CBD and kidney disease are not a match made in heaven, but the promise of CBD trials offers glimmers of hope for people living with impaired kidneys.
For the few who haven’t heard of it, CBD is short for cannabidiol. It’s a compound found in cannabis plants like hemp and marijuana. Yes, that marijuana, the plant lumped in with heroin as a Schedule I Narcotic by federal law, but which many US states have legalized for its medicinal and recreational uses.
Unlike its marijuana-based psychoactive cousin THC, CBD from industrial hemp is non-psychoactive and legal on the federal level. You can find it at dispensaries, drug stores, grocery stores, cosmetics stores, specialty stores, and for sale online in tincture, oil, topical, oral, edible, or beverage form.
Early trials of CBD have revealed numerous promising properties, including but not limited to:
- Blood pressure stabilization.
- Pain management.
- Antidepressant and anxiolytic properties.
- Anti-inflammatory properties.
The news about chronic kidney disease is not nearly as happy. The condition is not reversible and is curable only by a transplant procedure with a multi-year waiting list.
The prognosis is usually for only a few years’ survival after diagnosis. Worse still, the treatments available to prolong a patient’s life can sometimes seem as bad as the disease.
In short, patients with kidney disease deserve some good news. CBD and kidney disease is not ready for prime time, but early research points to promising directions in some current studies and are suggestive of where future studies might go. As a result, people who suffer from kidney disease are understandably curious about the impact this buzz-powered compound could have on their condition.
Kidney Disease: An Overview
The kidneys are two bean-shaped organs situated near the lower back on either side of the torso.
The job of the kidneys is to clean the blood and extract excess fluids. These fluids are then expelled from the body intermittently as urine. If the kidneys become impaired in their function, serious complications can follow.
People can live normal lives with just one functional kidney. However, the failure of both kidneys is a deadly condition; injury to one or both kidneys is often fatal.
“Kidney disease” is a broad descriptor for a variety of conditions that affect the kidneys and their function. Other terms for kidney disease include “renal disease” and “nephropathy” (referring to pathology of the “nephrons,” the functional unit of kidney activity).
Different types of kidney disease include:
Chronic Kidney Disease
The most common form of kidney disease is chronic kidney disease, affecting 37 million Americans or 15% of the adult population. 90% of affected individuals don’t even know they have it.
Like most chronic conditions, chronic kidney disease does not improve with time. Instead, the condition usually worsens until the kidneys can no longer function properly.
The most common cause of chronic kidney disease is high blood pressure. When the blood pressure increases, it puts strain on the delicate blood vessels where the blood gets cleaned (known as glomeruli).
Type 1 or type 2 diabetes can also contribute to the onset of chronic kidney disease. So can a diet high in animal protein, animal fats, sweets, and cholesterol, which increase the risk of kidney-damaging microalbuminuria.
Other risk factors include:
- Chemotherapy toxicity.
- Long-term use of lithium.
- Xanthine oxidase deficiency.
As the disease progresses, the kidneys may no longer filter fluids effectively, causing fluids to build up in the body. As a result, a patient may notice symptoms such as:
- Nausea and vomiting.
- Weakness and fatigue.
- Trouble sleeping.
- Reduced appetite.
- Changes in urine volume.
- Swollen ankles or feet.
- Twitching or cramped muscles.
- Itchy skin.
- Mental fogginess.
- Chest pain.
- Hypertension (high blood pressure).
- Difficulty breathing.
These symptoms can easily be mistaken for symptoms of other conditions, a major reason that chronic kidney disease can go undiagnosed until it has become advanced.
In the advanced stage, the kidneys may fail altogether and the buildup of excess fluids and lack of filtration can become life-threatening.
A patient who progresses to this stage of the disease may require dialysis, a procedure to clean the blood and remove excess fluids by artificial or secondary means.
Dialysis comes in two forms:
In hemodialysis, a machine draws the blood out of the body, passes it through a filter to clean it and remove excess fluids, then returns the cleansed blood to the body.
This procedure usually takes about eight hours and must be performed several days a week. It can be performed at a dialysis center or at home with the use of specialized equipment and disposable bags of dialysis fluid.
The blood can enter and exit the body either through needles inserted for the session or through permanent ports in the skin.
Hemodialysis performs some of the functions of the kidneys, but not all of them. Changes in diet and lifestyle, along with medications, may be needed as supplementary treatments.
While people can live productive lives while on hemodialysis, the procedure is disruptive, unpleasant, and deleterious to quality of life. Nevertheless, it remains the most common treatment for kidney failure.
This form of dialysis does not remove the blood from the body to clean it. Instead, a catheter port is installed in the abdomen and cleaning fluid is infused into the abdomen. The cleaning fluid accesses the blood through the peritoneum (inner lining of the belly), drawing out excess fluids and impurities.
