One of the things most nutrition professionals, along with doctors, tend to agree on is that vegetables are good for you. So you may be surprised to hear that it's possible for some vegetables to cause negative symptoms in people with certain health conditions.
In people who have a medical condition called gout or for those prone to kidney stones, vegetables high in purines — substances that break down to form a waste product called uric acid — may make pain worse. Although most vegetables are safe to eat on a low-purine diet, you may need to limit mushrooms, green peas, spinach, asparagus and cauliflower, depending on how they affect you personally.
Purines and Uric Acid
Purines aren't a problem on their own. They become a problem when the body breaks them down and creates uric acid. In normal circumstances and in healthy individuals, uric acid dissolves in the blood, where it travels to your kidneys and then is washed out of your body through your urine.
But if you have too much uric acid in your blood or you have a condition that makes it more difficult for your kidneys to effectively remove uric acid, it can lead to the formation of uric acid crystals, also called urate crystals.
Uric acid crystals are sharp, needle-like compounds that travel to the joints or tissues. The accumulation of uric acid crystals in the joints is called gout. If the crystals build up in your kidneys instead, it can lead to kidney stones, or hard deposits of uric acid in the kidneys.
A report published in the American Journal of Kidney Diseases in August 2017 notes that gout and uric acid kidney stones often go hand in hand. More specifically: Having gout doubles your risk of kidney stones.
What Is Gout?
Gout is a painful, inflammatory type of arthritis that affects the joints, often the joint of the big toe. Although gout can affect any of the joints, the Centers for Disease Control and Prevention notes that usually only one joint is affected at any given time. Aside from the big toe, the most commonly affected joints are the ankle, knee, elbow, wrist and knuckle joints.
In addition to intense pain in the affected joint, other symptoms of gout include:
Gout is characterized by flares, or periods of time when symptoms are intense, followed by periods of time when there aren't any symptoms at all, which is classified as remission. When you're in a flare, the most common treatments involve anti-inflammatory and pain management medications that make symptoms more bearable. In periods of remission, you may be able to prevent future flares with a combination of lifestyle changes, like following a low-purine diet.
Low-Purine Diet Suggestions
If you have gout, diet is essential to your quality of life. According to the Arthritis Foundation, about two-thirds of the purines in your body are made naturally. The rest come from the foods you're eating. Although you can't control your natural purines, you can reduce your body's burden by avoiding foods that are high in purines.
The foods that are highest in purines are:
- Game meats
- Organ meats
- Meat broth
- Meat gravy
When following a low-purine diet, it's best to avoid these foods completely. But what about vegetables? There are some vegetables that are moderately high in purines, but when it comes to purine-rich foods, vegetables may not cause as much harm as other foods.
Read more: 13 Types of Fish to Avoid Eating
Mushrooms, green peas, spinach, asparagus, broccoli sprouts and cauliflower are the vegetables that contain the highest amounts of purines. The Beth Israel Lahey Health Winchester Hospital recommends limiting these vegetables to no more than 1/2 cup total per day. However, science is unclear on whether high-purine vegetables can cause the same negative effects that occur with other high-purine foods.
According to a report published in the Biological and Pharmaceutical Bulletin in May 2014, even high-purine vegetables have not been shown to increase the risk of gout. Researchers speculated two things — that this may be because the purine content is three to four times less than the purine content in meats or it may be because they contain specific purines called adenine and guanine, and guanine doesn't seem to increase the amount of uric acid in the blood.
Tips to Reduce Uric Acid
In addition to avoiding foods high in purines, there are other things you can do to reduce the risk of uric acid accumulating in your blood, joints and kidneys. Make sure you drink 8 to 12 cups of fluid each day. This dilutes the uric acid in your urine and can help prevent kidney stones. Water is best, although herbal teas without caffeine are good too.
Avoid beer and other alcoholic beverages. Alcohol isn't considered a high-purine beverage, but it can prompt your body to make more purines, so it's best to avoid it as much as possible.
It's also a good idea to limit your intake of dietary fat, avoid any drinks sweetened with high-fructose corn syrup and eat small meals. If you're trying to lose weight, aim for a gradual loss of 1 to 2 pounds per week, instead of crash dieting and losing weight really quickly. Rapid weight loss can increase uric acid levels.
Talk to Your Doctor
The American Academy of Family Physicians notes that people react to food in many different ways. While studies may show that high-purine vegetables don't cause an increase in uric acid or gout symptoms for most people, that may not be true for you. What works for one person doesn't always work for someone else.
The best thing to do is work closely with your doctor to figure out how different foods affect you specifically, and then figure out a comprehensive treatment plan together, making any necessary adjustments as you go.
- Arthritis Foundation: "What Role Does Diet Play in Gout Management?"
- Institute for Quality and Efficiency in Health Care: "Gout: Overview"
- American Journal of Kidney Diseases: "Serum Uric Acid and Risk of Kidney Stones"
- Biological and Pharmaceutical Bulletin: "Total Purine and Purine Base Content of Common Foodstuffs for Facilitating Nutritional Therapy for Gout and Hyperuricemia"
- Arthritis Foundation: "5 Good Foods for Gout"
- National Institute of Diabetes and Digestive and Kidney Diseases: "Definition and Facts for Kidney Stones"
- American Academy of Family Physicians: "Low-Purine Diet"
- Mayo Clinic: "Gout"
- Arthritis Foundation: "Safe Foods for Gout"
- Mayo Clinic: "Gout Diet: What's Allowed, What's Not"
- Academy of Nutrition and Dietetics Renal Dietitians: "A Low-Purine Diet: Relief from Gout and Kidney Stones"
- Beth Israel Lahey Health Wincester Hospital: "Low Purine Diet"
- Centers for Disease Control and Prevention: "Gout"