Kidney Cancer And Alcohol: What You Need to Know

Introduction

Kidney cancer happens when abnormal cells in the kidney grow and form a lump (tumour). Most people have two kidneys, which are bean-shaped organs about the size of a fist, located towards the back of the tummy, just below the ribcage.¹

The most common type of kidney cancer in adults is renal cell carcinoma. In children, a rare form called Wilms’ tumour can occur.

Kidney cancer is becoming more commonly diagnosed, often because scans such as CT or ultrasound are used for other health reasons and pick up small tumours early. It is most often found in people over the age of 75. Men are about twice as likely to develop kidney cancer as women.²

General risk factors for kidney cancer

Several factors can increase the chance of developing kidney cancer. These include:

• Smoking – Smoking is one of the biggest risk factors. Current smokers have around a 30% higher risk, and former smokers about 15% higher risk, compared to people who have never smoked. In high-income countries, about 6% of kidney cancer deaths are linked to smoking
• Excess weight: Being overweight or obese increases the risk of kidney cancer. A body mass index (BMI) over 30 kg/m² is associated with a significantly higher risk. Globally, obesity is thought to contribute to around a quarter of kidney cancer cases
• High blood pressure (hypertension) – People with raised blood pressure are more likely to develop kidney cancer, even if they are on medication. The risk is even higher in people who are both overweight and have high blood pressure³
• Family history and genetics – If you have a close relative (such as a brother or sister) who has had kidney cancer, your risk is higher. This is partly due to shared genes and possibly shared lifestyle or environmental factors
• Occupational exposure – Some chemicals used in industries, such as trichloroethylene (TCE) and perchloroethylene, which are found in metal cleaning and degreasing, may increase the risk. Kidneys are particularly sensitive to these solvents⁴

 Alcohol as a potential risk factor

Research on alcohol and kidney cancer is not straightforward. Some studies suggest that light to moderate alcohol intake may lower the risk of renal cell carcinoma (the most common type of kidney cancer in adults). This may be because small amounts of alcohol can raise levels of “good” cholesterol (HDL-high density lipoprotein) and improve blood flow in small blood vessels. However, the protective effect is only linked with low levels of drinking – and drinking more does not increase the benefit.⁵

Alcohol consumption: overview

Alcohol is a psychoactive substance, meaning it affects how we think and feel. The main type people drink is ethanol. Other forms, such as methanol and isopropanol, are poisonous and used only in cleaning or manufacturing.

Globally, over 2 billion people consume alcohol, most commonly in drinks such as beer, wine, and spirits. Alcohol is made when sugars and starches are fermented – wine from grapes, beer from grains, and spirits by further distilling these products to produce stronger drinks.

Types of alcoholic drinks 

Based on the alcohol content 

Alcoholic drinks are usually divided into two main groups:

Fermented (undistilled) drinks – made by fermenting fruits or grains. These include wine (from grapes), beer(from barley, wheat, or other grains), and other drinks such as cider, mead, and sake.

Distilled drinks (spirits) – made by distilling fermented products, which removes water and makes the alcohol stronger. These include gin, whisky, brandy, rum, tequila, vodka, and others. Spirits have a much higher alcohol content and drinking too much can quickly lead to intoxication or even alcohol poisoning.⁶

Patterns of drinking

Health organisations use the idea of a standard drink to compare alcohol intake. In the UK, this is usually measured in units, but in the US it’s defined as a drink containing about 14 grams of pure alcohol.

Common drinking patterns include:

• Moderate drinking – up to one drink a day for women and two for men. This is sometimes linked with certain health benefits but still carries risks
• Binge drinking – having five or more drinks in a short time for men or four or more for women. This raises blood alcohol to dangerous levels (over 0.08%) and increases the risk of accidents, injuries, and alcohol poisoning
• Heavy drinking – regular binge drinking or consuming large amounts over time. This is strongly linked with long-term health problems, including cancer and kidney disease⁷

How the body breaks down alcohol

When you drink alcohol, your body needs to break it down (metabolise it) so it can be removed safely. This process mainly happens in the liver, but the effects vary from person to person.

