Eating Yogurt Lowers Risk of Breast Cancer: Study
Wed, April 21, 2021

Eating Yogurt Lowers Risk of Breast Cancer: Study

Yogurt is a dairy product known to enhance gut bacteria, promote bone health, strengthen the immune system, and help with weight management. It is also good for the heart. But did you know that eating yogurt also lowers one’s risk of breast cancer? / Photo by Ivan Dzyuba via 123RF


Yogurt is a dairy product known to enhance gut bacteria, promote bone health, strengthen the immune system, and help with weight management. It is also good for the heart. But did you know that eating yogurt also lowers one’s risk of breast cancer? A new study by Lancaster University pointed out that natural yogurt contains beneficial bacteria that reduces inflammation and is the same protective bacteria found in mothers who breastfeed their newborns.


Lactose-Fermenting Flora Also Found in Yogurt

Authors Auday Marwaha from the Biomedical & Life Sciences Faculty of Health and Medicine at Lancaster University and the team wrote that mammalian milk contains a range of bacteria caused by entero-mammary circulation. The entero-mammary pathway involves bacterial translocation from the gastrointestinal tract of the woman to the mammary gland and is believed to occur more frequently during the late stages of pregnancy. The most dominant flora (collective microorganisms and bacteria) found in the breast is the lactose-fermenting flora (microflora) believed to be protective.

Such beneficial lactose-fermenting flora commonly found in the breasts of women who have breastfed is also found in yogurt and milk. Co-author Dr. Rachael Rigby explained via science and tech platform Science Daily that lactation alters the microflora of the mother’s breast. It occupies the breast ducts not just during lactation but also after lactation for an unknown period of time.


Replacing Bad Bacteria With Good Ones

The team suggested that the microflora serves as protection since breastfeeding also reduces a woman’s risk of breast cancer by up to 4.3%. Various studies in the past have further shown that eating yogurt is linked to a reduction in the risk of breast cancer. This could be because harmful bacteria are replaced by beneficial bacteria. A human body contains approximately 10 billion bacterial cells. Most of these are harmless but some create toxins that trigger inflammation. When inflammation occurs, chemicals from the white blood cells are released into the affected tissues and the blood. The process helps protect the body from harmful germs and foreign substances but damages the body too. Periodontitis or gum disease is one of the common examples of chronic inflammation and is associated with prostatic, breast, pancreatic, colonic, oral, and esophageal cancer.

Stem Cell Genesis: Conventional vs. Hierarchical Model

A stem cell is a cell with the special ability to develop into specialized cell types and may be used to replace tissues and cells that have been lost or damaged due to disease. Although billions of stem cell mitosis (cell division) are happening every day within the human body, the chance that a single stem cell will acquire the deleterious mutation (genetic alteration that increases susceptibility to disease) remains “sufficiently low.” This makes cancer rare and mostly occurs at the end of a person’s lifespan. The value of deleterious mutations is approximately four in the common cancers, including prostate, lung, colon, and breast. The moment a single stem cell acquires such a deleterious set of mutations, it will then grow out of proportion and form a malignant tumor.

It is widely considered in the medical field that stem cells are dividing asymmetrically in a few days such that a daughter cell can also become a new stem cell and then undergo successive divisions. Throughout, it can produce 256 differentiated cells that form for one or two days before they will again be replaced by products of the other stem cell division. However, this conventional view “leads to a paradox,” the team said. It is because men live 30 times longer and are thousands of times larger than mice. If the conventional view will be applied, this should mean that the prevalence of cancer in men should be increased to 30 or multiplied to 1,000 and yet the prevalence of cancer in men and mice are the same.


Disruption in the Hierarchical Model

With the hierarchical model of stem cell genesis, on the other hand, the differentiated epithelial cells (those that line the surfaces of the body) are produced in less than 60 divisions. This is why cancer is rare in both men and mice unless the orderly progression of such a hierarchical model will be disrupted.  The risk of cancer increases if that happens. One process that can disrupt the hierarchy is inflammation as it destroys the quiescent or reversible state of the stem cell as well as the surrounding stromal cells. The researchers added that it is possibly effective to repair the hierarchy disruption in the first half of a person’s life but is less effective as they grow old because aging impairs that process.

Applying the hierarchical model in their breast cancer study, the group hypothesized that inflammation that is induced by bacteria also plays a role in the pathogenesis of cancer, but there are pathogens, such as commensal flora, that can prime the immune system when taken in low dose. To be more specific, the group mentioned lactose-fermenting bacteria found in mammalian milk that form the commensal flora.

The researchers suggested consuming natural yogurt because it contains beneficial bacteria that will help reduce a person’s risk of breast cancer.

Cancer Deaths by Type

Our World in Data, a scientific online publication that focuses on large global problems, included breast cancer as one of the leading forms of cancer deaths across high and middle-income countries. It took the lives of 611,625 people in the world in 2017. Included also in the list are tracheal, bronchus, and lung cancer with 1.88 million deaths worldwide, colon and rectum cancer (896,040 deaths), stomach cancer (864,989 deaths), and liver cancer (819,435 deaths).


Per Capita Consumption of Yogurt

Meanwhile, market research company Allied Market Research shared that the global yogurt market stood at $77,679 million in 2016 and is expected to reach $107,209 million by 2023. Countries with the highest per capita yogurt consumption are Germany, the Netherlands, France, Turkey, Saudi Arabia, and South Africa.

 In the US, its per capita consumption of yogurt in pounds per person through the decade are as follows: 6.5 (2000), 7 (2001), 8 (2002), 8.7 (2003), 9.2 (2004), 10.4 (2005), 11.1 (2006), 11.6 (2007), 11.8 (2008), 12.5 (2009), 13.5 (2010), 13.6 (2011), 14 (2012), 14.9 (2013), 14.9 (2014), 14.4 (2015), 13.7 (2016), 13.7 (2017), and 13.4 (2018). The US data is based on German database company Statista.

Doctors have recognized the role of diet and lifestyle to reduce the risk of breast cancer. If previous studies only highlighted consuming dark, green and leafy vegetables, and fruits, the new study shed light on the importance of yogurt intake.