Cancer Prevention – Is It Possible? Dr. AVS Suresh Explains


Medically Reviewed by Dr. AVS Suresh ,
October 20, 2020

Cancer prevention

How to prevent cancer: Let us first try to understand whether it is possible to prevent cancer or not.

If yes, then what percentage of possibility is there?

The answer…

There is a huge possibility of preventing cancer (up to 70%) and the remaining 30% risk of getting any type of cancer in a person’s lifetime is due to uncontrollable factors (two of such factors are your genes and the environment in which you live). Even unknown causes also come under this 30% risk mark.

There are several factors – in fact, many – which you can manage by making changes in your lifestyle. If you know the percentage of risk associated with each one, you will be able to take the best possible measures to minimize the risk.

In other words, cancer prevention is possible. You will also learn how to approach, deal with, and what steps to take.

Let us learn more about each factor and the percentage of risk associated with it and what measures you can take to minimize the risk.

Diet – The Risk of Cancer is 30 to 35%

Meat (Meat cooked at high temperatures increases the cancer risk)

If you have a habit of eating lots of red meat then cut down its intake.

Bowel, stomach, colorectal, and pancreatic cancer risk is high in meat-eaters. Processed meat (contains nitrites) – When we eat processed meat, nitrites in the meat get converted into cancer-causing N-nitroso compound – NOCs.

Furthermore, meat cooked at high temperatures produces these compounds: Heterocyclic amines (HCAs) and polycyclic amines (PCAs). Barbequing, deep-frying, and grilling meat produce these compounds. Excessive consumption of red meat is linked to an increased risk of cancer – particularly colorectal cancer.

Lean meat and fresh white meat such as fish and chicken, are not linked with an increased risk of cancer.

Carbohydrates turn into sugar in the blood. How fast they turn is measured as Glycemic index (GI). The higher the glycaemic index of food, the greater is the risk. For instance, processed foods – such as bacon, sausages, pizzas, salami, ham, fruit juices, sugar-rich energy drinks, and soft drinks are foods with a high glycemic index.

Low GI foods are good whereas high GI foods are bad for health.

High GI foods: white bread (70+), wheat roti (62 + or – 3)

Low GI Foods: beans, lentils (32+ or -3) Kidney beans, soya beans, chicken pea

Cancer-causing foods: Alcohol, red meat, processed meat, and meat products, processed foods, and sugar-sweetened drinks

Cancer prevention diet: Avoid meat cooked at high temperatures, but eat fish, green leafy vegetables, broccoli, garlic, spinach, carrots, beans, berries, citrus fruits, turmeric, nuts, cinnamon, tomatoes, flaxseeds, kale, and lettuce.

Cancer-fighting diet: The foods that fight cancer include apple, berries, cherries, carrots, cranberries, garlic, ginger, grapefruit, oranges, tea, walnuts, and whole grains.

Physical inactivity (sedentary lifestyle 7% risk)

The latest statistics show that the risk of getting cancer increases up to 10% in people who are physically inactive. The overall contribution of a sedentary lifestyle (physical inactivity) to cancer risk is 7%. If we remain physically active throughout the day, weeks, months, and even years, there is a very strong possibility of immensely reducing this risk.

What is physical activity in simple terms?

Physical activity is nothing but any movement that uses muscles and requires more energy than resting. For instance – walking, doing daily chores or activities, gardening, swimming, dancing, doing yoga, exercising, and engagement in sportive activities with children are all physical activities.

Sedentary life means sitting, reclining, resting, or lying down most of the time.

How to prevent cancer by physical activities: Women can reduce the risk of developing breast (natural breast cancer prevention) and endometrial cancers by up to 15 to 20% by increasing their physical activity levels. In general, the risk of bladder, colon, and stomach cancer can be reduced by up to 15 to 20% by involving in physical activities regularly.

Physical activity, in general, improves blood circulation, maintains hormonal balance, prevents high blood levels of sugar, reduces inflammation, improves the health of the immune system, boosts immune response, and helps prevent obesity.

How much physical activity is recommended?

The simple maths is this: daily 1 hour of physical activity is enough.

Overall, 400 plus minutes of activity in a week (100 to 150 minutes of walking, 150 minutes of moderate-intensity aerobic exercise plus 100 minutes of vigorous aerobic activity). In addition, muscle-strengthening activities, at least two sessions (25 minutes each for two days) in a week.

In addition to lowering the risk of any type of cancer, physical activity can lower the risk of heart disease, stroke, and diabetes.