The fluid must be infused and purged several times, in 30-40 minute cycles over the course of about eight hours, to effectively cleanse the blood. This can be done by a machine while the patient sleeps, or the patient can perform the fluid exchanges manually.
While some patients or doctors favor it, peritoneal dialysis is also disruptive, unpleasant, and deleterious to quality of life.
Alternatives to Dialysis
A failed kidney can be replaced with a functional kidney through kidney transplant surgery. The donor kidney can come from a live person or a deceased person.
The list for cadaver kidneys can be long. Many patients’ best chance of a timely transplant is to find a friend or family member who is willing to donate one of two healthy kidneys from their own body.
Some of the materials the kidneys cleans from the blood are particles of solid minerals. These minerals can crystallize and form solid masses or “stones” in the kidneys.
Most patients are able to pass these stones out of the body through urination, but the process of passing a kidney stone can be very painful.
Still, most cases of kidney stones are fairly benign. In rare circumstances, serious complications can arise and require surgery.
Certain drugs, infections, and congenital conditions can cause the glomeruli (tiny blood vessels where the cleansing takes place) to become inflamed. This condition is called glomerulonephritis.
Symptoms can include retention of fluid, foamy urine, or discolored urine (brown or pink). High blood pressure often accompanies glomerulonephritis.
Glomerulonephritis usually resolves itself with time.
Glomeruli are contained in a larger structure called the “nephron,” the functional unit of the kidney. A capsule of blood vessels is connected to the kidney structure by a tube called a renal tubule.
Interstitial nephritis is an inflammation of the renal tubule, often caused by drug allergies. Some autoimmune disorders, as well as potassium deficiency, excess of calcium, or certain infections, can cause the condition as well.
Symptoms of interstitial nephritis can include fluid retention, rash, swelling, weight gain, bloating, high blood pressure, nausea and vomiting, fatigue, fever, and bloody urine.
Any medication causing interstitial nephritis should be discontinued. The condition can be treated by anti-inflammatories. Residual effects may require a change in diet to reverse, including a reduction in protein or salt intake.
A bacterial infection may cause the entire kidney to become inflamed. This can cause permanent damage to the kidney and even threaten the life of the patient.
Symptoms of pyelonephritis (kidney inflammation) can include fever above 102°F (38.9°C), burning or painful urination, cloudy urine, bloody urine, pus in the urine, urine that smells of fish, torso or groin pain, or urinary incontinence.
Other symptoms could include chills, tremors, nausea and vomiting, sweat, delirium, and general illness.
Pyelonephritis can usually be treated with antibiotics. Patients may need to be hospitalized for severe inflammation and in extreme cases may require surgery.
Vesicoureteral reflux is a condition whereby urine flows in the wrong direction—back up the urethra into the bladder, sometimes back flowing into the kidneys.
This can damage the kidneys or cause urinary tract infections (see above).
Symptoms of vesicoureteral reflux include:
- Urinary tract infection.
- Strong sensation of needing to urinate.
- Urinary incontinence.
- Bloody urine.
- Cloudy urine.
- Bad urine odor.
- Reduced urine volume.
- Abdominal pain.
- Swollen abdomen (sign of a swollen bladder).
- Loss of appetite.
- Weight loss.
- Constipation or bowel incontinence.
- High blood pressure.
Severe cases of vesicoureteral reflux may require surgery or the injection of “deflux” gel into the bladder, which blocks the backflow of urine and directs it to its proper course out of the body. Antibiotics may be needed to treat the opportunistic urinary tract infections that follow the reflux.
Polycystic Kidney Disease
The kidneys frequently form cysts, or sacs of fluid, on their surface. These benign growths have no adverse effects and usually subside without yielding symptoms.
A genetic condition, however, may cause the kidney to grow frequent cysts all over the surface of the kidney. This is called polycystic kidney disease and can lead to kidney failure if the cysts impede the function of the kidneys.
If both kidneys fail due to polycystic kidney disease, the patient may require dialysis or a transplant.
Urinary Tract Infections
The urinary tract may become infected by a variety of harmful bacteria species. Infections of the bladder and the urethra rarely spread to the kidneys and can be treated easily with antibiotics and no long-term adverse effects.
If the infection spreads to the kidneys, however, it may lead to more serious effects, including kidney failure if left untreated.
Is CBD Safe for People with Kidney Disease?
While more tests are needed, CBD has proven itself to be a fairly benign substance. No evidence has indicated CBD as dangerous to patients with kidney disease or harmful to the kidneys.
CBD is excreted through the fecal route, with minimal kidney interaction.
However, CBD and kidney disease medications may interact in adverse ways and harm the liver. Before beginning a regimen of CBD to alleviate symptoms of kidney disease, consult with your doctor about any possible adverse interactions with your prescribed kidney disease medications.
