The Tribune - Spectrum



Sunday, October 29, 2000
Keeping fit

The ABC of Vitamin C

You know it’s the nutrient that can prevent colds. But do you know what else can Vitamin C do, asks Francis Sheridan Goulart.

THAT glass of orange juice on your breakfast table can help reduce your blood cholesterol level, fight cancer-causing agents, maintain your eyesight, improve your iron absorption, sharpen your awareness and provide you with many other health benefits. You thought it was just a good-tasting ounce or so of cold prevention.

The Vitamin C, also known as ascorbic acid, in orange juice does much more than stop sneezes. As a matter of fact, although scientists have disputed several of Vitamin C’s apparent benefits, the claim that seems to generate the most controversy is that it has the ability to prevent colds.

The first recorded health benefit of Vitamin C was that it cured scurvy, a disease marked by anaemia, lethargy, weakness, spongy gums and internal bleeding. Vitamin C deficiency can set in whether or not you drink your orange juice. In fact, dietary surveys reveal that 27 per cent of all diets provide less than the recommended daily minimum of ascorbic acid. For the record, Vitamin C is found in raw fruits and leafy vegetables, tomatoes, capsicums, and melons. No matter how much of a nutrition whiz you are, you may not know all the many good reasons to take Vitamin C in large or frequent doses. Here’s a list of ten.

EARLIER COLUMNS
When the kidneys fail
October 8, 2000
Put on your walking shoes
October 1, 2000
Ending life in smoke
September 24, 2000
Cholesterol in health and disease
September 10, 2000
Beware of the silent killer
September 3, 2000
Solution to  weighty problem
August 13, 2000
Back into shape after baby
July 30, 2000
When chubby isn’t cute
July 16, 2000
Help for the underweight
July 2, 2000
Pregnant and healthy
June 18, 2000
Water a must during workout
June 4, 2000
Push-ups for good posture
May 28, 2000
Nurse your injuries with ICE
May 14, 2000

The RDA may be too low for you. The U.S. Recommended Daily Allowance (RDA) for Vitamin C is 60 mg, the amount in one medium orange. But certain people need larger doses, according to Emmanuel Cheraskin, co-author of The Vitamin C Connection. In other words, the requirement for Vitamin C varies with each individual. Your daily need for Vitamin C is boosted by personal habits such as smoking, alcohol or caffeine intake, and drug usage — none of which the RDA takes into account. For example, studies have shown that smokers have 25 per cent less Vitamin C in their blood than do non-smokers (one cigarette burns from 25 to 100 mg Vitamin C). Other conditions also boost your daily Vitamin C requirement. Such factors include emotional stress, fever, infection, pregnancy, athletic activity and old age.

It fights free radicals and deactivates carcinogens. Many scientists have implicated free radicals, a highly destructive form of oxygen, as a cause of degenerative diseases such as cataracts and cancer. Researchers believe that the best way to stop the continuous damage caused by free radicals is to increase your intake of antioxidants. Excellent antioxidants include the mineral selenium and Vitamins E, A and C. Vitamin C also has been found to block the cancer-causing potential of nitrites, an additive found in salted picked and smoked foods. A study conducted at the Massachusetts Institute of Technology found that students at that university who took Vitamin C had their production of nitrosamines — the cancer-causing end product of nitrite digestion — reduced by an average of 81 per cent. 

How to get your daily dose

Food                                                      Mgs per cup

Broccoli spears, cooked                                 135

Orange juice, fresh                                        122

Sweet peppers, cooked                                  122

Lemon juice, fresh                                         113

Brussels sprouts, cooked                                113

Grapefruit juice, frozen                                   95

Cabbage greens, raw                                     50-70

Spinach, cooked                                             50

Tomato juice                                                  39

Fruits (Strawberries, melons, pineapple,           50-120                      

 mangoes)

 Vitamin C has been shown to prevent glaucoma. When most people think of a Vitamin that’s good for the eyes, they think of Vitamin A. There’s no doubt that Vitamin A helps fight night-blindness and xerophthalmia, a disease of the eye that can lead to blindness. But Vitamin A is not the only nutrient that helps maintain proper eyesight. Vitamin C has been found to control glaucoma, a

leading cause of blindness. In glaucoma, the eyeball hardens because of increased pressure on it created by fluids behind it. Several studies, however, have found that Vitamin C reduces this increased pressure. In his 1980 dissertation at New York University, Ben C. Lane, then a doctoral student in ophthalmology, found in a study of 60 people that increasing their average

Vitamin C intake from 75 mg to 1,200 mg reduced intraocular pressure by one-third. 

Vitamin C helps reduce cholesterol levels. The best way to reduce blood cholesterol levels is to cut your intake of saturated fats from milk, fatty meats and many cheeses and increase your intake of whole-grain products, fruits and vegetables. Could ingesting Vitamin C take a place with these hints? According to several sources, the answer is yes. The International Journal of Vitamin Research reports that one 500 mg tablet of Vitamin C taken twice daily reduces fat levels by an average of 13 per cent. The journal also notes that blood-fat levels are two to three times lower when the bloodstream is fortified with Vitamin C. Numerous studies performed in the United States, Czech Republic, England, India and South Africa have found that Vitamin C reduces blood-cholesterol levels. How Vitamin C accomplishes this feat is not clearly understood, though some scientist believe this effect has to do with Vitamin C’s ability to make the liver increase its rate of conversion of cholesterol to bile, a digestive liquid secreted into the intestine. High ascorbic-acid levels also enhance the body’s ability to keep cholesterol within the bloodstream, preventing the dangerous build-up of deposits along artery walls.

