Thursday, September 13, 2012

Horrors!  Fish oil supplements 'do NOT cut risk of heart attacks and strokes'

To food freaks this is like declaring God is dead!  But they're not giving up yet

Scientists claim fish oil supplements do not cut the risk of heart attacks and strokes despite being widely used and even prescribed for prevention.

A review of 20 studies involving almost 70,000 patients concluded that taking omega-3 fatty acids derived from fish oil had no significant effect on rates of heart attacks, strokes and heart-related deaths.

Previous trials have had conflicting results about whether supplements may protect the heart.

But fish oil supplements are approved on the NHS to prevent heart attack survivors from having a second attack and recommended in official guidelines.

Omega-3 polyunsaturated fatty acids (Pufas) are known to fight inflammation, one of the key processes that contribute to narrowing of the arteries.

Researchers conducting the new study analysed data on 7,044 deaths, 3,993 heart-related deaths, 1,150 sudden deaths, 1,837 heart attacks and 1,490 strokes.

The results, published in the Journal of the American Medical Association, showed no evidence of risk reduction associated with omega-3.

Dr Evangelos Rizos, from the University Hospital of Ioannina, Greece, who led the study, said 'In conclusion, omega-3 Pufas are not statistically significantly associated with major cardiovascular outcomes across various patient populations.

'Our findings do not justify the use of omega-3 as a structured intervention in everyday clinical practice, or guidelines supporting dietary omega-3 Pufa administration.'

Fish oil supplements are approved for prescribing on the NHS to patients after a heart attack, or who have metabolic syndrome or high triglycerides - unhealthy blood fats.

Omacor, which is licensed for post-heart attack treatment, has been shown in clinical trials to cut the risk of sudden death by up to 45 per cent.

Britons are currently advised to eat fish at least twice a week, including one portion of oily fish.  Oily fish contain the highest levels of omega 3 fatty acids, which are considered essential because the body cannot make them from other sources and must obtain them through diet.

Omega-3 fats are important throughout adult life for mental wellbeing but in particular help heart patients, and those with arthritis, by blocking the body's response to inflammation.

They work in several ways to reduce heart attack risk by cutting blood fats, reducing the chances of a blood clot and blocking dangerous heart rhythms that might otherwise prove fatal.
Omega-3 fats are important throughout adult life for mental wellbeing but in particular help heart patients, and those with arthritis, by blocking the body's response to inflammation.

Omega-3 fats are important throughout adult life for mental wellbeing but in particular help heart patients, and those with arthritis, by blocking the body's response to inflammation.

Dr Carrie Ruxton, from the industry-backed Health Supplements Information Service, said the EU Commission had recently authorised a favourable heart health claim for omega-3 fatty acids.

She questioned why only 20 studies were used in the analysis of existing trials, when 3,635 papers were considered.

She said 'Omega-3 fatty acids are well known for their heart health benefits with a significant body of evidence.'

Previous reviews found a 28 per cent reduced risk of all-cause mortality in people receiving omega-3 supplements, and a 16 per cent reduced risk of all-cause mortality.

'Moreover, the UK National Institute for Health and Clinical Excellence (NICE) recommends the consumption of 1000mg daily of omega-3 fatty acids (from fish oil) in patients who have had a heart attack' she said.

Dr Ruxton said many people failed to eat recommended levels of oily fish, which meant supplements might suit them better.

'Given the low intakes of omega-3 fatty acids in the UK and many people's apparent dislike of oily fish, a supplement containing omega-3 fatty acids may be appropriate for the maintenance of heart health' she added.


Dengue vaccine shows promise in clinical trial

Good news for Northern Australia, where Dengue is endemic.  Mosquito eradication keeps it under some control but Mosquito eradication is always imperfect

A major clinical trial of the frontrunner in the race for a dengue fever vaccine is showing great promise.

Every year, the World Health Organisation estimates between 50 and 100 million people are infected with the virus, and the most vulnerable are children and adolescents.

Scientists have been searching for a vaccine for the last 90 years.  But now a drug developed by a French company has shown encouraging results, protecting against three of the four types of dengue virus in Thai children.

Cameron Simmons, a professor working in Oxford University's clinical research unit in Vietnam, says the results are hugely encouraging.  "It's regarded as a neglected tropical disease. The sheer scale of the disease burden in dengue endemic countries is enormous," he told PM.  "It's a major public health problem, places enormous strain on often fragile healthcare systems."

The major clinical trial of the drug involved 4,000 primary school aged children in Thailand.

"We were optimistic and hopeful that we would see protection against all four dengue viruses," Professor Simmons said.  "What the study has shown us is that the vaccine seems to offer protection against three and not four of the dengue viruses.

"There's more research to be done to really try and understand why protection is not against all four but we're heading in the right direction. I think that's the important result."

There is no clinical difference between the four types of virus; the patient still presents with symptoms like muscle and joint pain, fever, rashes, hair loss, intense headache and extreme fatigue.

The one type of dengue not affected by the vaccine was the most prevalent type in the study's region, and there are concerns that may have dragged down the results.

The fact that it appears to have worked on the other three has already led to speculation that that could be enough to prevent severe disease, but Professor Simmons is not so sure. 

"I think a trial of that trivalent vaccine could be possible," he said.  "But it's going to need a lot more research to understand from a modelling perspective what a trivalent vaccine might do to the epidemiology of dengue in an endemic setting and also very importantly the cost effectiveness of such a vaccine."

Professor Simmons says even for countries like Vietnam, where child mortality rates from dengue fever are relatively low, any hope is welcome.  "The disease burden is enormous here, 10 to 15 per cent of the hospitalised patients in the hospital that I work in are dengue cases," he said.

"So it's one of the most important causes of hospitalisation for children. So the scale of the disease burden is enormous, public health importance is very large.  "One dengue virus infection actually predisposes you to a more severe infection a second time around and so it's a complicated disease in that fashion."

A third stage of the trial involving 30,000 people from South-East Asia and Latin America is due to deliver results in 2014.

Professor Simmons says he is hoping for a fully-fledged dengue virus vaccine within five to 10 years.


1 comment:

Anonymous said...

And the news reports the the Japanese
may have found that vitamin D makes your hair grow.