Coffee Can Prevent Aging Damage to the Brain
coffee—————– 
The most recent scientific studies indicate that caffeine, the most commonly ingested psychoactive drug in the world, is protective against a number of acute and chronic neurological disorders including stroke and Alzheimer’s disease.
High levels of serum cholesterol and associated damage to the blood brain barrier (BBB) has been suggested as important mechanisms in the development of Alzheimer’s disease. Studies conducted in animals and humans indicate that caffeine could be a protective drug against Alzheimer’s disease but the mechanisms have not been well understood.
Damage and injury to the blood brain barrier (BBB) breakdown occurs before brain cell damage in Alzheimer’s disease and strokes. Breakdown of the BBB may be the key to several aging neurological disorders. High levels of cholesterol are a risk factor for stroke, Alzheimer’s disease and other diseases. Too much dietary cholesterol can lead to the brain changes that are seen in Alzheimer’s disease. These brain changes include memory loss and learning problems, amyloid plaque formation, and brain cell death. High cholesterol diets have been shown to disrupt BBB. High cholesterol diets may contribute to the development of Alzheimer’s disease because it can cause injury to the BBB. Recent lab studies show that a high cholesterol diet did increase the leakage (damage) in the BBB.
Chronic ingestion of caffeine protects against disruption of the BBB, an early event in both acute and chronic degenerative brain diseases. Caffeine blocked high cholesterol diet induced BBB leakage in the rabbit brain. The BBB limits the entry of blood-borne pathogens, substances, drugs, and cells into brain tissues, and once the BBB is disrupted it can cause diminished neuron function.
Researchers showed conclusively that chronic ingestion of caffeine protects against disruption of BBB. The dose of caffeine (3 mg/day) used in this study for 3 to 4 kg rabbits is equivalent to an adult human weighing 70–80 kg consuming a single cup of coffee and is far less than the average caffeine consumption in the USA and Canada that is about 200 mg per person per day.
The most likely site of action where caffeine maybe exerting its protective effects against BBB disruption is the adenosine receptors which it blocks.
ref: http://www.jneuroinflammation.com/content/5/1/12
