15 replies to this topic

[stephen_b]

In PMID 18687433,

BACKGROUND: Fatty acid (FA) composition in serum has been associated with C-reactive protein (CRP), but associations with other markers of inflammation and endothelial function, e.g. adhesion molecules are unknown. We recently suggested a possible role of the lipogenic enzyme stearoyl coenzymeA desaturase-1 (SCD-1) in inflammation. This study investigates the associations between serum FA composition, including SCD-1 index, and various inflammatory and endothelial function markers. METHODS: 264 Swedish men and women aged 70 years participated in this cross-sectional population-based study. FA composition was measured in serum cholesteryl esters and was correlated to inflammatory markers (CRP, interleukin [IL]-2, IL-6, IL-8, tumor necrosis factor [TNF]-alpha, vascular cellular adhesion molecule [VCAM]-1, intercellular adhesion molecule [ICAM]-1, E-selectin, P-selectin, L-selectin, interferon-gamma, and monocyte chemoattractant protein [MCP]-1), using linear regression analysis. SCD-1 activity was estimated by FA product-to-precursor ratio (16:1/16:0). RESULTS: Serum FA composition was significantly associated with CRP and E-selectin but not with other inflammatory markers. After adjusting for BMI, smoking, physical activity, alcohol consumption and lipid-lowering therapy, the proportion of palmitoleic acid and SCD-1 index were positively correlated with CRP concentrations (P=0.003 and P=0.001, respectively). CONCLUSION: A FA composition reflecting high intake of saturated fat and a high SCD-1 index is independently related to CRP concentrations, but not to other markers of inflammation and endothelial function in this population of elderly men and women. Given the absent association between FA composition and the other markers, CRP may be the preferable marker to use when investigating potential relationships between FAs and low-grade inflammation.

In this population-based study, the only marker that fatty acid composition was related to was C-reactive protein. I'm not certain whether the statement "A FA composition reflecting high intake of saturated fat and a high SCD-1 index is independently related to CRP concentrations" means that both high SCD and SFA were predictive of elevated C-reactive protein.

In a 2008 study by some of the same authors (PMID 18062827),

After adding insulin resistance to the model, 18:1n-9, 18:2n-6 and SCD-1 remained significant predictors of CRP. A FA composition indicating low intake of 18:2n-6, high intake of SFA and high SCD-1 activity is, in a Swedish population of middle-aged men, associated with CRP concentrations 20 years later, even independently of obesity and insulin resistance.

As we know, observational studies can find association but not causation.

I'd like to get feedback from forum members who have adopted a high saturated fat diet: has there been any change in your C-reactive protein because of it?

Stephen

[Brainbox]

Does the article have any information about the breakdown of types of saturated fat that was consumed by the studied population? Or which types of saturated fats cause a raise in palmitoleic acid and SCD-1 index by non-statistical measurement? Do MCT's that are not refined have this effect?

Furthermore:

Stearoyl-CoA desaturase–1 (SCD1) catalyzes the synthesis of monounsaturated fatty acids from saturated fatty acids. Mice with a targeted disruption of Scd1 gene locus are lean and display increased insulin sensitivity. To examine whether Scd1 activity is required for the development of diet-induced hepatic insulin resistance, we used a sequence-specific antisense oligodeoxynucleotide (ASO) to lower hepatic Scd1 expression in rats and mice with diet-induced insulin resistance. Treatment of rats with Scd1 ASO markedly decreased liver Scd1 expression (~80%) and total Scd activity (~50%) compared with that in rats treated with scrambled ASO (control). Insulin clamp studies revealed severe hepatic insulin resistance in high-fat–fed rats and mice that was completely reversed by 5 days of treatment with Scd1 ASO. The latter treatment decreased glucose production (by ~75%), gluconeogenesis, and glycogenolysis. Downregulation of Scd1 also led to increased Akt phosphorylation and marked decreases in the expression of glucose-6-phosphatase (Glc-6-Pase) and phosphoenolpyruvate carboxykinase (PEPCK). Thus, Scd1 is required for the onset of diet-induced hepatic insulin resistance.

