We recently reported on a new finding that coffee consumption over the long term could increase the risk of cognitive problems — and that could also boost the risk of Alzheimer’s disease and dementia, but why?

A study from the c (ILSA) evaluated 1,445 people out of 5,632 individuals who were at least 65 years old and no more than 84, and it came to some rather alarming conclusions, according to a report from Financial Express. So the next time you want to take a stop at Starbucks, here are some things to consider.

They found that an increased rate of coffee consumption over time led to an increased risk of what is known as “mild cognitive impairment (MCI).” Researchers found a pretty clear association between coffee consumption and MCI in the study. MCI is considered a precursor to Alzheimer’s and other cognitive disabilities at a later age in life.

If you drink a moderate amount of coffee, you’re probably in the clear — in fact, you may have an advantage, as it appears to result in a reduced rate of MCI compared to those who don’t who rarely drink coffee.

As it turns out, as long as in you’re in that moderate range, you’re OK. It’s when you’re on either side of the spectrum that you should worry: those who drink more than 2 cups of coffee per day appear to have the same level of risk of MCI as those who rarely or never drink coffee, indicating that moderate is the way to go.

The study, published in the Journal of Alzheimer’s Disease, suggests that previous studies confirming that there are long-term protective benefits in consuming caffeine in moderate levels. But why is this the case for moderate consumption but not high consumption?

According to the Mayo Clinic, although coffee can be quite beneficial, drinking too much — say, four cups or more during the day — results in all sorts of unpleasant side effects, like insomnia, nervousness, upset stomach, and muscle tremors. Its influence on your sleep habits may be particularly damaging for those who drink a lot of it.

The study seems to suggest that, as in most cases, moderation is key no matter what the substance is. Coffee can have wonderful effects on your health, but if you drink too much of it, its side effects can take a toll on your daily life — and result in long-term problems that you can avoid by just limiting your intake.