A study in the open access publication, Journal of Neuroinflammation revealed that caffeine equivalent to just one cup of coffee a day could protect the blood-brain barrier (BBB) from damage that occurred with a high-fat diet.
The BBB protects the central nervous system from the rest of the body's circulation, providing the brain with its own regulated microenvironment. Previous studies have shown that high levels of cholesterol break down the BBB which can then no longer protect the central nervous system from the damage caused by blood borne contamination. BBB leakage occurs in a variety of neurological disorders such as Alzheimer's disease.
In this study, researchers from the University of North Dakota School of Medicine and Health Sciences gave rabbits 3 mg caffeine each day “ the equivalent of a daily cup of coffee for an average-sized person. The rabbits were fed a cholesterol-enriched diet during this time.
After 12 weeks a number of laboratory tests showed that the BBB was significantly more intact in rabbits receiving a daily dose of caffeine.
Caffeine appears to block several of the disruptive effects of cholesterol that make the blood-brain barrier leaky, says Jonathan Geiger, University of North Dakota School of Medicine and Health Sciences. High levels of cholesterol are a risk factor for Alzheimer's disease, perhaps by compromising the protective nature of the blood-brain barrier. For the first time we have shown that chronic ingestion of caffeine protects the BBB from cholesterol-induced leakage.
Caffeine appears to protect BBB breakdown by maintaining the expression levels of tight junction proteins. These proteins bind the cells of the BBB tightly to each other to stop unwanted molecules crossing into the central nervous system.
The findings confirm and extend results from other studies showing that caffeine intake protects against memory loss in aging and in Alzheimer's disease.
Caffeine is a safe and readily available drug and its ability to stabilise the blood-brain barrier means it could have an important part to play in therapies against neurological disorders, says Geiger.
biomedcentral/
Half of the new loci identified by Dr Frayling and colleagues contain genes whose functions are well documented. Some help regulate basic cell division, which may have implications for cancer research: unregulated cell division can lead to the growth of tumours. Other genes are implicated in cell-to-cell signalling, an important process in the early development of embryos in the womb. Yet others are so-called "master regulators", acting as switches to turn genes elsewhere in the genome on or off.
One locus in particular is also implicated in osteoarthritis, the most common form of arthritis involving the effects of wear and tear on the body's structures. This locus reinforces a similar link identified by a previous study, and may be involved in the growth of cartilage.
However, of the twenty loci identified by Dr Frayling and colleagues, half contain genes about which little or nothing is known. The researchers compare these findings to their work last year which identified the first common gene for obesity, the FTO gene. Even though the gene has been shown without a doubt to be influence body size, its role is still unclear.
"There may be more than a hundred genes which affect our height, many of which will work in surprising or unpredictable ways," says Dr Mike Weedon, lead author on the paper. "The challenge now for us is to understand how they influence growth in the body. This could open up new avenues for treating a range of diseases."
wellcome.ac/