The previous blog post was a little heavy on charts (PDF with all charts) from the laboratory analysis of one of our pasture grazed ribeye steaks. In this post I continue the comparison of our grassfed beef to two “typical” beef samples. First of all let’s summarize some of the discussion and charts from the earlier post, then we will address polyunsaturated fats:
Saturated Fatty Acids (SFA)
- Grassfed beef had a higher percentage of palmitic acid, used in the complex process of cell communication.
- Grassfed beef had a lower percentage of stearic acid, in our body this is converted to oleic acid, see below.
- Saturated fat is the preferred energy source of the heart.
- You probably knew our liver protects us from toxins but did you know saturated fat protects our livers!
- Since the early 1900s the food supply has not changed much in available SFAs, 50 gm/day vs. 56 gm/day (2004). +
- If fats are causing health changes in our population, SFA must not be the source of change.
- Finally as the Ohio State study points out, eating carbohydrates raise saturated fat levels in the blood but eating good portions of saturated fats does not raise SFAs in the blood (carbs are the problem, not fat).
Monounsaturated Fatty Acids (MUFA)
- Our grassfed beef sample had lower MUFA (~35% of fat) when compared to typical beef (~50% MUFA) (Chart 1).
- The primary MUFA for both grassfed and typical beef is oleic acid or olive oil (Chart 3).
- MUFA has been found to be the main fat in fatty tissue.
- Palmitoleic acid is the next MUFA found and is lowest in our grassfed beef vs. typical beef. Palmitoleic is the fatty acid the OSU study considers the most problematic when looking at human blood levels.
- Early 1900’s, Americans obtained 42% of their MUFA from fats/oils and 40% from meat/poultry/fish. +
- In 2004 Americans obtained 63% of their MUFA from fats/oils and only 22% from meat/poultry/fish. +
- The American food supply has increased in the use of vegetable oil MUFA by two-thirds while decreasing MUFA from meat by one-half.
- Overall MUFA in early 1900s = 47 gm/day in the food supply vs 79 gm/day in 2004 (+), an overall increase of MUFA by 60%!
- Appears like we have too much MUFA in our food these days, especially from vegetable oils.
- If fat is causing health changes in our population it may be due to over consuming MUFA.
Polyunsaturated Fatty Acids (PUFA) – Grassfeds Claim To Fame
- Our grassfed sample had the same Total PUFA when compared to typical beef (4%) (Chart 1), but looking at Chart 4 above, you will immediately note a difference in the PUFA makeup.
- The omega-6 and omega-3 fatty acids are both important in small amounts and the correct ratio!
- These “fatty acids are also precursors of eicosanoids (prostaglandins, thromboxanes, and leukotrienes), which are hormone-like compounds that regulate blood pressure, heart rate, vascular dilation, blood clotting, lipolysis, and immune response”. ++
- Omega 6s are for inflammation, such as blood clotting during an injury.
- Omega 3s are for anti-inflammatory functions during healing.
- Polyunsaturated fatty acids are essential because unlike SFA and MUFA, our bodies cannot make these, we must consume PUFA in the food we eat.
- Since we must consume these, it is a good thing we need just tiny amounts: “the requirement for essential fatty acids is infinitesimal under most conditions and can be easily met by eating a diet that includes traditional whole animal foods without necessarily adding any specific fats or oils.”++
- A current concern of PUFAs is omega 6 intake. With the reduced consumption of animal fats and eggs over the past few decades and an increase in vegetable oil consumption (corn and soy), the average American has too much omega 6 compared to omega 3s. Our bodies are constantly in a state of inflammation (Times Magazine 2004 “Fires Within” highlighted this issue).
- In 1995-2000 data, the ratio of omega-6 to omega-3 fatty acids in the food supply = 9.7:1. +++
- “This is much higher than the recommended ratio of 2.3:1.” +++
- Here is why grassfed meats have a claim to fame, note our steak with an omega 6 to 3 ratio of 2.0:1 matches the recommended ratio.
- Both typical beef samples have an omega 6 to 3 ratio that exceeds the U.S. food supply as a whole (12:1 and 17:1).
- Another possible problem with PUFAs is just plain over consumption resulting in oxidative stress.
- “PUFAs are uniquely vulnerable to oxidation because they are the only fatty acids with two or more double bonds, and it is the carbon that lies directly between two double bonds that is vulnerable to oxidation”. ++
- “The consumption of excess PUFAs increases oxidative stress”. ++
- Early 1900s = 13 gm/day in the food supply of PUFA vs 37 gm/day in 2004 (+), an overall increase of 35%.
- Do you think we are currently overconsuming PUFAs?
- Maybe too much of a good thing?
- Remember our need for PUFAs is “infinitesimal under most conditions”.
Summary and Lead In To Our Next Post
I apologize for referring back to the charts from the previous post (as one PDF document) and multiple references to numbers through percentages etc. If this is something you are really interested in, then I have tried to give some data and sources that can help you along your way. If you are like my wife Sheila, this maybe a little more info than you are looking for.
Here are some things for you to consider up to this point:
- Saturated Fats from meat/eggs/poultry is not the problem it has been portrayed to be and has not increased over the past century in our food supply.
- High Carb diets (low fat diet) causes increased saturated fat in the blood stream (OSU Study).
- Reducing meat consumption and increasing vegetable oils use in the U.S. has led to:
- Overall increased consumption of MUFAs.
- This fat is hard for us to burn.
- Overall increased consumption of PUFAs.
- Vegetable oils are high in omega 6s and has thrown our ratio of omega 6 to 3 far above the recommended levels (possibly causing a continuous state of low grade inflammation in our bodies).
- PUFAs are very important but at very small quantiles, over consumption can cause oxidative stress.
- Overall increased consumption of MUFAs.
Our next post will be a Fat Finale and we will look at:
- The all-important Conjugated Linoleic Acid (CLA).
- Give a final overview of what you get with one of our grassfed steaks.
- Give you some final food for thought on grassfed vs. typical beef.
- Hiza, H.A.B., & Bente, L. (2007). Nutrient Content of the U.S. Food Supply, 1909-2004: A Summary Report. (Home Economics Research Report No. 57). U.S. Department of Agriculture, Center for Nutrition Policy and Promotion.
++ Precious Yet Perilous – Weston A Price Foundation website, 2010 article.
+++ Gerrior, S., Bente, L., & Hiza, H. (2004). Nutrient Content of the U.S. Food Supply, 1909-2000. (Home Economics Research Report No. 56). U.S. Department of Agriculture, Center for Nutrition Policy and Promotion.