Chronic exposure to particulate air pollution may accelerate cognitive decline in older women, researchers suggest.

In a large, prospective study led by a researcher at Rush University Medical Center, women who were exposed to higher levels of ambient particulate matter (PM) over the long term experienced more decline in their cognitive functioning over a four-year period.

Higher levels of long-term exposure to both coarse PM (PM2.5-10) and fine PM (PM2.5) were associated with significantly faster cognitive decline.

PM air pollution consists of small particles suspended in the air. Particles that are less than 2.5 microns in diameter, which is 1/30th the width of human hair, are called fine PM and particles larger than 2.5-10 microns is called coarse PM.

These associations were present at levels of PM exposure typical in many areas of the United States.

There are few recent studies that analyze air pollution and cognitive function in older adults, but this is the first study to examine change in cognitive function over a period of time and whether exposure to the size of particulate matter is important.

Jennifer Weuve, MPH., ScD, assistant professor of the Rush Institute of Healthy Aging and the principal investigator of the study, along with her colleagues, evaluated air pollution, both coarse and fine, in relation to cognitive decline in older women using a study population from the Nurses' Health Study Cognitive Cohort, which included 19,409 U.S. women ages 70 to 81 for a 14-year period going back as far as 1988.

"Our study explored chronic exposure to particulate air pollution in relation to decline in cognitive functioning among older women. Very is little known about the role of particulate matter exposure and its association with cognitive decline," said Weuve.

Exposure to particulate air pollution is associated with cardiovascular risk, which itself may play a role in causing or accelerating cognitive decline.

"Unlike other factors that may be involved in dementia such as diet and physical activity, air pollution is something we can intervene on as a society at large through policy, regulation and technology," said Weuve.

"Therefore, if our findings are confirmed in other research, air pollution reduction is a potential means for reducing the future population burden of age-related cognitive decline, and eventually, dementia," concluded Weuve.

Starving yourself on alternate days can make you live longer, according to scientists.

A group of Americans have said that fasting on and off can boost brain power and help to lose weight at the same time.

The National Institutes for Aging said their research was based on giving animals the bare minimum of calories required to keep them alive and results showed they lived up to twice as long.

The diet has since been tested on humans and appears to protect the heart, circulatory system and brain against age-related diseases like Alzheimer's.

'Dietery energy restriction extends lifespan and protects the brain and cardiovascular system against age-related disease,' said Mark Mattson, head of the laboratory of neurosciences at the NIA and professor of neuroscience at John Hopkins University in Baltimore.

Scientists studying the human genome have found that each of us is carrying around 20 genes that have been completely inactivated, suggesting that not all switched-off genes are harmful to health.

A team at Britain's Wellcome Trust Sanger Institute is developing a new catalogue of so-called "loss-of-function" (LoF) gene variants to help identify new disease-causing mutations, and say their work will help scientists better understand the normal function of human genes.

Working as part of a larger study called the 1000 Genomes Project, the team developed a series of filters to identify common errors in the human genome, which maps the entire genetic code.

"The key questions we focused on for this study were how many of these LoF variants were real and how large a role might they play in human disease," says Daniel MacArthur of the Sanger Institute, who worked on the team.

The researchers looked at nearly 3000 possible LoF variants in the genomes of 185 people from Europe, East Asia and West Africa. Their findings were published today in the journal Science.
Zeroing in on how many

Loss of function variants are genetic changes that are predicted to severely disrupt the function of genes. Some are known to cause severe human diseases such as muscular dystrophy and cystic fibrosis.

Previous genome sequencing projects have suggested there are hundreds of these variants in the DNA of even perfectly healthy individuals, but researchers were not able to tell exactly how many.

In this study, the filters revealed that 56 per cent of the 3000 possible LoFs analysed were unlikely to seriously affect gene function.

But of the true LoF variants, 100 are typically found in the genome of each European, the researchers say, and 20 affect both copies of the gene - meaning they are likely to result in complete loss of gene function.

"This shows that at least 1 per cent of human genes can be shut down without causing serious disease," says Mark Gerstein, a professor of biomedical informatics from Yale University in the United States, who also worked on the study.

"We were able to use the differences between such 'LoF-tolerant' genes and known human disease genes to develop a way of predicting whether or not a newly discovered change in a gene is likely to be severely disease-causing."
Immediately useful

Chris Tyler-Smith, who led the team at the Sanger Institute, says the findings would prove immediately useful for current DNA sequencing studies in patients with particular diseases.

The results produced a list of more than 1000 LoF variants, he says, "and in most cases little or nothing is known about how these genes work or what they do.

"By studying the people carrying them in detail, we should get new insights into the function of many poorly known human genes."

Food scientists have found a way of measuring how we register the saltiness of crisps which could lead to new ways of producing healthier crisps - without losing any of the taste. The research by scientists at The University of Nottingham could lead to significant salt reduction in all snack foods.

The research, published on Thursday February 16 2012 in the Royal Society of Chemistry journal Food & Function, follows an investigation into how salt is released from crisps into the mouth.

