WHY FOOD SUDDENLY FELT SO IMPORTANT

Before Stu was diagnosed, food was something we loved. We loved eating out, cooking, going for dinner and sharing food with friends. We even had KFC on our wedding night (yuk - I absolutely would never eat KFC these days!). Food was enjoyable and social and normal.

Then Stu got brain cancer and suddenly food became another thing I felt I needed to understand. When someone you love is diagnosed with an aggressive cancer, you start looking for anything that might make a difference. Treatment decisions, second opinions, clinical trials, supplements, exercise and, inevitably, food. I read constantly and there was an enormous amount online about cancer diets, sugar, carbohydrates, dairy, organic food, fasting, ketogenic diets and foods that supposedly helped fight cancer. Some of it was useful. Some of it was contradictory. Some of it was presented with a level of certainty that, looking back now, wasn't justified.

But at the time I wasn't calmly assessing the quality of nutritional research. My husband had glioblastoma and I wanted to keep him alive. If changing what we ate had even the slightest possibility of helping, of course I was going to investigate it.

WHAT WE CHANGED

We changed quite a lot. We reduced refined sugar and carbohydrates, increased the amount and variety of vegetables Stu ate and became much more conscious of the quality of the food we bought. Where we could, I bought organic produce. Food became another part of the enormous protocol we were building around Stu alongside conventional treatment and everything else we were investigating.

I was particularly interested in foods and ingredients that were being researched in relation to cancer, which is partly how our kitchen ended up full of cruciferous vegetables, turmeric, ginger, berries, nuts, seeds and various things Stu would almost certainly never have voluntarily put on a shopping list before diagnosis.

Juicing became part of that too because it was an easy way of getting more vegetables into him. I've written separately about exactly what we did on the Juicing page.

None of this replaced Stu's oncology treatment. It sat alongside surgery, radiotherapy, chemotherapy and the other treatments and approaches we pursued. And I think that distinction matters much more to me now than it probably did when I was frantically reading about food and cancer in 2020.

THE RAINBOW DIET

One of the resources I found genuinely useful was The Rainbow Diet. What I liked was the practical idea of getting a really broad range of colourful plant foods into Stu's diet rather than obsessing over one particular "superfood". At a time when I was reading an overwhelming amount of conflicting information about cancer and nutrition, it gave me something tangible to work with.

Could I get more colours onto his plate? Could I get more vegetables into something he would eat? Could I vary what we were buying rather than repeatedly reaching for the same handful of supposedly healthy foods? That was useful to me.

There are wider claims made around cancer diets, individual foods and natural compounds that go considerably further than current clinical evidence supports. Of course, a lack of evidence isn't the same thing as evidence that something has no effect, particularly where something just hasn't been properly studied. But I wouldn't treat any book or diet as a treatment protocol for glioblastoma on that basis either. I still like the basic principle I took from The Rainbow Diet: eat a varied diet containing lots of different plant foods.

Current cancer-prevention guidance also encourages a diet rich in wholegrains, vegetables, fruit and beans, although that is very different from evidence that a particular diet can treat an existing cancer. World Cancer Research Fund

SUGAR, CARBOHYDRATES & CANCER

This deserves its own section because if you start researching cancer and food, it doesn't take long before you encounter some version of: Sugar feeds cancer.

Cells throughout the body use glucose for energy. Cancer cells also use glucose and many cancers have altered metabolism, which is one reason tumour metabolism is such an interesting area of research. But that doesn't mean you can selectively starve a tumour by removing sugar from someone's diet while leaving the rest of the body unaffected.

I became very conscious of sugar and refined carbohydrates after Stu's diagnosis and reduced them significantly. I still believe that was the right thing for us to do. Eating well, reducing highly processed foods and giving Stu's body the best nutritional support we could felt like an important part of looking after him alongside his treatment, and I still feel that way now.

Where I would be more careful is with the phrase "starving cancer". Cancer metabolism is far more complicated than the idea that if you stop eating sugar, you simply stop feeding the tumour. The body regulates glucose very tightly and can make glucose from other nutrients, so eliminating sugar from someone's diet doesn't mean a tumour suddenly has no access to glucose.

That doesn't mean I think diet is irrelevant. Far from it. It means I'd separate making thoughtful nutritional choices as part of someone's overall care from claiming that eliminating a particular food can, by itself, treat glioblastoma.

The ketogenic diet is interesting in brain tumour research because it changes the body's primary fuel source. But as of 2026 there still isn't clinical evidence showing that a ketogenic diet can cure or control a brain tumour. Human research remains limited, and very restrictive diets can also cause problems including weight loss, constipation and fatigue. Anyone considering one during brain tumour treatment should do it with their medical team and an appropriately trained dietitian. The Brain Tumour Charity. That's quite a different message from some of the certainty we encountered online when Stu was ill.

WHAT STU ATE

Despite the amount of research I did, our lives didn't suddenly become an Instagram feed of immaculate bowls of organic vegetables. I was feeding a real person with brain cancer.

Stu still needed meals he wanted to eat. He needed enough energy and protein. He needed food that worked around treatment, appointments and how he was feeling that particular day. And sometimes I needed to get something on the table whilst simultaneously researching a treatment, sorting medication, working and caring for him. I tried to make his diet as varied and nutritious as I reasonably could. There were lots of vegetables, salads, good sources of protein, nuts, seeds, berries and the various ingredients I'd read about and decided we were going to shoehorn into his diet somehow. There was also normal food. That feels important to say.

