8 Healthy Vegetables That Can Sometimes Harm You

A veggie-rich diet can lower your cancer risk and protect your heart, but overeating certain veggies can be dangerous if you have certain health conditions.

Gloria Tebelman/RD.com, Istock/Elisanth

You have heartburn

An unidentified substance in tomatoes and tomato-based products can cause acid reflux. People with digestive upset could try eliminating tomatoes for two or three weeks to see if things feel better. These 33 healthy foods are way more nutritious than you thought.

Gloria Tebelman/RD.com, Istock/Erickson Photography

You take blood-thinning drugs

If you take a blood-thinning drug such as warfarin (Coumadin), it’s important to maintain steady blood levels of vitamin K—sudden increases can lessen the effects of the drug. That means it’s important to be consistent with your vegetable intake, since this is where most of your vitamin K comes from. Try to eat similar amounts of vegetables every day. If you like veggies that are particularly high in vitamin K, such as kale, Swiss chard, spinach, mustard greens, and turnip greens, stick with half a cup a day, eaten at about the same time daily.

Gloria Tebelman/RD.com, Istock/anna1311

You have a history of kidney stones

One in five people who form calcium oxalate kidney stones (the most common type) have high levels of oxalates in their urine. If you have a history of kidney stones, limit oxalate-rich foods, such as rhubard, spinach, beets, and beet greens. These are the 8 clear signs you’re not getting enough vegetables.

Gloria Tebelman/RD.com, Istock/LOVE_LIFE

You have gout

Watch your asparagus intake. The spears contain purines, substances that promote the overproduction of uric acid that precipitates painful attacks of gout.

Gloria Tebelman/RD.com, Istock/Diane Labombarbe

You have certain allergies

Eating such foods as artichokes may provoke an allergic reaction in people who are sensitive to ragweed allergens. People sensitive to latex may have an allergic reaction to avocados. Many people sensitive to aspirin may suffer an allergic reaction to radishes, which contain salicylates, compounds similar to the drugs’ active ingredients. These are the 21 common food myths that are wildly untrue.

Gloria Tebelman/RD.com, Istock/pjohnson1

You have an inflammatory GI disorder

If you have ulcerative colitis or Crohn’s disease, your doctor might recommend avoiding or minimizing your intake of cabbage, which contains bacteria that live naturally in the intestinal tract and cause gas and bloating. You might also want to limit your intake of other cruciferous veggies like cauliflower, broccoli, and Brussels sprouts if they trigger symptoms.

Gloria Tebelman/RD.com, Istock/numbeos

You’re watching your weight

Be picky about eggplant-based dishes. Eggplants’ spongy texture soaks up fat. In fact, deep-fried eggplants soak up four times as much fat as French-fried potatoes. Keep calories to a minimum by baking, broiling, roasting, or stewing. If sautéing, use a nonstick pan and little oil. On the other hand, these are some of the healthiest vegetables you can eat.

Gloria Tebelman/RD.com, Istock/Suzifoo

You have an underactive thyroid

Turnips contain two goitrogenic substances, progoitrin and gluconasturtin, which can interfere with the thyroid gland’s ability to make its hormones. These compounds don’t pose a risk for healthy people who eat moderate amounts of turnips, but anyone with hypothyroidism should cook this vegetable since cooking appears to deactivate goitrogens. Find out more about the 17 “healthy” foods you actually need to avoid.