Dr. Ian Fisk, a lecturer in the Division of Food Sciences, said: "The 'salt burst' from crisps is only released into the mouth 20 seconds after chewing begins. This means that in many cases the crisp may have already been swallowed before the majority of the salty taste is detected. Our aim is to develop a series of technologies that accelerate the delivery of salt to the tongue by moving the burst from 20 seconds to within the time that you normally chew and swallow. This would mean that less salt would be needed to get the same amount of taste.

Excess salt in the diet has been linked to high blood pressure and cardiovascular disease. The World Health Organization's recommendation for daily salt intake is just five grams. Many of us have twice this amount. The reduction of salt intake is now a major challenge for health authorities and the food industry.

Why is salt in our food?

Salt isn't just a flavor enhancer. Historically it has been added to enhance shelf life, improve functionality and control fermentation. Common foods including bread, meat products, breakfast cereals, cheese and popular snacks are among major dietary contributors to our salt intake.

There is now a clear need for the food industry to find ways of preserving these attributes while maintaining the consumer experience.

Crisps tasted under strict supervision

Salt release is complicated and the panel of 10 tasters were chosen for their ability to eat repeatedly 'under instruction'.

Working with Xing Tian, a Masters Project student, Dr. Fisk brought together the consumer panel of food tasters to chew crisps a prescribed number of times and hold them in their mouths for 60 seconds. The crisps were then swallowed as normal.

By taking tongue swabs and analysing the results on equipment capable of detecting sodium content they were able to monitor the salt levels as they peaked and troughed. Unlike other studies Dr. Fisk's research truly identified the moments of maximum intensity and maximum value.

Salt in crisps sits both on the surface and is embedded in the surface oil. So the salt has to be physically separated from the crisp bolus (chewed material), solubilized in the saliva and then moved to the salt receptors in the tongue for the brain to register the taste before being swallowed.

Dr. Fisk said: "After 20 seconds we detected a peak in saliva salt concentration. The panellists confirmed that they too detected an increase in salt perception at around this time."

Patients with end stage organ failure in the state can hope to prolong their life with the state government launching the Cadaver Transplant Programme. The programme paves the way for transplantation of vital organs harvested from brain-dead person in patients with chronic ailments.

The organs that can be transplanted include eyes, heart, lungs, liver, pancreas, kidneys, heart valves, skin, bones, bone marrow, connective tissues, middle ear, blood vessels and small intestine.

Though the government of India had passed the Transplantation of Human Organs Act in 1994, the state government had not framed rules to implement it in the state, which has the highest number of heart patients in the country and a large number of patients with liver and kidney related diseases.

The orders issued this week give legal backing for the organ transplantation. Issued under the Federal Act, the orders specify norms for determining brain death and procedures for removing and transplanting the organs.

The consent of relatives is a must for removing organs from brain dead persons and the person requiring organs needs to register with the health authorities. The order contains detailed guidelines for determining priority in making the organs available to patients. A provision would be incorporated soon for allowing donors to make donations to patients of their choice.

The government has set up a Core Committee for Cadaver Transplantation under the supervision of the Director of Medical Education to coordinate various functions related to the cadaver transplantation and a Cadaver Transplant Advisory Committee under the Health Secretary.

The Cadaver Transplant Programme was formulated on the basis of the report of an expert committee, which studied the implementation of the programme in the neighbouring states of Tamil Nadu and Andhra Pradesh.

Tamil Nadu has been a role model in cadaver transplantation. The state recorded a deceased donor rate of 1.3 per million as against 0.15 per million population in the country as a whole. Experts say that if the country can push the rate to the Tamil Nadu level it can easily meet the demand for organs. The current demand in the country for kidney transplants is 150,000; liver, 200,000 and heart, 150,000.

India now does only 3,000 kidney transplants and 500 liver transplants a year because there are not enough donors. Though 140, 000 lives are lost in the country through road accidents every year, the precious organs that could save the lives of many have been going waste.

Kerala too could meet the demand for vital organs to a great extent if a programme was in place to retrieve the organs of nearly 4000 road fatalities a year. The Cadaver Transplant Programme may help the state to tap this potential. However, experts say that simply laying the guidelines for cadaver transplant alone will not solve the problem. Though it simplifies the legal procedures there are social and ethical issues to be tackled.

In spite of high literacy people have not been coming forward to donate the organs. Health activists believe this is mainly because of ignorance, superstitious beliefs and religious restrictions. Private initiatives in the past have not been able to break these barriers. The Society for Organ Retrieval & Transplantation (SORT), one such initiative launched under the auspices of Indian Medical Association in 2000 could attract only 1500 donors in the last 12 years.

The society had to wait till 2004 for the first ever multi-organ transplantation. It was made possible by the members of the family of one Ramachandran Nair, who was declared brain dead following a road accident in June 2004. Three patients received the deceased's live and kidneys.

Sort has been organizing seminars on 'Religion and Organ Donation' involving religious heads to create awareness on organ donation. The Rotary Club of Trichur City has also been running a campaign involving doctors, NGOs, hospitals and others concerned to encourage organ donation. It has set up a body called RISORT (Rotary Initiated Society for Organ Retrieval and Transplantation) to popularise cadaver transplant in the state.