1. Step one – alcohol to acetaldehyde
   • The enzyme alcohol dehydrogenase turns alcohol (ethanol) into acetaldehyde
   • Acetaldehyde is a toxic chemical and is linked to DNA damage and cancer risk
2. Step two – acetaldehyde to acetate
   • Another enzyme, acetaldehyde dehydrogenase, quickly changes acetaldehyde into acetate, which is much less harmful
3. Step three – safe removal
   • Acetate is then broken down into water and carbon dioxide, which leave the body through breath and urine⁸ 

How alcohol can lead to cancer

Scientists have found several ways alcohol increases the risk of cancer:

• DNA damage from acetaldehyde
  When alcohol is broken down, it produces acetaldehyde – a toxic chemical. Acetaldehyde can damage DNA and stop it from repairing properly. This can cause abnormal cell growth, which may develop into cancer
• Oxidative stress
  Breaking down alcohol also produces reactive oxygen species (ROS), which place stress on the body’s cells. These molecules can damage DNA, proteins, and fats, increasing the chance of cancer⁹
• Hormonal changes
  Alcohol can raise oestrogen levels in the body. High levels of oestrogen are linked with an increased risk of breast cancer
• Nutrient absorption problems
  Drinking alcohol makes it harder for the body to absorb important nutrients such as folate and vitamins A, C, D, and E. These nutrients normally help protect the body from cancer. When levels are low, the body is more vulnerable
• Helping other toxins enter the body
  Alcohol can act like a “carrier”, making it easier for harmful substances (for example, the chemicals in tobacco smoke) to get into cells and cause damage¹⁰

What studies say about alcohol and cancer

Research into alcohol and cancer risk is complex, and the findings are not always consistent.

Possible protective effects at low levels

Some studies suggest that light to moderate drinking (for example, a small glass of wine a day) may have protective effects for the heart and brain (cognitive impairment and ischemic heart disease) when compared with heavy drinkers. However, this does not mean alcohol is “safe” or “good” for health.¹⁶

Risks of drinking more

• Binge drinking (drinking a large amount in a short time) can lead to accidents such as falls, car crashes, burns, and drowning. It also increases the risk of unsafe sex, sexually transmitted infections, and unplanned pregnancies¹⁷
• According to public health data, excessive alcohol use causes thousands of deaths each year worldwide
• Even moderate drinking (just one or two drinks per day) has been linked to an increased risk of certain cancers. In 2020, it was estimated that around 100,000 cancer cases globally were linked to alcohol¹⁸

Other factors that make a difference

It can be difficult for scientists to separate the effects of alcohol from other lifestyle factors. For example:

• Smoking – the combined effect of smoking and drinking increases cancer risk significantly
• High blood pressure – linked with higher risk of kidney cancer
• Being overweight or obese – increases overall cancer risk
• Family history – if a close relative has had cancer, your personal risk is higher

Different types of drinks

Whether it is beer, wine, or spirits, all alcoholic drinks contain ethanol, the substance that increases cancer risk. The type of drink does not make alcohol safer.

Why research is tricky

Much of the data on alcohol use comes from people reporting their own drinking habits. This is often inaccurate because:

• People may under-report how much they drink
• They may not remember their drinking patterns accurately
• Drink sizes vary, so people may misjudge what counts as “a drink”
• Drinking habits differ across cultures and social groups, which makes it harder to compare studies

Alcohol and kidney health

Alcohol affects the kidneys in several ways, especially when consumed in large amounts over time.

• Moderate drinking (one drink a day for women, up to two for men) is unlikely to cause immediate harm for most healthy people
• Heavy drinking, however, puts a strain on the kidneys and can cause long-term damage

How alcohol harms the kidneys

• Dehydration and electrolyte imbalance – alcohol acts as a diuretic (makes you urinate more), which can lead to dehydration and upset the balance of essential salts in the body
• High blood pressure – heavy drinking is a major cause of raised blood pressure, which is one of the leading risk factors for kidney disease and kidney failure
• Reduced kidney function – over time, the kidneys lose their ability to filter waste products and maintain the right balance of fluids

Effects of heavy drinking

People who drink more than about 3 drinks per day (women) or 4 drinks per day (men) have a higher risk of kidney problems. In these cases, the kidneys are forced to work much harder than normal.¹¹

Heavy drinking can also cause electrolyte imbalances in, including:

• Sodium (hyponatremia) – too little sodium in the blood, sometimes seen in heavy beer drinkers
• Phosphate and potassium – long-term alcohol use can cause abnormal levels of these minerals, which are vital for muscle and nerve function
• Magnesium (hypomagnesemia) – low magnesium levels are common in chronic heavy drinkers and can cause muscle cramps or seizures
• Calcium – excess calcium loss in the urine can lead to muscle spasms and low blood sugar¹²

Link with the liver

Alcohol can also damage the liver, which in turn affects kidney function. Advanced liver disease often leads to kidney failure, making alcohol-related damage to both organs more severe.¹⁵

Alcohol and kidney disease

For people who already have chronic kidney disease(CKD), drinking alcohol can have mixed effects.

