Fast and rest to live fit and long

Traditional medicine systems such as Ayurveda, homoeopathy, and naturopathy recommend fasting to treat various ailments. Grandmothers have long practised diet restrictions and the use of specific foods to tackle simple fevers or manage chronic healthcare problems.

“The best of all medicines are rest and fasting,” said well-known American statesman, writer Benjamin Franklin, while Mahatma Gandhi used fasting as an effective political tool against the British during the freedom movement as well as to maintain his lifestyle.

However, the exact benefits of dietary restrictions or fasting on the human health system have not been scientifically well understood.

Now, a scientific team, including Nooruddin Khan from the University of Hyderabad and Bali Pulendran of the US, has found a mechanism by which the body is able to adapt to nutrient scarcity and thus explain the benefits of diet restrictions.

The scientists have identified a gene — GCN2 (General controlled non-repressedkinase) — which is a metabolic sensor involved in amino acid (building blocks of protein) starvation. The activation of this gene is the key to boosting vaccine-induced immunity. They stumbled upon this mechanism while studying immune responses to the Yellow Fever vaccine (known to be among the most effective vaccines).

The research pointed out that low-protein diet or caloric restriction can help boost immunity. Explaining the role of the gene, Khan told BusinessLine that it can sense a starvation-like condition in the stomach and gets activated. It starts cleaning up the system (autophagy) by getting rid of unwanted proteins and organic substances, in turn raising immunity and suppressing the inflammation process in the gut.

Restricting amino acids without leading to a malnutrition condition will dramatically bolster vaccine-induced immunity and protection of intestinal inflammation. In simple words, dietary restrictions or a balanced diet can protect us from a variety of disorders, especially inflammatory ones, and extend lifespan.

The scientists suggest that vaccine additives, called adjuvants, that are effective in stimulating the gene and regulate a response to starvation within cells would be potent in stimulating long-lasting immunity. They have been using this knowledge to engineer vaccines against infections such as dengue, TB and HIV.

The researchers are identifying molecules (plant-based derivates) than can activate or mimic the gene function. In addition they are trying to use them as adjuvants and blend them with existing vaccines to improve their efficacy, said Khan.

In a research paper published in the March16 issue of Nature , Pulendran and Khan have shown that a low-protein diet or drugs that mimic its effect on immune cells could be tools for the treatment of inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis.

Mice fed with a low-protein diet (2 per cent, compared to 16 per cent in standard diet) or a diet lacking only the amino acid leucine, were protected from signs of colitis, such as weight loss and bloody diarrhoea. On the other hand, mice lacking the GCN2 gene were not protected from colitis when fed a low-protein diet, which demonstrated the protective role of the gene.

The researchers interpret the findings to have implications for the treatment of inflammatory bowel diseases and autoimmune diseases such as rheumatoid arthritis and psoriasis. For the pharma industry, this understanding could open up avenues for developing drugs.

At the UoH, Khan’s team is probing the biology of nutrient sensing and immunological regulations in diseases such as TB, dengue and HIV.

COMMENT NOW