly stored, nitrate-containing vegetable juice may accumulate bacteria that convert nitrate to nitrite and contaminate the juice. High levels of nitrite can be potentially harmful if consumed.

Consult with your physician before starting a high-nitrate diet if you have cardiovascular disease or associated risk factors. A high-nitrate diet may interact with certain medications such as organic nitrate (nitroglycerine) or nitrite drugs used for angina, sildenafil citrate, tadalafil, and vardenafil.⁸

It is the total diet or overall eating pattern that is most important in disease prevention and achieving good health. It is better to eat a diet with a variety than to concentrate on individual foods as the key to good health.

References:

1.        USDA National Nutrient Database: Turnip greens, cooked, boiled, drained, without salt, National Nutrient Database for Standard Reference Release 26, accessed 3 June 2014.

2.        Powerful prostate cancer fighters - from arugula to wasabi, cruciferous veggies pack a powerful punch, Webb, Densie PhD, RD., Today’s Dietitian
, Vol. 13 No. 10 P. 20, accessed 3 June 2014.

3.        Alpha-lipoic acid, Nutrition 411, last reviewed August 2012, accessed 3 June 2014.

4.        Anticancer compounds found in food, Machowsky, Jason, MS, RD, CDN, CSCS, Nutrition 411, last reviewed February 2012, accessed 3 June 2014.

5.        Bone health: looking beyond calcium, Nutrition 411, last reviewed March 2009, accessed 3 June 2014.

6.        Choline, Nutrition 411, last reviewed December 2008, accessed 13 February 2014.

7.        Depression and diet, Nutrition 411, review Date November 2008, accessed 20 February 2014.

8.        Reap the benefits of beetroot juice — evidence suggests it improves heart health and athletic performance, Ellen Coleman, MA, MPH, RD, CSSD, Today’s Dietitian
, Vol. 14 No. 2 P. 48, February 2012 Issue, accessed 8 September 2014.