The recently published (and highly criticized) Dietary Guidelines For Americans state:
The recommendation to limit intake of calories from saturated fats to less than 10 percent per day is a target based on evidence that replacing saturated fats with unsaturated fats is associated with reduced risk of cardiovascular disease. The limit on calories from saturated fats is not a UL set by the IOM. For most calorie levels, there are not enough calories available after meeting food group needs to consume 10 percent of calories from added sugars and 10 percent of calories from saturated fats and still stay within calorie limits.
Recommendations to limit saturated fatty acids (SFAs) to <10% of calories persist, despite a spate of recent meta-analyses showing no relationship between saturated fat consumption and coronary heart disease (CHD, also known as ischemic heart disease (IHD)).
In addition, it should be abundantly clear by now that not all SFAs behave the same with respect to our lipids or our IHD risk.
Wide Variety Of Saturated Fats
Most SFAs come from animal origins, including meat and dairy products. The types of SFAs differ markedly between meat and dairy products; the associated nutrients and their interaction with SFAs also differs widely and all of this is likely to affect the risk of IHD.
For example, in the MESA (Multi-Ethnic Study of Atherosclerosis) study, each 5-g/d intake of dairy SFAs was associated with a 16% lower risk of IHD, whereas each 5-g/d intake of meat SFAs was related to a 29% higher risk of IHD.
Despite this, current guidelines continue to repeat the unsubstantiated recommendation to consume low fat dairy over full fat dairy.
Lower Risk Of Heart Disease With Dairy Saturated Fats
Hopefully, a paper just published in the American Journal of Nutrition, will provide the nail in the coffin of the concept that all saturated fats are similar in their affects on blood lipids and cardiovascular risk and should be restricted.
This study found that higher intakes of SFA in 35,597 Dutch men and women were associated with lower risks of ischemic heart disease (IHD).
In other words, the more SFA the Dutch eat, the less their chance of having a heart attack.
And, the association “did not depend on the substituting macronutrient.” Those who ate less saturated fats and more “healthy” polyunsaturated fats did no better than those who substituted carbohydrates.
The association was dependent “on the chain length and food source of SFAs.”
The authors noted that the lower risk of IHD was driven by consumption of:
short-to-medium chain SFAs (myristic acid, the sum of pentadeclyic and margaric acids, and SFAs from dairy sources including butter, cheese, and milk and milk products.
Skeptics amongst my readers might think that this study was funded by the dairy industry, but as Marion Nestle pointed out on her Food Politics blog, support came from Unilever, who would have a vested interest in promoting their low saturated fat/high polyunsaturated fat margarines as substitutes for butter fat. This is only one of 11 industry-funded studies with findings different from what the sponsors would have liked, versus 105 studies with findings supporting products of the sponsors (since Marion has been tracking such studies).
It’s likely that some saturated fats, especially when eaten immoderately, without an otherwise balanced and diverse diet, can increase your risk of heart disease.
However, the saturated fats that come from dairy products are clearly not contributing to heart disease risk or obesity and our nutritional guidelines should recommend full fat dairy, not low fat or non fat products that require addition of added sugar to maintain palatability.
6 thoughts on “More Evidence That Dairy Fat Is Associated With A Lower Risk of Heart Disease”
Regarding the Dutch study — a couple of points. Firstly, the hazard ratios were very small (in the range of 0.9). This raises the possibility of a confounding artifact.
The authors themselves suggest the possibility of such an artifact, both in the abstract and discussion, to wit:
“We cannot exclude confounding by unmeasured initiation of cholesterol-lowering therapy during follow-up.”
This is a problem with all such large population prospective diet history studies. We can infer that patients with higher total cholesterol levels are more likely to be placed on therapy with statins and other cardioprotective agents. For all we know, people with higher saturated fat intake were more likely to require subsequent interventions and it was these interventions which improved their outcomes, relative to subjects not receiving interventions.
I think that a prudent conclusion is that the Dutch study did not provide a final nail in the coffin of anything. It’s a good study, which provided a wealth of data. It’s provocative, but not definitive.
You assume that lowering cholesterol through use of statins produces confounding benefits. I’m sure you’ll be able to find faults in this:
We are every one of us subject to preference bias It’s characteristic of humanity.
The trick is to recognize it, then give it a good intellectual observation. That’s not so characteristic.
I know it’s not always about me (my ex-wife was quite clear on this point) AND that data is not the plural of anecdote, but Whole Foods now stocks this insanely good Belgian chocolate milk. I use to drink it sips at a time, but having already seen the data questioning the role of saturated fats in heart disease, I started drinking about a quart a day and my various blood lipid levels have never been better.
What’s odd is that another analysis of the same cohort found no association between dairy intake and CHD or stroke. http://www.internationaljournalofcardiology.com/article/S0167-5273(12)00301-4/abstract.
Another Dutch study also found no relation but a small increase in risk with higher intake of butter… Any thoughts on why?.. http://ajcn.nutrition.org/content/93/3/615.
Erik, the first study you reference does, indeed, seem to be of the same Dutch cohort but has slightly different objectives. It’s odd that there is only one author similar between the two studies and that the current study doesn’t clearly refer to the first. There did emerge at least a signal that some forms of dairy are protective as they conclude “High intakes of total and low-fat dairy may be associated with a lower risk of CHD among participants without hypertension, while fermented dairy could be associated with a reduced risk of stroke.”Interestingly, two of the authors on the first study were supported by the Dutch Dairy council whereas, Unilever supported the second. I have sent an email to the authors to ask them your question.
The second study I’ve looked at before. The authors looked at multiple associations and severely tortured their data to extract some very weakly significant findings. This is usually a sign that the findings are not clinically significant and will not be reproduced. Butter and dairy fat was associated with only a 4% increased risk of mortality over 10 years and this was only in women.
All three of these studies are inherently limited due to being observational but to me add to the conclusion that there is no scientific basis for recommending a reduction in dairy fat consumption to the general public.
Have you gotten a response from those Dutch authors?
Anything new on the subject since??