Cancer treatment can affect appetite, weight and someone's ability or desire to eat. If someone is losing weight, the nutritional priority may be getting enough calories and protein into them rather than following an increasingly restrictive idea of a "perfect" cancer diet. Macmillan's current guidance specifically recommends getting advice from a dietitian when someone is struggling to eat or maintain their weight. Macmillan Cancer Support

GETTING NUTRITIONAL SUPPORT

We didn't work all of this out on our own. We sought nutritional advice and worked with people including Patrice Surley. At the time I wanted people who were prepared to look beyond "just eat a balanced diet" because I wanted to understand whether nutrition could play a meaningful role alongside everything else we were doing. I still think asking for nutritional support can be incredibly useful. What I understand better now is that who the advice comes from matters.

A registered dietitian is a regulated healthcare professional who can assess and treat nutritional problems, including the very practical problems cancer creates around weight loss, appetite and treatment side effects. The titles nutritionist and nutritional therapist mean different things and don't carry the same regulatory status. Macmillan Cancer Support

That doesn't mean I think every complementary practitioner has nothing useful to offer. We worked with people who gave us useful support and I wouldn't rewrite our experience to pretend otherwise. But if you're making significant dietary changes during cancer treatment, particularly a restrictive diet or one involving supplements, I'd involve your oncology team and ideally an oncology dietitian too.

WHEN EATING BECOMES HARD

There is another side to cancer nutrition that can get completely lost amongst conversations about turmeric and broccoli. Sometimes someone just needs to eat.

Cancer and treatment can cause nausea, appetite loss, taste changes, constipation, diarrhoea, a sore mouth and weight loss. If someone can't eat enough, nutritional advice may involve increasing calories and protein, eating smaller meals more frequently or using nutritional drinks or supplements. Macmillan Cancer Support. That can look very different from the food we conventionally think of as "healthy".

And I still remember being absolutely astounded by the sheer amount of junk food available in the vending machines in oncology waiting rooms. But I understand the other side of this much better now too. If someone with cancer is losing weight and struggling to eat, a calorie is not morally good or bad. Maintaining weight and strength can become more important than whether every ingredient would make it onto someone's list of cancer-fighting foods.

WHEN FOOD BECOMES ANOTHER TREATMENT

This is probably the part I wish people talked about more. When you are caring for someone with cancer, food can become another enormous responsibility. You aren't just making dinner anymore.
You're standing in a supermarket reading labels. You're wondering whether you should buy organic. You're worrying about sugar. You're trying to remember which vegetables contain which compounds. You're making juices. You're reading studies. You're cooking things the person you love doesn't particularly want to eat and then feeling anxious when they don't eat them. And underneath all of that can be a horrible unspoken thought: What if this matters? What if the thing I put on his plate makes a difference? I remember having meltdowns worrying I was serving food that would make the tumour grow and that is an extraordinary amount of pressure to attach to dinner. 

There were times when my determination to feed Stu what I thought was best for him undoubtedly put pressure on both of us. I was trying to protect him. He was trying to live through brain cancer while his wife attempted to persuade him that yet another vegetable was apparently essential to his continued existence. Neither of us needed food to become another battleground.

HINDSIGHT

WHAT WE KNOW NOW THAT WE WISH WE'D KNOWN THEN

Do I regret changing Stu's diet? No. We ate a broader range of vegetables. We ate less processed food. I became much more interested in nutrition and in what we were putting into our bodies. Juicing gave me a practical way of getting things into Stu that he otherwise wouldn't have eaten. Some of the changes we made were probably good changes regardless of whether they had anything whatsoever to do with glioblastoma. Would I carry quite so much responsibility for every fucking thing he ate if I could do it again? No. That's different.

When someone has a cancer as aggressive as GBM, you desperately want cause and effect. You want to believe that if you can find the right combination of treatments, supplements, food and lifestyle changes, you can influence what happens next. Maybe some of the things we did helped Stu. Maybe they didn't. We will never know. What I do know is that he was my husband, not my patient. We had always loved food. We'd had KFC on our wedding night for fuck’s sake.

I wish I'd understood a little earlier that looking after Stu's nutrition and letting us enjoy food weren't opposing ideas. A meal didn't always have to earn its place by fighting cancer. Sometimes dinner could just be dinner.

CURRENT INFORMATION · 2026

MACMILLAN · DIET & FOOD SUPPLEMENTS
A useful starting point for diet during cancer treatment, supplements and choosing an appropriately qualified nutrition professional. Macmillan is clear that there is no specific diet everyone with cancer should follow and no diet or food supplement should replace conventional cancer treatment.

MACMILLAN · BUILDING-UP DIET
Practical information if cancer or treatment is causing weight loss or poor appetite, including increasing calories and protein and when to ask for dietetic support.

MACMILLAN · EATING PROBLEMS & CANCER
Information about appetite, nausea, taste changes and other problems that can make eating difficult during treatment.

THE BRAIN TUMOUR CHARITY · KETOGENIC DIET & BRAIN TUMOURS
A useful evidence-based overview of what is currently known and, importantly, what isn't known about ketogenic diets and brain tumours.

WORLD CANCER RESEARCH FUND · DIET & CANCER
Evidence-based information about dietary patterns, wholegrains, vegetables, fruit and beans. Much of this evidence relates to cancer prevention rather than treating an existing glioblastoma, which is an important distinction.

food and diet