A diet rich in apples, garlic, cruciferous vegetables such as broccoli, brussels sprouts, cabbage, cauliflower and kale, Vitamin C rich foods such as citrus fruits and yogurt may help prevent/reduce the risk of lung cancer. Also, the intake of Glutamine, Folic Acid, Vitamin B12, Astragalus, Silibinin, Turkey Tail Mushroom, Reishi Mushroom, Vitamin D and Omega3 may help in reducing specific treatment induced side-effects, improving quality of life or reducing depression and other symptoms in lung cancer in various stages. However, smoking, obesity, following high fat diet with foods containing saturated fats or trans-fats such as red meat, and consuming beta-carotene supplements by smokers can increase the risk of lung cancer. Avoiding smoking, eating a well balanced diet with the right foods, being physically active and doing regular exercises are inevitable to stay away from Lung Cancer.
Lung Cancer Incidence
Lung cancer is the most commonly occurring cancer across the world. According to the World Health Organization, approximately 2 million new lung cancer cases are diagnosed each year, and around 1.76 million deaths due to lung cancers are reported every year. It is the second most commonly occurring cancer in men and women in the United States. About 1 in 15 men and 1 in 17 women have a chance of developing this cancer in their lifetime.(American Cancer Society)
Types of Lung Cancer
Before deciding on the best, appropriate treatment, it is very important for the oncologist to know the exact type of lung cancer the patient has.
Primary Lung and Secondary Lung Cancers
Those cancers that begin in the lungs are called Primary Lung Cancers and those cancers which spread to the lungs from a different site in the body are called Secondary Lung Cancers.
Based on the type of cells in which the cancer starts growing, the Primary Lung Cancers are classified into two.
Non-Small Cell Lung Cancer (NSCLC)
Non-small cell lung cancer is the most common type of lung cancer. About 80 to 85% of all lung cancers are Non-small cell lung cancers. It grows and spreads/metastasizes more slowly than small cell lung cancer.
Following are the three main kinds of NSCLC, named after the type of cells in the cancer:
- Adenocarcinoma : Adenocarcinoma is the most common type of lung cancer in the United States which usually begins along the outer sections of the lungs. Adenocarcinoma accounts for 40% of all lung cancers. It starts in the cells that would normally secrete substances such as mucus. Adenocarcinoma is also the most common type of lung cancer in people who have never smoked, though this cancer also occurs in current or former smokers.
- Large cell carcinomas: Large cell carcinomas refers to a group of cancers with large, abnormal-looking cells. It accounts for 10-15% of all lung cancers. Large cell carcinomas may begin anywhere in the lungs and tend to grow quickly, making it harder to treat. A subtype of the large cell carcinoma is the large cell neuroendocrine carcinoma, a fast-growing cancer similar to small cell lung cancers.
- Squamous cell carcinoma : Squamous cell carcinoma is also known as epidermoid carcinoma. It accounts for 25% to 30% of all lung cancers. Squamous cell carcinoma usually begins in the bronchi near the middle of the lungs. It starts in the squamous cells, which are flat cells that line the inside of the airways in the lungs.
Small Cell Lung Cancer (SCLC)
Small Cell Lung Cancer is a less common form and accounts for about 10% to 15% of all lung cancers. It usually spreads faster than NSCLC. It is also known as oat cell cancer. According to the American Cancer Society, about 70% of people with SCLC will have the cancer already spread at the time they are diagnosed.
Mesothelioma is yet another type of Lung cancer that is mostly associated with asbestos exposure.
Carcinoid tumors of the lung account for less than 5% of lung tumors and start in hormone producing (neuroendocrine) cells, most of these growing slowly.
During very early stages of lung cancer, there may be no signs or symptoms. However, as the disease progresses, the symptoms of lung cancer develop.
Following are the main symptoms of lung cancer:
- Coughing up blood
- Cough that doesn’t go away in 2 or 3 weeks
- Persistent chest infections
- Persistent breathlessness
- Lack of appetite and unexplained weight loss
- Pain while breathing or coughing
- Long-standing cough which gets worse
- Persistent tiredness
There are several risk factors that can lead to developing lung cancer and start showing the symptoms. (American Cancer Society)
Smoking tobacco is by far the leading risk factor for lung cancer which accounts for 80% of lung cancer deaths.
Some of the other risk factors include:
- Secondhand smoke
- Exposure to radon
- Exposure to asbestos
- Exposure to other cancer-causing agents in the workplace including radioactive substances such as uranium, chemicals such as arsenic and diesel exhaust
- Arsenic in drinking water
- Air pollution
- Family history of lung cancer
- Exposure to radiation therapy for treating a previous cancer such as breast cancer.