Link.

Edited by Brainbox, 11 April 2009 - 12:20 AM.

[Skötkonung]

I'd like to get feedback from forum members who have adopted a high saturated fat diet: has there been any change in your C-reactive protein because of it?

Stephen

I've been doing a paleo style diet that is rich in fats for awhile and not had any increase in c-reactive protein or homocysteine. It is my opinion that these types of studies do not clearly indicate a causation between fats and bad health as the researchers do not adjust for other poor dietary habits associated with those who generally eat a lot of fat - especially high sugar and other refined carbohydrates, total activity levels, and poor quality lipid profiles. Tribes such as the Masai, who eat a lot of red meat (rich in fats), seem to do quite well in terms of health and even have low homocysteine levels.

That said, grass fed beef is usually low in saturated fats and high in healthy unsaturated fats (omega 3/6). We know that nutritionists say people shouldn't eat excessive quantities of saturated fat. Yet they say the human body requires a proper balance of the right fats. And we know that the proper balance of the right fats comes automatically from animals grazing lush grasslands. That's why we can eat their visible fat. Since this study is based on saturated fat, it promotes the wrong kind of fat, not the meat or proper balance of nutrients.

The bottom line is that saturated fats are perfectly healthy when eaten in a correct ratio to other healthy fats, carbohydrates, protein, and activity levels.

[JackChristopher]

It bothers me that studies can leaving so much detail and make overgeneralized claims. But as BrainBox and Skotkonung point out those are nearly meaningless without context. You shouldn't say, high-fat diet bad for health, or high-carb improves anti-inflammatory response base on so little.

Am I missing something? Do researchers think it's OK to label high-fat as bad regardless of the type of fat, and dietary and lifestyle context?

If true, that's a shame.

And it's absurd when we know that a saturated fat like stearic acid converts to oleic in the body. And that oleic acid (found in EVOO) is thermogenic. Or that medium chain triglycerides process differently than other forms of sat fat.

[tunt01]

i really need to give up on eating dark chocolate and just buy pure cocoa powder..... :(

[TheFountain]

Tribes such as the Masai, who eat a lot of red meat (rich in fats), seem to do quite well in terms of health and even have low homocysteine levels.

All this indicates is the possibility of genetic variability. Hence the okinawan diet which is high in carbs yet the population doesn't suffer poor health, in fact the complete opposite. People need to stop with the arrogant assertions based on their personalities.

[Matt]

Masai life expectancy is poor, don't use them as an example.

[Johan]

Masai life expectancy is poor, don't use them as an example.

Yes, but it might be that their life expectancy is poor because of lack of access to modern medicine, rather than dietary factors. The only way to reliably find out would be to give the Masai access to every aspect of medicine that we have, while still keeping them on their traditional diet.

[Skötkonung]

Tribes such as the Masai, who eat a lot of red meat (rich in fats), seem to do quite well in terms of health and even have low homocysteine levels.

All this indicates is the possibility of genetic variability. Hence the okinawan diet which is high in carbs yet the population doesn't suffer poor health, in fact the complete opposite. People need to stop with the arrogant assertions based on their personalities.

Do you have any evidence to indicate this is true? Even the Okinawan population isn't completely genetically homogeneous as not all individuals possess the ApoE longevity gene. Surely, someone amongst the Masai would not posses this hypothetical genetic protection and would have the diseases claimed to be associated with a high fat diet. The Masai (like the Okinawans) have been very well studied and what has made them remarkable to researchers is their lack of diseases of aging such as arthosclerosis. Of course, they do die of other causes (as was mentioned in other posts) such as infection, child birth, common accidents, etc.

