Cholesterol. Now there's a topic, and I've decided to start blogging about it (tag: cholesterol series).
It used to be very simple. High cholesterol was bad, if you have it, you might have a heart attack and therefore should pull out all the stops and get it down. The things that caused it were saturated fat and eating cholesterol. That was then.
Now we know that most cholesterol is made in the liver and that levels are genetically controlled. There are various types of cholesterol, some of which are helpful (HDL) and some of which are seriously damaging (VLDL). We understand that cholesterol is not the only biomarker of actual disease risk, but that inflammation markers (C-reactive protein, homocysteine), Apolipoprotein-B levels and Apo-E genotype status all factor into it.
We know that certain fibres like beta-glucan from oats, and other plant substances like phytosterols can affect cholesterol absorption and that other plant substances do cool stuff to cholesterol metabolism in the liver. They may, for example, increase breakdown of HMG-CoA-R (the enzyme that facilitates cholesterol synthesis) and/or increase cholesterol removal by, for example, upregulating bile acid synthesis.
This, of course, is my current field of research. There's a lot to say, but let's start with the simple stuff. When it comes to lipid metabolism, turmeric (Curcuma Longa) is a good thing to eat.
|Turmeric Chicken Stirfry|
The active component in turmeric is curcumin, which makes up about 2% of actual turmeric. If you are only interested in therapeutic effect, you can buy curcumin capsules.
The main benefits of curcumin:
The main benefits of curcumin:
- Upregulates expression of the LDL receptor, increasing LDL (bad cholesterol) removal from the body
- Inhibits the processes of inflammation and early atherosclerosis
- It is an antioxidant
- May lower triglycerides at higher doses
There are a few caveats, the main one being that most studies have been either on animals or cultured liver cells rather than humans - obviously, it's not really feasible to feed people curcumin then biopsy their livers - I can see issues with recruiting volunteers for that. There don't seem to be any randomised controlled studies that have focused completely on curcumin as a method of lowering blood lipids in humans.
The other issue seems to be dose. My best guess for minimal effective intake is 1.7 mg per kg of curcumin (based on a rabbit study), so about 5 g (1 tsp) a day of turmeric for a 60kg human. There doesn't seem to be any upper limit or evidence of toxicity.
1 tsp is the amount sprinkled on my chicken stirfry in the pics and it was about right, flavour-wise. Another tasty method of consumption is sauteed turmeric cauliflower (that's a trick I learned from Kek). Also, who needs another excuse to eat more curry? Not me.
For those of you that want to geek out a bit, I'll list some references below, and if you have any favourite turmeric recipes, please link it up in the comments. Ranting about cholesterol is also ok. ;) Just go right ahead.
Some light bedtime reading:
Coban, D., Milenkovic, D., Chanet, A., Khallou-Laschet, J., Sabbe, L., Palagani, S. Berghe3, W. Mazure, A. & Morand, C. (2012). Dietary curcumin inhibits atherosclerosis by affecting the expression of genes involved in leukocyte adhesion and tensendothelial migration. Molecular Nutrition and Food Research, 56, 1270-1281.
Fan, C., Qian, Y., Wo, X., Yan, J. & Gao, L. (2005). Effect of curcumin on the gene expression of low density lipoprotein receptors. Chinese Journal of Integrative Medicine, 11(3). 201-204.
Fan, C., Wo, X., Dou, X., Xu, L., Qian, Y., Luo, Y. & Yan, J. (2006). Regulation of LDL receptor expression by the effect of curcumin on sterol regulatory element pathway. Pharmacological Reports, 58. 577-581.
Ramirez-Tortosa, M. C., Mesa, M. D., Aguilera, M. C., Quiles, J. L., Baro, L., Ramirez-Tortosa, C. L., . . . Gil, A. (1999). Oral administration of a turmeric extract inhibits LDL oxidation and has hypocholesterolemic effects in rabbits with experimental atherosclerosis. Atherosclerosis, 147(2), 371-378.