What is kelp?
Some kelp are brown in color and can be up to 100 feet long. Other species such as Ecklonia radiata are native to waters around western Australia.
According to the National Oceanic Administration, huge kelp canopies exist in shallow waters and provide shelter and nutrients for a variety of marine life. Like plants on land, seaweed requires sunlight and prefers to grow in nutrient-rich bodies of water.
Certain kelps, such as sugar kelp (Saccharina latissima), thrive in cold waters off the coasts of Connecticut and Maine. These plants are being grown and harvested as a new sea vegetable. According to the Connecticut Department of Agriculture, seaweeds such as kelp extract inorganic and organic nutrients from seawater, making it naturally nutrient-rich.
6 benefits of kelp
1. Low in calories
There are many benefits of kelp to consider. Kelp contains relatively few calories but has a variety of important nutrients. According to the USDA, a 3.5-ounce serving of raw kelp contains only 43 calories.
According to Harvard Health Publishing, eating low-calorie, nutrient-dense plant-based foods may help reduce the risk of several health conditions, including heart disease.
2. It is the birthplace of minerals
Because kelp absorbs nutrients from the surrounding saltwater environment, it is rich in minerals.
According to the U.S. National Library of Medicine, kelp is rich in minerals such as sodium, which are responsible for maintaining the body's fluid balance. One serving of kelp contains 10% of the recommended daily intake.
Kelp also contains small amounts of minerals such as iron, zinc, phosphorus and potassium.
According to the UCSF Medical Center, it contains 168 milligrams of calcium, which is more than many vegetables such as kale and collard greens. Your body needs calcium to maintain strong bone and muscle function.
Kelp also contains high amounts of magnesium, with 121 mg or 29% of the daily value per serving. Magnesium benefits include maintaining muscle and nerve function and regulating blood pressure.
Kelp is also a good source of iron, containing 2.8 mg per serving, or 16% of the daily value. Iron helps you maintain healthy blood cells. It also contains some manganese, potassium, and zinc, which help fight oxidative stress in the body.
3. Rich in vitamins
According to the USDA, kelp is an excellent source of vitamin K, providing 82% of the daily value per serving. Vitamin K is necessary for proper blood clotting and bone metabolism.
Folic acid is an important nutrient for pregnant women and helps prevent birth defects. One serving of kelp provides 180 micrograms, or 45% of the daily value, making it a good source of nutrients.
Kelp also contains the B vitamins riboflavin, pantothenic acid and thiamine, which are needed for normal metabolism and energy production. Additionally, you'll get some vitamin C and vitamin E, which help fight oxidative damage to your cells.
4. It contains antioxidants
Seaweeds such as kelp contain antioxidants, which help reduce disease-causing free radicals and reduce the risk of diseases such as cancer and heart disease.
According to a September 2014 study in Ocean Medicine, antioxidant compounds in seaweed are linked to slower progression of cancer, particularly colorectal and breast cancer. Researchers highlight the importance of seaweed in fighting certain cancers.
5. It provides iodine
According to the National Library of Medicine, the recommended daily intake of iodine for adults is 150 micrograms. People who are pregnant or breastfeeding need 50% more.
Your body needs iodine to produce thyroid hormone properly. Low iodine levels, in turn, can cause hypothyroidism, leading to symptoms of fatigue, depression, weight gain, and intolerance to cold.
6. It can help treat obesity
Seaweed contains several compounds that may have anti-obesity benefits. According to a March 2014 study in Food Chemistry, a natural fiber called alginate extracted from kelp can help prevent 75% of fat absorption in the intestines. Researchers say this could be a viable treatment option for people with obesity.
To help prevent iodine deficiency problems, iodine is often added to table salt. If you follow a low-sodium diet or consume special salt that does not contain iodine, kelp is one of the best natural food sources of iodine.
Severe iodine deficiency can lead to an enlargement of the thyroid gland, called goiter, according to the National Institutes of Health. Moderate iodine deficiency can also lead to lower IQs in infants and children and impaired cognitive abilities in adults. Not getting enough iodine during pregnancy may cause permanent damage to the fetus.
Kelp Supplement Side Effects
Eating kelp is generally considered safe, but kelp supplements may cause side effects in some people.
Iodine in kelp and hypothyroidism
For example, kelp supplements may adversely affect people with hypothyroidism due to their high iodine content. Kelp supplements often contain thousands of times the recommended daily limit of iodine, causing more harm than good.
The Mayo Clinic says too much iodine may worsen hypothyroidism symptoms in people with thyroid abnormalities, especially if iodine deficiency is not the primary cause of hypothyroidism.
According to the American Thyroid Association, the recommended daily intake of iodine for adults is 150 mg, and for those who are pregnant or breastfeeding, the recommended daily intake is 220 to 290 mg.
Arsenic in kelp
Kelp supplements are also particularly high in arsenic. According to the August 2017 study in Analytical Methods: Advancing Methods and Applications, high levels of arsenic are inherently toxic and carcinogenic.
According to a February 2018 study in Analytical & Bioanalytical Chemistry, kelp supplements can cause side effects such as diarrhea, nausea, and general weakness. While the authors initially thought arsenic might be the culprit, others later suggested that excess iodine might also be the cause.
How much is too much?
Although kelp has many health benefits, its high iodine content may make it dangerous to take too much. If you have thyroid disease, iodine allergy, kidney or liver disease, consult your doctor before taking kelp supplements.
Although the upper limit for iodine is 1,100 micrograms, the FDA sets the safe standard for iodine content in kelp supplements at no more than 225 micrograms per day.
It is safe to consume kelp as food, but too much iodine in kelp supplements can overstimulate the thyroid gland, causing inflammation and increasing the risk of thyroid cancer. Large doses of iodine can cause nausea, fever, weak pulse, or a burning sensation in the throat, mouth, and stomach.
kelp interaction
Certain medications, medications, and vitamins can interact with kelp supplements. Taking kelp with the following substances may cause harmful side effects:
- digoxin (lanoxin)
- potassium supplements
- Potassium-sparing diuretics, such as triamterene (Dyrenium, Maxzide, Dyazide), amiloride, and spironolactone (Aldactone)
- Thyroid medications, such as Levoxyl (Synthroid), liothyronine (Cytomel), liotrix (Thyrolar), and Armor Thyroid
How to eat kelp
Although kelp is available in supplement form, it's best to get your nutrients from whole foods. Kelp can be found in Japanese or Korean restaurants and dishes, and you can buy it raw or dried at many specialty grocery stores.
It's easy to incorporate kelp into your diet, along with plenty of vegetables from land and sea. You can add organic dried kelp to soups or use raw kelp strips in salads and entrees. Use dried kelp flakes as seasoning.
Kelp can be eaten hot in soups or stews, cold with oil and sesame seeds, or even blended into smoothies or vegetable juices.