CBD shows no signs of being dangerous to people of different ages, races, or other demographics. But the lack of specific evidence may inspire pregnant mothers to be cautious with CBD, as they should be with other substances. Lab experiments demonstrate that CBD changes the placental barrier, and studies show it is present in breast milk.
The most common side effects of CBD use are fatigue, diarrhea, and fluctuations in weight and appetite.
Kidney Disease Symptoms: Where Could CBD Fit In?
CBD is not a cure for kidney disease; most forms of kidney disease have no cure. Treatment, especially for chronic kidney disease, focuses on managing symptoms. The beneficial effects of CBD and kidney disease symptoms overlap in several ways.
To understand the potential utility of CBD with kidney disease, it helps to understand how CBD interacts with the body.
CBD is one of many cannabinoids, or compounds abundant in cannabis plants. Psychoactive THC is another cannabinoid, abundant in marijuana but not in hemp.
Many people (especially those who associate cannabinoids with illegal drugs) don’t realize that the human body produces cannabinoids as well, similar or even identical to those produced by cannabis plants.
The body even has a system of cell receptors called the endocannabinoid system, and they reside on cell membranes. The receptors themselves are called CB1 and CB2. Cannabinoids can attach to those receptors on the cell membranes and have a profound impact on the function of the cells.
The endocannabinoid system is not well understood, but it seems to play a role in body homeostasis, which refers to the body’s internal balance.
THC, the psychoactive cannabinoid found in marijuana plants, can actually bind itself to the endocannabinoid receptors when people smoke or ingest marijuana or THC extract.
CBD actually does not bind to human endocannabinoid receptors. However, the presence of CBD in the system seems to stimulate production of natural endocannabinoids, which do bind to CB1 and CB2 receptors and aid in body homeostasis.
Here are some ways in which CBD might help alleviate the symptoms of kidney disease.
Reduction of Inflammation
Many studies of both humans and animals have demonstrated the ability of CBD to reduce inflammation.
These studies include treatment of human multiple sclerosis patients, humans with joint inflammation due to arthritis, rats with surgical incision pain, and rats with sciatic nerve inflammation.
Though the mechanism behind these anti-inflammatory properties is not completely clear, it is expected to be stimulation of the endocannabinoid system.
Several forms of kidney disease are inflammatory in nature. These include glomerulonephritis, interstitial nephritis, and pyelonephritis. Future CBD studies may reveal that these anti-inflammatory properties translate to reduction of kidney inflammation.
The same mechanism that reduces inflammation has boosted the profile of CBD as an analgesic. CBD has shown promise in its ability to alleviate inflammatory pain from causes like arthritis, sciatic nerve inflammation, and surgical incisions.
Other studies of cannabinoids have shown a widespread propensity of these compounds to relieve pain. A study of patients taking a synthetic cannabinoid designed to mimic THC showed patients to be between 43% and 300% more likely to report a 30% or better reduction of chronic neuropathic pain.
Kidney disease may be painful. The source of this pain could include kidney inflammation, kidney stones, kidney or urinary tract infection, and incisional pain from kidney surgery, intravenous needle insertion, or dialysis port installation.
Nausea is a common symptom of kidney disease. CBD has been shown in studies to interact with serotonin receptors, stimulating hormones that alleviate nausea. Kidney disease patients prone to vomiting may benefit from CBD as an anti-nausea agent.
Symptoms of kidney disease, including pain, urinary incontinence, nausea, anxiety, side effects of medications, or the mechanics of home dialysis can result in an inability to sleep. Insomnia is a common secondary effect of kidney disease.
In a 2019 test of 72 subjects, 66.7% who received CBD reported improved sleep cycles.
The properties of CBD that treat these conditions could help improve the sleep cycle of CBD patients. The endocannabinoid system may also help regulate the body’s circadian rhythm, the cycle of sleepiness and wakefulness.
While it isn’t a treatment for kidney disease per se, getting a better night’s sleep may help improve the quality of life of kidney disease patients, who sorely need it.
Fluctuations in appetite are another common symptom of kidney failure. This can lead either to unhealthy weight gain or dangerous weight loss.
CBD has shown the ability in animal tests to help regulate appetite, leading to loss of excess body weight in rats.
These animal tests do not necessarily translate to human results, but some patients try CBD as a treatment for anorexia nervosa. Kidney disease patients suffering from loss of appetite might benefit from CBD as a stimulant for the appetite.
Other effects CBD may have on appetite and weight management include the replacement of white fat cells with brown fat cells, a property demonstrated in test tube studies. White fat is more associated with diseases related to excess body weight.
Kidney disease correlates strongly with heart failure and cardiovascular conditions like diabetes or high blood pressure. Most of the fatalities from chronic kidney disease are actually due to heart failure. Kidney impairment can result in fluid buildup around the heart or other cardiovascular complications.
