Diet has long been associated with overall health, but can everyday food choices also influence the risk of developing cancer? According to Dr. Naveen Kumar Kushwaha, consultant – surgical oncology at Rajiv Gandhi Cancer Institute & Research Centre, while no single food or diet can completely prevent cancer, maintaining healthy dietary habits can significantly contribute to lowering the risk.
Dr. Kushwaha explains that cancer develops due to a combination of factors including age, genetics, environmental exposures, infections, tobacco use, alcohol consumption, obesity, physical inactivity and diet. “Food alone cannot prevent cancer, but it plays an important role in influencing biological processes such as inflammation, insulin regulation, gut health and body weight, all of which are linked to cancer risk,” he says.
One of the most effective dietary strategies, according to Dr. Kushwaha, is increasing the intake of plant-based, fibre-rich foods. Vegetables, seasonal fruits, whole grains, pulses, beans, sprouts, nuts and seeds provide essential vitamins, minerals, antioxidants and dietary fibre that support healthy cell function and digestive health. A fibre-rich diet also promotes a healthy gut microbiome, the diverse community of microorganisms in the digestive tract that is increasingly being recognised for its role in maintaining overall health.
He recommends that adults aim for 25–30 grams of dietary fibre daily and follow a simple plate model: half the plate filled with vegetables and salads, one-quarter with whole grains such as wheat, brown rice or millets, and the remaining quarter with protein sources including dal, curd, paneer, eggs, fish, poultry, soy or legumes.
In contrast, diets high in processed foods, excess red meat, sugary beverages and refined carbohydrates can contribute to weight gain, chronic inflammation and metabolic disturbances. According to Dr. Kushwaha, excess body weight has been associated with an increased risk of several cancers, including post-menopausal breast cancer, colorectal, endometrial, kidney and oesophageal cancers.
Processed meat deserves particular attention. Dr. Kushwaha notes that products such as sausages, bacon, ham, salami and other preserved meats have been linked to a higher risk of colorectal cancer due to preservatives and harmful compounds formed during processing and high-temperature cooking. He adds that red meat should also be consumed in moderation, with healthier protein alternatives such as fish, eggs, poultry, legumes and curd forming a larger share of the diet.
Citing the International Agency for Research on Cancer (IARC), Dr. Kushwaha points out that processed meat has been classified as carcinogenic to humans (Group 1), while red meat has been categorised as probably carcinogenic (Group 2A), primarily in relation to colorectal cancer.
Addressing a common misconception, Dr. Kushwaha clarifies that sugar does not directly “feed” cancer cells. “All cells in the body require glucose for energy,” he explains. However, excessive consumption of sugary drinks, sweets, refined flour products and ultra-processed foods can lead to obesity and insulin resistance, which may indirectly increase cancer risk. He advises replacing packaged snacks and sugary foods with healthier alternatives such as fruits, roasted chana, sprouts, makhana, curd and nuts in moderation.
Alcohol, meanwhile, remains one of the most well-established dietary risk factors for cancer. Dr. Kushwaha says alcohol consumption has been linked to cancers of the mouth, throat, oesophagus, liver, breast and colorectum. “From a cancer prevention perspective, avoiding alcohol altogether is the safest option. No amount of alcohol can be considered completely safe,” he emphasises.
The way food is prepared is equally important. According to Dr. Kushwaha, repeatedly consuming foods that are charred, heavily browned, grilled at very high temperatures or deep-fried can expose the body to potentially harmful compounds. He recommends healthier cooking methods such as steaming, boiling, pressure cooking, baking and sautéing with minimal oil to preserve nutritional value while reducing unnecessary health risks.
Dr. Kushwaha also cautions against relying on supplements marketed as “anti-cancer” products. While certain supplements may be medically indicated in cases of nutritional deficiency or specific health conditions, they should never replace a balanced diet. Similarly, foods such as turmeric, garlic, broccoli, green tea or berries may contribute to a healthy dietary pattern, but none can independently prevent or cure cancer.
Beyond diet, Dr. Kushwaha stresses that cancer prevention requires a comprehensive lifestyle approach. Avoiding tobacco in all forms, maintaining a healthy body weight, engaging in regular physical activity, getting adequate sleep, limiting alcohol intake, protecting the skin from excessive sun exposure, receiving recommended vaccinations and participating in age-appropriate cancer screening programmes all contribute to lowering cancer risk. He notes that an estimated 30–40% of cancers worldwide are considered potentially preventable through healthy lifestyle measures.
Importantly, he reminds people that diet cannot replace regular medical screening. “Some cancers develop silently. Mammograms, Pap smears, colorectal cancer screening, oral examinations and other recommended screening tests remain essential, particularly for individuals with increased risk due to age or family history,” he says.
Summing up, Dr. Kushwaha believes that cancer prevention is less about following restrictive diets and more about making sustainable, evidence-based lifestyle choices. Consistently eating more vegetables, fruits, whole grains and pulses while reducing processed foods, alcohol and unhealthy cooking practices can improve overall health and help lower the burden of preventable cancers. At the same time, he urges people to avoid misinformation and seek timely medical evaluation if they experience warning signs such as unexplained weight loss, persistent pain, abnormal bleeding, lumps or prolonged digestive symptoms.
While healthy eating is a powerful tool for long-term wellness, Dr. Kushwaha concludes, early diagnosis and appropriate medical care remain equally critical in the fight against cancer.