Excess Body Weight [Obesity – overall risk 5 to 11%]  

Excess body weight or obesity is associated with an increased risk of breast, endometrial (uterine), and ovarian cancers in women; prostate, male breast cancer, liver, colon, rectum, kidney, oesophageal, gallbladder, thyroid, pancreas, and stomach cancer in males.

Obese people also have a higher risk of high blood pressure, heart disease, and type 2 diabetes.

  • BMI more than 30 is considered obese
  • BMI between 25 to 30 is overweight
  • BMI between 18.5 to 25 is considered as healthy

If you are obese, then aim for reducing at least 5% to 10% of your body weight – and, next gradually aim for more.

Stress, depression, and other mental issues

Feeling psychological stress from time to time is normal, but experiencing high levels of psychological stress over a long period of time can cause mental and physical issues.

People who experience long-term stress have digestive problems, anxiety, depression, sleep problems, urinary problems, and weaken the immune system. They are more prone to the common cold, flu, and other viral infections. A weakened immune system can make you prone to cancer as well.

Can stress cause cancer is not yet clear, but these could be the possible links:

  • Stress weakens the immune system
  • Stress can lead to a state of inflammation
  • Stress inhibits anoikis (a process that kills diseased cells and prevents them from spreading)
  • People under chronic stress may turn to unhealthy habits -such as smoking, drinking alcohol, unhealthy eating, and overeating.

Overall, there still isn’t enough conclusive evidence to definitely say whether stress causes cancer or even increases someone’s risk.

In a nutshell, your body becomes hospitable to cancer if you are under chronic stress. It can help cancer grow and spread in numerous ways.

Solution: Take stress seriously and learn the ways to manage it properly – if it is difficult to manage, then take professional help.


The only risk factor that increases the 100% risk of cancer is smoking. It is a well-established fact now. 9 out of 10 cancer deaths are caused by smoking cigarettes or due to exposure to second-hand smoke – side stream or mainstream smoke.

Smoking not only causes lung cancer but also damages nearly every vital organ of the body including the heart, brain, mouth, tongue, stomach, blood vessels, skin, eyes, bones, and kidneys. Cigarette smoke releases thousands of harmful and carcinogenic chemicals in the body that damage DNA and cause cancer.

Hazards of Smoking

Smoking can cause cancer almost anywhere in the body – mouth, tongue, esophagus, lungs, stomach, colon and rectum, pancreas, bladder, liver, kidney. Smoking increases breast cancer risk in women and prostate cancer risk in men several times. After quitting smoking, a person can reduce the risk of cancer by almost 50% within the first couple of years and after 10 to 15 years of quitting smoking, the risk can be reduced further to almost 70%.

Quitting smoking is the best way to cancer prevention

Smoking shortens your life by 10 to 15 years. If you want to add 10 to 15 years more to your life, then quit smoking or else be ready to die younger.

Alcohol Consumption

People who consume alcohol are three times at risk of getting any type of cancer compared to non-drinkers. Excessive alcohol consumption increases the risk of liver, stomach, colon and rectum, pancreatic, esophagus, larynx, head and neck cancer, mouth and lungs cancer in men, and breast cancer in women. The more a person drinks the more is the risk. Alcohol breaks down in the body into a chemical called acetaldehyde – which damages DNA and causes cancer. Even moderate and light drinkers too have a slightly increased risk of developing some types of cancers.

How Does Alcohol Increase the Risk?

Alcohol generates oxygen-containing chemically reactive molecules in the body (oxygen species). These molecules damage DNA and proteins in the body by oxidation. Alcohol also impairs the ability of the body to absorb a wide range of nutrients including vitamin C, vitamin D, folate, B complex vitamins, vitamin A, vitamin E, and carotenoids. Excess alcohol intake is also linked to an increased risk of breast cancer due to increased levels of estrogen hormone in the blood. In addition, certain carcinogenic substances – such as phenols, asbestos fibers, nitrosamines, and hydrocarbons make their way into alcohol during its manufacturing process.

People who smoke and drink are almost three times more likely to develop cancer than those who neither drink nor smoke.

Alcohol makes it easier for the toxic chemicals from cigarette smoke to pass through the mouth and throat and then into the bloodstream.

The best cancer prevention strategy is to avoid alcohol completely.

Exposure to chemicals in the environment

[pollutants (air and water pollutants) Cancer risk from the chemical is up to 7 to 19%]

International Agency for Research on Cancer (IARC) and World Health Organization (WHO) estimate that 7% to 19% of cancers are due to exposure to toxic substances in the environment.

