High blood pressure 高血压

Blood pressure is the force applied against the walls of the arteries as the heart pumps blood through the body. The pressure is determined by the force of the heart, the amount of blood pumped and the size and resistance of the arteries. The force (blood pressure) may be higher when arteries are blocked by atherosclerosis, when blood is thicker (e.g. less water content or higher salt content) or when there are abnormal hormone levels.

What do blood pressure number indicate?

Diastolic Systolic  Pulse pressure
Normal range 60-80 100-130 35-45

Blood pressure readings are given in two numbers. The top number is the maximum pressure your heart exerts while beating (systolic pressure), and the bottom number is the amount of pressure in your arteries between beats (diastolic pressure). The numeric difference between your systolic and diastolic blood pressure is called your pulse pressure. For example, if your resting blood pressure is 120/80 millimetres of mercury (mm Hg), your pulse pressure is 40 — which is considered a normal and healthy pulse pressure.

The pulse pressure may be abnormal even if the absolute blood pressure readings are within the ‘normal’ range.

  • If the pulse pressure is below 40, it may indicate low heart power and/or very viscous blood (which is typical for diabetes patients)
  • If the pulse pressure is above 40, it may indicate constricted arteries and atherosclerosis.

Possible signs and symptoms

Usually, no symptoms are present. Occasionally, there may be a mild headache. If, under high blood pressure, the headache is severe or symptoms below are experienced, please advise visiting the doctor immediately:。 Other symptoms include: fatigue, confusion, vision changes, crushing chest pain, heart failure, blood in urine, nosebleed, irregular heartbeat or buzzing in the ears.

Applied nutrition

Please refer to the section: applied nutrition for heart disease.

Supplement Benefit Suggested Dosage

Magnesium 鎂

Overview

Every organ in the body, especially the heart, muscles, and kidneys, needs the mineral magnesium. It also contributes to the makeup of teeth and bones. Most important, it activates enzymes, contributes to energy production, and helps regulate calcium levels, as well as copper, zinc, potassium, vitamin D, and other important nutrients in the body.

You can get magnesium from many foods. However, most people do not get as much magnesium as they should from their diet. Foods rich in magnesium include whole grains, nuts, and green vegetables. Green leafy vegetables are particularly good sources of magnesium.

Although you may not get enough magnesium from your diet, it’s rare to be severely deficient in magnesium. Certain medical conditions, however, can upset the body’s magnesium balance. For example, an intestinal virus that causes vomiting or diarrhea can cause temporary severe magnesium deficiencies. Some gastrointestinal diseases (such as irritable bowel syndrome or IBS and ulcerative colitis), diabetes, pancreatitis, hyperthyroidism (high thyroid hormone levels), kidney disease, and taking diuretics can lead to deficiencies. Too much coffee, soda, salt, or alcohol, as well as heavy menstrual periods, excessive sweating, and prolonged stress can also lower magnesium levels.

Symptoms of magnesium deficiency may include agitation and anxiety, restless leg syndrome (RLS), sleep disorders, irritability, nausea and vomiting, abnormal heart rhythms, low blood pressure, confusion, muscle spasm and weakness, hyperventilation, insomnia, poor nail growth, and even seizures.

Uses

Getting enough magnesium may enhance the effectiveness of conventional treatment for the following conditions:

Asthma
Several studies show that intravenous (IV) magnesium and magnesium inhaled through a nebulizer can help treat acute attacks of asthma in children 6 – 18 years of age, as well as adults. Low levels of magnesium may increase risk of developing asthma. A population based clinical study of more than 2,500 children 11 – 19 years of age found that low dietary magnesium intake may be associated with risk of asthma. The same was found in a group of more than 2,600 adults 18 – 70 years of age.

Depression
Inadequate magnesium appears to reduce serotonin levels, and antidepressants have been shown to raise brain magnesium. A 2008 study found that magnesium was as effective as the tricyclic antidepressants in treating depression among people with diabetes.

Diabetes
People who have type 2 diabetes often have low levels of magnesium in the blood. A large clinical study of over 2,000 people found that getting more magnesium in the diet may help protect against developing type 2 diabetes. Some studies suggest that taking magnesium supplements may help blood sugar control and insulin sensitivity in people with diabetes or prediabetes.

