Updated 13 April 2017

Prevent cancer through nutrition

Eighty percent of all cancers are due to identified factors, and therefore are potentially preventable. And 35 to 50 percent of cancers are linked to food.

Eighty percent of all cancers are due to identified factors, and therefore are potentially preventable, according to the National Cancer Institute. And 35 to 50 percent of cancers are linked to food.

Although no single food or nutrient can prevent cancer, nutrition can definitely reduce the risk of developing some types of cancer. The survival rates of people who have cancer can also be improved.

Eat natural, wholegrain foods
One should always choose foods that are as close to their natural state as possible, says Lauren Atkinson, Discovery's nutritionist.

Refined products, such as white rice, usually have had the nutritious part of the grain removed during processing. These products may be enriched, i.e. they have certain vitamins and minerals added back to them. While "enriched" may sound healthy, many valuable nutrients removed during the refining process are never added back.

In addition, many refined products add other ingredients that are not desirable, such as sugars, salt or fats. It is best to select whole wheat bread over refined flour breads, fresh fruits and vegetables over canned, whole grain cereals over cereals that are heavily sugared, brown rice over white rice and so forth.

Prevent cancer with fibre
Different types of fibre have different effects on the body, but they are generally classified into soluble and insoluble fibre. Both are very important.

The best way to increase your fibre intake is by eating a varied plant-based diet as well as the skins and peels of fruits and vegetables wherever possible, as well as whole grain breads and cereals and legumes.

Restricted fat = reduced risk
Populations with the highest levels of fat consumption have the highest death rates from breast and colon cancer.

Many studies indicate that fat in foods increases the risk for cancer, and it may also adversely affect breast cancer survival rates.

Although the total amount of fat one eats is a concern, animal fat appears to be much more harmful than vegetable (plant) fat.

Prevent cancer with fruit and veggies
Antioxidants are substances that seek out and destroy the naturally occurring toxic molecules called free radicals, which can cause extensive damage to the body's cells. The damage done by free radicals is called oxidative stress, and this is thought to be involved in cancer development.

Vegetables in particular contain high doses of these cancer-fighting antioxidants, as well as being low in fat and high in fibre. In fact, they're so efficient when it comes to fighting cancer, the National Cancer Institute's dietary guidelines for cancer prevention recommends a goal of at least five servings of fruit and vegetables daily.

The main antioxidant found in fruit and vegetables is carotenoid, which is the pigment that gives fruits and vegetables their dark colours. These appear to help prevent cancer, while beta-carotene (specifically found in dark green and yellow vegetables) helps protect against lung cancer and may even help prevent cancer of the bladder, mouth, larynx, oesophagus, breast and other parts of the body.

Too much iron = increased risk
Iron encourages the formation of cancer-causing free radicals and although the body does require a certain amount of iron for healthy blood cells, beyond this it can become harmful. Once iron is absorbed by the digestive tract, the body stores it.

"Iron overload", or accumulating more iron than is needed, is dangerous because the body has no way of ridding itself of the excess. If you do have excessive iron stores and you want to reduce them, the only way is by donating blood. So it's a great opportunity to help yourself and save a life at the same time.

Alcohol = increased risk
Excessive intake of alcohol increases the risk for cancer of the breast, mouth, pharynx, oesophagus and liver. It also increases the risk for stomach, liver and colon cancer. When combined with smoking, these risks increase dramatically.

Alcohol should be limited to no more than one drink a day for women and two drinks a day for men.

Tobacco = increased risk
Apart from all the other harm smoking causes, it's also directly related to mouth, oesophageal and lung cancer, and has been shown to cause an increase in risk of cancer of the pancreas, stomach and bladder.

Smoking can also decrease appetite, which would in turn decrease nutrient intake.

Heterocyclic amines = increased risk
Heterocyclic amines (HCAs) are carcinogenic chemicals formed from the cooking of muscle meats such as beef, pork, poultry and fish.

Factors that influence HCA formation include the type of food, cooking method, temperature and length of time of cooking, but high temperature is the most important factor, with frying, broiling, and braaing producing the largest amounts of HCAs.

Other sources of protein, e.g. milk, eggs, tofu, and organ meats such as liver, have very little or no HCA content naturally or when cooked. And exposure to HCAs can be reduced by varying methods of cooking meats such as microwaving meats more often, especially before frying, broiling, or braaing, as well as avoiding making gravy from meat drippings.

Overweight = increased risk
Higher body weight is harmful to the body in a variety of ways, for example increased risk of heart disease, but in women in particular, it also increases the risk of breast cancer after menopause.

The good news is that before menopause, weight does not increase risk, so if you are menopausal, there's still time to get your weight under control and reduce your risk.

Prevent cancer with exercise
Exercise helps the body to use food effectively. It also builds lean muscle and burns kilojoules. Even without weight loss, exercise is associated with a lower risk of colon and breast cancer.

Since exercise also speeds up transit time of food leaving the body, it may also reduce the risk of colon cancer. But make sure you consult your doctor before starting any exercise programme.

"To reduce your risk of any kind of cancer, a diet that is high in fibre, low in animal and trans-fat, and high in fruit and vegetables is the most powerful prescription," said Lauren Atkinson, Discovery's nutritionist. – (Health24)


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