Nutrition - breast cancer

Tuesday 08 May 2018

This month I want to focus on breast cancer and nutrition. As you can imagine there is a huge amount of research available, some is based on observational studies, other research is centered on a lab, and some is in clinical trials.

As this is a single blog, you will appreciate that I have looked at the main points only. I focused most of my research on Cancer research UK, Macmillan, Breast, the CUP report, The Journal of Breast Cancer (2013) and Cancer Active amongst some others.

Of course, there are many types of breast cancer. Cancer research concluded that there are 10 different categories, and whilst most breast cancers are hormonally driven, roughly 20% are not.

Despite the differences, there are many common denominators that could be considered when looking at nutrition.
Although most of the evidence is anecdotal and more research is needed, there seem to be many very convincing facts that are really worth considering such as the following:

  • Keep weight within the normal BMI range. Fat cells in the body are biologically active and produce hormones and proteins which are chemical messengers and affect the way that the cells function.
  • Therefore, the more fat we have, the more hormones (including oestrogen and progesterone) and growth factors are present. The hormone insulin, which is designed to regulate our blood sugar levels, can have some negative effects if it becomes too high, either through the wrong sort of diet or being overweight.

When people are overweight more insulin is present in the body. It is thought that increased insulin affects the levels of growth factors available to the body. Free or unbound growth factors tell cells to divide unchecked by our normal control mechanisms.

Fat cells also attract immune cells to body tissues. These immune cells release chemicals that cause long lasting inflammation which can raise the risk of cancer. Insulin can also interfere with the efficiency of the liver in its role of detoxifying excess oestrogen.

  • Include Curcumin in your diet. I think that Curcumin is the most researched spice. It has been shown to have huge potentially positive effects against cancer. According to Hilda Glickman in her book Take Breast Cancer off the Menu, it has so many anti- cancer functions, it is stunning.
  • Two of the benefits, one researched by the University of Munich in Germany, showed that curcumin can reduce the incidence of metastases in breast cancer. Metastases is associated with an increase in two pro-inflammatory proteins, and curcumin can alter the expression of these damaging proteins, and so inhibits spread.
  • Curcumin is found in turmeric, which has been shown to make the receptors on the breast cells less sensitive to oestrogen.
  • Piperene found in black pepper can enhance the absorption of curcumin by a factor of 1,000.

So, make sure that you add pepper to your turmeric-rich soups and stews and casseroles. Other ways to add it to the diet is to put it in scrambled egg or omelettes, or to any root vegetables that are mashed like sweet potato, carrot or swede. Mix with brown rice.

  • Eat sufficient fibre to prevent constipation. Fibre can protect against breast cancer by removing excess oestrogen from the body. The oestrogen in the gut attaches itself to the fibre and is carried out in the stools. Ways to increase fibre is through eating plenty of fruits and vegetables, porridge, brown rice, millet and quinoa. Also peas, beans, lentils, nuts and seeds. Always drink plenty of water which also helps to prevent constipation.
  • Check your vitamin D status. Many of those with breast cancer have been shown to be deficient in vitamin D. Observational studies show that breast cancer is more prevalent in areas where there is less sunlight. Although this itself does not prove that low levels of vitamin D cause cancer, when taken together with other studies it seems to be a major factor, and research seems to bear this out.
  • More than 1,000 laboratory and epidemiological studies have linked breast cancer to low levels of vitamin D. An article published in the British Journal of Cancer concluded that 'our finding suggests that high levels of vitamin D status is weakly associated with low breast cancer risk but strongly associated with better breast cancer survival’.

Vitamin D has been shown to support the immune system in its fight against rogue cells and has the ability to normalize and correct cancer cells. It may be worth having a simple blood test to get levels checked. It can be done by the NHS.

Foods rich in vitamin D are oily types of fish (salmon, tuna, sardines, trout mackerel), egg yolk, fortified foods (most cereals and plant based milks) and mushrooms that have been left in the sunlight for 30 minutes. You can even now buy mushrooms high in vitamin D.

