Nutrition is a modifiable risk factor for cancer, which can be lowered by medical nutrition therapy from a dietitian. Annica Rust elaborates further.
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The World Health Organisation documented cancer as a leading cause of death worldwide in 2020. The risk of developing cancer is dependent on modifiable and non-modifiable risk factors. Non-modifiable factors include: genetic predisposition, gender, age and ethnicity, whilst modifiable risk factors are related to environment and lifestyle, such as nutrition and activity factors. A dietitian plays an important role by providing medical nutrition therapy (MNT) for cancer prevention, treatment, survivorship, and palliation.
1. Cancer prevention and survivorship
Dietitians will focus on providing individualised MNT for cancer prevention and survivorship. More generalised recommendations would include: to be physically active for at least 30 minutes per day; to be of a healthy weight; avoiding consumption of energy-dense foods and sugary drinks; increasing intake of foods with a plant-based origin (a diet rich in whole grains, vegetables, fruits and beans); limiting consumption of red meat, alcoholic beverages, salt and processed meats; breastfeeding your infant and not replacing a balanced diet with supplements.
2. Cancer treatment
Nutrition plays a vital role in the development of cancer due to the dietary compounds which can modify a few cancer-causing processes, such as carcinogen metabolism, cell differentiation, and tumour growth. The type of tumour, its location, grade, stage, and medical treatment thereof can influence digestion, absorption, and metabolism of food and may contribute to nutrition-related symptoms. These include: nausea and vomiting; changes in taste and smell; bowel changes; difficulty speaking; anorexia; pain; and fatigue. It’s important to consult with a dietitian for nutritional management of these symptoms.
Nutrition intervention goals
Dietitians keep nutrition intervention goals in mind when planning treatment for cancer patients. Nutrition intervention goals are to preserve lean body mass; to prevent and/or reverse nutrient deficiencies; preventing malnutrition and to minimise nutrition-related side effects, whilst maximising the quality of life.
Optimal nutritional care will improve recovery after treatment, prevent complications, and will shorten the length of hospital stays. The nutritional needs depend on the type and stage of cancer, as well as the treatment regime (chemotherapy and radiation). Most cancer patients’ protein and energy requirements increase during treatment, as protein requirements are increased to repair the tissue that has been damaged by chemotherapy. Inadequate energy intake will cause the breakdown of lean body mass to supply the body with energy.
Dietitians are required to take a nutritional assessment. The assessment information together with your prognosis, presence of other diseases, degree of malnutrition, intent of treatment, anticancer therapies, and the ability to eat are used to calculate your nutritional needs and to accordingly provide MNT. Oral nutritional support is the gold standard in nutrition care to achieve nutritional goals. Oral support includes: dietary modifications, oral supplementation, or the improvement of current dietary plans. If nutritional needs can’t be met orally, nutritional therapy can be provided via a feeding tube to the stomach or small intestine or where it bypasses your stomach and intestines and is delivered directly into your veins.
Malnutrition is prevalent among cancer patients. The indicators of malnutrition are unintentional weight loss, low nutrient intake, and low serum albumin levels (measured from blood results). Cancer cachexia is a wasting syndrome associated with protein-energy malnutrition. Weight loss in cancer patients is often due to a loss of muscle and adipose tissue, which can, if left untreated, progress to severe wasting.
Body mass index (BMI) can be misleading in cancer patients with pre-existing obesity as a higher or normal BMI can’t indicate the difference between the loss of lean body mass or body fat mass. Accordingly, dietitians play an important role in the early identification of malnutrition in such patients, which can improve prognosis and quality of life.
Palliative care is an approach to improve your quality of life and your family’s when curative care is no longer considered by your medical team. The primary goal is to improve your quality of life and to keep you as comfortable as possible.
Dietary recommendations don’t focus on weight loss or weight gain, but rather on identifying and managing the nutritional factors that have a negative impact on your quality of life.
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- The American Institute for Cancer Research.2023. https://www.aicr.org/wp-content/uploads/2020/01/aicr-cancer-prevention-recommendations-scaled.png
- https://www.rdnutritionconsultants.com/single-post/top-10-reasons-to-see-an-oncology-dietitian | https://www.oncology-sa.co.za/diet-and-nutrition-during-cancer-treatment/
MEET THE EXPERT – Annica Rust
Annica Rust is a registered dietitian practicing at the Breast Care Unit at Netcare Milpark Hospital, as well as in Bryanston. She assists with medical nutritional therapy for cancer prevention, treatment, survivorship and palliation. She gives individualised nutritional care to prevent or reverse nutrient deficiencies, nutrition-related side effects and malnutrition to maximise quality of life.
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