Increased risk of death replacing saturated fat w/ veg. oil
AlabasterVerve
Posts: 3,171 Member
Study raises questions about dietary fats and heart disease guidance
Tuesday, February 5, 2013 - 10:38
Dietary advice about fats and the risk of heart disease is called into question on bmj.com today as a clinical trial shows that replacing saturated animal fats with omega-6 polyunsaturated vegetable fats is linked to an increased risk of death among patients with heart disease.
The researchers say their findings could have important implications for worldwide dietary recommendations.
Advice to substitute vegetable oils rich in polyunsaturated fatty acids (PUFAs) for animal fats rich in saturated fats to help reduce the risk of heart disease has been a cornerstone of dietary guidelines for the past half century. The most common dietary PUFA in Western diets is omega-6 linoleic acid (n-6 LA for short).
UK dietary recommendations are cautious about high intakes of omega 6 PUFAs, but some other health authorities, including the American Heart Association, have recently repeated advice to maintain, and even to increase, intake of omega 6 PUFAs. This has caused some controversy, because evidence that linoleic acid lowers the risk of cardiovascular disease is limited.
An in-depth analysis of the effects of linoleic acid on deaths from coronary heart disease and cardiovascular disease has not previously been possible because data from the Sydney Diet Heart Study - a randomised controlled trial conducted from 1966 to 1973 - was missing.
But now, a team of researchers from the US and Australia have recovered and analysed the original data from this trial, using modern statistical methods to compare death rates from all causes, cardiovascular, and coronary heart disease.
Their analysis involved 458 men aged 30-59 years who had recently had a coronary event, such as a heart attack or an episode of angina.
Participants were randomly divided into two groups. The intervention group was instructed to reduce saturated fats (from animal fats, common margarines and shortenings) to less than 10% of energy intake and to increase linoleic acid (from safflower oil and safflower oil polyunsaturated margarine) to 15% of energy intake. Safflower oil is a concentrated source of omega-6 linoleic acid and provides no omega-3 PUFAs.
The control group received no specific dietary advice. Both groups had regular assessments and completed food diaries for an average of 39 months. All non-dietary aspects of the study were designed to be equal in both groups.
The results show that the omega-6 linoleic acid group had a higher risk of death from all causes, as well as from cardiovascular disease and coronary heart disease, compared with the control group.
The authors then used the new data to update an earlier meta-analysis (a review of all the evidence). This also showed no evidence of benefit, and suggested a possible increased risk of cardiovascular disease, emphasizing the need to rethink mechanisms linking diet to heart disease.
The researchers conclude that recovery of these missing data “has filled a critical gap in the published literature archive” and that these findings “could have important implications for worldwide dietary advice to substitute omega-6 linoleic acid (or polyunsaturated fatty acids in general) for saturated fatty acids.”
In an accompanying editorial, Professor Philip Calder from the University of Southampton says the new analysis of these old data “provides important information about the impact of high intakes of omega 6 PUFAs, in particular linoleic acid, on cardiovascular mortality at a time when there is considerable debate on this question.”
Calder says the findings argue against the "saturated fat bad, omega 6 PUFA good" dogma and suggest that the American Heart Association guidelines on omega-6 PUFAs may be misguided. They also "underscore the need to properly align dietary advice and recommendations with the scientific evidence base."
To coincide with publication of this paper, the BMJ is pulling together examples of missing data it has uncovered, as part of its “open data” campaign. We are also asking researchers to tell us about any other documented examples of missing data, to build a picture of the full extent of the problem which is undermining evidence based medicine worldwide.
The current best estimate is that half of all the clinical trials that are conducted and completed are never published. Even when they are, the underlying data that the results are based on is rarely open to external analysis - which is a cornerstone of proper scientific scrutiny. This means doctors cannot be certain that the drugs they are prescribing daily are properly evaluated for safety and efficacy.
