Understanding the links between nutrition and childhood cancer

When children have cancer, one of the biggest daily challenges is feeding them. The cancer itself often causes weight loss. Cancer treatment can make children feel nauseous and lose their appetites just when they should be getting better nutrition to help them through the rigours of treatment.

Enter Amy Lovell. A lecturer in nutrition and dietetics at the University of Auckland’s Faculty of Medical and Health Sciences, she’s also a casual paediatric dietitian at Starship Child Health. She has seen how children with cancer struggle to eat, the weakness this causes and the distress their families experience. 

Despite this, few specifics are known about how cancer and cancer treatment affect children’s body composition and nutrient intake, never mind about how best to provide nutritional support for paediatric cancer patients. With newly announced research funding from the University of Auckland’s Centre for Cancer Research, the up-and-coming researcher is working to change that.

“Research abroad has shown links between nutrition and outcomes like infection, longer hospital stays and even survival,” says Lovell, noting New Zealand data is lacking. “And yet, particularly for child cancer, nutrition doesn’t get the attention it needs.”

Lovell suspects nutritional inequities may be behind the differences in survival that emerge between Māori and non-Māori as children diagnosed with cancer grow older. She wants to prove it.

“Without the data demonstrating the need for nutritional intervention, health professionals have a hard time advocating for interventions that may reduce inequalities and enhance Māori childhood cancer survivors' wellbeing long-term,” says Lovell.

How cancer affects children’s bodies

Children eat a lot for their body size because they’re growing, which demands energy. Having cancer demands even more. If these energy needs aren’t met, the body’s muscle stores are used, further weakening the patient. Even once treatment begins, the side effects patients experience can also cause weight loss.  

“Chemotherapy doesn’t just attack cancer cells. It attacks all cells in the body, particularly the ones that replicate frequently, like the cells that line our gastrointestinal tract from our mouth right through to the end,” says Lovell. “These treatments can cause mouth pain, affect our bodies’ ability to absorb nutrients well, cause massive amounts of nausea and make our tastebuds interpret tastes differently, so foods we love start to taste like metal.”

All this is true for adults as well as children. But children are extra vulnerable because even healthy children tend to be picky eaters. Children who feel nauseated or who are experiencing taste changes are less likely than adult cancer patients to regularly drink something like a chalky supplement drink. 

“They feel unwell, so they don’t eat, and because they don’t eat, they feel more unwell,” says Lovell. 

While weight loss is common, excessive weight gain can also occur, often as a side effect of steroid treatment. Unlike the steroids some athletes illegally use to put on muscle, the steroids used to treat some types of cancer can lead to increased fat mass and losses in muscle mass.

How cancer affects families and survivors

Cancer places tremendous strain on whānau. Families often travel long distances to access treatment and may have to stay in temporary accommodations where cooking is difficult. Even for Auckland families, having a child with cancer imposes costs – both financial and emotional. 

“Though hospitals provide food, families want to provide foods their children are interested in eating,” says Lovell. “Feeding your child is such a primal thing as a parent. You feel it’s something you should be able to do no matter what. So we see parents spending time making food and then their children not being interested in eating it, thus perpetuating a cycle of frustration for both child and parent.”

All these factors often result in children falling into unhealthy dietary habits.

“When a child has a small appetite, parents may feel any calorie is a good calorie. Unfortunately, that means McDonald’s might take a front seat in children’s diets,” says Lovell. “Because treatments are getting better, we need to think about what happens to survivors as they get older. We know some cancer medications are hard on people’s hearts while others affect the pancreas. So we’ve already got increased risks of heart disease and diabetes, and if children develop unhealthy changes in body composition, with more fat mass than lean muscle mass, we’re potentially exacerbating those risks.”

Feeding a child being treated for or recovering from cancer may come with other complications. Children may have suppressed immune systems, making them extra vulnerable to foodborne disease. Children who had feeding tubes may need to relearn how to eat. What’s more, families returning to smaller centres may have little support, since the hospitals close to them may not have dietitians with training in paediatric oncology – or any paediatric dietitians at all.

Researching children’s body composition and micronutrient status

Lovell and colleague Gemma Pugh, who is research lead with the National Child Cancer Network, have received a grant from the Centre for Cancer Research to collect foundational data on children being cared for at the Starship Blood and Cancer Centre in Auckland, which treats nearly three-quarters of the 150 children diagnosed with cancer every year in New Zealand.

The researchers aim to track participating children over a year, starting when they’re diagnosed and regularly taking blood samples and body composition measurements as well as noting their nutritional history and current dietary intake. The blood samples will be analysed for signs of micronutrient abnormalities and malnutrition. 

Researchers in Scotland and the Netherlands have shown micronutrient deficiencies in child cancer patients are associated with poor outcomes, including treatment tolerance, treatment-related toxicity, risk of infection, impaired wound healing, patient quality of life and chronic disease into adulthood. It’s vital to do similar research in New Zealand to understand what’s going on in our population – particularly different communities within our population, says Lovell.

“While there are no differences in the diagnosis of childhood cancer in Māori versus non-Māori in New Zealand, we do see inequities in survival emerge between Māori and non-Māori with increasing age. Providing insight into the nutritional status and body composition of children with cancer, as well as how changes in nutritional status affect cancer outcomes, will enable health professionals to better support whānau during their child's cancer journey.”

Lovell and Pugh have also applied for a grant to do a data-linking study using the New Zealand Children’s Cancer Registry, which has collected data from paediatric patients for more than 20 years. 

“We’ll look at complications like infection, relapse and death over five years, with data from around 600 patients,” says Lovell. “I think that will give us a clear picture of the relationship between a child’s nutrition status, their diagnosis and what happens later on.”

The big picture on nutrition and childhood cancer

Lovell has many more reserach plans. With a summer student, she wants to do a qualitative study interviewing paediatric cancer patients and their whānau to better understand their needs and their experience of treatment. The study will use a Kaupapa Māori-consistent research approach.

Longer term, Lovell would like to trial targeted nutrition and physical activity therapy interventions in childhood cancer patients. That research would aim to improve treatment outcomes through nutritional invertentions and appropriate exercise to maintain muscle mass.

Lovell has an ambitious vision for changing cancer treatment approaches across New Zealand to include more emphasis on nutrition. She’d like to see standardised guidelines on nutrition and physical activity for childhood cancer patients; regular monitoring of patients’ height, weight and micronutrient status; more support for parents; and more ongoing dietetic support across the country, including for longer-term childhood cancer survivors.

“I get quite frustrated when people don’t understand the value and importance of nutrition in the clinical setting,” says Lovell. “I really want nutrition to be prioritised as a key pillar in the care pathway for children with cancer. It’s not an optional extra. It has real impacts on outcomes. My research is about proving that.”


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