Though most Namboothiris practised Vedic culture in the beginning of the twentieth century, the whole community had to face several setbacks. One of the reasons for the setbacks is the marriage practice among Namboothiris, popularly called "Sambandham" or a casual marriage alliance with girls belonging to other castes. Only marriages within Namboothiri castes, performed through rituals in the traditional style were considered as marriages. Sambandham is not supported by blessings from individual gods,through Mantrams and advices to the bride, through "veli othu", a part of Rigveda. The Namboothiri believed that the girl, during infancy, childhood and youth, is under the wings of gods Soman, Gandharvan and Agni respectively. God Viswavasa protects her virginity. Hence the bridegroom has to thank Viswavasa for protecting her till marriage and then marry her in the presence of Agni. (To know more about marriage, Click here). This is why Sambandham is just a casual relationship for Namboothiris.

Until 1933, only the eldest brother was entitled to marry within the Namboothiri caste. His younger brothers were supposed to practice pure "Brahmacharyam" by being unmarried and to dedicate themselves to preserve Vedams and rituals. The eldest brother was supposed to marry for building up future generations. The younger sons were meant for inheriting the Vedic traditions from their ancestors and passing it on to their future generations (the eldest brother also had a major role in preserving the Vedic tradition) Apart from this, those younger brothers, who opted to marry within the caste were excommunicated (Bhrastu) from the family. By putting such pressures, the elders in the community might have thought that, the younger brothers would concentrate on their traditional job of practising bachelorhood, preserving and transmitting Vedams. Except for a few intelligent and studious ones, most younger brothers turned to more lucrative and worldly affairs like Sambandham.

Other communities, especially Nayars and Kshathriyas encouraged Namboothiris to have Sambandham with girls in their communities. The objective behind this encouragement was to "purify" their future generations with the Namboothiri blood and also to elevate their families to higher levels in the society due to a Namboothiri relationship. It was a fact that Namboothiris could not just resist such attractions in terms of money, sex and leisurely life-style.

Namboothiris thus married Kshathriya (Kovilakams, royal families), Nayar, Warrier, and Pisharoti girls and the children from such marriage alliances belonged to the matrilineal (Marumakkathaayam) lineage of their mothers. This, interestingly, led to situations like a Nayar son of a Namboothiri could not eat or bathe with his father, or a Namboothiri could not eat food prepared by his Nayar wife. Namboothiri Spinsters remained abandoned in the community. Namboothiri Yogakshema Mahaasabha ( Click here ), a revolutionary group of Namboothiris and founded in 1908, took a decision in 1919 and agitated for marriage of all Namboothiris within the community. Sabha declared the marriages of younger brothers from within the community as official, irrespective of whether the elder brothers were married or not. This revolutionary meeting was held in "Bharatheebhooshanam" at Thrissur on 25th Medam 1094 (1919 A.D.). The aim was embodied in the Madras Namboothiri Act of 1933. In the same year, the Madras Marumakkathaayam Act was passed, by which Sambandham was considered as a regular marriage, conferring on the children the same rights of inheritance and property as held by children whose parents were both Namboothiris. The declaration and these Acts led to a sudden decline in the number of Sambandham marriages, and this unethical practice ended shortly (in about ten years). Following these acts, Namboothiri land was increasingly partitioned and property dispersed.

The stoppage of Sambandham led to a liberation of Namboothiri wives and girls. They were the major sufferers due to unavailability of Namboothiri boys for marriage because of the practices of polygamy and parallel Sambandhams by elder sons.

Due to the dispersal of properties, financially sound Namboothiri families became middle class while middle class families became poor. Financially poor families really struggled to cope up with the new environment. As a result, most Namboothiri youths had to leave their Vedic education and practice and switch over to modern (formal) education and profession.

Intelligence and a simple life-style were the only tools the youths inherited, except a few from financially upper middle class families. The Thrissur Brahmaswam Madhom, which was originally founded in the seventh century to teach Rigvedam, offered free food and stay to these studious boys. Most of these boys later became executives and professionals and took their families financially back to middle or upper middle class, while a minority of them miserably failed in formal education also. Some barely managed with income from priesthood in temples. The 1963 Kerala Land Reforms Act and the 1970 amendment of it added oil to flame. Under the original Act, cultivating tenants were made eligible to purchase the right, title and interest from the landlord. They could exercise this right by applying to a land tribunal. Except the properties of a few landlords who anticipated such an Act, the leased properties of Namboothiris were lost to tenants, and this further reduced the income of Namboothiris. The 1970 amendment of the Act clarified that this procedure was applicable if the owner of the land was a religious, charitable or educational institution. The net result was that most temples also lost their income and so did the poor and temple-dependent Namboothiris.

Due to such uncertainties and sudden decline of income from priesthood, most Namboothiri youngsters lost interest in Vedic culture and ritual performances. But a very few members of equally small number of families stood firm against all such tides throughout the twentieth century, and finally ended up as the torch-bearers of Vedic Namboothiri culture. Prominent among them are the families of Cherumukku Vaidikan and Thekkat Vaidikan (both of Sukapuram Graamam). Some of the recently expired Vedic experts include Erkkara Raman Namboodiri and Naraas Somayaaji. A very few families still keep the tradition of "Agnihothram". Pioneer among them is the Maarath Kavapra Mana at Edapal in Malapuram district. The Saamavedi doyen family Nellikkattil Mammannu Mana has a rare achievement that its three successive generations, all christened Neelakandhan, have performed Athiraatram in the 20th century; in 1901, 1918 and in 1956.

According to Erkkara Raman Namboodiri as quoted by Frits Staal, more than 120 Agnishtoma (somayaagam) and five Atiratra-agnicaya (Athiraathram) have been performed between 1911 and 1970. The last Athiraathram was performed in Paanjaal (near Thrissur) in 1975. Athiraathram was performed 18 times during the last 125 years and six times during the last 75 years.