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I am a New Zealand registered nurse and nutritionist (Grad Cert Sci: nutrition, Massey Univ). I am a Certified Zone Instructor, and have worked teaching Zone diet principles to hundreds of clients over the last 10 years. More recently after finding that eating Paleo food choices was the "icing on the cake" health wise, I have become a Paleo enthusiast and teacher. Follow me on twitter @juliannejtaylor

Beef and butter, a bad combination for your heart?

In this interesting study – beef was eaten with either saturated fat from dairy or monounsaturated fat, in the context of a low carb diet. Blood lipids were measured to see what difference the fat type made.

In nutrition studies we used to hear all about saturated fat, and the positive effect of low saturated fat diets on cholesterol levels. Times are a-changing. There are a growing number of researchers who are looking beyond total and low density lipoprotein cholesterol (LDL). It is increasingly recognised that LDL by itself is a poor predictor of cardiovascular disease (CVD) risk. There are many people who get heart attacks who have normal LDL.

The focus for these researchers is on atherogenic dyslipidemia. What is this – you are probably asking? Atherogenic – ” Refers to the ability to initiate or accelerate atherogenesis—the deposition of atheromas, lipids, and calcium in the arterial lumen” or simply – clogging your arteries.  Dyslipidemia – an abnormal cholesterol profile. Atherogenic dyslipidemia is a cholesterol pattern that leads to atherosclerosis. It is characterised by a particular triad: elevated triglycerides (TG), reduced High density lipoprotein (HDL) often called ‘good cholesterol’, and increased levels of small LDL particles.

LDL is made in different sizes. LDL is a transporter of fats (triglycerides and cholesterol) in the blood stream. Small dense LDL particles carry less lipids. The small size leads to a number of problems which are thought to contribute to atherosclerosis. They are more susceptible to oxidation and are pro-inflammatory to vascular endothelium. They bind more tightly to arterial proteoglycans and penetrate into the arterial wall more easily. They also have a lower affinity for the LDL receptor than larger LDL. As a result they stay longer in circulation, which gives them more potential to oxidse and increase atherosclerotic damage.

LDL normally binds to the LDL receptors on the cell surface, and then gets taken onto cells, so removing the LDL from the bloodstream. Here is a diagram of the LDL being taken inside a cell, the LDL particle is broken down into cholesterol and amino acids.

Confused? Here is a great little animated clip of an LDL particle connecting with an LDL receptor and being taken into a cell. LDL Receptor pathway

Anyhow – back to the influence of diet on LDL particle size. A number of studies show that the best way to influence this antherogenic triad is a reduced carbohydrate diet. This is so even if the diet is high in saturated fat. This 6 week study [Limited Effect of Dietary Saturated Fat on Plasma Saturated Fat] compared two low carbohydrate diets, one high in unsaturated fat, and one in saturated fat. 12% calories as carbohydrates, 29% as protein and 57% from fat.

In both diets TG reduced: by 39%, in SFA, and 34% in UFAdiet. HDL increased by 14% in SFA and 8% in UFA. LDL increased in both 21% in SFA and 9% in UFA diet. However the HDL: LDL ratio remained almost unchanged from baseline in both. What did improve on both diets was the LDL particle size – which increased the same amount (this is good, we want large LDL).

Back to the beef study – it was done to see if beef protein influenced lipid measurements when it was eaten as part of a low carbohydrate diet. The study really compares saturated fat plus beef, with monounsaturated fat plus beef, and the resulting changes in lipids. The diet contained 31%E carbohydrates, 31%E protein, and 38%E as fat, either 8% sat fat or 15% sat fat.The participants previously ate a higher carbohydrate diet (50%E carbohydrate)

Changes in Atherogenic Dyslipidemia Induced by Carbohydrate Restriction in Men Are Dependent on Dietary Protein Source

Previous studies have shown that multiple features of atherogenic dyslipidemia are improved by replacement of dietary carbohydrate with mixed sources of protein and that these lipid and lipoprotein changes are independent of dietary saturated fat content. Because epidemiological evidence suggests that red meat intake may adversely affect cardiovascular disease risk, we tested the effects of replacing dietary carbohydrate with beef protein in the context of high- vs. low-saturated fat intake in 40 healthy men. After a 3-wk baseline diet [50% daily energy (E) as carbohydrate, 13% E as protein, 15% E as saturated fat], participants consumed for 3 wk each in a randomized crossover design two highbeef diets in which protein replaced carbohydrate (31% E as carbohydrate, 31% E as protein, with 10% E as beef protein).
The high-beef diets differed in saturated fat content (8% E vs. 15% E with exchange of saturated for monounsaturated fat). Two-week washout periods were included following the baseline diet period and between the randomized diets periods. Plasma TG concentrations were reduced after the 2 lower carbohydrate dietary periods relative to after the baseline diet period and these reductions were independent of saturated fat intake. Plasma total, LDL, and non-HDL cholesterol as well as apoB concentrations were lower after the low-carbohydrate, low-saturated fat diet period than after the low-carbohydrate, high-saturated fat diet period. Given our previous observations with mixed protein diets, the present findings raise the possibility that dietary protein source may modify the effects of saturated fat on atherogenic lipoproteins.

The  actual changes – very small LDL fell 10% on low SFA diet and 2% on high SFA diet. Phenotype B LDL fell only on the low SFA diet. Total LDL increased on the SFA diet and fell on the low SFA diet. Non HDL-C fell significantly on the low SFA diet: 3.42 to 2.98, and to 3.37 on the high SFA diet. (HDL fell very slighty on the low SFA diet, but not on the high SFA diet)

So what to make of this? If you are eating beef – have it with olive oil? If you are eating butter – don’t eat it with beef – choose another protein?