Additionally, the leading cause of chronic kidney disease is high blood pressure. People with early-stage chronic kidney disease or risk factors to develop it in the future could prevent the condition by managing blood pressure.
A recent placebo-controlled study of nine adult men showed a reduction in resting blood pressure for the study participants who received CBD. The benefit decreased under the conditions of a stress test.
CBD has also shown promise in mood management (see below). Mood plays a key role in the regulation of blood pressure.
CBD also has antioxidant properties, which have been shown in animal tests to reduce cardiovascular cell death and inflammation.
A study of diabetic mice showed that doses of CBD correlated with a 56% reduction in inflammation due to diabetes.
Both type 1 and type 2 diabetes are risk factors in the development of chronic kidney disease—one of the reasons why diabetes is such a serious condition.
Diabetes is an inflammatory condition that affects the body’s ability to regulate blood sugar. Management of lifestyle factors, including diet, play a big role in the prevention and management of the condition.
The ability of CBD to reduce inflammation and manage the appetite may contribute to the prevention of type 2 diabetes, and possibly to the management of the symptoms of type 1 and type 2 diabetes.
Several animal studies have demonstrated the promise of CBD to reduce symptoms of depression and anxiety. This is possibly due to the ability of the endocannabinoid system to regulate internal homeostasis, including those impacting mood.
Mood plays a key role in the regulation of blood pressure. High blood pressure is a major risk factor for the development of chronic kidney disease.
More importantly for people who already have kidney failure, treatments like dialysis have a major impact on the patient’s quality of life. This can lead to depression. Long waits on kidney donor lists can lead to anxiety.
CBD and kidney disease could be a match if for no other reason than CBD’s potential ability to improve how patients cope with a tough diagnosis and treatment regimen.
Regulation of Kidney Function
As mentioned, the endocannabinoid system helps the body maintain internal balance. Proper kidney function plays a big role in that internal balance. If CBD stimulates the production of natural cannabinoids that bind to CB1 and CB2 receptors, it could improve kidney function, preventing chronic kidney disease or alleviating the symptoms of other kidney conditions.
Why More Research is Needed Around CBD and Kidney Disease
As you probably know, cannabis products have been heavily stigmatized and, until recently, widely criminalized in the US and many parts of the world. Cannabis is still illegal in a number of countries, and marijuana and THC are illegal in the US at the federal level.
While restrictions on cannabinoids like CBD have been relaxed, their widespread acceptance lags far behind other compounds, many of which have enjoyed years or even decades of scientific testing.
Cannabis has hundreds of years of folkloric medicine and anecdotal evidence that may attest to its effectiveness in certain health conditions, but the number of modern, scientific trials available for peer review are few and far between, partially due to the stigma and the illegality.
What studies do exist suffer from many limitations, including:
- Studies of animals and not humans.
- Limited sample sizes.
- Lack of placebo control.
- Focused on alternate cannabinoids like THC or synthetic THC cannabinoids.
- Contradictory studies.
To earn widespread acceptance as an effective treatment, the interaction of CBD and kidney disease needs much more clinical study. These studies must be double-blind controlled, study a large sample size of human patients, focus on CBD, and demonstrate consistent results to be scientifically relevant.
Additionally, studies must address the health risks of various forms of CBD ingestion. Smoking of CBD-rich marijuana or vaporized CBD oil may impair lung function at the same time as it alleviates renal symptoms. Sugary CBD edibles or beverages may worsen diabetes, high blood pressure, or heart disease.
The interaction of CBD with other medications, including kidney disease medications, also needs further study. Doctors are also working to better understand the side effects of CBD, its effect on the endocannabinoid system, and the way it might differently affect people in different demographics, including factors of age and other medical conditions.
Anecdotal and folkloric reputation doesn’t cut it when it comes to FDA approval and other markers of legitimacy.
Patients with kidney disease must be realistic. CBD has no proven direct effect on the underlying causes of kidney disease. The potential benefits of CBD currently focus on the management of symptoms and secondary conditions.
While more testing is needed—probably years’ worth of testing—there may nevertheless not be sufficient reason to wait. The widespread decriminalization of CBD attests to a profile thus far of safety and potential.
Most experts agree that there is little risk to patients with kidney disease trying CBD as a supplemental treatment. It is not a replacement for dialysis and prescribed medication. However, for patients in search of relief for symptoms, CBD may check many of the relevant boxes based on early trials.
Some experts also see the potential use of CBD for kidney disease as part of a much-needed movement toward acceptance of cannabinoids and their medicinal properties, opening the door for more conclusive studies.
The jury is still out on CBD and kidney disease. However, with few attractive treatment options and uncertain prognosis, CBD may be worth a try for the alleviation or reduction of some symptoms.