CanHOPE is a non-profit cancer counselling and support service provided by Parkway Cancer Centre, Singapore.


Nutrition – FAQ

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Understanding nutritional needs in various cancer treatment is important in caring for them. You may read or been advised by well-meaning friends and family to avoid certain foods or to take supplements. However, some of the information may be contradicting with each other and thus causing confusion.

These frequently asked questions provide clarification and allow you to make an informed choice.

1. Does sugar feed cancer cells?

Carbohydrate is the main source of energy for our body, and it is the only source of energy for our brain. Carbohydrate is broken down into simple sugar in the process of digestion and sugar is the simplest nutrient to be utilised by our body cell. Various carbohydrate foods that we commonly take are fruits, dairy products, rice, noodles, bread, crackers, bean products, and starchy vegetables including potatoes, corn, tapioca, and also drinks and desserts that are sweetened. Hence, there is no need to avoid sugar totally as the body cells would not be able to recognise what is the source of carbohydrate at absorption stage. However excessive sugar intake is not encouraged as sugar itself has no other nutrients but providing calories only. In addition to that, excessive intake of simple sugar could increase our blood sugar more rapidly compared to intake of complex carbohydrate. When our blood sugar level is high, our pancreas will release insulin to convert the sugar. Hyperinsulinemia or excessive production of insulin is thought to cause inflammatory responses in our body that may lead to increased risk of cancer.

2. Are dairy products harmful for our body?

Recombinant bovine growth hormone (rbGH) is class of hormone that increases the amount of milk dairy cows produce. Some suggest that although rbGH itself appears safe, it may increase the amount of other chemicals in the body that might in turn cause cancer. There is currently no definitive proof one way or the other. In response to the lack of certainty, Japan, Canada, Australia, New Zealand and the European Union have banned rbGH. On the other hand, the United States Food & Drug Administration (US FDA) has approved the use of rbGH on the basis that it is biologically inactive in humans.

3. Is honey safe to be consumed? / Is honey better to substitute sugar?

Honey is made up of fructose (~38%), glucose (~31%), water (~17%) and the remaining carbohydrate are maltose, sucrose and some complex carbohydrate. It contains also trace amount of vitamins and minerals, like vitamin C, iron, calcium, phosphate etc.

Honey has anti-bacterial and anti-fungal properties, and it also acts as an anti-oxidant. Hence, taking honey has its benefits. However, if one is on active treatment e.g. chemotherapy, radiation therapy or undergoing stem cell transplantation, honey is not safe to be consumed as most honey is not pasteurised and it may contain pollens or even bacteria that could cause allergy or infection.

You may purchase the pasteurised honey, but you will not obtain its good properties as all the active enzyme would be destroyed under the high temperature during pasteurisation.

4. Is it safe to consume red meat? How much is too much?

Red meat provides nutrients that are not found in white meat, such as iron, zinc and vitamin B12. These nutrients are important in the formation of red blood cells and haemoglobin. Having it once or twice a week would provide sufficient nutrients. On the other hand, if consume too much or too often or in their high fat form, may increase risk of coronary illness and certain cancers.

5. Why is there so much hype about soy beans? Should I avoid it?

Isoflavones is phyto-nutrient found abundantly in soy bean that is also known to be a phyto-estrogen. Phyto-estrogen is a plant estrogen naturally occurring in plant that may act like estrogen in human body. The concern was highlighted particularly for a specific group of cancer patients, i.e. ER positive responsive breast cancer who are prescribed with estrogen-blocker following chemotherapy treatment. There are multiple studies done in different part of the world, different population, race and ewthnicity. It is concluded that phytoestrogen in soy bean do not adversely affect this breast cancer population. Hence, it is advisable to consume soy bean and its products in the frequency and quantity as previously consumed.

6. Can I take supplements during treatment?

There are many type of supplements available in the market that offer various health benefits and claims. One must exercise caution when choosing supplements. Do have a good understanding on reason of taking these supplements. Multi-vitamins and minerals pill which consists of no more than the upper limit of RDA (Recommended Daily Allowance) for all their nutrients are safe to be consumed during treatment.

Antioxidant vitamins & minerals supplements, or phyto-nutrients & phyto-chemicals that act as antioxidants are not encouraged to be consumed during treatment. There are controversies in the benefit of taking these supplements in patients undergoing cancer treatment.

