We need more articles like this one by Prof Dr Geetha Viswanathan (emphasis mine):
Makara Sankranti, also called the harvest festival or Pongal, falls on January, 14 or 15, when the sun passes from one zodiac sign to another. This festival marks the beginning of Sun’s journey to northern hemisphere, called utharayana.
Homes are cleaned, white-washed, and red mud smeared along the walls. In front of the house fresh cow dung is smeared and designer rangoli designs made. A make-shift stove is built on the verandah and a new mud pot decorated with turmeric leaf and rhizome used to cook newly-harvested rice in the presence of sunshine. Sweet pongal is prepared, offered to Sun God and distributed to all.
In the evening a mixture of roasted gingili seeds, dry coconut copra, and jaggery is distributed to all friends and relatives along with sugar candy.
On the third day cows are decorated after bath, their horns painted, and body smeared with turmeric. A small heap of dry hay is burned. Each cow is forced to cross the fire at least three times. Then camphor is burnt and aarthi is shown to the cow, especially to the udder and back. The cow is fed with sweet pongal and gingili mixture.
All that is not meaningless tradition. There is hard-core science behind it. White-washing the house with calcium carbonate (collected from molluscan shells) helps to kill spiders and other insect vectors in house. Fresh cow dung in presence of sunlight produces methane which forms a thin film in front of our house and prevents entry of bacterial pathogens and also kills microbes. Red mud will close all pores in the house which are breeding place for many vectors.
Cooking rice in presence of sunlight helps to get vitamin – D for one full year. Gingily is a good antioxidant; dry kenel of coconut is anti bacterial agent and anti viral agent. Dry coconut has saturated fatty acid which prevents infections. Dry coconut has lauric acid, which is a very good antiviral agent oil in the nut helps to rejuvenate the muscles and enhances hair growth and premature aging of our skin.
During this season that signals the end of winter and beginning of spring followed, is the optimum period for viral and bacterial colony to breed. Mumps, measles causing adenoviruses breed fast during this period. These viral infections can even cause damage to chromosome 17 and create a chromosomal or genetic disorder which can be passed on to next generation. Eating coconut gingili mixture with anti viral agent helps to prevent the viral attack. Turmeric used in pongal is also an antiviral agent.
Cowpox viruses belonging to poxvirus, foot and mouth disease virus and anthrox leptospirosis are found to breed during this season, which is their optimum period. These cause disease in cow and buffalos, encephalitis infection is transmitted through milking. Cowpox milker’s node, Orthopox virus causes infections in cows, buffalos, mouse, monkey, rabbit, camel at temperatures between 25- 41 degree centigrade. Cowpox is absent in Europe because the temperatures are lower than the optimum for the virus.
Crossing the fire by the cows reduces the chance of the infection; camphor arathi will also prevent infection of theses virus because camphor is an anti viral agent.
So it can be seen clearly that our ancestors had a good reason to do what they did. It is time we realised that.
I'm just amazed at how our ancestors took a proactive approach to health rather than our our reactionary approach, and that too, we depend on artificial means like manufactured pills compared to their simple clean natural ways.