As we age, our dietary needs change. We need more of some nutrients and less of others, may need to scale back on intense exercise, and often introduce new medications to manage health conditions. But there’s one food registered dietitians say you should be extra careful about eating as you get older — and it might surprise you: grapefruit.
According to three registered dietitians, grapefruit is a food older adults need to be cautious about consuming. Despite its reputation for being packed with vitamin C, grapefruit can negatively interact with certain medications.
“Grapefruit and grapefruit juice are known to interfere with statins, which are used to reduce cholesterol,” said Sarah Hormachea, a registered dietitian at Nourish. “A compound in grapefruit called furanocoumarins competes with the enzyme in our liver that is used to metabolize statin medications.”
The amount of grapefruit that’s dangerous varies, so always consult your doctor. Generally, one whole grapefruit or a glass of grapefruit juice can negatively interact with certain medications.
Maria Emerick, another registered dietitian, adds that grapefruit can also interact with blood thinners like warfarin. “This can lead to higher levels of the medication in the body, increasing the risk of side effects or toxicity,” she said.
Statins and blood thinners aren’t the only medications affected. Research shows grapefruit could impact certain blood pressure medications, heart rhythm medications, and mood medications (although it’s safe to consume grapefruit with the most common antidepressants).
It’s not just grapefruit you need to be wary of. Foods high in vitamin K, such as kale, spinach, and collard greens, can be dangerous when consumed excessively while taking certain medications.
“Foods rich in vitamin K can interfere with the effectiveness of blood thinners like warfarin. Vitamin K helps blood clot, which counteracts the blood-thinning effects of warfarin. Individuals on warfarin need to maintain consistent vitamin K intake daily and monitor their diet accordingly,” Emerick said.
Most doctors won’t advise you to avoid vitamin K altogether, but consistency in dosage is key. For example, the daily recommendation for vitamin K is 120 mcg for men and 90 mcg for women. A cup of raw spinach has 145 mcg, and a cup of cooked broccoli has roughly 220 mcg. So, if you have a cup of raw spinach one day, try to keep your intake consistent.
Shelley Balls, a registered dietitian for Consumer Health Digest, adds that certain drugs, such as antacids, antibiotics, aspirin, and drugs for cancer, seizures, and high cholesterol, may also require you to limit vitamin K-rich foods. “If you are taking any of those drugs, you may want to limit or avoid vitamin K-rich foods under the guidance of a doctor. Sometimes you can still include these foods but focus on getting approximately the same amount each day to stabilize your medication dosage,” she said.
For those on little or no medication, it’s still essential to watch your diet. “You’ll definitely want to try to drink less alcohol,” Hormachea said. “As we age, our body’s ability to digest alcohol can change dramatically. Liver function declines, leading to a slower metabolism of alcohol.”
Alcohol can stay in the system longer with more pronounced effects, and many medications are contraindicated for alcohol consumption.
Additionally, limit processed foods like fast food, ready-made meals, packaged snacks, and sugar-sweetened beverages. These products, often chemically altered and supplemented with additives, can increase risks of cardiovascular disease, type 2 diabetes, anxiety, depression, obesity, poor sleep quality, and overall mortality, according to Emerick.
While it’s always a good idea to talk to your doctor about food and medication interactions, being mindful of your diet can help maintain your health as you age. And maybe skip that second glass of wine tonight!