Makes you smarter and thinner and protects against cancer?
Caffeine, one of the world’s most used substances, improves wakefulness, mood, and attention and may increase apoptosis (which might protect against carcinogenesis). A population-based study and an animal study have recently examined several possible benefits of caffeine.
In the “Three City Study” in France, 4197 women and 2820 men without dementia diagnoses (mean age, 74) underwent several cognitive tests three times over 4 years. Caffeine consumption and multiple other demographic, medical, and lifestyle variables were analyzed. There was no relation between cognitive decline and caffeine consumption for men. Among women, however, a dose-response relation was found: After other variables were controlled for, drinking at least three cups of coffee or tea per day protected against decline in verbal skills; a trend for protection of visuospatial memory was also found. The rate of dementia did not change, although the relatively short follow-up (4 years) may have obscured any effect.
In a preclinical study, Lu et al. examined the effect of voluntary exercise and various amounts of caffeine on tissue fat and ultraviolet B (UVB) light-induced apoptosis in hairless mice. Previously, the researchers had demonstrated that each intervention separately stimulated apoptosis. Mice that were placed in cages with exercise wheels averaged 2 miles per day. Exercise plus caffeine significantly decreased dermal fat over 2 weeks (>75% decreases with higher caffeine doses). Low-dose caffeine plus exercise synergistically and significantly enhanced UVB-induced apoptosis. Caffeine plasma levels were similar to those in people ingesting one to four cups of coffee per day.
Comment: Caffeine may increase anxiety and blood pressure, and produce insomnia and rebound withdrawal headaches. However, it is not without potential benefits — in antitumor action and weight loss. Regarding weight loss, caffeine may have the edge over other drugs, such as topiramate, which, in addition to its expense, can produce significant cognitive impairment (see Journal Watch Psychiatry Aug 3 2005). A clinical study of the combined effects of caffeine and exercise on weight loss and cognition would be of great interest. Of course, the human equivalent of 2 mouse-miles per day may be a bit strenuous. Cup of joe, anyone?
Jonathan Silver, MD
Published in Journal Watch Psychiatry September 24, 2007
