Vitamin C Helps You to Fight Cancer

It is time to rewrite our nutrition textbooks. The textbooks of yesterday tell us that vitamin C prevents scurvy. They talk of the vitamin’s role in healing wounds. They explain that vitamin C aids in the formation of collagen, which holds cells together.

But an update is in order. It is not that vitamin C does not do these things. Rather, it does more – much more.

It may very well help to prevent cancer, says the Committee on Diet, Nutrition, and Cancer (of the U.S.). The panel members were impressed enough with studies of vitamin C and Cancer to advise us to eat foods rich in vitamin C every day.

Scientists have found that cancers of the stomach and esophagus are less common among people who eat diets rich in vitamin C. In fact, year-round access to foods rich in vitamin C may be one explanation for the dramatic fall in stomach cancer rates in the case of the United States.

Stomach cancer was common in the United States at the turn of the 20th century, when some fruits and vegetables were available only seasonally. We now have year round access to these fruits and vegetables, and many are rich in vitamin C. And stomach cancer is no longer common. It does remain a major health problem in some parts of the world.

A few studies also tie vitamin C to lower risk of bladder and colon cancer. But there is not enough research yet to make a firm judgment about vitamin C’s  ability to protect against these two forms of cancer.

How Vitamin C Protects Us

We have a pretty good idea of how vitamin C works to prevent cancer. Substances in food called nitrites can turn into cancer-causing nitrosamines during cooking or digestion. Bacon, of course, has a particularly bad record;  nitrosamines have often been found in it after cooking.

Laboratory scientists know that nitrosamines can be created by letting certain chemicals come in contact with each other. yet when vitamin C is added to the chemical mixture that normally results in nitrosamines, fewer of them form. In some cases, vitamin C has completely blocked the formation of nitrosamines.

Can the same thing happen in our bodies? Studies around the globe suggest that the answer is yes.

In the U.S., a team of  researchers found that the chances of developing cancer of the esophagus went down as the amount of fruits and vegetables in the diet went up. Researchers also know that Americans and Western Europeans have fairly low rates of stomach cancer. These countries enjoy access to a variety of fruits and vegetables.

On the other hand, fruit and vegetable intake is low in some of the regions where stomach and esophageal cancer are rampant. Iranians living along the coast of the Caspian Sea, for instance, have alarming rates of esophageal cancer. Researchers sent to find out why noted that fruits and vegetables were almost absent from the diets of these people.

Another Role for Vitamin C

Scientists have known for decades that vitamin C can block the chemical reaction called oxidation. Oxidation is the process that causes food to become rancid. Substances that prevent oxidation are called antioxidants.

Until recently, no one realized that antioxidants might help protect against cancer. But they very well may. Scientists now believe that some chemicals cause cancer only if oxidized. By preventing oxidations, vitamin C may cut down on our exposure to cancer-causing chemicals.

The Recommendation and How to Meet It

“Eat fruits, vegetables…… daily, especially those high in vitamin C,” advises the Committee on Diet, Nutrition, and Cancer. This is going to be a popular recommendations. Almost everyone – from babies to adults – likes foods rich in vitamin C.

To follow the committee’s advice, take a look at the following chart. It rates foods as low, medium, or high in this vitamin.
How about animal foods? Animal foods are not listed because the supply less than 10 % of the vitamin C in our diet. Fruits and vegetables are the foods to depend on for this nutrient.

Vitamin C in Fruits and Vegetables

Low * Medium ** H i g h ***
Apples Apricots Asparagus
Celery Bananas Broccoli
Cucumber Beets Brussels sprouts
Grapes Blackberries Cabbage
Pears Carrots Cantaloupe
Plums Cherries Cauliflower
Pumpkins Corn Grapefruit
Dark green leafy vegetables Green pepper
Kale Kohlrabi
Mangoes Lemons
Peaches Limes
Potatoes (white) Oranges
Spinach Peas
Summer squash Pineapple
Watermelon Raspberries
Winter squash Strawberries
Sweet potatoes
* Low: ** Medium: ** High:
Less than 5 mg per average serving. 5 to 20 mg per average serving. More than 20 mg per average serving.

Adapted from the work of Committee on Diet, Nutrition, and Cancer, National Academy of Sciences, USA, 1989

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