Owing to the rising awareness around food intolerances, experts have been flooded with many questions — one of them being if milk can make one fall sick. Addressing such concerns, dietitian Anjali Mukherjee took to Instagram to share, “Growing up, we were all taught one thing, milk is great for our health, especially if we want strong bones and teeth. With that still being true, over the years many people have developed certain intolerances and other issues linked to milk. Hence, researchers have begun to study the possible causes of this.”
According to her, milk may cause certain health problems due to the presence of a protein fragment called A1-beta-casein, found in regular cow milk. “This protein has been linked to various health issues such as cold, congestion, sinus, fatigue, inflammation, body stiffness, type 2 diabetes, autism, and other neurological problems,” Mukherjee added, further sharing that A2 milk does not contain the mutated A1-beta casein and therefore, is the “healthy milk”.
However, she was quick to point out that it is still not known whether this mutation affects everyone, or just some, or it affects everyone a little bit and gets accumulated over the years, or it accumulates only for some. She added that selective breeding or breeding only cows that produce A2 milk can help.
To understand more, we reached out to Garima Goyal, a registered dietitian, who told indianexpress.com that the evidence existing at present is “insufficient and inconclusive”. “The main causative factor is the release of a peptide called beta-casomorphin-7 (BCM-7), which causes inflammation in the gut and can cause digestive symptoms. Linking A1 beta-casein with type 1 diabetes, researchers have concluded that consuming A1 milk in childhood increases the risk of type 1 diabetes. These studies are only observational, so concluding A1 casein to be the main causative factor is still not for sure,” she explained.
What is the difference between A1 and A2 milk?
A normal cow’s milk contains two types of beta-casein — A1 and A2. “Of late, marketed A2 milk only contains the A2 beta-casein and not the mutated A1 beta-casein. The scientific debate going around the healthiest milk revolves around whether A1 beta-casein is more harmful than A2 casein,” Garima explained.
According to a 2019-National Center for Biotechnology Information (NCBI) review, human-based evidence from clinical trials and epidemiological studies published prior to October 2017 provide moderate certainty for adverse digestive health effects of A1 beta-casein compared with A2 beta-casein but low or very low certainty for other health effects.
Komal Patel, clinical nutritionist, Fit India Ambassador and founder, Diet Studio mentioned that A1 milk is associated as a risk factor for human health hazards as it can “potentially affect numerous opioid receptors in the nervous, endocrine and immune system”. “It is also known to be an oxidant of low dietary lipoproteins (LDL) and oxidation of LDL is believed to be responsible for the formation of arterial plaque. Therefore, consumption of beta-casein A1 milk is associated as a risk factor for type-1 diabetes, coronary heart disease, arteriosclerosis,” said Patel.
What should one consume?
If you are doing well, drinking milk is still encouraged as it is a good source of protein and calcium, mentioned Dr Abhinav Gupta, consultant, gastrology, Narayana Multispeciality Hospital, Jaipur.
“Milk is slightly acidic but far less from the gastric acid naturally produced by the stomach. Milk does help to temporarily absorb gastric acid but research has shown that milk stimulates acid production, which can make you feel sick again if it doesn’t suit you,” said Dr Gupta.
Although the amount of lactose in A1 and A2 milk is the same, people have observed fewer gastric symptoms after consuming A2 milk, Goyal noted. “Research is still ongoing on whether there are some other components in the milk that may cause abdominal symptoms and discomfort. Those who are struggling with digestive issues with milk consumption, should definitely give A2 milk a try,” she mentioned.
However, those allergic to milk will be allergic to A2 milk too, and those who are lactose intolerant will not be able to consume A2 milk as it contains the same content of lactose”, Goyal mentioned.