I don't understand what you mean by "people need to stop with the arrogant assertions based on their personalities." Can you indicate where I was being arrogant? I apologize if I was conveying my point in that manner.

[Matt]

I don't have enough time this morning to look at the studies but I *think* that Masai have very low cholesterol despite high saturated fat diet. Somewhere between a Total Cholesterol of 120-150mg/dl. They also tend to have higher activity levels and periodic low energy intake

Edited by Matt, 12 April 2009 - 11:59 AM.

[Johan]

I don't have enough time this morning to look at the studies but I *think* that Masai have very low cholesterol despite high saturated fat diet. Somewhere between a Total Cholesterol of 120-150mg/dl. They also tend to have higher activity levels and periodic low energy intake

According to [url="http://"http://wholehealthsource.blogspot.com/2008/06/more-masai.html"]this post[/url], the Masai also have a dietary cholesterol intake of up to 2,000 mg/day, and yet they still have very low serum cholesterol levels.

[AgeVivo]

Masai have very low cholesterol despite high saturated fat diet.

a while ago i was watching a documentary on TV about Masai. It said that Masai were eating a lot of mixed bark along with meat, it prevented cholesterol to be absorbed. (not sure why nor wether it is true ;-)

[wydell]

Right, and they tend to die before age 50. So I am not sure what conclusion you can make about the Masai.

I don't have enough time this morning to look at the studies but I *think* that Masai have very low cholesterol despite high saturated fat diet. Somewhere between a Total Cholesterol of 120-150mg/dl. They also tend to have higher activity levels and periodic low energy intake

According to [url="http://"http://wholehealthsource.blogspot.com/2008/06/more-masai.html"]this post[/url], the Masai also have a dietary cholesterol intake of up to 2,000 mg/day, and yet they still have very low serum cholesterol levels.

[stephen_b]

Right, and they tend to die before age 50. So I am not sure what conclusion you can make about the Masai.

That they have good lipid profiles and don't die of heart disease.

[woly]

But how often do people die of heart disease before the age of 50, regardless of their cholesterol profile?

[Skötkonung]

But how often do people die of heart disease before the age of 50, regardless of their cholesterol profile?

The onset of heart disease can usually be predicted by a Cardiac Risk Assessment. My guess is that if someone is eating a high fat diet their entire life and health problems were likely to occur, their cardiac biomarkers would indicate the formation of the disease long before it onset. The same can be done for potential type 2 diabetics with a hemoglobin A1C test.

You can read more about it here. ATHEROSCLEROSIS IN THE MASAI in American Journal of Epidemiology.

That said, I don't think a diet super high in saturated fat is likely to be healthy for you. Grass fed beef, which is distinctly different from what we buy at grocery stores, contains a completely different lipid profile. While our grain fed beef can be high in saturated fats (depending on the grade), grass fed beef is alternatively high in omega 3/6 unsaturated fats. These "healthy" fats in conjunction to an active lifestyle help to balance out the saturated fats found in the Masai diet. A diet skewed heavily in the favor of saturated fats probably wouldn't be the healthiest, especially for sedentary people lacking an abundant source of vegetables or healthy omega 3/6 fats. Nuts and seeds also contain saturated fat and I do not think there is anything wrong with eating coconuts every once in a while.

From the above link:
"The Masai vessels enlarge with age to more than compensate for this disease. It is speculated that the Masai are protected from their atherosclerosis by physical fitness which causes their coronary vessels to be capacious."

Regarding life expectancy:
"In poor countries, life expectancy numbers are skewed, because so many children die at birth. If you have ten people die at birth and ten die at age 90, the average life expectancy is still only 45 years. However, in this particular case I do not think it is very relevant, because life expectancy at age 15 in Kenia is still only 60 years. It is also interesting to note that one of the reasons that the Masai have such a high neonatal mortality rate is exactly because of their beliefs about a healthy diet: Masai women eat less food during pregnancy because they want smaller babies."