Claims on Breast Milk for Cancer Treatment
WHAT IS THE TRENDING NEWS STORY
The health benefits of breast milk have long been flouted, but experts are now testing whether a compound found in mother’s milk could help treat cancer. The accidental discovery of the effects of a compound found in breast milk, and nicknamed Hamlet, could mean a more effective and targeted way to kill cancerous tumor cells. Researchers from the University of Lunt in Sweden have revealed some positive results from studying the effects Hamlet has on bladder cancer patients.
WHY THE STORY HAS MISINFORMATION
Breast milk is the perfect nutrition for infants, a result of millions of years of evolution, finely attuned to the requirements of the infant. Breast milk contains many complex proteins, lipids, and carbohydrates, making it an interesting subject of study for many more applications. During 1995, investigations took place on the effect of human milk on bacterial adherence to a human lung cancer cell line, where researchers were surprised to discover that the milk killed cancer cells. Further years of investigations determined that HAMLET (human α-lactalbumin made lethal to tumor cells) is apparently the protein responsible for this property, but it was also determined that HAMLET was present not only in human milk, but also in cow milk, as a variant of multimeric α-lactalbumin. Considering this association, some studies pointed out that endogenous human α-lactalbumin is a molecule that, even if it has proven properties as a co-factor in lactose synthesis, did not have tumoricidal properties.
HAMLET is a molecular complex of partially unfolded human α-lactalbumin and oleic acid, but this is not its predominant form. In its predominant form, α-lactalbumin is a protein with a high affinity to calcium, making it a fairly inflexible molecule, and binding to calcium is required for the protein to maintain a native conformation. In order to become a flexible molecule and being able to form a complex with oleic acid, α-lactalbumin needs to be transformed to its unfolded state (which is not possible while bound to calcium). Unfolded states are possible for α-lactalbumin in the absence of metal ions or at low pH, conditions that are not present in the natural state of breast milk. Several studies keep pointing out that in this calcium-bound form, α-lactalbumin cannot be converted to HAMLET, and it does not induce cell death.
These conditions, however, could be present after consuming human breast milk. The low pH present in the stomach allows calcium to be liberated, theoretically allowing the possibility for HAMLET, the complex with oleic acid, to be formed. Some studies have shown that breastfed children have a reduced risk of developing several types of cancers, thereby supporting this theory. However, the mechanisms have not been thoroughly studied yet. HAMLET was proved in vitro to possess capabilities as an apoptosis-inducing agent with broad, yet selective, cytotoxic activity with several researchers studying the potential pathways and cellular targets for this protein. Unfortunately, not many studies are being performed in vivo to study the impact of breast milk or HAMLET on several types of cancer. One study used an animal model (mice) to prove the efficacy of HAMLET against colon cancer. Interestingly, orally administered HAMLET reduced tumor progression and mortality while accumulating specifically in tumor tissue. However, we must remember that animal model results do not often transfer over to human patients, making this information inaccurate and misleading, and should not be considered definitive until further studies are performed.
Other researchers, given the fact that the anti-tumoral activity of HAMLET came just after the formation of a complex with oleic acid (OA), decided to study the expression of similar properties by other complexes formed between OA and arachidonic acid and by OA itself. Results of these studies suggested that the protein portion of these complexes (such as α-lactalbumin) may not be the cytotoxic component against tumor cells, pointing out at OA as the real cytotoxic agent by its own means in various tumor cells. This makes obvious the need for many more studies to investigate this topic before making any affirmation about the role of human breast milk as a potential new cancer treatment.