From Ergo Log
If you aren't a sporty type, but would like to be, you could consider lutein. The much neglected little brother of beta-carotene, lutein can help you to adopt an active lifestyle. According a Japanese animal study, published in PLoS One, the substance activates the 'marathon enzyme' AMPK.
Lutein is a carotenoid that is soluble in fat. Its chemical structure resembles that of beta-carotene and zeaxanthin. But unlike beta-carotene, lutein does not convert into vitamin A.
The human eye, the retina in particular, contains large amounts of lutein. Together with zeaxanthin, which is found mainly in the macula, lutein protects the eye against aggressive components in sunlight. Good food sources of lutein are kale and spinach.
Feed manufacturers sometimes add lutein to chicken feed so that the yolks develop a stronger colour. The body absorbs the lutein (and zeaxanthin) in egg yolks well. If you eat an egg a day the amount of these two carotenoids in your blood will rise, without there being negative effects on your cholesterol level, say researchers sponsored by egg producers. [J Nutr. 2006 Oct;136(10):2519-24.]
Government-funded research shows, however, that in some groups at least an increased egg consumption boosts the concentration of 'bad cholesterol' LDL – and with it the risk of cardiovascular disease. [Am J Clin Nutr. 1999 Aug;70(2):247-51.]
Megumi Matsumoto, of Nihon University, wondered whether lutein could be added to full fat milk. He gave lab rats milk, lutein or milk with lutein daily for nine weeks. A control group was given nothing.
The animals' cage had a treadmill in it. Matsumoto recorded the amount of kilometres the lab rats covered in the treadmill on a voluntary basis. He noticed that the combination of milk and lutein led to a drastic rise in the number of kilometres covered.
In the animals' muscle cells the combination of lutein, milk and exercise resulted in increased activity of the enzyme carnitine palmitoyltransferase 1 [CPT1]. This enzyme helps mitochondria to burn fats.
The combination also resulted in a rise in the total amount of AMPK [tAMPK] in the muscle cells as well as a noticeable rise in the amount of phosphorylated AMPK [pAMPK]. AMPK is an enzyme that becomes active when muscle cells have little energy available, and that stimulates muscle cells to develop. Substances that activate AMPK are often interesting for endurance athletes.
Matsumoto was able to show that when lutein was administered with milk it resulted in 2-3 times greater uptake than administering lutein without milk. He was also able to show that physical exercise reduced the amount of lutein in the blood. It seems that active muscles use lutein. Lutein helps muscles to perform better – which is why the rats spontaneously ran further when they were given lutein and milk.
The researchers gave their rats 1 mg lutein per kg bodyweight per day. Converted to the amount for an adult human that would mean 10-15 mg lutein per day. Athletes can easily ingest this amount by eating vegetables or taking supplements. These will work better when combined with foods that contain fats.
J Am Geriatr Soc. 2002 Dec;50(12):1929-33.