By far our most popular (and least harmful) addictive drug, caffeine is the stimulant in coffee, tea, chocolate, and soft drinks. It is also added to some painkillers, cold medications, weight loss supplements, and drugs used to promote mental alertness.
Within a few minutes after caffeine is ingested, it is absorbed from the small intestine into the bloodstream and carried to all the body’s organs. It speeds the heart rate, stimulates the central nervous system, increases the flow of urine and the production of digestive acids, and relaxes smooth muscles, such as those that control the blood vessels and the airways.
HOW IT HARMS
May cause insomnia.
Ingestion of caffeine late in the day can result in a sleepless night, and excessive intake can lead to caffeinism, a syndrome marked by insomnia, feelings of anxiety and irritability, a rapid heartbeat, tremors, and excessive urination. These symptoms abate with the gradual withdrawal of caffeine.
Irritates the stomach.
Caffeine, especially in coffee, increases the production of stomach acid; ulcer patients or people with GERD should limit caffeine consumption.
Reduces calcium absorption.
Caffeine reduces calcium absorption, which can increase the risk of osteoporosis, especially in older women.
Can cause withdrawal symptoms.
Sudden withdrawal can often cause headaches, irritability, and other symptoms that vary in severity from one person to another.
Aggravates heart conditions.
People with some types of heart-valve disease are very often advised to forgo caffeine altogether because it can provoke heart palpitations or other cardiac arrhythmias. Caffeine can also prompt a modest, temporary rise in blood pressure and speed up the heart rate.
HOW IT HEALS
Provides a boost of energy.
For many people a cup of coffee helps them “get going” in the morning, and coffee or tea breaks during the day give them a boost when energy lags.
May reduce cancer risk.
More than three cups a day lowers women’s risk of developing the most common skin cancer by 20%. Caffeine also cuts men’s risk of dying from prostate cancer.
Wards off depression.
Consuming at least two cups daily reduces women’s chances of becoming depressed by up to 20%.
Enhances athletic performance.
The stimulant in caffeine enhances mental performance by increasing alertness and the ability to concentrate. Studies confirm that 250 mg of caffeine (about two cups of strong coffee) increases endurance, presumably because caffeine increases your ability to burn fat for fuel.
May help control diabetes.
A study of 14,000 people in Finland found that women who drank three to four cups of coffee a day cut their risk of developing diabetes by 29%. For men, it was 27%. Researchers aren’t sure why, but they suspect that the antioxidants in coffee help deliver insulin.
Knocks down migraines.
Although caffeine may trigger migraines in some people, when a migraine strikes, a few cups of coffee do help relieve the pain. Caffeine is so effective at helping to shrink swollen blood vessels in the brain, it’s one of the key ingredients in over-the-counter migraine medicines.
WHO SHOULD LIMIT CONSUMPTION
The following people should limit coffee consumption to one or two cups a day. Tea and other caffeinated beverages may be okay.
• Ulcer sufferers
• Heart patients
• Seniors with hypertension
• Women, especially those who are pregnant, nursing, or have osteoporosis
• Migraine sufferers
AVERAGE CAFFEINE CONTENT
ITEM MG
COFFEE (5 OZ/148 ML)
Decaffeinated 1–5
Espresso (2 oz/60 mL) 90–100
Drip method 100–180
Instant 65–120
TEA (5 OZ/148 ML)
Brewed, 1 min 9–33
Brewed, 5 min 20–50
Decaffeinated 1–5
Iced tea (from mix) 22–36
SOFT DRINKS
(12 OZ/355 ML)
Coca-Cola (Cherry, Classic, or diet) 46
Diet Pepsi 36
Dr. Pepper (regular and diet) 40
Pepsi-Cola 38
RC Cola (regular and diet) 48
Sunkist Orange 40
CHOCOLATE
Baking chocolate (2 oz/60 g) 70
Cold chocolate milk (8 oz/237 mL) 2–7
Hot cocoa (6 oz/180 mL) 5
Sweet or dark chocolate (2 oz/60 g) 40
THE BOTTOM LINE
• Caffeine is a double-edged sword. It has both benefits and drawbacks. For example, it can trigger or help alleviate migraine headaches.
• For most people, caffeine is safe, but if you have ulcers, heart disease, hypertension, or osteoporosis, or are pregnant or breastfeeding, you will want to limit consumption.
Friday, 25 April 2014
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