Vitamin C maintains your body’s structure. Nails, rivets and concrete keep buildings together. Humans, on the other hand, are assembled with their own ‘cement’ known as collagen. Made of protein, collagen binds all fibrous tissue: skin, tendons, bone cartilage and matrix, ligaments and other connective tissue. Vitamin C is responsible for the formation and maintenance of collagen and the arterial framework through tissues bound by it. A well-maintained collagen structure promotes healing of wounds, fractures, bruises, small-scale hemorrhages and bleeding gums.

Vitamin C helps maintain your iron balance. Does work tire you out completely? Do you feel exhausted when you wake up? Are you constantly too tired even to eat? Does every little effort wear you out? If you answered yes to at least two of these questions, you may have ‘tired blood’. Supplement makers might have you believe that this is a symptom of iron deficiency, because iron is the component of your red blood cells that allows them to carry oxygen. But in order to properly use iron, you need Vitamin C. A study conducted at the University of Washington in Seattle concluded that as Vitamin C intake goes up, so does iron-absorption. Another study conducted at the University of Goteborg in Sweden came to a similar conclusion: ‘Adding orange juice to breakfast more than doubled iron absorption.’ If you think you have ‘tired blood’ the most important factor to consider is your iron intake. Excellent sources of iron include spinach, dried figs, raisings, prunes, raw greens, kidney beans and cooked cracked wheat. But if you seem to be getting enough iron, ask yourself if you’re getting enough Vitamin C.

Vitamin C is a mental nutrient. The brain is one of the two organs in the body that contain the most Vitamin C. (The other organ is the adrenal glands, which sit atop your kidneys. Their secretions regulate your reactions to emergency stress). And Vitamin C plays a major role in brain function. Two researchers at Texas Women’s University found that grammar school students who had higher blood levels of Vitamin C fared better on IQ tests than those with lower amounts. Michael Lesser, author of Nutrition and Vitamin Therapy, says that a daily dosage of 6,000 to 8,000 mg of potassium ascorbate, another form of Vitamin C, can noticeably increase brain activity. Vitamin C can also help spark good feelings within you. In the brain, Vitamin C induces the production of serotonin C induces the production of serotonin, a brain chemical that induces both sleep and positive emotions. It also works with Vitamin B6 to convert the amino acid phenylalanine into norepinephrine, another mood-boosting body chemical.

Caffeine depletes your body’s Vitamin C, and the right teas replenish it. Like cigarettes, caffeine robs your body of Vitamin C. Therefore, you should avoid caffeinated beverages like coffee, cola and tea. In fact, some teas contain as much Vitamin C-depleting caffeine and thobromine (a caffeine-related stimulant) as instant coffee. As an alternative, look for decaffeinated versions of these beverages. Or better yet, keep an eye out for a tea that’s loaded with Vitamin C. Rosehip tea has 20 times the Vitamin C of oranges. Other high-C teas include spearmint, peppermint and lemongrass.

If you’re taking aspirin, take Vitamin C. Drugs, including aspirin, are known to lower ascorbic-acid levels. In 1936, two researchers at Iowa State University found that children taking aspirin had increased Vitamin C levels in their urine — indicating that the body’s store of the nutrient was being depleted. Other drugs that reduce Vitamin C levels include the antibiotic tetracycline, anticonvulsants, arthritis drugs, barbiturates and oral contraceptives. How do you counteract their effect? Take time-release Vitamin C supplements, which release Vitamin C into your blood throughout the day, or natural pain relievers such as willow-bark or feverfew. In her book The Right Dose, Patricia Hausman claims that 2,000 mg of L-trytophan, a precursor of serotonin work as well as one aspirin tablet.

Vitamin C is safe at any dosage. Several serious side effects have been attributed to taking 2,000 mg or more of Vitamin C daily, including blood clotting, kidney stones and infertility. Others claim that high Vitamin C doses distort blood glucose measurements, which is an important consideration for diabetics. These claims are incorrect, according to Cheraskin. In fact, the only health problem high Vitamin C doses may cause with any frequency is diarrhoea. To avert "mega dose diarrhoea", reduce your dosage or switch to sodium ascorbate preparations, which improve your intestines tolerance of Vitamin C. Your intestines will eventually adapt to the presence of high levels of Vitamin C, even without these measures. In fact, some practitioners claim that a dosage that causes mild diarrhoea can build the intestinal tolerance of Vitamin C up to 30,000 mg.

These are only a few of the reasons to increase your Vitamin C intake. It won’t cure or prevent every disease in the book, but it’s an essential nutrient that’s needed for the normal function of many systems in your body. Vitamin C is an integral part of a preventive medicine program.The benefits it offers are reasons enough to make sure you get your daily dose.

Home This feature was published on October 22, 2000Top