5 foods that can affect prescription medications

It’s important to eat certain foods in moderation

SAN ANTONIO – There are some foods that can negatively affect prescription medications you take on a daily basis.

Medical professionals say dairy, leafy greens, grapefruit, alcohol and foods with the amino acid tyramine in them all can impact how a prescription medication works.

Here’s a look at each and why it’s important to be aware.


This includes food like milk, cheese and fortified juices. Dairy has calcium in it. If too much calcium is consumed at the same time as taking antibiotics, it can interfere with the absorption of the drug.

“It’s important to avoid calcium rich foods at least an hour before or maybe two hours after taking the antibiotics,” Lead Registered Dietitian Vijaya Bolta of Alamo Nutrition Consultants said.

Leafy Greens

This includes kale, spinach and collard greens. These types of vegetables have Vitamin K in them.

Vitamin K is great to eat, but it needs to be done consistently. Too much of the vitamin doesn’t allow for blood thinners to work properly.


Grapefruit and grapefruit juice affects the drug Statins. This type of drug can be found in medicines for high cholesterol, high blood pressure and antidepressants.

“People say, well, I don’t drink grapefruit, but you might drink maybe sodas, that have grapefruit extracts or grapefruit juice in them,” Bolta said.

Amino Acid: Tyramine

This includes aged and cured meats, hard cheeses, red wine and soy products. Tyramine helps regulate blood pressure. A high build up of tyramine in our body can cause blood pressure to spike, which can be dangerous.

“If that happens, our blood pressure can rapidly go up, which can cause you to feel dizzy, headaches, nausea, vomiting and potentially even a stroke,” Bolta said.


Any type of alcohol can affect medications like antihistamines, aspirin, antibiotics, sleeping pills plus many more.

“It’s really important to avoid drinking alcohol while taking any of these medications,” Bolta said.

It’s important to note you don’t have to cut these foods out of your life. However, it’s recommended that you talk with your doctor and pharmacist when trying a new medication.

“Any time a new medication is prescribed, you want to ask if are there any foods that might interact with them,” Bolta said.

About the Author:

Halee Powers is a KSAT producer primarily focused on digital newscasts and events.