I think there is a lot of evidence implicating saturated fat in disease. However, there’s a new study which is raising doubt as to the effect of saturated fat on heart disease:

Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk: A Systematic Review and Meta-analysis, Annals of Internal Medicine, 18 March 2014

The New York Times reported on it yesterday:
Study Questions Fat and Heart Disease Link

Someone had anonymously linked the New York Times article on my blog. They made no comment.

It’s a meta-analysis with, the authors admit, “potential biases from preferential publication and selective reporting.” Here’s some data:

In observational studies, when the top and bottom thirds of baseline dietary fatty acid intake were compared, relative risks (RRs) for coronary disease were:

1.02 (95% CI, 0.97 to 1.07) for saturated
0.99 (CI, 0.89 to 1.09) for monounsaturated
0.93 (CI, 0.84 to 1.02) for long-chain ω-3 polyunsaturated
1.01 (CI, 0.96 to 1.07) for ω-6 polyunsaturated
1.16 (CI, 1.06 to 1.27) for trans fatty acids

For circulating fatty acids, RRs were:

1.06 (CI, 0.86 to 1.30)
1.06 (CI, 0.97 to 1.17)
0.84 (CI, 0.63 to 1.11)
0.94 (CI, 0.84 to 1.06)
1.05 (CI, 0.76 to 1.44)

In randomized, controlled trials (RCTs), RRs were:

0.97 (CI, 0.69 to 1.36) for α-linolenic
0.94 (CI, 0.86 to 1.03) for long-chain ω-3 polyunsaturated
0.89 (CI, 0.71 to 1.12) for ω-6 polyunsaturated fatty acid supplementations

Note that circulating trans fatty acids had almost the same RR as saturated fat, in fact, trans fats trended more protective? Note also that in RCTs, omega-6 was more protective than omega-3. There is a lot of inconclusiveness here.

These are effects relative to cardiovascular disease (CVD). They did not look at diabetes, arthritis, cancer, or other inflammatory-based diseases. Even if it is true that saturated fat has no impact on CVD, it has been shown to increase the risk for other chronic diseases.

It’s conclusion:

“Current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.”

“Not clearly.” Does that remind you of anything? Why did this study get published at all? Recall this study:

Long Term Toxicity Of A Roundup Herbicide And A Roundup-Tolerant Genetically Modified Maize, Food and Chemical Toxicology (FTC), 19 September 2012.

It found more breast cancer, liver and kidney damage in rats fed GMOs.

The publisher was hounded by industry groups like Monsanto to retract it. He resisted for a year, defending it!, then gave in saying:

“Unequivocally, the Editor-in-Chief found no evidence of fraud or intentional misrepresentation of the data. … Ultimately, the results presented (while not incorrect) are inconclusive.”

It was retracted, not because it was incorrect, but because it was “inconclusive.” This present study is also inconclusive. The authors admit as much. Shall we expect it to be retracted? Can you think of any industry that would benefit by keeping this study circulating? Industry doesn’t have to combat science, all they have to do is plant seeds of doubt, and they’ve won.

________Here’s yet another reason why I believe saturated fat contributes to the development of chronic diseases. It was buried in the comments on the New York Times article:

“The results of reducing animal fat consumption in Finland led to greatly reduced cardiovascular disease rates.” -wbgrant

Fat and Heart Disease: Yes We Can Make a Change – The Case of North Karelia (Finland), Annals of Nutrition and Metabolism, July 2009

“The combined efforts of all stakeholders have greatly helped people to reduce the intake of saturated fat and to replace this with unsaturated fat. This has been associated with an improved quality of the dietary fat (e.g. in 1972, over 90% of the population used butter on their bread compared to <5% at present) and a remarkable reduction in blood cholesterol levels. It has led to a 80% reduction in annual CVD mortality rates among the working aged population, to a major increase in life expectancy and to major improvements in functional capacity and health.

There is strong medical evidence that CVD (like many other chronic diseases) is preventable or could be delayed to a more advanced age. A population-based prevention programme is the most cost-effective way and in many cases the only affordable option for major public health improvements. To prevent CVD and to promote heart health, dietary changes are crucial, especially the change in the quality of fat. These changes can have a major impact in relatively short time and can lead to dramatic improvements in public health in the long run.”