If you're a committed coffee drinker, you may worry a little about the way you need caffeine to function. You can probably rest easy. The research showing coffee’s health benefits continues to roll in, with very few studies suggesting that it is bad for health — at least at moderate levels.

Coffee drinking has been linked to a reduced risk for a number of diseases, including cancer. Type 2 diabetes can now be added to that list, and, according to a new study, those who maintain or even increase their coffee consumption over the years may see an even greater reduction in diabetes risk.

The data for the new study came from three huge long-term studies — the Nurses' Health Study, the Nurses Health Study II, and the Health Professionals Follow-up Study — that have tracked people in the health field for over 20 years.

People who drank at least three cups of coffee per day consistently through the years had the lowest risk for developing diabetes.

More than 48,000 people were included in the analysis, which recorded their dietary and lifestyle habits, along with any diseases and health problems they developed over the years. Of particular interest was coffee and tea consumption, which was noted every four years — in this way, the authors could see how increases or decreases in consumption over time might be linked with disease risk.

People who were coffee drinkers had a reduced risk for developing type 2 diabetes. And looking at the changes in consumption, the team, from Harvard's School of Public Health, found that people who increased their coffee intake by about one and a half cups per day had an 11% reduced risk of developing diabetes over the next four years, compared to those whose consumption didn’t change.

Decaf coffee didn’t provide the same effect and neither did tea, but that may be partially because there were relatively few tea drinkers in the study. Other studies have shown that tea does offer its own benefits.

The best results were seen in people who drank at least three cups of coffee per day consistently through the years. They had the lowest risk for developing diabetes — a 37% lower risk than people who drank one or fewer cups per day over the years.

The very large number of participants and the long period over which they were followed suggest the findings are pretty solid. What’s particularly interesting is that the apparent benefits of coffee seem to develop over a relatively short period — just four years. In other words, it’s doesn’t take a lifetime of coffee consumption to have a positive effect on your health.

While the study found that coffee drinkers were less likely to develop diabetes, it didn't show why this occurred. So it may be too early to prescribe drinking more coffee as a preventive measure for diabetes or other diseases, but if you’re already a devout coffee drinker and aren’t feeling any ill effects, you may just want to keep doing what you’re doing.

The study is published in the journal Diabetologia.