Dr. Sundeep Mishra reviews the A1 and A2 milk controversy that has recently been receiving much flak in India for negatively impacting heart and metabolic health.

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Is milk food or fad?

Whether milk (a bodily fluid meant to feed newborns) is a food or fad is humanity’s oldest health debate raging for at least the past ten thousand years. On one hand, it has been considered a perfect food because it is an important source of nutrients and micronutrients, but on the other hand, not only is there an issue of allergy/indigestion but also moral and economic issues.

Ayurveda strongly recommends having milk not only for its many health and beauty benefits but also to promote Ojas (a state that is achieved when proper digestion is achieved). However, Ayurveda is partial to cow milk for its benefits considered a part of Sattvic food. Tradition aside, milk is among the oldest food to be tested in scientific laboratories and the reality is that while all female mammals naturally produce it, its composition varies with each species.

Some studies suggest that consumption of cow milk is associated with greater muscle mass and bone density, and lower risk of type 2 diabetes, childhood obesity, stroke and cardiovascular disease. However, many people have trouble digesting lactose (sugar) in cow milk, on the other hand, 1/10th may be allergic to the cow milk protein casein. Mahatma Gandhi famously recommended goat milk which is practically similar to cow milk, but with a higher protein content and possibly less allergenic (less casein) but has similar amount of lactose. Thus, it might be useful for those allergic to cow milk. Human milk has 4.5% fat, but camel milk has only 2.5% fat and so could be good for dieting. Interestingly, whale milk has 34.8% fat and is therefore incredibly fattening.

Plant-based milks

1. Almond milk- It lacks both casein and lactose, and therefore is ideal for those who were allergic to cow milk. Unfortunately, almond milk has a higher sugar content and has lesser protein with incomplete amino acid profile.
2. Soy milk- Fortunately, soy milk has a complete amino acid profile but is not completely non-allergic: nearly 1/4th of cow milk-allergic infants showed sensitivities to soy milk. Furthermore, it also contains phyto-estrogens, which mimicking the effect of natural oestrogen may cause hormonal disruptions; an issue in puberty.
3. Coconut milk- It is rarely consumed as a milk substitute. Coconut allergies are rare. However, the milk is lower in protein but much higher in fat. Moreover, the protein content is of inferior type.
4. Rice milk- Rice milk is another option in case of allergies but it has an unfavourable nutritional profile, and may lead to malnutrition if used exclusively.

The devil in A1 milk

Milk consists of about 87% water and 13% of milk solids constituting fat, lactose, minerals and protein. More than 95% of the cow milk proteins are constituted by caseins and whey proteins of which beta-casein is the 2nd most common protein (about 30-35%). Beta-casein occurs as 12 genetic variants but A1 and A2 are most common; A1 in the animals of North American/European origin (Holstein, Friesian, Ayrshire, and British Shorthorn) and A2 in animals of Orient (Asian, Jerseys, Guernsey, and African cows).

Sheep, goat, yaks, buffalo, camels, donkeys and Asian cows naturally contain more A2 beta casein protein. Indian native dairy cow and buffalo have only A2 allele. Digestion of A1-beta-casein protein by digestive enzymes can yield the peptide beta-casomorphin-7 (BCM-7), which is a bioactive seven-amino peptide which is implicated in adverse gastrointestinal effects of milk consumption, which may closely mimic lactose intolerance. Furthermore, it can interact with other human systems; nervous (brainstem), endocrine and immune system.

BCM-7 is known to be an oxidant of LDL an important contributor in formation of arterial plaque. BCM-7 is an opioid peptide and may induce sleepiness. Some studies have suggested that BCM-7 may be linked to type 1 diabetes, infant death, autism, and gastrointestinal inflammation. However, the most worrying could be an accelerated risk of atherosclerosis and subsequent coronary artery disease (CAD).

What about India?

Indian cattle and buffalo breeds have the highest (99 - 100%) of the A2/A2 genotype and A1/A1 genotype is almost absent or very rare among them. In India, most of the native cows produce A2 milk; 15 zebu cattle breeds (Kangayam, Nimari, Red Kandhari, Malnad Gidda, Kherigarh, Malvi, Amrit Mahal, Kankrej, Gir, Sahiwal, Hariana, Tharparker, Rathi, Mewati and Red Sindhi) and 8 river buffalo breeds (Murrah, Mehsana, Marathwada, South Kanara, Manipur, Assamese Swamp, Nili Ravi and Pandharpuri). How much of the branded milk that is available in the Indian market is A1, from crossbred or foreign cows? Buffalo milk or goat milk, however, is still A2.

Disclaimer- The views and opinions expressed in this article are those of the author's and do not necessarily reflect the official policy or position of M3 India.

The writer, Dr. Sundeep Mishra is a Professor of Cardiology.