As we age, our dietary needs (and needs overall) start to change. We need more of some nutrients and less of others, we may need to scale back on intense exercise routines, and we often start to introduce new medications to manage specific health conditions.
But back to food: With the ever-changing state of our bodies and health, it can be hard to know how to properly nourish ourselves at different life stages. But there’s one food registered dietitians say you should be extra careful about eating as you get older — and we’re going to guess you didn’t see this one coming.
According to three different registered dietitians we spoke with, there’s one food people need to be cautious about consuming as they get older: grapefruit. If your jaw is on the floor, we don’t blame you. Grapefruit is packed with vitamin C and is great for you, right?
Normally, yes. But for anyone taking medication to manage a health issue, grapefruit may interact negatively with it.
“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 exact amount of grapefruit that’s dangerous to ingest will vary based on a handful of factors, and you should always talk to your doctor about the amount that’s safe for you (if any). But in general, one whole grapefruit or glass of grapefruit juice is enough to negatively interact with certain types of medication.
Maria Emerick, another registered dietitian, adds that grapefruit can also interact negatively with blood thinners like warfarin, which is often known by the brand name Coumadin. “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 types of medications that grapefruit might interact negatively with. Research shows grapefruit could have an impact on certain blood pressure medications, heart rhythm medications, certain mood medications (although it’s worth noting that it’s safe to consume grapefruit with most common antidepressants) and more.
Be careful of foods high in vitamin K, too.
But it’s not just grapefruit you need to be wary of. Foods high in vitamin K that you probably think of as good for you — like kale, spinach and collard greens — can be dangerous when you consume too much of them 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 encourage you to avoid vitamin K altogether (although you should always check with them!). The most important thing to keep in mind with vitamin K and certain medications is consistency in dosage. For example, the daily recommendation for men and women over 19 is 120 mcg and 90 mcg respectively, and 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 (mixed into a salad, for example), make sure to try to keep that level consistent with whatever vitamin K-rich greens you consume the next day.
Shelley Balls, a registered dietitian and nutritionist for Consumer Health Digest, adds a few additional drugs to the list. “These can include antacids, antibiotics, aspirin and drugs for cancer, seizures and high cholesterol,” she said. “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 foods high in vitamin K in your diet but focus on getting approximately the same amount each day so you can stabilize your medication dosage required to manage your condition, while still enjoying dark greens in your diet.”
What if you’re not on any medication?
If you’re on little or no medication, you may be wondering what foods you should try to eat less of. The answer to that probably isn’t as surprising — and by the way, these foods (and drinks) are on the list for people who are on medication, too.
“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.”
This can result in alcohol staying in the system for longer, she added, with a more pronounced and prolonged effect. “Decreased production of enzymes involved in alcohol metabolism (like ADH and ALDH) can put older adults at a higher risk of alcohol-related toxicity. Many medications used by older adults are also contraindicated for alcohol consumption.”
You should also work to limit your consumption of processed foods, such as fast food, ready-made meals, packaged snacks and sugar-sweetened beverages, Emerick said. “These products are manufactured from chemically altered ingredients derived from foods and supplemented with additives to improve taste, texture, appearance, and shelf life, with minimal to no inclusion of whole foods,” she said. “Research indicates a direct link between ultra-processed foods (UPFs) and increased risks of cardiovascular disease, type 2 diabetes, anxiety, depression, obesity, poor sleep quality, and overall mortality.”
Moreover, Emerick added, UPFs often replace more nutritious foods like fruits, vegetables, legumes, nuts, and seeds in diets, leading to lower consumption of beneficial vitamins, minerals, fiber, probiotics, antioxidants and anti-inflammatory agents. “As it is typical for appetite to diminish with age, every mouthful becomes increasingly important,” she said.
While the advice to limit alcohol and UPFs is pretty standard, it’s always a good idea to talk to your doctor about what foods any medications you’re taking may interact with. They’ll have the most information on this topic, and may also have suggestions for how to meet nutritional needs while steering clear of certain nutrient-dense foods like grapefruit or spinach. In the meantime, you should probably skip that second glass of wine tonight!
This article originally appeared on HuffPost.