• Protein in the urine (proteinuria) and a lower filtering ability of the kidneys (GFR) are sometimes seen in people with CKD who drink alcohol
• Some research suggests that light drinking may have small benefits, such as raising “good” cholesterol (HDL) and reducing the risk of type 2 diabetes, which is itself a risk factor for kidney disease
• However, even moderate drinking can carry serious risks for people with CKD. It may increase the chance of problems such as stroke (cerebral hemorrhage), especially when combined with high blood pressure

Because of these risks, people with CKD should only drink alcohol, if at all, in very small amounts and ideally after discussing it with their GP or kidney specialist.¹³

Recommendations for cancer survivors

For people who have had kidney cancer (or any cancer), it is strongly recommended to limit or avoid alcohol. Drinking alcohol may:

• Increase the risk of the cancer coming back
• Make cancer treatments less effective
• Weaken the body’s ability to find and destroy abnormal cells

If you are trying to cut down or stop drinking alcohol, here are some useful strategies:

• Choose alcohol-free alternatives – such as mocktails, non-alcoholic beers or wines, and herbal teas
• Stay active – activities like walking, cycling, or yoga can help reduce cravings and improve wellbeing
• Practice mindfulness – relaxation techniques and meditation can improve focus, reduce stress, and help manage urges to drink
• Spend time with supportive friends and family – enjoying social activities that don’t involve alcohol can make it easier to stay on track¹³ 

Public health and prevention

Safe drinking guidelines

International health organisations, including the World Health Organization (WHO) and UK health authorities, advise that:

• There is no completely safe level of alcohol – drinking less is always better for your health
• If you choose to drink, men and women are advised not to regularly drink more than 14 units per week(spread across several days)
• People who are pregnant or planning a pregnancy should avoid alcohol completely
• Alcohol is not recommended for young people under 18, or for those taking medicines that affect the liver or kidneys
• If you do not currently drink alcohol, it is not advisable to start for health reasons

Public awareness and prevention

Raising awareness about kidney health and alcohol-related risks is vital. This includes:

• Education campaigns about risk factors, early detection, and treatment options for kidney cancer
• Encouraging people to manage lifestyle conditions such as high blood pressure, obesity, and diabetes, which increase kidney cancer risk
• Discouraging tobacco use and excessive alcohol consumption, both of which damage the kidneys
• Supporting age-appropriate screening and monitoring for those at higher risk, to detect kidney cancer early and reduce mortality¹⁴

FAQs

What is kidney cancer and who is most at risk?

Kidney cancer is a growth of abnormal cells in the kidneys. It is more common in adults, especially men, and risk is higher in people who smoke, have high blood pressure, are overweight, or have a family history of kidney cancer.

Can drinking alcohol cause kidney cancer?

The link between alcohol and kidney cancer is not fully clear. Small amounts of alcohol may have some health benefits, but heavy drinking or binge drinking increases the risk of kidney damage and may contribute to cancer development.

How does alcohol affect the kidneys?

Alcohol can harm the kidneys by causing dehydration, high blood pressure, and electrolyte imbalances. Long-term heavy drinking can make it harder for the kidneys to filter waste, which may lead to kidney disease.

Is it safe for people with kidney disease to drink alcohol?

People with kidney disease should limit or avoid alcohol. Even small amounts can worsen kidney function or interfere with treatment. Doctors usually advise non-alcoholic drinks as a safer alternative.

What steps can I take to reduce my risk of kidney cancer?

You can reduce your risk by avoiding smoking, keeping blood pressure under control, maintaining a healthy weight, limiting alcohol, staying physically active, and attending regular check-ups for early detection of kidney problems.

Summary

Kidney cancer is an abnormal growth of cells in the kidney, most commonly seen in adults, and is more frequent in men than women. Several factors increase the risk, including smoking, high blood pressure, obesity, family history, and certain occupational exposures.

The relationship between alcohol consumption and kidney cancer is complex:

• Light to moderate alcohol intake may have some protective effects on heart health and circulation, but evidence for kidney cancer prevention is not conclusive
• Heavy or binge drinking increases the risk of kidney disease, affects kidney function, raises blood pressure, and may contribute to cancer development
• Alcohol can also affect the kidneys indirectly through electrolyte imbalances, dehydration, and liver damage, which in turn stresses kidney function

Key points for patients:

• Limiting alcohol is generally recommended, especially for individuals with kidney disease or cancer survivors
• Non-alcoholic alternatives and healthy lifestyle practices such as regular exercise, balanced diet, and mindfulness can support overall kidney health
• Public health guidelines suggest no more than 14 units per week for adults who choose to drink, spread over several days, and complete abstinence for pregnant individuals or those on medications affecting the liver or kidneys
• Awareness, early detection, and managing other risk factors like hypertension, obesity, and diabetes are crucial for reducing kidney cancer risk

Overall, while some studies suggest mild benefits of moderate alcohol, the potential risks outweigh the benefits, especially at higher levels of consumption. Long-term, high-quality research is needed to fully understand alcohol’s impact on kidney cancer.