One of the signs of old age is progressive loss of memory that invariably reduces the quality of life and eventually leads to development of diseases like Alzheimer's amongst some old age people. Shrinking of the brain is an indication of its ability to remember and greater the shrinkage, higher will be the neurological damage that leads to dementia like situation. Scientific findings do indicate that if such damages can be prevented or reduced, the cognitive decline due to old age can be prevented to a great extent. The ability of Vitamin B12 to arrest or slow down the process of memory decline is a relatively new finding that can go a long way to address the alarming situation faced by the old age population which does not realize the deficiency of this vitamin in the diet and its serious consequences. In a country like USA, mandatory as well as voluntary fortification and enrichment of processed foods may reduce the chances of deficiency to a greater extent than what we face in India. Even then serious consideration is required regarding the effectiveness of synthetic vitamins, especially their absorption and biological efficacy.
B12 deficiency is commonly asymptomatic and only when anemia is precipitated one becomes aware of the low levels of this vitamin in the body. Recommended Daily Allowance (RDA) is in the range of 0.3 to 2 microgram, depending on the age of the population under consideration. Neurological signs of B12 deficiency can occur without any symptoms of anemia which can manifest in sensory disturbances due to damage to peripheral nerves and eventual irreversible death of nerve cells, It is claimed that almost 40% of world population suffer from low values of B12 below 350 pg/liter in blood but even those with 600 pg/liter may also come under deficiency category. In a typical western diet, B12 level is as high as 5-7 microgram per day but the uncertainties regarding absorption can cause serious imbalances in the body which is influenced by pepsin, hydrochloric acid, R-protein, pancreatic enzymes, intrinsic factor, calcium and cell receptors. During old age due to atrophic changes in GI tract, B12 absorption can decrease significantly and more than one third of world population above 60 years are reported to be affected by this syndrome. About 1-5% of free B12 are absorbed by passive diffusion. One worry that haunts vegetarians is the loss of B12 swept away by the high fiber content in their diet and practically no absorption of B12 produced by the intestinal flora in the Colon. According to one estimate 92% of vegans, 64% of lactovegetarians and 47% of lacto-ovovegetarians suffer from B12 deficiency.
It was erroneously believed that with high meat consumption that is prevalent in many affluent countries, Vit B12 deficiency should not be a major cause of worry since animal based foods, especially red meat are rich in this vitamin. But this belief is seriously being challenged by the reported findings that B12 contained in these foods are poorly absorbed by the body thereby creating deficiency situation, not noticed under normal conditions. As low levels of B12 deficiency are not manifested readily in many people, sub-optimal concentrations in the blood can go unnoticed for long that can cause irreparable damage to the brain resulting in progressive development of dementia and Alzheimer's disease. It is a startling revelation that old age population with low levels of B12 suffer twice as much shrinkage of the brain as those with highest levels of this vitamin.
If the above conclusions, vis-a-vis B12, are true, is there no way one can prevent the onslaught of dementia and related diseases as a consequence of the relentless process of aging?. One suggestion that is worth considering calls for increasing the intake of milk as one ages to meet the optimal need of B12. With millions of processed products available in the markets world over, milk consumption is declining and this is true especially with younger population which does not imbibe the habit of drinking milk regularly. The life style changes taking place at young age, involving replacement of milk with foods which are not as complete in nutrition as milk, continues during old age also that has serious health consequences as brought out by these studies. A daily consumption of half a liter of milk is considered adequate to keep the B12 levels at a safe range and keep at bay dementia and Alzheimer's. More encouraging is the ability of human body to store 2-7 mg of B12 and regular consumption of milk during young age can help to build up this storage to maximum levels.
Milk contains about 7 microgram B12 per liter and daily consumption of two cups of milk will provide more than the RDA of B12 for an adult. One uncertainty with regard to milk is the stability of B12 during processing with some claiming that more than 10% is destroyed even under the comparatively milder pasteurization temperature and what would be the consequences of repeated boiling as practiced in India. But this is not supported by any substantial data and for the time being one can feel comfortable with the fact that B12 resists boiling temperature conditions and it is unstable only under alkaline conditions. As pH of milk is invariably less than 7, unless it is adulterated with sodium carbonate or alkali, significant destruction of B12 is unlikely to happen during boiling. 'Milking' the goodness of the milk should be the motto as one reconciles to the process of aging with grace and serenity!