Coffee consumption doesn't increase or decrease the risk of lifestyle diseases such as obesity, Type 2 diabetes or metabolic syndrome, Danish researchers say.

A genetic study undertaken to investigate possible impacts of coffee drinking on the human body found the morning cup of java more than half of Americans start their day with showed no link to the risks of such diseases, they say.

Researchers at the University of Copenhagen and the Herlev and Gentofte Hospital drew their study from data about coffee drinking habits and diseases that develop as a result of lifestyle gathered from around 93,000 Danish subjects in the Copenhagen General Population Study.

"We are the first in the world to have investigated the relationship with genes associated with a lifelong high consumption of coffee," says Herlev and Gentofte medical student Ask Tybjaeg Nordestgaard.

"These genes are completely independent of other lifestyle factors, and we can therefore conclude that drinking coffee in itself is not associated with lifestyle diseases."

Several genes affect our desire to consume coffee, the researchers note, and those who possess those genes may drink more coffee than those who do not have the genes.

The scientists analyzed such genetic variations to uncover specific genes linked to high coffee intake and whether that affects risk for developing specific medical conditions.

Genetic variations associated with genes identified as CYP1A1, CYP1A2 and AHR were factors affecting an individual's coffee intake, they found.

However, those genetic variations showed no association with Type 2 diabetes or other lifestyle diseases, they say in the study published in the International Journal of Epidemiology.

While some previous observational studies have suggested a possible connection between coffee and disease, the new study yielded no statistical evidence to support that, researcher Borge Nordestgaard says.

"We can now see that the coffee genes are surprisingly not associated with a risk of developing Type 2 diabetes or obesity," he confirmed. "This suggests that drinking coffee neither causes nor protects against these lifestyle diseases."

Coffee is one of the world's most popular beverages; among coffee drinkers in the United States — about half the population — the daily consumption averages 3.1 cups.

Both men and women consume coffee equally, and about 65 percent of all coffee is consumed during morning hours.