Question:

"I’m having bloodwork done and I’m supposed to be fasting. Can I have my morning coffee? Water? Or nothing at all?”

Answer from Express Scripts Canada Pharmacist, Jessica Lau:

Eating or drinking before some blood tests can produce inaccurate results. Tests for blood sugar and cholesterol are two common examples. There are others. If your doctor has asked you to fast before a blood test, it is very important that you follow those instructions. He or she will always give you a time period. Usually 8, 12 or 24 hours prior to the test.

When fasting for a blood test, it’s OK to drink water, and you should continue to take any medications you’re on unless your doctor specifically told you not to.

Unfortunately, those are the only exceptions. Here are a few other things that may not be obvious, but that you should avoid:

• Coffee, even black coffee is not OK, and may affect your results.
• Smoking is also a no-no. If you’re fasting for a blood test, resist those cravings.
• Chewing gum can speed up digestion and that can affect your blood test. Even sugarless gum is off limits.
• Lastly, you should avoid strenuous exercise during the fasting period. It can also affect digestion.

For many of us, going about our day without eating can be very challenging. Going without that morning coffee can be even harder. Try to schedule your blood test as early as possible in the morning.

Finally, if you can’t resist or accidentally eat during the fasting period, tell your doctor, and if necessary, reschedule the test. The most important thing is to get accurate results so you can get the treatment you need.

Until next time, I’m Jessica Lau and this has been ‘Ask the Pharmacist’.

I wish you good health.