Lindsey Tanner of the Associated Press reports a new study is claiming that some coffee drinkers may be at greater risk for nonfatal heart attacks. Research found a genetic trait that splits coffee drinkers into two groups, those with a reduced risk of heart attack or those at an increased risk:
Research on more than 4,000 people in Costa Rica found that about half had the trait and were considered "slow caffeine metabolizers." The other half had the opposite trait, which caused their bodies to rapidly break down or metabolize caffeine, and coffee-drinking in this group appeared to reduce heart attack risks.
Among slow-metabolizers, those who drank two or more cups of coffee daily were at least 36 percent more likely to have a nonfatal heart attack than those who drank little or no coffee. Even higher risks were found for younger slow metabolizers -- those under 50. They were up to four times more likely to have a heart attack than slow metabolizers in their age group who drank little or no coffee.
University of Toronto researcher and co-author of the study, Ahmed El-Sohemy remarks:
The new study "clearly illustrates that one size does not fit all," El-Sohemy said. "Perhaps in the future we'll be making different (dietary) recommendations based on people's genetic makeup."
Here are Dr. Fuhrman's thoughts on consumption of caffeinated beverages from his book Eat to Live:
Clearly, excessive consumption on caffeinated beverages is dangerous. Caffeine addicts are at higher risk of cardiac arrhythmias that could precipitate sudden death.1 Coffee raises blood pressure and raises cholesterol and homocysteine, two risk factors for heart disease.2
Besides increased risk of heart disease, there are two other problems. First caffeine is a stimulant that allows you to get by with less sleep and reduces the depth of sleep. Such sleep deprivation results in higher levels of the stress hormone cortisol and interferes with glucose metabolism, leading to insulin resistance.3 This insulin resistance, and subsequent higher baseline glucose level, further promotes heart disease and other problems. In other words, caffeine consumptions promotes inadequate sleep, and less sleep promotes disease and premature aging. Adequate sleep is also necessary to prevent overeating. There is no subsidence for adequate sleep.
The second issue is that eating more frequently and eating more food suppresses caffeine-withdrawals headaches and other withdrawal symptoms. When you are finally finished digesting the meal, the body more effectively cleans house; at this time people experience a drive to eat more to suppress caffeine-withdrawal symptoms. You are prodded to eat again, eating more food than you would if you were not a caffeine addict.
1. Mehta, A., A. C. Jain, M.C. Mehta, and M. Billie. 1997. Caffeine and cardiac arrhythmias: an experimental study in dogs with review of literature. Acta Cardiol. 52 (3):273-83.
2. Nurminen, M.L., L. Niittymen, R. Korpela, and H. Vapaatalo. 1999. Coffee, caffeine and blood pressure: a critical review. Eur. J. Clin. Nutr. 53 (11): 831-39; Christensen, B., A. Mosdol, L. Rettersol, et al. 2001. Abstention from filtered coffee reduces the concentration of plasma homocysteine and serum cholesterol—a randomized controlled trail. Am. J. Clin. Nutr. 74(3):302-07.
3. Spiegel, K., R. Leproult, and E.V. Van Cauter. 1999. Impact of sleep debt on metabolic and endocrine function. Lancet 354 (9188): 1435-39.