Effects of Coffee on Blood Pressure and Blood Sugar

Dear Mayo Clinic: I love drinking coffee. I often drink several cups a day. Recently I was diagnosed with diabetes and high blood pressure. My doctor advised me to cut back on my favorite drink because it’s not good for my blood sugar or blood pressure. Can you give me some insight as I thought coffee was good for my health?

Various studies indicate that coffee has some health benefits, but it is not without its drawbacks, mainly due to caffeine.

Coffee may offer some protection against:

  • Parkinson’s disease
  • Type 2 diabetes
  • Liver disease, including liver cancer
  • Heart attack and stroke.

The average adult in the United States drinks about two 8 oz (237 ml) cups of coffee a day, which can contain about 280 mg of caffeine.

For most healthy young adults, caffeine does not seem to significantly affect blood sugar.

On average, consuming up to 400 mg of caffeine per day seems safe.

However, caffeine affects each person differently.

For someone who already has diabetes, the effects of caffeine on insulin action may be associated with higher or lower blood sugar levels.

For some people with diabetes, about 200 mg of caffeine – the equivalent of one to two 8 oz (237 ml) cups of brewed black coffee – can cause this effect.

If you have diabetes or have trouble controlling your blood sugar, limiting the amount of caffeine in your diet may be beneficial.

The same goes for the effect of caffeine on blood pressure.

The blood pressure response to caffeine differs from person to person.

Caffeine can cause a brief but dramatic increase in your blood pressure, even if you don’t have high blood pressure.

It is not known what causes this spike in blood pressure.

Some researchers believe caffeine may block a hormone that helps keep our arteries widened.

Others believe that caffeine causes our adrenal glands to release more adrenaline, which causes blood pressure to rise.

Some people who regularly drink caffeinated beverages have higher average daily blood pressure than those who don’t.

Others who regularly drink caffeinated beverages develop caffeine tolerance.

And therefore, caffeine has no long-term effect on their blood pressure.

If you have high blood pressure, ask your healthcare professional if you should limit or stop drinking caffeinated beverages.

The US Food and Drug Administration (FDA) says 400 mg of caffeine per day is generally safe for most people.

However, if you’re concerned about the effect of caffeine on your blood pressure, try limiting the amount of caffeine you drink to 200 mg per day, which is about the same amount typically found in one to two cups. 8 oz (237 ml) of brewed black coffee.

Keep in mind that the amount of caffeine in coffee, energy drinks, and other beverages varies by brand and brewing method.

Also, if you have high blood pressure, avoid caffeine right before activities that naturally raise your blood pressure, such as exercise or heavy physical labor.

This is especially important if you are outdoors and exercising.

To see if caffeine can raise your blood pressure, check your blood pressure before you drink a cup of coffee or another caffeinated drink and then again 30 to 120 minutes after.

If your blood pressure increases by about five to 10 mmHg, you may be sensitive to caffeine’s ability to raise blood pressure.

Women who are pregnant, trying to get pregnant or breastfeeding should also be careful with caffeine.

High consumption of boiled, unfiltered coffee has been associated with a slight increase in cholesterol levels.

Additionally, researchers found that postmenopausal women who regularly drank caffeinated beverages, such as coffee, tea, or soft drinks, had more bothersome vasomotor symptoms, such as hot flashes, compared to menopausal women. other postmenopausal women who did not use caffeine.

Keep in mind that the actual caffeine content of a cup of coffee or tea can vary widely.

Factors such as processing and brewing time affect the caffeine level.

It’s best to check your beverage, whether it’s coffee or another drink, to get an idea of ​​how much caffeine it contains.

The best way to reduce caffeine intake is to do so gradually over several days to a week to avoid withdrawal headaches.

But double-check any medications you take, as some cold medicines are made with caffeine.

This is especially common in headache medications. – By Cynthia Weiss/Mayo Clinic News Network/Tribune News Service

Rachel J. Bradford