Wednesday, August 09, 2006

The Data Buzz

Making headlines this week:

Ahead of publication of the data, is a study claiming to find that a meal high in saturated fat negatively effects HDL (the so-called "good" cholesterol).

The study is due for publication in the Journal of the American College of Cardiology, August 15th. Since the data is not yet available for review, I will wait (unlike those in the media jumping up and down to vilify saturated fats) until I can read through the full-text of the paper before analyzing the results/conclusions reached.


Dr. Mike Eades wrote about an article in the Wall Street Journal about a study showing the importance of fat for micronutrient bioavailability.

A good read - just remember to come back!

ScienceDaily: Compound In Dairy Products Targets Diabetes

Interestingly, the lead researcher is suggests "that in addition to a well-balanced diet, it is advantageous to incorporate CLA as a dietary supplement, or to seek out new products that enrich foods such as butter, margarine and ice cream with CLA."

Folks, CLA is naturally occuring in pastured (grass-fed, not grain fed) ruminant animal meats (cows, goats, lamb, deer, etc.) as well as whole milk and milk products from those animals. "The compounds are predominantly found in dairy products such as milk, cheese and meat, and are formed by bacteria in ruminants that take linoleic acids -- fatty acids from plants -- and convert them into conjugated linoleic acids, or CLA," says Jack Vanden Heuvel, professor of molecular toxicology in Penn State's College of Agricultural Sciences and co-director of Penn State's Center of Excellence in Nutrigenomics.

Unfortunately the feedlot animals, fed a steady diet of grains to fatten them or increase milk production, that dominant the food supply in the US, is lower in CLA.

But, CLA supplements are industrial hydogenated fats, which some studies have found problematic in supplement form:

Diabetologia, 2004: Supplementation with trans10cis12-conjugated linoleic acid induces hyperproinsulinaemia in obese men: close association with impaired insulin sensitivity

In obese men, t10c12CLA induces hyperproinsulinaemia that is related to impaired insulin sensitivity, independently of changes in insulin concentrations. These results are of clinical interest, as hyperproinsulinaemia predicts diabetes and cardiovascular disease. The use of weight-loss supplements containing this fatty acid is worrying.

Journal of Lipids Reseach, 2003: Efficacy and safety of dietary supplements containing CLA for the treatment of obesity: evidence from animal and human studies

In this study, researchers found that CLA supplements decreased insulin sensitivty, raised fasting plasma glucose levels, and increased the concentration of C-reactive protein, a marker of inflammation and an independent predictor of cardiovascular risk. The authors also noted evidence that manmade CLA may produce enlargement of the liver and insulin resistence.

If you want to understand the process of making supplements of CLA, here is a patent to read from one company's process: United States Patent: 5554646


Ethylene glycol (1000 g) and 500 g potassium hydroxide (KOH) are put into a 4-neck round bottom flask (5000 ml). The flask is equipped with a mechanical stirrer, a thermometer, a reflux condenser, and a nitrogen inlet. (The nitrogen introduced in first run through two oxygen traps). Nitrogen is bubbled into the ethylene glycol and KOH mixture for 20 min and the temperature is then raised to C. 1000 g of linoleic acid, corn oil, or safflower oil is then introduced into the flask. The mixture is heated at C. under an inert atmosphere for 2.5 hours.

The reaction mixture is cooled to ambient conditions and 600 ml HCl is added to the mixture which is stirred for 15 min. The pH of the mixture is adjusted to pH 3.

Next, 200 ml of water is added into the mixture and stirred for 5 min. The mixture is transferred into a 4 L separatory funnel and extracted three times with 500-ml portions of hexane. The aqueous layer is drained and the combined hexane solution extracted with four 250-ml portions of 5% NaCl solution.

The hexane is washed 3 times with water. The hexane is transferred to a flask and the moisture in the hexane removed with anhydrous sodium sulfate (Na.sub.2 SO.sub.4). The hexane is filtered through Whatman paper into a clean 1000 ml round bottom flask and the hexane removed under vacuum with a rotoevaporator to obtain the CLA.

The CLA is stored in a dark bottle under argon at C. until time of use.

Personally, I don't recommend the use of CLA supplements. Nature has a very simple process - ruminent eats grass/forage rich with LA and its converted to CLA. No need to make it ourselves in a process of hydrogenation. Haven't we learned our lesson yet about processing oils?

Instead of spending money on these supplements, spend your money on quality grass-fed meats and dairy products.

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