Written by Leonard Smith, M.D.
In a recent meta-analysis published in the journal Annals of Internal Medicine, researchers selected 72 individual studies on the effects of polyunsaturated and saturated fats on coronary disease (heart disease).1 They concluded, "Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats."
As you can imagine, the media went to town with this one. Somehow omega-3 fats were teased out, yet again, as ineffective for heart disease protection. And saturated fats were let off the hook as the heart disease villain. While there is some truth to the saturated fat findings—other recent studies have come to similar conclusions—when we take a closer look at the data, we see a completely different picture when it comes to the omega-3s.
Those people with the highest levels of circulating long-chain omega-3 fats were found to have a 16 percent decreased risk of coronary disease compared to those with the lowest levels. That's a substantial decrease if you ask me. However, according to the statistical analysis, it was not "significant" enough. Quite interestingly, when we look at the data for EPA and DHA—the two fatty acids most important for heart disease prevention—there was absolutely a significant decreased risk. Those people with the highest levels of EPA, DHA, or both EPA and DHA together, had a 22, 21, and 25 percent decreased risk of developing heart disease. Incredulously, no one even mentioned this. I call that irresponsible reporting of the data.
Irresponsible indeed. As it turns out the data was incorrect. Shortly after the study was published, the lead author, Rajiv Chowdhury, MD, PhD, was called out for a large number of inaccuracies. One of the most important corrections made was to the omega-3 data. People with the highest levels of circulating long-chain omega-3 fats actually had a 13 percent decreased risk of developing heart disease, but now the data was statistically significant. I know that may not make much sense, but it has to do with the range of all values. As Mark Twain has said, "Figures don't lie, but liars figure."
One of the study's own authors, Dariush Mozzafarian, MD, DrPH, stated, "Personally, I think the results suggest that fish and vegetable oils should be encouraged," but his voice was drowned out by other authors, a group of 14 total authors. Harvard School of Public Health's own Walter Willet, MD, DrPH, stated, "They have done a huge amount of damage." He called for a retraction of the study "with similar press promotion." He continued with his opinion of the current state of meta-analysis research, "…these days meta-analyses are often done by people who are not familiar with a field, who don't have the primary data or don't make the effort to get it." This is exactly what happened in this meta-analysis.
The bottom line is that the omega-3 fats that come from fish oil are absolutely beneficial for the heart, and this study actually proves it now that the data has been corrected. Yet these results are still being downplayed.
The studies we really need to notice are the ones that analyze red blood cell membrane levels of omega-3s. Those are the omega I pay most attention to because they show how much omega-3 was actually ingested and absorbed over a long time period, which is the most accurate reflection of tissue levels of these beneficial fats. That's where the magic happens.
I am getting tired of seeing inadequate omega-3 studies blasted through the news media, giving consumers incorrect and even dangerous information about these beneficial fats. There are literally thousands of clinical studies and tens of thousands of preclinical studies that show the benefits of these fats. Let's not forget about all that data.
|Printable Version||E-mail a Friend|