Swiss chard is a highly nutritious vegetable. Just one cup provides over three times the recommended daily allowance of vitamin K.
It is also commonly known as silverbeet, spinach beet, perpetual spinach, crab beet, and mangold.
Along with other leafy greens and descendants of the beet family, Swiss chard contains high levels of nitrates, which been shown to lower blood pressure, reduce the amount of oxygen needed during exercise, and enhance athletic performance.
This article is part of a collection of articles on the health benefits of popular foods.
According to the USDA National Nutrient Database, a 36-gram (g) cup of raw Swiss chard contains:
- 7 calories
- 0.65 g of protein
- 0.07 g of fat
- 1.35 g of carbohydrate, including 0.6 g of fiber and 0.4 g of sugar
One 36-g cup of cooked Swiss chard provides:
- 18 milligrams (mg) of calcium
- 0.65 mg of iron
- 29 mg of magnesium
- 17 mg of phosphorus
- 136 mg of potassium
- 10.8 mg of vitamin C
- 110 micrograms (mcg) of vitamin A
- 0.68 mg of vitamin E
- 298 mcg of vitamin K
- 5 mcg of folate
Swiss chard also contains lesser amounts of thiamin, riboflavin, niacin, pantothenic acid, vitamin B6, calcium, phosphorus, zinc, and selenium.
A cup of Swiss chard provides 44 percent of the daily allowance of vitamin A and 18 percent of the recommended amount of vitamin C.
However, consumers should not add salt to Swiss chard, because it already has 103 mg of sodium per raw cup, which is 4.5 percent of the recommended daily allowance.
Consuming fruits and vegetables of all kinds is associated with a reduced risk of many adverse health conditions.
Many studies have suggested that consuming more plant foods such as Swiss chard decreases the risk of obesity, diabetes, heart disease and overall mortality and promotes a healthy complexion, increased energy, and overall lower weight.
Lowering blood pressure
People whose diets are low in the minerals calcium, magnesium, and potassium are more likely to have high blood pressure.
These minerals are thought to reduce blood pressure by releasing sodium out of the body and helping arteries dilate.
Taking these minerals in supplement form will not provide the same health benefits as consuming them in food.
Swiss chard contains all three of these healthy minerals and can help improve intake, especially with magnesium.
A 2013 study published in the British Journal of Clinical Pharmacology, found that foods that are high in dietary nitrates, like Swiss chard, have multiple vascular benefits. These include reducing blood pressure, inhibiting platelet aggregation, and preserving or improving endothelial dysfunction.
Swiss chard contains chlorophyll, which may be effective at blocking the cancer-causing heterocyclic amines generated when grilling foods at a high temperature.
Consuming leafy greens and other vegetables high in chlorophyll along with grilled meats may hinder some of their carcinogenic effects.
Swiss chard contains an antioxidant known as alpha-lipoic acid. This has been shown to lower glucose levels, increase insulin sensitivity, and prevent oxidative stress-induced changes in patients with diabetes.
Studies suggest that it can also reduce the symptoms of peripheral neuropathy or autonomic neuropathy in people with diabetes. It may also protect against retinopathy, damage to the blood vessels that can affect people with diabetes.
However, the alpha-lipoic acid studied was given intravenously. Some studies have suggested that oral intake is not sufficiently effective.
Adequate vitamin K consumption can improve bone health. Vitamin K modifies bone matrix proteins, improves calcium absorption, and reduces urinary excretion of calcium.
Low intakes of vitamin K have been associated with a higher risk of bone fracture.
One way to increase vitamin K intake is by consuming leafy greens such as Swiss chard, arugula, and spinach. These also add extra calcium to the diet.
One 36-gram cup of raw Swiss chard contains 298 micrograms (mcg), of vitamin K. The recommended daily allowance in the United States is 120 mcg for men and 90 mcg for women.
Improving athletic performance
Dietary nitrates have been shown to improve muscle oxygenation during exercise.
This suggests that a higher intake of nitrates may enhance exercise tolerance during long-term endurance exercise.
In one study, beetroot juice, also high in dietary nitrates, improved performance by 2.8 percent over 11 seconds in a 4-kilometer (km) bicycle time trial. It improved it by 2.7 percent over 45 seconds in a 16.1-km time trial. Swiss chard has a similar nitrate content to beetroot.
A review published in 2015 suggests that an additional intake of nitrates probably has little or no effect on exercise performance, especially in trained athletes.
However, the beneficial effects of nitrates on the cardiovascular system may mean it can improve quality of life for those with cardiovascular, respiratory, or metabolic diseases. These conditions can make daily living difficult because of a lack of oxygenation.
Look for Swiss chard with firm, deep green leaves. Smaller leaves will be tenderer and have a milder flavor. Store chard in the refrigerator to keep fresh.
Swiss chard can be enjoyed raw in salads or on sandwiches or wraps, braised, boiled, sautéed or added to soups and casseroles.
Here are some tips to incorporate more Swiss chard (leaves and stems) into the daily routine:
- Add a handful of fresh Swiss chard leaves to an omelet or scrambled eggs.
- Throw a handful of Swiss chard leaves and stems into a fresh juice or smoothie before you blend.
- Sauté Swiss chard leaves and stems in a small amount of extra-virgin olive oil and season with freshly ground black pepper, minced garlic, and freshly grated Parmesan cheese. Eat as a side dish or as a baked potato topping.
- Add Swiss chard to salads, wraps, sandwiches, or flatbreads.
People who are taking blood-thinners such as Coumadin, or warfarin, should not suddenly change the number of foods they eat that contain vitamin K. Vitamin K plays a large role in blood clotting so it could interfere with the effectiveness of blood thinners.
It is important to remember that 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.