Dairy Culture of India

Cultures of Northern & Western parts of India, particularly of Indo Aryan (IA) language  population, is predominantly based on cows, milk, and milk products. The Cultural Evolution (CE) of this region has a strong influence not only on Hindu Vedic culture but also on many folk traditions of India. Both Lord Kriṣhṇa (Mahābharata and Bhāgavata), and Lord Rāma (Rāmāyaṇa) are associated with this region. Among all Avatārars of Lord Viṣhṇu, Kriṣhṇa has a very strong association with dairy culture. His early life starts in the divine world of Gokula, where he is a cowherd boy Gopāla. He loves butter and teases cowherd damsels. It is assumed that the same Kṛiṣhṇa is the wise statesman of the epic Mahābhārata where he advises Arjuna to fight the war and perform his duty as a warrior. Kṛiṣhṇa’s philosophical discourse on the battlefield is well known as Bhagavadgītā (“The Song of the God”). It is traditionally praised using the metaphor of the “cow’s milk”: 

सर्वोपनिषदो गावो दोग्धा गोपालनन्दनः। पार्थो वत्सः सुधीर्भोक्ता दुग्धं गीतामृतं महत् ।। (All the Upaniṣhad-s are the cows, Gopālanandana (Kṛiṣhṇa) is the milker, Pārtha (Arjuna) is the calf, men of purified intellect are the drinkers, and the supreme nectar Gītā is the milk). 

This spiritual culture couched in myths and anecdotes is supported by the reality on ground. Northern and Western India are the most dairy friendly regions of India compared to its southern and south-east regions. But why is it so?.. more so when about 65% of the adult human world population is not comfortable with drinking milk? To understand it, let us absorb a few biological details related to milk consumption.

Many of the people who suffer from drinking milk are unable to digest lactose, a complex sugar found in milk. Lactose can’t pass through the wall of the small intestines until broken into simple sugars by an enzyme called lactase. Lactase is generally found in all young mammals, but as mammals get older, many lose the ability to produce it: they become lactose intolerant (Lactase Non-Persistant or LNP) and are weaned away from the mother’s milk to more solid and varied food. Since almost all mammals are LNP, mammalian lactase persistence is said to be naturally selected in their biological evolution. Enzyme lactase however, persists in some adult humans. It enables them to digest lactose even when they are adults, making them Lactase Persistent or displaying Lactase Persistence (LP). LP is common in Europe, the Middle East, some parts of Africa, and India. Majority of LP Europeans carry a mutation -13910T. It seems to have originated somewhere in Europe around 7,500 years ago. In 2011, a Cambridge team, with researchers at CCMB Hyderabad, UCL, University of Tartu, Harvard and University of Chennai, reported that the -13910T mutation was also at relatively high frequency in India in those populations with a tradition of milk drinking and cattle rearing. This was not a new India-specific mutation, but a familiar genetic pattern – a single switch from C to T, characteristic of the common European mutation. The team claimed that the Indian mutation has the same origin as that found in Europeans; that it could lead back to the same people who may have migrated between Europe and India. 

Prof. Mark Thomas of UCL, a co-author of the report, said: “The genetic data doesn’t support some sort of large migration of people from Europe to India in the last 10,000 years. What’s more likely is that just a few migrants carried this mutation to India, and then it spread quickly.” 

The study also revealed large differences in the distribution of -13910T alleles in India with many southern and eastern populations – especially those who do not practice cattle rearing – having near zero frequencies. The mutation frequency of IE language groups was found to be 18.4 percent in 896 samples while overall it was 10.3 percent in 2284 samples. Even in the so-called dairy rich regions of IE language population, the LP gene frequency is not very high. Why then (a) there is so much folklore built around milk loving God-child Kṛiṣhṇa, and (b) there is a flourishing dairy industry in spite of the low LP occurrence? 

The first part of the answer is given by the memetics of CE. Indian culture developed dominant memes of devotion, love, as well as fun, through the stories and myths built around Lord Kṛiṣhṇa who loved cows and played pranks on friends and cowherd women. The other part of the answer is more complex. It has been shown that some LNP individuals can consume lactose-containing products without any obvious ill effects. This inter-individual variation of the amount of lactose tolerated by LNP people may be a result of variation in the composition of the gut flora (particularly the presence of lactic acid bacteria). Also, fermented dairy products (i.e. yogurt or cheese) contain less lactose, allowing their consumption by LNP individuals without expected symptoms. 

Two contrasting theories have been proposed to explain the co-distribution of LP and dairying practices. The culture-historical hypothesis argues LP developed, and was consequently selected, after milk production and dairy consumption spread. The opposing hypothesis (mentioned as the reverse-cause hypothesis) proposes that only populations whose frequency of LP was high enough adopted dairying. In other words, human groups were differentiated with regards to LP frequency by a process unrelated to milk consumption - through genetic drift -before the invention of dairying. This view specifically assumes that drinking milk would not necessarily have conferred any selective advantage.

The reasons why LP should provide a selective advantage are still open to debate. However, niche construction is possible whereby (a) the organisms significantly modify environmental conditions, (b) these modifications influence one or more selection pressures on a recipient organism, and (c) these selection pressures fix the mutation(s) in certain extreme circumstances in the procreative population of organisms. In the Indian subcontinent this niche construction supports the idea that LP coevolved with the cultural adaptation of dairying as a gene–culture coevolution process. We may call it gene-meme coevolution.