Arsenic is a potentially harmful carcinogen – it gets into the body through food and contaminated water.  Safe drinking water, farming, and irrigation practices reduce contamination.

Benzene – gets into the body through polluted air (automobile exhaust) and cigarette smoke, pesticides, synthetic fibers, plastics, inks, oils, and scented detergents. 50% of benzene comes from tobacco smoke.

Cadmium – People get exposed to cadmium by breathing tobacco smoke and contaminated foods.

Nickel – People get exposed to low levels of nickel through the air, water, food, and tobacco smoke.

Ethylene oxide – Major source is tobacco smoke.

Formaldehyde – Comes from press-wood products (plywood), glues and adhesives, press fabrics, and cigarette smoke

Radon (radioactive gas)– well water (check the water for the presence of radon before using it).

Vinyl chloride – air pollution through vinyl

Sulfur dioxide – from industrial pollutants

Paraquat (weedkiller) increases cancer risk

Spinach, peaches, celery, strawberries, and apples have the highest pesticide residues – prefer organic version.

Use organic fruits and vegetables to minimize exposure to pesticides (fungicides, insecticides, herbicides).


These are chemical substances that are used to soften plastic and are in some cosmetics – deodorant, nail polish, lotions, shampoo, and plastic bottles. Use phthalates-free plastic products, beauty products, and children’s toys.

The majority of us are unaware of BPA (Bisphenol A) – A chemical that is widely used in epoxy resins and polycarbonate plastics that are used for manufacturing water supply pipes, bottle tops, metal can linings, baby bottles, food and drinks packaging items. Even in low dose exposure, BPA can cause a wide range of health issues including low testosterone levels, low sperm levels, aggressive behavior, infertility, obesity, early onset of puberty, and prostate and breast cancer.

When you heat, wash or stress or apply force to the items (baby bottles, food containers, utensils) that have BPA, then the chemical leaches out from the product into the water and food. Infants, children, and adults ingest BPA along with the food.

How to prevent cancer: To reduce the risk of being exposed to BPA:

  • Avoid plastic containers in a microwave – it is better to use glass
  • Eat fresh fruits and vegetables
  • Avoid processed and can foods packed in plastic containers
  • Use steel, glass or bottles, mugs, porcelain cups, or containers
  • Use steel or glass water bottles
  • Use utensils and children toys labeled as BPA free

Exposure to radiations

 (Ionizing radiations – X-rays, Gamma rays, radiation therapy)

IARC (The International Agency for Research on Cancer) has classified X-Rays and Gamma radiation as known human carcinogens. Even very low doses of these two radiations can slightly increase cancer risk. However, the risk increases as the dose of radiation increases – the lower the exposure, the lesser is the risk, but there is no threshold below which these two radiations are considered as totally risk-free. For instance, the risk could be higher, if a person had more X-rays, CT or PET scans done. Even radiation therapy can also increase cancer risk, but the risk is low.

You should talk to your doctor about whether an X-ray, CT scan is necessary for you and also about the scans’ risks and benefits. Cancer patients should also discuss with their radiation oncologist how their radiation treatment could increase second cancer risk later on.

Bottom Line

The best bet to prevent cancer is to start taking action rather than learning, understanding, and forgetting all that you have learned. From today onwards make a commitment to adopt everything that you have learned from this article into your life – make changes in your lifestyle – be pragmatic and enjoy a healthy and wealthy life – if you do this, then you will have a 70% chance of preventing cancer in your lifetime.

And also, if you are at risk – then go for the following types of cancer screening – according to the risk you have. Consult your general physician or family physician to know the cancer risk you may have and to ask the doctor about different types of cancer screening tests.

Cancer Prevention – Cancer Screening Works

Colon cancer screening – Any expert Gastroenterologist or Endoscopist or surgical Gastroenterologist who specializes in the diagnosis and prevention of colon and colorectal cancer will guide you in colon cancer screening programs.

Cervical cancer screening – Dr. Geetha Nagasree recommends that every woman should undergo cervical cancer screening. When you see your gynecologist for regular gynecological health checkups, you should ask her for a PAP test.

One of the prominent causes of cervical cancer in women is an infection caused by human papillomavirus (HPV).

HPV Prevention: The best way to prevent HPV is to avoid high-risk sexual activity, sex with multiple sexual partners, and oral sex. HPV is also associated with oral cancer in males.

Vaccine against cervical cancer – HPV vaccine prevents cervical cancer. To know more about HPV vaccination, read:

Cervical Cancer Vaccine