Caffeine is a natural chemical that derives from plants, has no flavor, and stimulates your nervous system. It's found in some medicines and a variety of beverages including some soft drinks, teas and of course, coffee. This natural drug's effect on human health has been questioned, including its effect on cholesterol.
Caffeine and Cholesterol
In 1985, the "American Journal of Epidemiology" reported the discovery of "a significant relationship between coffee consumption and serum cholesterol" on Japanese men in Hawaii. Cola and tea containing caffeine were studied as well, however the tests came to the conclusion that tea and cola did not show a link to cholesterol. Conclusions stated that coffee and cholesterol showed a relationship, but not the caffeine from the coffee. More recent research from Dr. Michael J. Klag may reveal what exactly is in coffee that raises cholesterol.
Caffeine and Coffee
Msnbc.com reported that in 2001, Dr. Klag and fellow researchers at Johns Hopkins University School of Medicine analyzed over a dozen experiments that studied any possible link between coffee and cholesterol. The studies revealed that six cups a day of coffee did raise LDL or low-density lipoprotein -- "bad" cholesterol -- as well as increase total cholesterol. Researchers found that this link mainly came from unfiltered coffee.
Unfiltered vs. Filtered Coffee
Dr. Klag explains that terpenes -- natural oils in the unfiltered coffee -- were the reasons behind cholesterol increase, most of which are removed from filtered coffee. In 1994, Johns Hopkins researchers discovered a relationship between coffee and cholesterol; however, most of those experiments that showed this link had taken place prior to 1975. During the mid-1970s, filtering coffee makers became popular in the United States, reports msnbc.com. Filtered coffee doesn't alter cholesterol as much as unfiltered coffee does; however, there is some evidence by the Sahlgrenska University Hospital(CK) that may suggest a small correlation between filtered coffee and cholesterol as well. Swedish researchers explained in 2003 in "The European Journal of Clinical Nutrition" that people who typically consumed coffee daily, and who gave it up for three weeks showed a slight decrease in cholesterol, and an increase in cholesterol once they resumed drinking coffee.
Caffeine, Cholesterol and the Brain
Caffeine may not raise cholesterol, but it may block cholesterol from the brain. The "Journal of Neuroinflammation" reported a study conducted on rabbits in 2008, involving the blood-brain barrier. A blood-brain barrier -- both in humans and rabbits -- acts a protective shield between the blood supply and the brain, which defends the brain from harmful substances. If the barrier becomes leaky this leaves the brain vulnerable to health problems that may induce Alzheimer's. Rabbits fed high fat diets with caffeine supplements had blood-brain barriers that were "more intact than in those given no caffeine" reported BBC News in 2008. Researcher Dr Jonathan Geiger explained on BBC News that caffeine blocks harmful effects of cholesterol that could cause leakage in the blood-brain barrier, while a representative of the Alzheimer's Association reported that "this is the best evidence yet that caffeine equivalent to one cup of coffee a day can help protect the brain against cholesterol."
References
- Handbook of Experimental Pharmacology; Notes on the History of Caffeine Use; 2011
- The "American Journal of Epidemiology"; Coffee, Caffeine, and Serum Cholesterol in Japanese Men in Hawaii; J. DAVID CURB et al.; Feb. 1, 1985
- msnbc.com; Coffee and Cholesterol; Merritt McKinney
- The "European Journal of Clinical Nutrition"; Filtered Coffee Raises Serum Cholesterol: Results from a Controlled Study
- The "Journal of Neuroinflammation"; Caffeine Blocks Disruption of Blood Brain Barrier in a Rabbit Model of Alzheimer's Disease; Xuesong Chen et al.; April 3, 2008
- BBC News; Daily Caffeine 'Protects Brain'; April 2, 2008
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