A new study raises questions about current guidelines which generally restrict the consumption of saturated fats and encourage consumption of polyunsaturated fats to prevent heart disease. The research was published today, 18 March, in the journal Annals of Internal Medicine.
An international research collaboration led by the University of Cambridge analysed existing cohort studies and randomised trials on coronary risk and fatty acid intake.
They showed that current evidence does not support guidelines which restrict the consumption of saturated fats in order to prevent heart disease. The researchers also found insufficient support for guidelines which advocate the high consumption of polyunsaturated fats (such as omega 3 and omega 6) to reduce the risk of coronary disease.
Furthermore, when specific fatty acid subtypes (such as different types of omega 3) were examined, the effects of the fatty acids on cardiovascular risk varied even within the same broad 'family' – questioning the existing dietary guidelines that focus principally on the total amount of fat from saturated or unsaturated rather than the food sources of the fatty acid subtypes.
Dr Rajiv Chowdhury, the lead author of the research at the University of Cambridge, said: "These are interesting results that potentially stimulate new lines of scientific inquiry and encourage careful reappraisal of our current nutritional guidelines.
"Cardiovascular disease, in which the principal manifestation is coronary heart disease, remains the single leading cause of death and disability worldwide. In 2008, more than 17 million people died from a cardiovascular cause globally. With so many affected by this illness, it is critical to have appropriate prevention guidelines which are informed by the best available scientific evidence."
For the meta-analysis, the researchers analysed data from 72 unique studies with over 600,000 participants from 18 nations. The investigators found that total saturated fatty acid, whether measured in the diet or in the bloodstream as a biomarker, was not associated with coronary disease risk in the observational studies. Similarly, when analysing the studies that involved assessments of the consumption of total monounsaturated fatty acids, long-chain omega-3 and omega-6 polyunsaturated fatty acids, there were no significant associations between consumption and cardiovascular risk.
Interestingly, the investigators found that different subtypes of circulating long-chain omega-3 and omega-6 fatty acids had different associations with coronary risk, with some evidence that circulating levels of eicosapentaenoic and docosahexaenoic acids (two main types of long-chain omega-3 polyunsaturated fatty acids), and arachidonic acid (an omega-6 fat) are each associated with lower coronary risk.
Similarly, within saturated fatty acid, the researchers found weak positive associations between circulating palmitic and stearic acids (found largely in palm oil and animal fats, respectively) and cardiovascular disease, whereas circulating margaric acid (a dairy fat) significantly reduced the risk of cardiovascular disease.
Additionally, when the authors investigated the effects of omega-3 and omega-6 fatty acid supplementations on reducing coronary disease in the randomised controlled trials, they did not find any significant effects – indicating a lack of benefit from these nutrients.
Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation, which helped fund the study, said: "This analysis of existing data suggests there isn't enough evidence to say that a diet rich in polyunsaturated fats but low in saturated fats reduces the risk of cardiovascular disease. But large scale clinical studies are needed, as these researchers recommend, before making a conclusive judgement.
"Alongside taking any necessary medication, the best way to stay heart healthy is to stop smoking, stay active, and ensure our whole diet is healthy – and this means considering not only the fats in our diet but also our intake of salt, sugar and fruit and vegetables."
Louise Walsh | EurekAlert!
Using DNA origami to build nanodevices of the future
31.08.2015 | Institute for Integrated Cell-Material Sciences at Kyoto University
An ounce of prevention: Research advances on 'scourge' of transplant wards
28.08.2015 | University of Wisconsin-Madison
Longer, more severe, and hotter droughts and a myriad of other threats, including diseases and more extensive and severe wildfires, are threatening to transform some of the world's temperate forests, a new study published in Science has found. Without informed management, some forests could convert to shrublands or grasslands within the coming decades.
"While we have been trying to manage for resilience of 20th century conditions, we realize now that we must prepare for transformations and attempt to ease...
A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.
The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...
A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).
Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...
In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.
These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...
Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.
For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...
20.08.2015 | Event News
20.08.2015 | Event News
19.08.2015 | Event News
31.08.2015 | Awards Funding
31.08.2015 | Materials Sciences
31.08.2015 | Materials Sciences