With similar names and both being waste products, it’s no wonder urea and uric acid often get interchanged. Nevertheless, urea and uric acid (sometimes called urate) are not the same thing. Each compound has its own unique purpose and deserves some recognition for its role in our waste management system. Keep reading to learn the difference between urea vs uric acid so you’ll never mistake them again.
What Is Urea?
Urea often takes the spotlight in discussions about bodily waste, and for a good reason. When we indulge in protein-rich meals, the body breaks these proteins down, resulting in the production of ammonia. Given its toxic nature, ammonia isn’t something our bodies want to hold on to. Therefore, the liver steps in to detoxify the body. It transforms ammonia into urea, which is a compound our system can tolerate.
From its birthplace in the liver, urea embarks on a journey through our bloodstream, pays a visit to the kidneys, and finally gets escorted out via the urine. This process ensures we effectively eliminate the surplus nitrogen that results from protein metabolism and causes ammonia production.
What Is Uric Acid?
Uric acid is a product of the breakdown of purines, which are substances found in our own body cells as well as in many foods. When cells die and get recycled, or when we munch down on purine-rich foods, our body gets to work processing these purines, and uric acid is born. While this compound can be a friend to our body, acting as an antioxidant, it has a notorious side. When accumulated in excess, uric acid can crystallize in our joints, resulting in the painful condition known as gout. The term ‘uric acid’ refers to solid form of this acid, while ‘urate’ is its name when it is in it soluble form in the blood.
Urea vs Uric Acid: Origins, Functions, And Toxicity
- Origins: As highlighted, urea originates from the breakdown of proteins, while uric acid is a byproduct of purine metabolism. Urea is produced in the liver whereas uric acid is mainly produced in the kidneys.
- Functions: Both serve as a mechanism to expel waste from the body. Urea gets rid of excess nitrogen to prevent ammonia toxicity caused by the breakdown of proteins, whereas uric acid acts as an antioxidant and protects our cells from damage.
- Toxicity: Urea is relatively non-toxic and is safely eliminated through urine. High levels of urea can be caused by kidney failure and may cause nausea and weakness, though in such cases there are other toxins at play as well (1). Similarly, at normal levels, uric acid can be beneficial, but excessive amounts can take residency inside the body and cause gout or kidney stones if not efficiently flushed out.
- Made as a result of purine metabolism
- Helps by acting as an antioxidant
- High levels may cause gout or kidney stones.
Factors Influencing Uric Acid Levels
While managing urea isn’t a matter of concern for many people, reducing uric acid levels is a serious matter for the millions of people suffering from gout worldwide. Uric acid levels are affected by many different factors. Here are some risk factors that influence uric acid levels:
- Lifestyle Choices: Factors like a purine-rich diet, dehydration, and alcohol consumption can raise uric acid levels. Additionally, certain medications can also impact its concentration.
- Physical Activity: Physical activity can help reduce uric acid levels by normalizing insulin levels, which in turn, may facilitates the removal of uric acid from the body (2). This means that simple activities like walking can help with high uric acid.
- Sleep Patterns: Research indicates that lack of sleep can increase uric acid levels (3), possibly because sleep disruption affects various metabolic functions.
- Aging: Uric acid levels tend to increase with age (4), with the risk of gout starting from as young as 30 (5). Interestingly, men are more likely to develop gout at a younger age while women are more likely to be affected by high uric acid after menopause (5).
- Genetics: High uric acid levels seem to be hereditary, meaning that if there is gout in your family history then you are at a higher risk for gout (6).
- Time of Day: Uric acid levels are not consistent throughout the day and are believed to have their own circadian variation (7). They have been observed to be at their highest in the early morning and lower at night, however the study had a small sample and further investigation is required (8).
Conclusion: Urea vs Uric Acid
While sharing similarities, urea and uric acid are unique in their origins, functions, and pathways of elimination. Recognizing their differences can offer better insights into our overall health. It’s unlikely that you will experience symptoms of high urea, but high levels of uric acid are fairly common and can cause symptoms such as kidney stones or gout. Keep an eye on your body’s signals, stay informed, and always consult a professional when in doubt.