Men, cancer, and nutrition

Sindi-marie de Beer shares tips on how to fuel the fight when it comes to men, cancer, and nutrition.

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When it comes to cancer, men face some distinct risks and nutrition can play a powerful role in both prevention and recovery. In South Africa, prostate cancer is the most common cancer in men, with 1 in 15 men affected. Colorectal cancer is also a major concern, affecting 1 in 77 men, according to data from CANSA. 

But the good news is what’s on a man’s plate can shape his path.

Understanding the landscape: top five cancers affecting men

• Prostate cancer
• Colorectal cancer
• Lung cancer
• Melanoma
• Non-Hodgkin’s lymphoma

Each of these cancers comes with its own set of challenges but many share a common thread: the risk of malnutrition, particularly in advanced stages or during treatment. Whether caused by the cancer itself or by treatment side effects, poor nutritional status can seriously affect quality of life and recovery outcomes.

Why nutrition matters

Nutritional status before, during, and after treatment is critical yet often overlooked. Factor in cancer care. Many people assume malnutrition only occurs in underweight individuals, but that’s far from the truth. Even those who are overweight or obese can suffer from sarcopenia (loss of muscle mass) which is associated with poorer outcomes and reduced tolerance to treatments like chemotherapy.

Prostate cancer treatments, especially androgen deprivation therapy (ADT), are known to increase fat mass and reduce muscle mass. Some testosterone-related therapies may also lead to weight gain, pushing men toward obesity, which is linked to a higher risk of cancer recurrence and mortality.

Maintaining a healthy nutritional status is not just about weight; it’s about preserving lean muscle, supporting immune function, and ensuring the body is equipped to handle the demands of treatment.

Lifestyle habits that matter

It’s not just what you eat, how you live matters too. Certain lifestyle habits can significantly increase your risk for cancer:

• Smoking (of any kind, not just cigarettes)
• Alcohol consumption — yes, even in small amounts
• Physical inactivity

Smoking alone is linked to more than 14 types of cancer, not just lung cancer. If you’re serious about reducing your risk, quitting smoking and drinking and staying active are non-negotiables.

Building a protective diet

Fibre-rich foods

According to the EPIC study, diets high in fruits, vegetables, and fibre are strongly linked to a reduced risk of cancers, especially colorectal and prostate cancers. 

Fibre from whole grains, legumes, vegetables, fruit, and nuts supports digestive health and may help regulate hormones involved in cancer development.

Fat quality over quantity

Not all fats are created equal. Healthy fats, like monounsaturated fats (MUFA) and polyunsaturated fats (PUFA), found in foods like olive oil, nuts, seeds, avocados, and oily fish are associated with a lower risk of high-grade prostate cancer.

On the flip side, trans fats, found in ultra-processed and fast foods, are linked to increased prostate cancer risk and contribute to heart disease, diabetes, and other non-communicable diseases.

While high-fat dairy products (full-cream milk, cheese, and yoghurt) have been linked to a higher and more aggressive form of prostate cancer, red meat showed no significant association with prostate cancer in some studies. Though it remains a known risk factor for colorectal cancer and should be eaten in moderation.

Meat, dairy, and plant-based diets

While vegetarian diets haven’t shown strong preventive effects for prostate cancer, some studies suggest they may improve short-term treatment outcomes. Interestingly, no strong association was found between prostate cancer risk and consumption of alcohol, caffeine, or sweetened beverages.

Key protective nutrients

Certain vitamins and nutrients may play a protective role in men’s cancer risk:

• Vitamin K2 (menaquinone), found in nattō, sauerkraut, hard cheeses, leafy greens, organ meats, and kefir, has been linked to reduced prostate cancer risk.
• Vitamin B6 and methionine, found in pork, poultry, fish, eggs, nuts, and dark leafy vegetables, are associated with a lower risk of lung cancer.
• Diets rich in vitamins C, E, beta-carotene, riboflavin, thiamine, folate, iron, calcium, magnesium, and potassium are also associated with lower risks of several cancers, including breast cancer which, though rare, does occur in men.

DID YOU KNOW?

Vitamin C and E may help protect against distal colon cancer, and vitamin B6 has shown benefits across multiple cancer types.

Lycopene and tomatoes

Tomatoes, rich in lycopene a powerful antioxidant, have long been touted as a prostate cancer fighter. While some studies support this claim, others remain inconclusive. Other lycopene-rich foods include watermelon, pink grapefruit, guava, and papaya. There is no harm in eating these foods, but there is no promise that it will prevent prostate cancer. 

The power of legumes

Legumes like soya beans, lentils, and chickpeas offer multiple benefits. Not only do they show protective effects against prostate and colorectal cancers, but they also help manage cholesterol and support overall cardiovascular health.

The bottom line

Nutrition is more than fuel, it’s part of the body’s defence system. For men facing cancer, eating well can mean better treatment tolerance, improved quality of life, and stronger long-term outcomes.

An ideal diet for a man facing cancer or one who wants to prevent cancer consists of lots of fruits and vegetables, wholegrains and legumes, moderate in animal proteins, moderate in mono-and-polyunsaturated fats, and very low in trans fats (processed foods). 

A balanced, plant-forward diet rich in whole foods, fibre, and healthy fats, paired with active lifestyle habits is one of the best investments men can make for their health.