Diet
After a cancer diagnosis, many people try to take back some control by exploring diet and nutrition. Whilst turning to Doctor Google is tempting, the Penny Brohn UK charity suggests being wary of anything online claiming to ‘cure cancer’ and instead, advise adopting a ‘whole life’ approach to cancer treatment, balancing mind, body, spirit and emotions. Finding a way to enjoy nutritious foods that support our bodies, but also our emotional and mental wellbeing, allows us to eat in a way that is supportive and joyful.
It is important not to place extra, unnecessary stress on yourself following a cancer diagnosis, so avoid adding food-based guilt to the mix of emotions you may already be feeling. We don’t need to eat perfectly for every meal, every single day and we need to have some level of flexibility for a healthy diet to work for us long term. There are some simple dietary factors that can have a huge impact on our health during and after treatment, but it is important to never replace advice given by your healthcare team.
The information and recommendations below have been compiled from the Penny Brohn UK Charity website and their Webinar ‘Eat Well with Cancer’. It is important that you discuss dietary changes with your medical team.
- Be a healthy weight. Being overweight can lead to excess inflammation, difficulty with blood sugar management and other complications. Bear in mind that adopting a healthy, balanced diet and following the rest of these top tips is often enough to support weight loss without it being your main focus.
- Be physically active. How this looks will vary from person to person. You may find it helpful to look at the Cancer Prehab and Cancer Rehabilitation pages on the Knowledge Base page. Research shows that for a number of cancers, including bowel cancer, a programme of exercise can improve recovery and reduce the risk of cancer recurrence. The World Cancer Research Fund website also has useful information and advice about increasing physical activity.
- Eat a diet rich in vegetables, fruit and beans, including chickpeas and lentils. Penny Brohn advises that in an ideal world, we should aim for at least five servings (a chunky handful being one serving) of these foods each day. These foods are really high in vitamins and minerals and also high in fibre. Fibre is important because it helps remove waste products from the bowel quicker, improves gut bacteria, keeps inflammation at healthy levels, helps us maintain a healthy weight, releases energy slowly, stabilises our appetite and supports blood sugar levels. Please note, there may be times during or after treatment that you are required to follow a low-fibre diet. It is important to follow advice given by your medical team, but you can request further support around nutritious ways to follow a low fibre diet on the Penny Brohn UK website.
- Eat a diet rich in whole grains. For example, opt for whole grain over white bread/pasta/rice. Wholegrain is a better source of fibre, as well as containing important minerals such as selenium, potassium and magnesium. Whole grains take longer to digest than refined grains, so they keep us fuller for longer, helping to balance energy levels throughout the day. They are also full of nutrients!
- Add a range of herbs and spices to your meals.
- Limit fast foods and processed foods which are high in fat, starches and sugar.
- Limit red meat and processed meat. When eating good quality red meat, remember that the whole plate is important! Red meat has inflammatory properties, but if the rest of the plate contains lots of anti-inflammatory foods, then the meal as a whole may reduce inflammation.
- Limit consumption of sugar and sweetened drinks. Over consumption of sugar increases blood sugar levels and triggers the release of insulin, which in turn can increase inflammation in the body, cause weight gain and according to research, may even encourage the growth of cancer cells.
- Limit alcohol consumption. Alcohol is a carcinogen. However, as Penny Brohn follows the ‘whole life approach’, it is important to consider where alcohol fits in to your life and in what quantity. Some people decide to exclude alcohol from their diet entirely, while others find that having a drink with a friend once a week is a really important part of their emotional resiliency and overall wellbeing. If this is the case, you could focus on the quality of the product and opt for a good quality glass of red wine, which has anti-cancer properties when consumed in moderation!
- Do not use supplements for cancer prevention. Bear in mind that you can’t supplement your way out of a bad diet or lifestyle. However, if you are struggling with certain things during treatment then there may be value to some supplementation. There are many treatment interactions, so always discuss any supplements with your oncologist and medical team.
Overall, dietary pattern and the longevity of your diet is key. If you’re feeling overwhelmed or over restricted, focus on adding in handfuls of compound rich foods as a starting place. Rather than focusing on things to cut out of your diet, you could think about adding lots of nutritional value first. Below are some examples of foods with anti-cancer compounds that can be easily added to your meals, though again it is important to consult your medical team when making changes to your diet.
Polyphenols:
- Brightly coloured berries, including frozen berries.
- Dark chocolate.
- Red wine (remember to drink in moderation!)
- Turmeric
Glucosinolates:
- Dark, leafy greens, including kale, broccoli, spinach, watercress, cabbage, cauliflower. As little as 5 portions a week can have a big impact.
Lycopenes:
- Tomato puree
- Fresh tomatoes (lycopenes increase when tomatoes are cooked in fat. You could roast them in good quality olive oil)
Glucans:
- Mushrooms (There are all sorts of varieties including shiitake, maitake, oyster. A wide variety is great, but adding any mushrooms to your diet is a positive. Button mushrooms are easily available. Top tip – leave mushrooms in the sunshine to increase their vitamin D content)
Some further points from Penny Brohn…
Dairy: overall, eating dairy as a couple of normal portions per day is ok. Research varies hugely because types of dairy and how dairy is eaten varies hugely, so the evidence is inconsistent. For hormone receptive cancers, large portions, multiple times a day may have an increase in risk. Penny Brohn’s advice is to consider fermented dairy sources, natural yoghurt and Greek yogurt (which is also high in protein). Enjoy dairy as part of a balanced plate, not crowding out other foods.
Soy: There is much debate around soy and cancer, but research has consistently found that soy is very protective and a useful food to have before and after diagnosis. Soy is also varied – soy in processed foods won’t have the beneficial nutrients. Tofu, soy beans, organic soy milk, miso and whole-food sources of soy are best.
Organic foods: if these are not an option, then don’t worry about it. Don’t miss out on eating beneficial foods just because organic foods are not available to you. Evidence around organic food is a bit mixed, but there is lots of robust evidence around the foods mentioned above. Be targeted with your money when choosing organic foods – opt for organic meat, eggs and dairy if you’re being strategic with funds. If organic is available to you and is affordable then that’s great, but don’t worry if not.
Fasting: fasting is being researched and there is some exciting, but early-days, evidence around the benefits of fasting. However, it is currently unconfirmed whether it’s safe for all people with cancer to fast, and you may be required to eat at specific times in order to take certain medications. You could consider whether you can extend your overnight fast – a 12 hour fast overnight can give a lot of the same benefits. If you are considering fasting, it is essential you check with your medical team that this is safe for you.
Visit our Fasting page if you wish to find out more.
To conclude…
Whilst reading about nutrition and cancer can feel overwhelming for some, there are some brilliant books recommended by Penny Brohn, available on their website shop, that come from huge evidence bases. Please be self-compassionate and start from wherever you are. What you eat may change day to day depending on your health and mood and that is ok! Don’t create too much additional mental effort if you are finding it difficult – gently ease in to nutrition and dietary changes in a way that suits your own needs. According to research, the common features of anti-cancer diets are: increase whole grains, fruit, vegetables and beans and decrease processed foods. Ultimately, finding a nutrient-rich diet style that suits your own needs is the most important thing!
‘Eat food, not too much, mostly plants’ – Michael Pollan
Contributor: Lizzy Welsh