Breast cancer is the most common cancer diagnosed in females globally and has become the growing global health problem over the last few decades. In North America and Europe, this cancer is more prevalent as compared to the Asian countries. One of the major reasons behind this fact is the difference in dietary habits and patterns of countries.
Many evidences explained a negative correlation between breast cancer risk and whole grains intake, demonstrating that whole grains might have anti-cancer actions against breast cancer. Whole grains are the most important and basic food source which are necessary to provide the body the required energy.
Being enriched with potent bioactives, this class of food exhibits a well-defined role in managing breast carcinogenesis.
Let's take a look how whole grains help to keep you protected from breast cancer risk:
- Whole grains general benefits
- Whole grains phytochemicals
- Whole grains and breast cancer risk
Whole grains general benefits
Many foods are known to be the keystones for breast cancer prevention. Whole grain bioactives are also one of them. Wheat, rice, oats, barley, sorghum, rye, millets and maize are some of the essential whole grains that are rich in carbohydrates, minerals, vitamins and proteins.
Intake of these foods regularly helps to get prevention from diabetes, cardiovascular diseases and obesity. These potent health benefits of whole grains are due to its potential phytochemicals, which are known to provide anticancer, anti-inflammatory and antioxidant actions.
Whole grains phytochemicals
The phytochemicals present in whole grains are alkylresorcinols, phenolic acids, hydroxycinnamic acids, avenanthramides, carotenoids, alkylresorcinols, plant sterols, lignans, anthocyanins, tocols and tricuspide A.
Whole grains and breast cancer risk
Earlier, whole grains' role in colorectal cancer prevention was well studied. It is due to their dietary fiber function straight into the colon and small intestine. Various experimental analyses have shown that bioactives of whole grains show anti-breast cancer properties via modulating the immune system, inhibiting proliferation and metastasis of breast cancer cell lines.
Below, there are common whole grains and their role in lowering the risk of breast cancer. Let's explore those in little detail:
Wheat is one of the major cultivated crops around the globe. Wheat and their processed products are known to be the staple food and consumed to get adequate energy to the body's day-to-day body functions.
The actives of germinated wheat flour has found significant inhibitory impact upon various human breast cancer cell lines, including triple negative, ER and TNBC via apoptotic mechanism.
The phytochemicals which are behind this activity are alkylresorcinols. These are most abundantly present phenolic lipids in the wheat, rye and barley. These bioactives are directly absorbed into the plasma, therefore also used as biomarkers of rye and grain wheat consumption.
This bioactive exhibits potential anti-cancer activities, including anti-carcinoma and antioxidant along with reducing obesity, suppressing adipocyte lipolysis, improving insulin sensitivity and glucose tolerance.
Whole Grain Rice
Rice is another major food consumed all around the world. About for 50% of the globe's population, this is a staple food. Asia is the biggest consumer of rice. As compared to white rice (deprived of bran, germ and husk), whole grain rice, such as brown rice, black rice and red rice contain greater content of bioactive like tocotrienols, tocopherols, phenolics and oryzanol.
Black rice was found to be rich with anthocyanidins and showed extensive role against breast cancer metastasis. Anthocyanins present in black rice are known to inhibit the invasion and migration of breast cancer cells. Black rice is also known to possess anti-metastasis action (by inhibiting pulmonary metastasis and lowering transplanted tumor growth) against breast cancer.
Further, it is also explored that bioactive peptides present in rice are also known to have potential cancer preventive and management actions along with lowering the risk of infective diseases and cardiovascular disorders. Many of the peptides of whole grains are known to have potential anticancer activity against gastrointestinal (GI) cancer.
Oats are known to be an excellent source of soluble dietary fibers (β-glucans) and health-promoting phytochemicals. Β-glucans found to be very effective against number of cancer cell lines.
Oral consumption of these glucans found to have immunomodulatory impact against advanced breast cancer. This action is due to the stimulation of peripheral blood monocytes via glucans.
Talking about phytochemicals of oats, avenanthramides present in abundance. Avenanthramide-C explored to lower the viability of human breast adenocarcinoma via inducing apoptosis and sub G1 cell, leads to activating Caspases and DNA fragmentation.
Sorghum is known as the 5th most economical crop around the globe. The bioactive sorghum, such as, anthocyanidins, tannins, phytosterols, phenols and policosanols dispense extensive health benefits.
Anthocyanins from red sorghum bran possess potential anti-proliferative action against MCF-7 breast cancer via stimulating apoptosis and DNA fragmentation. Sorghum 3-deoxyanthocyanidins have also proven to be cytotoxic against cancer cells.
Besides 3-deoxyanthocyanidins, sorghum tannins are also found to have potential anticancer properties. In one of the analyses, it is found that being rich in tannins, sorghum bran extract inhibits the activity of aromatase, a key enzyme in the synthesis of estrogen, and an essential target for breast cancer treatment (chemotherapy).
Synergistic role of whole grain and chemotherapy
Some of the whole grain bioactive compounds also exhibit a synergistic effect along with certain chemotherapy drugs. These bioactives work in two ways, either reducing the associated adverse effects or sensitizing the tumor cells.
It is found that wheat grass juice consumed by breast cancer patients under combined treatment (5-fluorouracil, doxorubicin, and cyclophosphamide) is known to lower the associated toxicity and chemotherapeutic dosage, without affecting drugs efficacy.
The rice bran bioactives, ferulic acid and δ-tocotrienol also known to work synergistically together to reduce the proliferation of MCF-7 breast cancer cells. Other bioactives from rice bran like arabinoxylan and biobran also work synergistically with paclitaxel against MCF-7 breast cancer cells.
It can be seen how effective the whole grain products are in cancer prevention. Whole grains are also better than refined foods in the context of other health benefits also. It keeps your cholesterol and sugar levels up to the mark and lowers the risk of heart problems and obesity significantly. Overall, whole grains are a boon to humans and must be included in the diet in place of refined grains.
Also, read how plant-based diet helps in cancer prevention.