No single food can protect against or treat bladder cancer. However, studies indicate a nutritious, balanced diet helps reduce the risk of many cancers.

There is no guaranteed way to prevent bladder cancer, and a person cannot manage all risk factors that increase their risk of developing bladder cancer, such as age or family history. However, there are some things a person can do to lower their risk, such as following a nutritious, balanced diet.

Adequate nutrition is also vital for individuals during and after cancer treatment. It helps provide essential nutrients the body needs, helps maintain strength, and reduces the side effects of cancer treatment.

Read on to learn more about what foods people with bladder cancer may wish to consume and avoid.

A note about sex and gender

Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Doctors do not recommend one specific diet to treat or help prevent bladder cancer. However, evidence suggests certain dietary patterns may help lower the risk of bladder cancer and other cancers.

The American Cancer Society (ACS) states that some research indicates that a diet rich in fruits and vegetables may reduce the risk of bladder cancer.

While not all studies agree with this finding, following certain beneficial eating habits has many health benefits, including reducing the risk of other types of cancer.

For example, a 2022 review of studies found the Mediterranean diet to have a protective effect against bladder cancer. Researchers stated that following this diet may reduce a person’s risk of developing bladder cancer, but more studies are needed to confirm this.

Some people with cancer may consider special diets, such as vegan, macrobiotic, and ketogenic diets, to try alongside their treatment. However, there is little evidence suggesting these diets will improve their outcomes.

When an individual has bladder cancer, their nutritional needs depend on their circumstances and the symptoms and treatment side effects they are experiencing. A registered dietitian can help counsel them on ways to get adequate nutrition.

Several studies have aimed to identify specific nutrients that may play a role in causing or fighting bladder cancer. However, the results have been inconclusive.

The ACS recommends following a “healthy eating pattern” at all ages. A healthy eating pattern may include the following foods:

Fruits

Fruits supply the body with important vitamins, minerals, and antioxidants during cancer treatment. However, people should carefully consider their specific circumstances when making fruit choices.

For example, fruits high in fiber, such as apples and berries, can promote bowel regularity if someone is experiencing constipation. And low fiber fruits, such as bananas, could be helpful for those experiencing diarrhea.

A 2022 study suggests the following fruits may help reduce the risk of developing bladder cancer:

However, researchers need to conduct further studies to confirm their findings. People should generally aim for around 1.5 to 2 cups of fruit each day.

Vegetables

As well as containing a variety of vitamins and minerals, some vegetables are rich in antioxidants.

Cruciferous vegetables, such as broccoli, Brussels sprouts, and kale, contain phytochemicals that may slow the growth of several cancers, according to 2012 research.

A 2021 study found an association between higher intakes of total and non-starchy vegetables and a reduced risk of bladder cancer among females.

Common non-starchy vegetables include:

Whole grains

Whole grains have more nutrients and fiber than refined grains because they include all parts of the kernel that manufacturers discard during the processing of refined grains.

A 2020 study concluded that higher intakes of whole grains and dietary fiber, individually and in combination, may reduce the risk of bladder cancer.

Examples of whole grains include:

At least half of the grains people consume should be whole grains.

Protein sources

Protein is an essential dietary element to help the body grow and repair and keep the muscles and bones functional. Consuming enough protein is crucial during cancer treatment for healing, energy levels, and fighting infection. Additionally, consuming enough protein during cancer treatment is crucial when experiencing appetite loss and nausea.

Sources high in protein include:

People should eat around 0.8 grams (g) of protein per kilogram (kg) of body weight daily. For example, a person weighing 80 kg (175 pounds) would need about 64 g of protein per day.

The ACS recommends selecting protein foods such as fish, poultry, and beans more frequently than red meat.

Beneficial fats

The body needs fat to function. It uses fat, protein, and carbohydrates for energy as calories and stores extra calories to maintain skin and hair and insulate the body.

There are two main types of healthy fats: monounsaturated and polyunsaturated fats.

Plant foods such as nuts, avocados, and olive and canola oils contain monosaturated fats. Polyunsaturated fats are in animal and plant foods such as nuts, seeds, salmon, and vegetable oils.

One large 2022 study suggested that a higher intake of monounsaturated fats and plant-based oils may lower the risk of bladder cancer in females.

Water

The ACS states that some evidence shows drinking plenty of fluids could lower a person’s risk of bladder cancer.

Individuals who drink enough daily fluids, particularly water, typically have lower rates of bladder cancer. This may result from them emptying their bladders more often, helping prevent chemicals from remaining in the bladder for prolonged periods.

The ACS advises that a healthy eating pattern limits or avoids the following:

Research from 2018 found an association between Western dietary patterns and a higher risk of bladder cancer recurrence. A Western diet is high in fat, animal meat, processed products, and foods with added sugars.

According to research, there is little benefit from taking dietary supplements while having cancer treatment. Many individuals who eat a balanced, varied diet will likely get enough vitamins and minerals from that.

Although there is evidence that a diet high in fruits, vegetables, and other plant-based foods may reduce cancer risk, there is inconsistent evidence about dietary supplements decreasing cancer risk.

Some dietary supplements may interact with cancer therapies, such as chemotherapy and radiation therapy, and reduce their effectiveness. People with bladder cancer should only take dietary supplements on the advice of a doctor or dietitian.

No specific food group or nutrient can treat bladder cancer or help prevent it.

There is some evidence that dietary patterns high in fruits and vegetables, such as the Mediterranean diet, may help reduce the risk of bladder cancer. However, more research is necessary to confirm these findings.

Doctors recommend individuals with bladder cancer eat a nutritious, balanced diet to help maintain their strength and reduce the side effects of cancer treatment.