Perhaps this study points to why red meat (and possibly particularly beef) is linked in epidemiological studies to a greater risk of heart disease.

From the article:

Hence, the present findings suggest an interaction between saturated fat and one or more nonfat components of beef on lipoprotein metabolism. Because there is little evidence for a major role of dietary protein composition on lipoprotein metabolism, this interaction is not likely to be caused by specific amino acids within beef protein. However, saturated fat might be interacting with a micronutrient or other component that is more abundant in beef than in other food protein sources. For example, systemic iron stores have been associated with altered lipid metabolism and there is evidence that heme iron absorption is substantially increased by saturated fat and, in particular, stearic acid, which is abundant in dairy fat.

An interesting study, showing an interaction between 2 foods that was unexpected given earlier studies showing a much smaller difference in the effect of fat types on lipid profiles, in the context of a low carbohydrate diets.

 

 

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14 Responses to “Beef and butter, a bad combination for your heart?”

  1. James #

    so, am i to understand that the issue is not meat, but meat eaten in combination with some saturated fats such as butter. can you clarify the results a bit, the article is very technical, and i understand a lot of it, but can’t seem to put the pieces together to come up with a conclusion that i can apply to my daily life. I don’t eat red meat every day, and when i do, it is usually cooked with a bit of coconut oil and eaten with veggies.

    thanks

    James

    April 8, 2012 at 2:23 pm Reply
    • The study authors say that it may be wise to limit saturated fat when you eat beef. Both diets had some saturated fat – but one was musch lower, replaced by mono-unsaturated fat (e.g. olive oil)
      I’d suggest use mostly olive oil – or other high monounsaturated fat, when you are having more red meat in your diet. And less saturated fat – butter, coconut oil, lard etc. However saying this – the fat used in this was dairy fat, which is different from coconut oil. Coconut oil may not have the same response.

      April 8, 2012 at 3:21 pm Reply
      • James #

        thanks for the clarification! i do not intake any dairy products other than a bit of asiago cheese as an added touch to my salads and such. I have seen my overall cholesterol drop and my bad cholesterol fall below ‘optimal’ levels since changing to a paleo template before christmas. i cook exclusively in coconut oil and use olive oil and balsamic vinegar as dressing on my salads. are you suggesting that the study may be inaccurate about all saturated fats due to it’s use of dairy. could you expand on that a bit please!?

        thank you for your answers! you have great information!

        April 8, 2012 at 3:28 pm Reply
        • The authors don’t exactly know themselves, they speculate it is some interaction between saturated fat – and it may specifically be saturated fat in dairy – (which is a different chain length that SFA in coconut oil) and something in red meat, they dont think it is the protein – it might be the high iron content.
          If our cholesterol is looking good on the diet you are eating now – I think you should be okay!

          April 8, 2012 at 3:46 pm Reply
          • James #

            i am currently in a massage therapy program, and we just finished a section on chained fatty acids! it is so cool to actually know what that means to me physiologically! it would be nice if the researchers were able to actually figure out the correlation before making stabs-in-the-dark about such a critical issue.. sort like the ‘red meat will give you heart attack’ scare we have lived with for so many years!

            thanks again!

            April 8, 2012 at 3:49 pm
  2. Hi Julianne,

    I also wonder about the quality of the meat and butter, i.e. I wonder if they are from grass fed or feed lot animals. Could that make a difference?

    Tony
    emotionsforengineers

    April 9, 2012 at 3:16 am Reply
    • I imagine that grass fed would be better, because the fat is better, probably less saturated and more mono.

      April 9, 2012 at 11:00 am Reply
  3. Nice to know.

    The reason that I do not eat butter is it is insulinogenic, like all dairy. Excess insulin causes cravings and hunger, when we are insulin resistant, and pre-diabetic/undiagnosed diabetic, controlled by diet. The insulin level tells the story, not BG.

    April 9, 2012 at 4:08 am Reply
  4. Tam #

    I’d like to see a similar study using grass fed beef and ghee…

    April 9, 2012 at 12:44 pm Reply
    • Indeed, also beef and coconut oil.

      April 9, 2012 at 12:46 pm Reply
  5. Honora #

    Yes, the findings raised a few questions. Appreciated the link to the video showing how LDL is transported into the cell. Clarified things a bit for me (no pun intended)! I noticed my basic lipid profile (TG, total, HDL, LDL, risk ratio) is virtually unchanged in the last year since I’ve been having about 2 tabs of coconut oil/day. About 5 years ago when I got it checked, I had the good pattern A for LDL. Be interesting to see how that’s going. It’s all a lot more complicated than the mainstream likes to make it out to be.

    April 10, 2012 at 9:46 pm Reply
  6. Helen Carpenter #

    I won’t trust any study that doesn’t take into account the differences between industrially raised beef feed inappropriately with grains and shot with antibiotics and hormones, and naturally grazed beef free from hormones and antibiotics. I can TASTE the difference. There are so many things wrecking havoc in our bodies. Just like dairy vs. raw dairy is not alike (with the way is reacts in our bodies)……the same thing would occur with industrial raised beef vs. naturally raised beef.

    We’re not talking the same thing here.

    April 15, 2012 at 11:39 pm Reply
    • True you would have to do this specifically with grass fed beef in a repeat study to see what the difference is.
      However the majority of beef eaten in the USA is not grass fed, so this study is applicable if you are eating that. I think the study points to a potential issue, but what the problem is needs more research.

      April 16, 2012 at 8:43 am Reply

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