(American Journal of Clinical Nutrition) -- Elevated serum concentrations of homocysteine (tHcy) and cholesterol are associated with increased risk of ischemic heart disease (IHD). Previous studies found that consumption of large amounts of unfiltered coffee resulted in increases in serum tHcy and cholesterol, suggesting a specific effect related to brewing methods.

Read the full story

By Howard LeWine, M.D.
Harvard Medical School

How does this article relate to you?

Here's another study on coffee that again raises the question, "Is too much coffee bad for you?" This recently published study looks at whether filtering coffee vs. not filtering coffee makes a difference. This study doesn't give us a firm answer, but it hints that filtering isn't that crucial.

So what's the bottom line with coffee? Enjoy it, regardless of whether you choose caffeinated or decaffeinated. There probably is some amount of caffeine (from coffee, tea and caffeinated soft drinks) above which real health hazards exist. I am still unclear as to what that level is for an otherwise healthy adult.

What changes do you need to make?

My recommendations to patients are pragmatic. If even one cup of coffee makes you jittery or anxious or interferes with sleep, that is one cup too many. I am honest with patients. I don't know if 10 cups of coffee per day is too much, but four cups per day is my own limit.

For people with heart rhythm irregularities and high blood pressure, some may find that coffee does aggravate the situation. I make this assessment individually. My general advice is moderation; sip rather than gulp the caffeine.

What is most interesting about this article is the discovery of higher blood levels of homocysteine and lower blood levels of the B vitamin folic acid in coffee drinkers. High homocysteine and low folic acid levels correlate with higher risk of coronary heart disease. But that still does not make coffee the bad guy.

I do recommend that you take a multiple vitamin each day when you sit down to have your coffee. Some vitamins don't sit well on an empty stomach, so it is best to take your vitamins with a piece of whole-grain toast. Substituting a B complex vitamin or adding one to the multiple vitamin will also give you that extra folate.

What can you expect in the future?

You can expect to see a lot more studies about coffee and caffeine. And as you read about these, keep in mind that hundreds of studies have already looked to find something wrong with coffee. And they haven't. So it will take some really strong, convincing evidence from more than one study to get me to give up my coffee.

Related links:

Nutrition Area

The Caffeine Quiz

Caffeine