Oral Cancer and Nutrition

Introduction

Oral cancer is a broad term that includes cancer of the oral cavity originating in the mouth. These include cancer of the lips, tongue, and floor of the mouth, which are the commonest among these. Other oral cancers are cancer of cheeks, gums, roof of the mouth, tonsils, and salivary glands. Nearly up to 50% of oral cancers are diagnosed at an advanced stage. In the early stages, most patients are not symptomatic and do not try to find medical help until they show clear symptoms such as pain, bleeding, or a mass in the mouth or neck if lymphatic spread is already present. In the realm of health, the connection between diet and disease is often profound. When it comes to oral health, the impact of nutrition on preventing and combating oral cancer cannot be overstated.

Understanding oral cancer

What are the fundamentals of oral cancer? What are the different types and risk factors for these cancers? And what is the association between diet and oral cancers? Let’s try to become familiar with the important facts that may help you to make important decisions about your food choices to prevent  oral cancer.

Occurrence and risk factors

Oral cancers are the 6^th most common type of cancer worldwide. Occurrence is higher among:

• Adults, mostly above 50 years of age
• Incidence is higher in males
• White people have a higher chance of getting oral cancer as compared to other races
• The user of tobacco in any form, e.g, cigarettes, cigars, pipes, chewing tobacco, and snuff
• Heavy alcohol consumption is also among the major risk factors¹
• Betel nut chewing
• Poor oral hygiene and poor nutrition
• Genetics 
• Weakened immune system
• Human papillomavirus is mainly responsible for squamous cell carcinoma especially at the base of the tongue and the tonsillar area in younger individuals²

Types of oral cancer

There are several types of oral cancers based on the site of origin, types of cells involved, and whether they are malignant or benign. Following are a few types of oral cancers:^3,4

Squamous cell carcinoma 

This is the most common type of oral cancer and it accounts for more than 90% of all oral malignancies and is a significant public health concern.

Oral verrucous carcinoma (OVC)

Is a type of oral squamous cell carcinoma (OSCC), No clear aetiology has been found for this lesion, but human papillomavirus, chewing betel nuts, and ultraviolet radiation are suggested as probable causes.

Adenocarcinoma

Usually occurs in the salivary glands present in the oral cavity.

Mucoepidermoid Carcinoma

Primarily found in the major and minor salivary glands.

Lymphomas

This type may develop in the lymphoid tissue of the oral cavity.

Melanoma

This type can originate from the lips and inside the mouth. This is a rare but aggressive malignancy.

Sarcomas

It’s a rare type that may originate from muscles, bones, and blood vessels.

Basal Cell Carcinoma

Develops from basal cells in the skin and may affect the lips.

The link between diet and oral cancer

Nutrition is an important modifiable parameter, which can have a major impact on oral health. Over the years, it has been established that our dietary choices play a pivotal role in either elevating or modifying the risk of developing oral cancer. Several dietary nutrients contribute to protection against cancer, increasing the risk for development, growth, and spread. Let's explore what we eat can be a powerful ally or a potential challenger in this battle.⁵

Protective nutrients 

Certain nutrients, micronutrients, and food components can act as protective elements against the development of oral cancer. This protective effect can be gained from diets high in fruits and vegetables and low in red meat. The beneficial effect of a diet rich in vegetables and fruits is due to different micronutrients, such as polyphenols, lycopene, catechins, flavins, curcuminoid, fibre, minerals (especially selenium, zinc, and copper), carotenes, vitamins (A, B, C, and E), folate and omega 3 acids.^6,7

Vitamins, minerals, and trace elements

Convincing studies are showing that a diet rich in antioxidants and essential minerals is indispensable for a healthy mind and body. Even trace elements like zinc, copper, selenium, chromium, cobalt, iron, etc. also play fundamental roles in the prevention of oral cancer. These nutrients have a special place in preventive health medicine.⁷

Vitamins have proven to protect the body from the increasingly high levels of free radicals derived from the environment and dietary sources. Vitamin A protects oral mucosa and also prevents cell damage. Vitamin C boosts the immune system and helps in healing, whereas vitamin E offers rich antioxidant properties and is useful in combating oxidative stress, which is a triggering feature in most types of cancer. Thiamine, riboflavin, niacin, folic acid, and cobalamin are different types of vitamin B. Vitamin B is not only needed for DNA synthesis and repair but is also important for energy metabolism.⁸ Hence, diets (fruit and vegetable) rich in vitamins and minerals could interfere in the initiation of cancer propagation and may also play a role in the suppression of tumour genes. 