Noise related hearing loss
One study suggests that taking magnesium may prevent temporary or permanent hearing loss due to very loud noise.

Arrhythmia and heart failure
Magnesium is essential to heart health. Studies suggest a possible association between a modestly lower risk of CHD in men and increased magnesium intake. In one study of women, higher dietary intakes of magnesium were associated with a lower risk of sudden cardiac death. Magnesium helps maintain a normal heart rhythm and is sometimes given intravenously (IV) in the hospital to reduce the chance of atrial fibrillation and cardiac arrhythmia (irregular heartbeat). People with congestive heart failure (CHF) are often at risk for developing cardiac arrhythmia.  One well designed study found that taking magnesium orotate for a year reduced symptoms and improved survival rates compared to placebo in people with CHF. Magnesium and calcium work together at very precise ratios to ensure your heart functions properly.

Results of studies using magnesium to treat heart attack survivors, however, have been mixed. Some have reported lower death rates, as well as fewer arrhythmias and improved blood pressure when magnesium is used as part of the treatment following a heart attack.

High blood pressure
Eating low fat dairy products, along with lots of fruits and vegetables on a regular basis, is associated with lower blood pressure. All of these foods are rich in magnesium, as well as calcium and potassium. A large clinical study of more than 8,500 women found that a higher intake of dietary magnesium may decrease the risk of high blood pressure in women. A few studies also suggest that magnesium supplements may help lower blood pressure, although not all studies agree.

Migraine headache
A few studies suggest that taking magnesium supplements may help prevent migraine headaches. In addition, a few clinical studies suggest that magnesium supplements may shorten the duration of a migraine and reduce the amount of medication needed. People who have migraine headaches tend to have lower levels of magnesium compared to those with tension headaches or no headaches at all.

Some experts suggest combining magnesium with the herb feverfew along with vitamin B2 (riboflavin) may be helpful when you have a headache.

However, some studies suggest that magnesium sulfate may be less effective than prescription medications for preventing migraines in those who have 3 or more headaches per month. The only exception to this may be women who get migraine headaches around the time of their period.

Osteoporosis
Not getting enough calcium, vitamin D, magnesium, and other micronutrients play a role in the development of osteoporosis. To prevent osteoporosis, it is important to get enough calcium, magnesium, and vitamin D; to eat a well balanced diet; and to do weight bearing exercises throughout life.

Preeclampsia and eclampsia
Preeclampsia is characterized by a sharp rise in blood pressure during the third trimester of pregnancy. Women with preeclampsia may develop seizures, which is then called eclampsia. Magnesium, given in the hospital intravenously (IV), is the treatment of choice to prevent or treat seizures associated with eclampsia or to prevent complications from preeclampsia.

Premenstrual syndrome (PMS)
Scientific studies suggest that magnesium supplements may help relieve symptoms associated with PMS, particularly bloating, insomnia, leg swelling, weight gain, and breast tenderness. One study suggests that a combination of magnesium and vitamin B6 may work better than either one alone.

Dietary Sources

Rich sources of magnesium include tofu, legumes, whole grains, green leafy vegetables, wheat bran, Brazil nuts, soybean flour, almonds, cashews, blackstrap molasses, pumpkin and squash seeds, pine nuts, and black walnuts. Other good dietary sources of this mineral include peanuts, whole wheat flour, oat flour, beet greens, spinach, pistachio nuts, shredded wheat, bran cereals, oatmeal, bananas, and baked potatoes (with skin), chocolate, and cocoa powder. Many herbs, spices, and seaweeds supply magnesium, such as agar seaweed, coriander, dill weed, celery seed, sage, dried mustard, basil, cocoa powder, fennel seed, savory, cumin seed, tarragon, marjoram and poppy seed.

It is a good idea to take a B vitamin complex, or a multivitamin containing B vitamins, because the level of vitamin B6 in the body determines how much magnesium will be absorbed into the cells.

Upper Limits

The Council for Responsible Nutrition recommends an upper limit of 400 mg per day (supplemental) for healthy adults.

Sources

University of Maryland Medical Center
Council for Responsible Nutrition