Wednesday, January 20, 2010

Diabetes caused by genes and not by overeating? How pesky!

Diet undoubtedly has a role in controlling the effects of diabetes once you've got it but that is a long way from saying that diet causes diabetes. Yet that is the constant claim. I have looked at the "evidence" for that claim previously

One of the largest genetic studies ever undertaken has discovered nine new genes linked to type 2 diabetes, opening a door to new understanding and possible treatment. Scientists from 174 research centres around the world, who studied the genes and blood glucose level of more than 120,000 volunteers, were able to identify a set of genes that control the body’s response to glucose in the blood.

It is hoped the discovery could lead to new treatments for diabetes, which affects more than 220 million people worldwide. Ninety per cent of those have type 2 diabetes, also known as late-onset diabetes because it typically develops later in life. It occurs when the tissues of the body become resistant to the effects of insulin, needed to regulate glucose. Sufferers may control the disease with diet and exercise but often have to take drugs and in more serious cases have to inject insulin.

Jim Wilson, a geneticist from Edinburgh University who heads the Scottish cohort study, said: “This is an incredibly important finding. The discovery of these new genes influencing blood-sugar levels is the first step on the important journey to developing new therapies for diabetes. “It opens up a whole new area of research to find which proteins are ‘druggable’. Genetics is like a can-opener: it allows us to get inside and understand what’s going on.”

The hope is that in five to ten years scientists will be able to pinpoint which individuals are genetically susceptible to developing type 2 diabetes, and that there will be a drug available which can prevent its onset. “What we have found may not contribute to personalised medicine becoming a reality today, but it will contribute to it happening tomorrow,” Dr Wilson said.

The work, published today by Nature Genetics and the Sanger Institute in Cambridge, involved an unprecedented degree of collaboration. The 122,743 research subjects came from 50 population studies, in the US, Canada, Iceland and Europe, including Scotland, England, Germany, Netherlands, Finland, Italy, Spain, France, Switzerland, Iceland and Sweden. The work, called MAGIC (Meta-Analyses of Glucose and Insulin-related traits Consortium), is the largest association study published to date. The Scottish research focused upon the ORCADES (Orkney Complex Disease Study) cohort, involving up to 2,000 healthy volunteers from Orkney. The work was funded by the Chief Scientist Office of the Scottish Government and the Royal Society.

The nine new genes include those that influence blood sugar levels and also the first gene influencing levels of insulin. A subset of the genes was associated with diabetes itself.

Dr Wilson said the biological pathways that the genes highlighted were those involved in the control of blood sugar and might point to novel drug targets for glycaemic control. The pathways included not only glucose transport and sensing and pancreatic cell development, but also circadian rhythms and fatty acid metabolism.

To find out which genes are involved in glucose control, the team studied the genes of 50,000 healthy volunteers, also measuring glucose. It then sought to replicate the findings in approximately 75,000 more people.


The fish oil religion again

An ancient religion indeed. And there is no doubt that it can prevent some vitamin deficiencies, which is valuable. But the report below is all theory. There is a lot we don't know about telomeres yet

Fish oils may hold the key to longer and healthier life, claim researchers. They say omega-3 fatty acids from fish oil may have a direct effect on extending the lifespan of cells. Their study is the first to link the oils - either from fish or supplements - with the body's ability to resist premature ageing. The 'elixir of life' discovery was made in heart disease patients, who are already advised to increase their fish intake to ward off repeat heart attacks.

Scientists from the University of California, San Francisco, looked at the effect of omega-3 fatty acids on 608 outpatients with heart disease. They found higher levels of omega-3 slowed down damage to DNA contained in telomeres - tiny 'caps' on the ends of chromosomes which help protect against inflammation and other ageing processes. Having longer telomeres is a sign of being biologically younger and also of being healthier. As people age, their telomeres get shorter and they become more susceptible to certain illnesses. Scientists believe this process is at the heart of many age-related diseases, and may even place a final limit on human lifespan.

Nutritionist Dr Carrie Ruxton, speaking on behalf of the Health Supplements Information Service, said: 'If this link between high omega-3 fatty acid levels and reduced ageing is confirmed in other studies, this has important implications for intakes of omega 3 fatty acids.'

At the start of the study, measurements were taken of the length of telomeres in the patients' white blood cells. The tests were carried out again after five years, and showed a clear link with omega-3 intake, says a report in the Journal of the American Medical Association. Patients consuming the least omega-3 had the fastest rate of telomere shortening while those in the top 25 per cent of consumption levels had the slowest rate.

Lead researcher Dr Ramin Farzaneh-Far said animal research has shown that rodents live a third longer when given a diet enriched with fish-derived omega-3. He said the latest study demonstrated 'a potentially novel pathway for the anti-ageing effects of omega-3 fatty acids'.

Omega-3 fatty acids are found in oily fish such as mackerel, herring, salmon, sardines or trout - and fish oil supplements - as well as soya beans, rapeseed oil, flaxseed, pumpkin seeds and walnuts. White fish is also a healthy food although it contains lower levels of essential fatty acids. But, said Dr Ruxton, Britons fail to consume recommended minimum levels of two fish portions each week, one of which must be oily.


1 comment:

Anonymous said...

I work in seafood and health research. I am convinced that dietary modification, including adding more fish to the diet, can improve quality of life for many suffering from chronic ailments. Improving quality of life i.e. less pain and better mobility is not the same as claiming outlandish and frankly outrageous levels of benefit from fish or any of it's component parts. Real information of value to the public stands to be buried under the avalanche of exaggerated crap coming out of abysmal research and science by press release.
If EPA and DHA are so amazingly good for human beings why hasn't selective pressure operated to enhance out own capacity to produce these lipids?