Foods to embrace

Following are a few examples of foods that you should embrace regularly in your lifestyle and try to keep a higher intake of these foods to ensure sufficient levels of above mentioned nutrients in your body.^8,9

• Fruits with fibre and antioxidant properties (especially papayas, avocados, berries, and kiwi)
• Citrus fruits ( oranges, lemon, grapefruits)
• Vegetables especially leafy greens
• Fortified plant-based milk
• Legumes,
• Whole grains,
• Low-fat dairy
• Fish
• Beans
• Oysters, and sardines, (these are foods rich in antioxidants and with high omega-3 fatty acids, and flavonoids)
• Olive oil

Foods to avoid

Other than alcohol and tobacco, there seems like an increased risk of oral cancer with certain foods including those rich in pro-inflammatory factors. There are specific dietary nutrients that are directly responsible for the excess production of pro-inflammatory chemicals in the body, thereby powering the processes of tumour initiation and progression. This is even triggered more if the person is a smoker or an alcoholic. Examples of foods that are considered promoting inflammation are:¹⁰

• Refined grains (white flour)
• Sugar rich beverages
• Red meat (beef, lamb)
• Processed meat (sausages)
• Deserts and sweets (cakes, donuts)
• Fried food (French fries etc.)
• Food rich in saturated fat and trans fat (fast food, margarine)
• Dairy products with high-fat content (full cream milk or cheese)
• Diets with high salt content

Tobacco, alcohol and oral cancer

Studies have shown enough evidence that tobacco and alcohol are major culprits in the aetiology of oral cancer. Tobacco is one of the  most important carcinogenic factors of squamous cell carcinoma of the oral cavity (which makes up 90% of all oral cancer). According to pieces of evidence based on several research works, tobacco can cause epigenetic change in oral epithelial cells, inhibit immune functions of the host, and through its toxic metabolites cause oxidative stress on tissues to induce squamous cell carcinoma.¹¹

Though alcohol is not the only risk factor for oral cancer, it plays a major role in the pathology of primary tumours and recurrences of tumours. Intake of alcoholic beverages is associated with nutrient deficiency, which appears to trigger the onset of oral carcinogenesis.¹²

Summary 

Remember that the power to protect your oral health lies on your plate. Maintain a balanced diet rich in anti-inflammatory food and avoid diets with pro-inflammatory potential that may reduce the risk of developing oral cancer. Your fruits and vegetables should be your best friends. Please remember you can empower yourself with actionable intuitions. Learn simple yet effective tips to incorporate a cancer-preventive diet seamlessly into your daily life.

FAQs

What is the diet inflammatory index (DII)?

DII represents a unique tool for judging diet quality and has the potential to be used for guiding individuals in adjusting dietary goals to help decrease levels of inflammation, and ultimately, ‌reduce the risk of certain chronic health conditions like cancer.¹³

What are different diets that reduce inflammation?

There is a whole range of diets that you can include in your daily routine to lower the inflammation-producing factors in your body. Some examples are fruits, vegetables (especially green ones), high-fiber carbohydrates, leaner proteins eg, fish and lentils, less sugar, less fat, limiting alcohol, avoiding tobacco, and being conscious of your fat intake.¹⁴

Is malnutrition a cause of oral cancer?

The scientific literature shows that malnutrition is reported as a risk factor for the onset of oral cancer. It is emphasized in the literature that a lack especially of micronutrients like vitamins essential minerals and trace elements appears to increase cancer incidence, including squamous-cell carcinomas of the oral mucosa. Deficiency in vitamins and other nutrients due to malnutrition can affect the immune system and DNA repair mechanisms, making cells more susceptible to tumor transformations. The importance of adequate intake of vitamins is acknowledged in helping to prevent the development of diseases, including cancer. Therefore, pay attention to your diet and nutritional balance, which is essential to reduce the risk of developing cancerous conditions.¹⁵