  • Increase the levels of cruciferous vegetables in the diet. These vegetables are broccoli, cauliflower, bok choy, dark green leafy cabbage, kale, purple sprouting, Brussels sprouts, water cress, turnip, and collards. Cruciferous vegetables are the most protective of all of the vegetables for breast cancer.
  • Apart from their rich anti-oxidant and anti-inflammatory properties they contain glucosinolates which break down into indoles, including indole- 3 -carbinol (13C) and DIM. These compounds have more than one function in the body. They can change oestradiol (a strong cancer forming oestrogen) into a weaker one called oestrone which is not cancer forming.
  • Another way that they help is connected to the breast cell receptors themselves. If indoles are present when oestrogen tries to attach to the breast cells, the cells do not divide as fast as usual. A 2012 study showed that a branded compound called Breast Defend reduced metastases and progression in triple negative breast cancer. It contained Indole 3 carbinol and DIM.

There are many, many research papers about the potential benefits of cruciferous vegetables. In order to gain any benefit, research says that we should be having at least 2 kilos of cruciferous vegetables a week. Here are a few ideas of how they can be used;

  • Make a coleslaw with chopped red or white cabbage.
  • Mix cabbage with cooked potato to make the delicious dish colcannon
  • Add to soups and stews
  • Make pickled cabbage
  • Add cooked or raw broccoli to rice salads or pasta dishes
  • Add broccoli sprouts to sandwiches
  • Roast cauliflower with spices
  • Try making cauliflower pizza crust
  • Dairy food? I have mentioned this because I do know that many people decide to give up dairy foods when diagnosed with oestrogen driven breast cancer.

The research on this is very mixed. The reasons for not having dairy products are that milk does contain 35 different hormones including oestrogen. It also has high levels of growth factor and in most cases antibiotic residues.

The research into whether we should have dairy or not is mixed. One study published by the National Cancer Institute found that those who consume more high fat dairy foods have a greater risk of breast cancer. On the other hand, Dr. C Horner argues that the protein in milk known as casein stops the growth factors from breaking down.

Many oncologists recommend drinking milk to get calcium for bone health. It is my opinion that you can get more than enough calcium in the diet if you eat plenty of dark green leafy vegetables, nuts, seeds and tinned fish. Also, many of the plant based milks available as alternatives to cow’s milk are fortified with calcium and vitamin D.

So it is a matter of choice here. I do get asked what makes some oestrogen strong and cancer promoting, and some oestrogen weak. It is a very complex story because to a degree the way that our liver handles oestrogen will determine this.

But, many of the answers lie in the environment, namely Xeno-oestrogens. These are compounds that we absorb into our bodies that mimic oestrogen. These are found in plastics, fat of intensely reared animals, herbicides and pesticides and recycled drinking water.

Other drivers of strong oestrogen are too much coffee, alcohol and sugar in the diet. I must also mention soya and soya products because the story of soya and breast cancer seems to keep changing.

The present recommendations are that if you have always had soya in the diet then to continue as this could be potentially beneficial. If you have never had any soya in the diet then do not start. To introduce it, as a result of diagnosis can possibly be detrimental. I will obviously keep you up to date if the story changes.

Remember that soya has been controversial because it is rich in phyto-oestrogens or plant oestrogens. But these oestrogens are very different to the oestrogen that we produce ourselves because they are much weaker.

Research on reduced calorie intake

Finally, there is some very interesting work relating to reduced calorie intake (also called induced fasting) prior to chemotherapy, being carried out in the University Hospital in Manchester by Michelle Harvey SRD. PhD, a dietitian.

Preliminary studies have shown that ladies that do this, have far less side effects without losing effectiveness of the treatment. It works because it reduces chemo related stress on normal cells, without jeopardising treatment for killing cancer cells.

Induced fasting does not mean having no food, but a calorie restricted intake for a period of time.

If you would like to know more about this then do contact a professional and discuss with your consultant. It is not common practice and many oncologists may not be familiar with the idea, so do not take it upon yourself to do it unless under professional guidance.

Blog originally written by Caroline August 2017 - links updated 2021

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