Blueberries are distinctive for their deep bright colour, and have potent antioxidant and anti-inflammatory properties. Phytochemicals in blueberries have a range of anti-cancer properties and there is evidence to suggest that blueberries anticancer properties are of particular importance in triple negative breast cancer (TNBC).
In triple negative breast cancer studies, blueberries have been reported to influence a number of key regulatory pathways that:
- Reduce inflammation
- Slow the growth of cancer cells
- Reduce the spread of cancer cells
- Induce apoptosis (cell death) of triple negative breast cancer cells
There are many different subtypes of triple negative breast cancer cells.
Researchers investigating the effects of blueberry on TNBC cells have conducted separate studies looking at:
- Blueberry extract in vitro¹
- Blueberry juice in mice¹
- Blueberry powder in mice¹
In Vitro
Adams and Phung et al (2010) tested blueberry extract against different TNBC cell lines in vitro¹. It was reported that the blueberry extract was most effective against the most aggressive cell line (MDA-MB-231) of triple negative breast cancer.¹
In Vivo
Blueberry juice was then tested in mice with MDA-MB-231 TNBC tumours, where it was reported that mice treated with blueberry had significantly smaller tumour weight.¹
♦ Interestingly, the study group reported that the dose of blueberry used in this study would be the equivalent of around 122g of fresh blueberries per day for a person weighing 60kg.¹
Adams and Kanaya et al (2011) conducted a study whereby mice with MDA-MB-231 TNBC were fed two doses (5% or 10%) of freeze dried blueberry powder and were shown to have 75% and 60% lower tumour volume respectively, in comparison to mice who received no blueberry powder.²
Finally, whole blueberry powder was shown to inhibit triple negative breast cancer tumour growth and metastases in mice.² Mice fed 5% whole blueberry powder were shown to have 70% fewer liver metastases and 25% fewer lymph node metastasis in comparison to the control group.
♦ The study group reported that the human equivalent dose of a 5% whole blueberry diet would be around 300g of fresh blueberries (~2 cups a day).
The bioavailability of phytochemicals from natural foods is the subject of much discussion. Studies have been conducted in animal models, and we don’t know if the effects would be the same in humans. It has been suggested that we may not absorb enough of these phytochemicals from food to gain a therapeutic response of this magnitude. However, the potent anti-inflammatory and anti-cancer properties of phytochemicals is well researched.
Blueberries: Nutritional Info (per 100g)
Between 50kcal to 70kcal
Between 10g to 15g carbohydrate (of which 10g sugars)
1.5g to 2g fibre
In the United Kingdom, a single portion of fruit or vegetables is described as 80g in weight. Due to the sugar content of fruits, it is wise to spread fruit out evenly throughout the day to avoid spikes in blood sugar levels. This is of particular importance for anybody concerned about pre-diabetes or diabetes.
An 80g portion of blueberries provides on average around 8g sugar. To put this into context:
Sugar Content of Fruits (Average Values per 100g)
- 100g Banana = 20g sugars
- 100g Apple = 11.5g sugars
- 100g Blueberries = 10g sugars
- 100g Orange = 8.5g sugars
- 100g Strawberries = 6g sugars
Note: An average small to medium-sized eating apple or orange weigh’s more than 100g.
Below are the key journal articles published in 2010, 2011 and 2014, relating to the inhibitory effects of blueberries in triple negative breast cancer cell lines.
References:
- Adams, L.S, Phung, S., et al. Blueberry Phytochemicals Inhibit Growth and Metastatic Potential of MDA-MB-231 Breast Cancer Cells Through Modulation of the Phosphatidylinositol 3-Kinase Pathway. Cancer Research. 2010. 70(9). 3594-3605.
- Adams, L.S, Kanaya, N., et al. Whole Blueberry Powder Modulates The Growth And Metastasis of MDA-MB-231 Triple Negative Breast Tumors in Nude Mice. The Journal of Nutrition. 2011; 141(10): 1805-1812.
- Adams, L.S, Kanaya, N., et al. Whole Blueberry Powder Inhibits Metastasis of Triple Negative Breast Cancer in a Xenograft Mouse Model through Inflammatory Cytokines. Nutrition and Cancer. 2014; 66(2): 242-248.
- Israel, B.B, Tilghman, S.L., et al. Phytochemicals: Current Strategies for Treating Breast Cancer. Oncology Letters. 2018. 15(5). 7471-7478.
♦ Suggested Reading and Related Posts on TNBC:
http://www.demeraradelight.com/category/breast-cancer/
http://www.demeraradelight.com/copper-chelation-triple-negative-cancer/
http://www.demeraradelight.com/methionine-and-triple-negative-breast-cancer/
http://www.demeraradelight.com/luteolin-and-triple-negative-breast-cancer/