海帶的所有好處和副作用

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.

    Review

    All comments are moderated before being published

    HealthyPIG Magazine

    View all
    癌症如何擴散:從一個器官走到另一個器官的旅程

    癌症如何擴散:從一個器官走到另一個器官的旅程

    癌症最令人畏懼的地方,不單在於原發腫瘤本身,而是它能夠 轉移(Metastasis) —— 由原本的器官擴散至身體其他部位。事實上,大多數癌症致命的原因,並非來自腫瘤的「原居地」,而是因為它在其他重要器官(如腦、肝、骨、肺)形成了新的腫瘤。

    腦癌種類全面介紹|常見類型與特徵

    腦癌種類全面介紹|常見類型與特徵

    腦癌(Brain Cancer)泛指源自腦部或蔓延至腦部的惡性腫瘤。臨床上可分為兩大類: 原發性腦腫瘤(Primary Brain Tumors):由腦部細胞本身變異而成。 繼發性腦腫瘤(Secondary / Metastatic Brain Tumors):由其他器官的癌細胞(如肺...
    死亡氣味 :科學如何理解生命最後的氣息

    死亡氣味 :科學如何理解生命最後的氣息

    人類死亡後,身體嘅代謝同細胞運作會急劇改變,隨住時間推進,組織開始分解,產生一系列特有嘅氣味化合物。呢種 死亡氣味 (Odor of Death) 唔單止係動物可以嗅到,亦成為法醫學 (Forensic Science) 研究嘅重要領域。甚至有人提出,狗可能能夠嗅到人「臨終前」嘅早期氣味改變。

    狗隻能否嗅出疾病甚至死亡?——從嗅覺科學到臨床研究

    狗隻能否嗅出疾病甚至死亡?——從嗅覺科學到臨床研究

    人類同狗相處幾千年,唔少人都曾經觀察到:狗似乎「知道」主人唔舒服,甚至有人報告狗會喺主人臨終前出現異常行為。呢啲現象令科學家開始研究:狗隻係咪真係可以嗅出疾病,甚至察覺死亡徵兆?

    答案係:狗確實能透過超強嗅覺 (Olfaction) 偵測身體嘅代謝變化,從癌症、糖尿病,到感染性疾病。但關於「臨終氣味」嘅研究仍然有限,更多係臨床觀察。

    幻覺:大腦點樣自己製造「假影像」

    幻覺:大腦點樣自己製造「假影像」

    幻覺 (Hallucinations) 並唔係靈異現象,而係一種 大腦自我製造影像或感覺 嘅過程。當冇外界刺激存在,但大腦卻產生「真實感受」時,就叫幻覺。研究指出,幻覺源於 大腦訊號錯亂神經傳導物質失衡,甚至同 睡眠失調 有密切關係。

    心理學上的「預知錯覺」:點解我哋以為自己可以預測未來?

    心理學上的「預知錯覺」:點解我哋以為自己可以預測未來?

    好多時候,我哋都會有種感覺:「咦!我早就預測到會發生!」,甚至覺得自己擁有「第六感」。但從心理學角度睇,呢種「預知」其實並唔係超能力,而係 大腦嘅認知偏差 (Cognitive Biases)記憶錯亂 (Memory Errors) 造成。以下三個心理現象,最常被誤以為係「預知未來」

    大腦嘅「預測功能」:點解我哋係一部預測機器

    大腦嘅「預測功能」:點解我哋係一部預測機器

    科學研究一直證實,所謂「超自然預知 (Precognition)」並冇可靠證據。但人類大腦本身卻具備一種極強嘅 預測功能 (Predictive Function)。從神經科學角度嚟睇,大腦其實係一部 Prediction Machine(預測機器),不停利用以往經驗去推測未來,再根據新收到嘅感官訊號作出修正。呢種能力解釋咗點解人類可以快速反應、避開危險,甚至提升學習同決策效率。

    遲起身唔等於懶!夜貓同雲雀原來係基因決定

    遲起身唔等於懶!夜貓同雲雀原來係基因決定

    有啲人天生 早睡早起,朝早 6 點自然醒身,精神奕奕;但亦有人喺夜晚最有活力,凌晨兩三點先想瞓。呢種差異唔係單純習慣問題,而係與 Chronotype(睡眠型態) 有關。Chronotype 由基因 (Genetics)、年齡 (Age)、生活環境 (Environment) 一齊決定,直接影響你嘅睡眠時間、精神狀態同工作效率。

    腦淋巴系統:大腦喺瞓覺時點樣「清垃圾」

    腦淋巴系統:大腦喺瞓覺時點樣「清垃圾」

    我哋成日聽人講「瞓覺可以休息大腦」,但其實睡眠唔單止係休息,仲係大腦清理廢物嘅關鍵時刻。近年神經科學發現咗一個重要嘅系統:Glymphatic System(腦淋巴系統),負責喺瞓覺時清除代謝廢物,包括同 阿茲海默症 (Alzheimer’s disease) 有關嘅 β-amyloid(β-類澱粉蛋白)。