For more details, go to bmj.com/open-data
http://www.bmj.com/press-releases/2013/02/04/study-raises-questions-about-dietary-fats-and-heart-disease-guidance
Critics of the study are saying the original study only showed 6 more deaths and that that was likely the result of the trans fats and not the omega 6 polyunsaturated fats.
http://www.smc.org.au/2013/02/round-up-dietary-fats-and-heart-disease-bmj-experts-respond/
Tuesday, February 5, 2013 - 10:38
Dietary advice about fats and the risk of heart disease is called into question on bmj.com today as a clinical trial shows that replacing saturated animal fats with omega-6 polyunsaturated vegetable fats is linked to an increased risk of death among patients with heart disease.
The researchers say their findings could have important implications for worldwide dietary recommendations.
Advice to substitute vegetable oils rich in polyunsaturated fatty acids (PUFAs) for animal fats rich in saturated fats to help reduce the risk of heart disease has been a cornerstone of dietary guidelines for the past half century. The most common dietary PUFA in Western diets is omega-6 linoleic acid (n-6 LA for short).
UK dietary recommendations are cautious about high intakes of omega 6 PUFAs, but some other health authorities, including the American Heart Association, have recently repeated advice to maintain, and even to increase, intake of omega 6 PUFAs. This has caused some controversy, because evidence that linoleic acid lowers the risk of cardiovascular disease is limited.
An in-depth analysis of the effects of linoleic acid on deaths from coronary heart disease and cardiovascular disease has not previously been possible because data from the Sydney Diet Heart Study - a randomised controlled trial conducted from 1966 to 1973 - was missing.
But now, a team of researchers from the US and Australia have recovered and analysed the original data from this trial, using modern statistical methods to compare death rates from all causes, cardiovascular, and coronary heart disease.
Their analysis involved 458 men aged 30-59 years who had recently had a coronary event, such as a heart attack or an episode of angina.
Participants were randomly divided into two groups. The intervention group was instructed to reduce saturated fats (from animal fats, common margarines and shortenings) to less than 10% of energy intake and to increase linoleic acid (from safflower oil and safflower oil polyunsaturated margarine) to 15% of energy intake. Safflower oil is a concentrated source of omega-6 linoleic acid and provides no omega-3 PUFAs.
The control group received no specific dietary advice. Both groups had regular assessments and completed food diaries for an average of 39 months. All non-dietary aspects of the study were designed to be equal in both groups.
The results show that the omega-6 linoleic acid group had a higher risk of death from all causes, as well as from cardiovascular disease and coronary heart disease, compared with the control group.
The authors then used the new data to update an earlier meta-analysis (a review of all the evidence). This also showed no evidence of benefit, and suggested a possible increased risk of cardiovascular disease, emphasizing the need to rethink mechanisms linking diet to heart disease.
The researchers conclude that recovery of these missing data “has filled a critical gap in the published literature archive” and that these findings “could have important implications for worldwide dietary advice to substitute omega-6 linoleic acid (or polyunsaturated fatty acids in general) for saturated fatty acids.”
In an accompanying editorial, Professor Philip Calder from the University of Southampton says the new analysis of these old data “provides important information about the impact of high intakes of omega 6 PUFAs, in particular linoleic acid, on cardiovascular mortality at a time when there is considerable debate on this question.”
Calder says the findings argue against the "saturated fat bad, omega 6 PUFA good" dogma and suggest that the American Heart Association guidelines on omega-6 PUFAs may be misguided. They also "underscore the need to properly align dietary advice and recommendations with the scientific evidence base."
To coincide with publication of this paper, the BMJ is pulling together examples of missing data it has uncovered, as part of its “open data” campaign. We are also asking researchers to tell us about any other documented examples of missing data, to build a picture of the full extent of the problem which is undermining evidence based medicine worldwide.
The current best estimate is that half of all the clinical trials that are conducted and completed are never published. Even when they are, the underlying data that the results are based on is rarely open to external analysis - which is a cornerstone of proper scientific scrutiny. This means doctors cannot be certain that the drugs they are prescribing daily are properly evaluated for safety and efficacy.
