 |
|
|
|
|
|
|
“As Type 2 diabetes rarely appears before the age of 40 and many older people stop or lessen coffee drinking, dietary advice may soon be developed that includes coffee as a safe and useful drink in a diabetes prevention programme”
|
|
|
| Coffee and Diabetes |
|
|
|
There is increasing evidence that drinking coffee may substantially
reduce the risk of developing the most common form of diabetes, Type 2 diabetes, which is the major contributor to the epidemic rise, worldwide, of this disease. The growing body of published research suggests that alongside other lifestyle measures, such as weight control and exercise, regular coffee drinking may also have a protective effect against developing Type 2 diabetes.
With the numbers of people involved, such findings are exciting and significant. It is estimated that in 2000, there were approximately 150 million individuals with the disease and this number is likely to double by 2025 (1). In Europe the number will increase from approx. 16 million in 1994 to 24 million in 2010 (2) and the Centres for Disease Control and Prevention in the USA estimate over 18 million Americans have diabetes, and Type 2 diabetes accounts for over 90 percent of that total.
In a recent interview, Professor J. Tuomilehto, from the Diabetes and Genetic Epidemiology Unit, University of Helsinki, Finland, said, “As Type 2 diabetes rarely appears before the age of 40 and many older people stop or lessen coffee drinking, dietary advice may soon be developed that includes coffee as a safe and useful drink in a diabetes prevention programme”.
It is known that, although coffee reduces insulin sensitivity, other components found in coffee such as chlorogenic acids and magnesium may have beneficial effects. A recent study in the Netherlands (3) found that men, who drank seven cups of coffee a day, were 50% less likely to develop diabetes than those who drank two cups a day. Studies published this year produced similar conclusions. A long term US study (4), over a period of 12-18 years, found that compared to non-coffee drinkers, men who drank more than six cups of caffeinated coffee per day, lowered their risk of Type 2 diabetes by about half, and women reduced their risk by nearly 30%. The effects were also seen among those who drank decaffeinated coffee, but these were more modest. There was a 25% risk reduction for men and 15% for women.
Similar results were discovered in a major study in Finland (5) that involved more than 14,000 people. As Finland has the highest rate of consumption of coffee in the world, it was possible to determine the risk of diabetes at high levels of consumption. In this study the heavy coffee drinkers i.e. those who drank ten or more cups a day, were even less likely to suffer from the disease. Such high consumption reduced the risk by 79% for women and 55% for men. It was also good news for those who drank more moderate amounts – three to four cups a day – their risk of diabetes was reduced by 29% for women and 27% for men.
The mechanism, or process by which coffee exerts its beneficial effect, is as yet unclear. Coffee is a complex compound and its composition will be affected by many factors including, roasting, blending and brewing. Whilst caffeine is thought to play a significant role, coffee is also a major source of chlorogenic acids, components that exhibit antioxidant properties.
Chlorogenic acids are thought to inhibit one of the enzymes involved in the formation of glucose in the small intestine (6,7), and the inhibition of this enzyme is a commonly used approach to controlling high blood glucose levels or hyperglycaemia. Such elevated blood levels over time lead to the serious complications of this disease.
Caffeine and another coffee component, theophylline, are also strong stimulants of pancreatic cells, where the body produces its insulin (8). People develop Type 2 diabetes because the cells in the muscles, liver and fat do not use insulin properly. Eventually the pancreas cannot make enough insulin to meet the body's needs, so interfering with the body's ability to store energy from food.
CONCLUSION
Whilst there is a significant evidence to show that drinking coffee can substantially reduce the risk of developing Type 2 diabetes, further research is clearly needed to evaluate the true role of coffee in this disease and to have a better knowledge of the beneficial effects of its key components. However from early indications, we can look forward to seeing coffee included in the dietary recommendations for a Type 2 diabetes prevention programme.
REFERENCES
1. King H, Aubert RE, Herman WH. Global burden of diabetes, 1995-2025: prevalence, numerical estimate, and projections. Diabetes care 1998; 21: 1414-31.
2. Amos AF, McCarty DJ, Zimmet P The rising global burden of diabetes and its complications: Estimates and projections to the year 2010. Diabet Med 1997; 14: S7-S85.
3. Van Dam RM, Feskens EJM. Coffee consumption and risk of type 2 diabetes mellitus. Lancet 2002; 360: 1477-78.
4. Salazar-Martinez E, Willett WC, Ascherio A, Leitzmann M, Manson JE, Stampfer MJ, Hu FB. Coffee consumption and risk of Type 2 diabetes in men and women. Ann Intern Med. 2004;140: 1-8.
5. Tuomilehto J, Hu Gang, Bidel S, Lindstrom J, Jousilahti P. Coffee consumption and risk of Type 2 diabetes mellitus among middle-aged Finnish men and women. JAMA 2004;291: 1213-19
6. Hauri HP, Wacker H, Rickli EE, Bigler-Meier B, Quaroni A, Semenza G. Biosynthesis of sucrase-isomaltase. Purification and NH2-terminal amino acid sequence of the rat sucrase-isomaltase precursor (pro-sucrase-isomaltase) from fetal intestinal transplants. J Biol Chem. 1982;257:4522-4528.
7. Matsui T, Ueda T, Oki T, Sugita K, Terahara N, Matsumoto K. alpha-Glucosidase inhibitory action of natural acylated anthocyanins. 1. Survey of natural pigments with potent inhibitory activity. J Agric Food Chem. 2001;49:1948-1951.
8. Tuomilehto J, Tuomilehto-Wolf E, Virtala E, LaPorte R. Coffee consumption as trigger for insulin dependent diabetes mellitus in childhood. BMJ. 1990;300:642-643
|
|
 
|
|