Immune enhancing supplements such as amino acids, protein powder are safe to be consumed during treatment. However, ensure supplements are manufactured by a reputable pharmaceutical company. For any other supplements, it is best to discuss with the Oncologist and/or Dietitian to ensure that you are getting the benefit of these supplements and not overloading your body with the unnecessary pills.

7. Should I go for organic products?

Foods are considered organic food if they are produced without genetic modification, no chemical fertilisers used and with restricted used of conventional pesticides. For livestock, no antibiotic or growth hormones are given. Organic food can be included in the diet of cancer patients but is not always necessary. Given the limited use of food preservatives, organic foods may spoil faster and they may have potentially higher amounts of biotoxins due to the lack of externally applied herbicides/fungicides. Hence, when deciding to buy organic foods, we need to consider the source of the organic foods, it would be ideal if the organic farm that supplies the produce is nearby to ensure shortest transportation time and therefore provide optimum nutritional quality. It is also advisable for consumer to weigh the benefit of organic foods e.g. fruit with hard inedible skins versus fruit with soft & easily bruised skin.

8. What are genetically modified foods (GMO)?

Genetically modified foods are foods produced from organisms that have had specific changes introduced into their DNA using the methods of genetic engineering. These techniques allowed the engineering of crops to be resistance to pathogens, herbicides and/or provide better nutrient profiles. There is broad scientific consensus that food on the market derived from the genetically modified crops poses no greater risk to human health than conventional food.

9. Would I be able to take Traditional Chinese Medicine during cancer treatment?

Traditional Chinese Medicine (TCM) uses completely different ways of assessing health and illnesses. Alternative therapy using TCM to replace conventional cancer treatment such as chemotherapy is not advisable. However, using TCM herbs to help reduce side effects of cancer treatment may be possible.

Do consult your Oncologist for a referral to a TCM physician who will manage your conditions together.

Do avoid taking TCM herbs on the first cycle of treatment to enable your Oncologist to assess your body response to the treatment better.

10. What about Alkaline diet?

Alkaline diet is a dietary protocol based on the consumption of foods which burn to leave an alkaline residue. Foods are classified as alkaline, acidic or neutral according to the pH of the solution created with their ash in water. Diet supposed to maintain the pH of slightly alkalinity of 7.35 to 7.45 of blood without stressing the body’s regulators of acid-base balance. Challenges with this diet include classifications of food, quality of foods before eaten and the mechanism of digestion. Given the fact that our body react naturally to maintain the pH balance by increasing or decreasing respiration, mopping up excess hydrogen ions and eliminating the excess through urination, the role of alkaline diet remains in question.

11. Are there any foods or diets that cause cancer?

There are many ‘anti-inflammatory’ diets and while each plan has its own twist, all are based onthe general concept that constant or out-ofcontrol inflammation in the body leads to ill health, and that eating to avoid constant inflammation promotes better health and can keep disease away.

Example of inflammatory foods for cancer are thought to be:

  • Moulds & toxins: e.g. Aflatoxin in cereals, grains and peanuts and Fumonisin in maize
  • Food preparation;
    • Heterocyclic amines – cooking meat at high temperature, e.g. deep frying
    • Polycyclic aromatic hydrocarbons – produced in meat and fish that has been grilled or barbecue over direct flame
    • N-nitroso, formed in foods containing added nitrates/nitrities, e.g. in meat and fish preserved with salt, preservatives, smoking or drying

The above has been known to increase risk of cancer.

12. Is there any diet to prevent reccurence?

The World Cancer Research Fund and American Institute for Cancer Research reviewed thousands of studies and provided summary of factors that help in preventing cancer and cancer recurrence.

These are:

  • Body Fatness: Be as lean as possible within the normal range of body weight
  • Physical Activity: Be physically active as part of everyday life
  • Limit consumption of energy-dense foods, avoid sugary drinks
  • Eat mostly foods of plant origin
  • Limit intake of red meat and avoid processed meat
  • Limit alcoholic drinks; men not more than 2 drinks per day and women not more than1 drink per day
  • Limit consumption of salted foods, smoked foods, avoid mouldy cereals, grains and pulse
  • Aim to meet nutritional needs through diet alone, if supplement is needed, ensure of known reason