For more details, go to bmj.com/open-data
http://www.bmj.com/press-releases/2013/02/04/study-raises-questions-about-dietary-fats-and-heart-disease-guidance
Critics of the study are saying the original study only showed 6 more deaths and that that was likely the result of the trans fats and not the omega 6 polyunsaturated fats.
http://www.smc.org.au/2013/02/round-up-dietary-fats-and-heart-disease-bmj-experts-respond/
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Replies
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LOL
Not at the study, but at the ping pong game of healthy today kill you tomorrow.0 -
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Fat Head's Tom Naughton has an entertaining blog post up where he quotes the Forbes article about this same study (along with the study itself). It's long and I'm not going to post the whole thing here but this one bolded paragraph of his just about sums up his blog post:
"The Lipid Hypothesis is a crock of @#$%. Cholesterol doesn’t cause heart disease. Saturated fat doesn’t cause heart disease. TIME magazine, your doctor, your government health officials, and everyone else who warned you to cut back on saturated fats, switch to vegetable oils, and lower you cholesterol to save yourself from heart disease had no @#$%ing clue what they were talking about."
http://www.fathead-movie.com/index.php/2013/02/07/surprise-surprise-animal-fat-beats-vegetable-oil-in-rediscovered-study/
edited to switch out html for bbcode0 -
Butter tastes better than margarine.
Done. Science.0 -
I always laugh at headlines like "Increased risk of death by...."
Pretty sure your probability of death is 100%.
Now if it said "Increased risk of EARLY death by...." or "Increased risk of PAINFUL death by...."
I'd take it more seriously.0 -
LOL
Not at the study, but at the ping pong game of healthy today kill you tomorrow.
lol my thoughts exactly0 -
:bigsmile:Butter tastes better than margarine.
Done. Science.
It wasn't the taste of margarine that bothered me so much as it was that disgusting layer of water that formed when you put it on toast. Gross. I stopped eating it 20 years ago when I started buying my own groceries -- I've eaten tons of "heart healthy" vegetable and canola oil though. :frown:0 -
I always laugh at headlines like "Increased risk of death by...."
Pretty sure your probability of death is 100%.
Now if it said "Increased risk of EARLY death by...." or "Increased risk of PAINFUL death by...."
I'd take it more seriously.
lololololololol0 -
Butter tastes better than margarine.
Done. Science.
hahahahahahahahhahhahahahh0 -
:bigsmile:Butter tastes better than margarine.
Done. Science.
It wasn't the taste of margarine that bothered me so much as it was that disgusting layer of water that formed when you put it on toast. Gross. I stopped eating it 20 years ago when I started buying my own groceries -- I've eaten tons of "heart healthy" vegetable and canola oil though. :frown:
The thing that always gets me wondering is: what vegetable exactly produces oil?0 -
yep0 -
The thing that always gets me wondering is: what vegetable exactly produces oil?
[/quote]
^^^ meee tooo!0 -
Trans fats... now those were a big oooppps. But otherwise, cow fat, canola oil, coconut... it's a dose thing. Too much fat, too little movment, throw in smoking and a daily sugar buzz for good measure....0
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Your wasting your life obsessing about this!:devil:0
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I never even thought about it until I joined MFP last year and started to look into what I should be eating for health (diabetes, heart disease and cancer are all in my family). I grew up in the 80's so I was bombarded with the low fat message and remember all the news reports when they stopped using saturated fats in movie theaters and fast food restaurants. It never even occurred to me that there wasn't solid science backing up those recommendations.
:bigsmile:Butter tastes better than margarine.
Done. Science.
It wasn't the taste of margarine that bothered me so much as it was that disgusting layer of water that formed when you put it on toast. Gross. I stopped eating it 20 years ago when I started buying my own groceries -- I've eaten tons of "heart healthy" vegetable and canola oil though. :frown:
The thing that always gets me wondering is: what vegetable exactly produces oil?
Vegetables are good for you so of course vegetables oils are better than animal fats... it all just seemed to make so much sense at the time.0
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