- Inherited Genetic changes that may lead to lung cancer
Stages and Treatment for Lung Cancer
When a patient is diagnosed with lung cancer, a few more tests need to be done to find out the extent of spread of the cancer through the lungs, lymph nodes, and other parts of the body which implies the stage of the cancer. The type and stage of lung cancer helps the oncologist decide on the most effective treatment for the patient.
NSCLC has four main stages:
- In Stage 1, the cancer is localized in the lung and has not spread outside the lung.
- In Stage 2, the cancer is present in the lung and surrounding lymph nodes.
- In Stage 3, the cancer is present in the lung and lymph nodes in the middle of the chest.
- In Stage 3A, the cancer is present in lymph nodes only on the same side of the chest where cancer first started growing.
- In Stage 3B, the cancer has spread to lymph nodes on the opposite side of the chest or above the collarbone.
- In Stage 4, the cancer has spread to both lungs, area around the lungs, or to distant organs.
Depending on the type and stage of the disease, lung cancer is treated in several ways.
Following are some of the most common types of treatments used for lung cancers.
- Radiation therapy
- Targeted therapy
Non-small cell lung cancers are usually treated with surgery, chemotherapy, radiation therapy, targeted therapy, or a combination of these treatments. The treatment options for these cancers depends on the stage of the cancer, overall health and lung function of the patients and other traits of the cancer.
Chemotherapy works better in fast growing cells. Hence, small cell lung cancers which grow and spread rapidly are usually treated with chemotherapy. If the patient has a limited stage disease, radiation therapy and very rarely, surgery may also be considered as the treatment options for these lung cancers. However, it’s still less likely to be completely cured with these treatments.
Role of Diet in Lung Cancer
Right Nutrition/Diet including the right foods and supplements is important to stay away from life threatening diseases like lung cancers. It also plays an important part in supporting the cancer treatment, improving quality of life, maintaining the strength and body weight and helping to cope with the treatment side effects. Based on clinical and observational studies, here are some examples of the foods to eat or avoid when it comes to lung cancer.
Foods to Avoid And Eat as Part of Diet to Reduce Lung Cancer Risk
Beta-Carotene and Retinol Supplementation may increase the Risk in Smokers and those exposed to Asbestos
- Researchers from the University of Michigan School of Public Health, National Institutes of Health (NIH) in Bethesda and National Institute for Health and Welfare in Finland evaluated data from the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study involving 29,133 male smokers, aged between 50 and 69 years and found that beta-Carotene intake increased the risk of lung cancer in smokers regardless of the tar or nicotine content of cigarettes smoked. (Middha P et al, Nicotine Tob Res., 2019)
- Another previous clinical trial, the Beta-Carotene and Retinol Efficacy Trial (CARET), done by the researchers of Fred Hutchinson Cancer Research Center, Washington evaluated data from 18,314 participants, who were either smokers or had a history of smoking or exposed to asbestos and found that the supplementation of beta-carotene and retinol resulted in a 28% increased incidence of lung cancer and a 17% increased deaths compared with participants who didn’t receive the supplements. (G S Omenn et al, N Engl J Med., 1996; Gary E Goodman et al, J Natl Cancer Inst., 2004)
Obesity may Increase the Risk
Researchers from Soochow University in China carried out a meta-analysis of 6 cohort studies obtained through literature search in PubMed and Web of Science databases up to October 2016, with 5827 lung cancer cases among 831,535 participants and found that for every 10 cm increase in waist circumference and 0.1 unit increase in waist-to-hip ratio, there was a 10% and 5% increased risk of lung cancer, respectively. (Khemayanto Hidayat et al, Nutrients., 2016)
Red Meat Consumption may Increase the Risk
Researchers from the Shandong University Jinan and Taishan Medical College Tai’an in China carried out a meta-analysis based on data from 33 published studies obtained from literature search carried out in 5 databases including PubMed, Embase, Web of science, the National Knowledge Infrastructure and Wanfang Database until June 31, 2013.The analysis found that for every 120 grams increase in intake of red meat per day, the risk of lung cancer increased by 35% and for every 50 grams increase in intake of red meat per day the risk increased by 20%. (Xiu-Juan Xue et al, Int J Clin Exp Med., 2014)
Cruciferous Vegetable Intake may Reduce the Risk
A large-scale population-based prospective study in Japan called the Japan Public Health Center (JPHC) Study, analyzed a 5 year follow-up questionnaire-based data from 82,330 participants including 38,663 men and 43,667 women who were aged between 45-74 years without a previous history of cancer and found that a higher intake of cruciferous vegetables such as broccoli, brussels sprouts, cabbage, cauliflower and kale may be significantly associated with a reduced risk of lung cancer among those men who were never smokers and those who were past smokers. However, the study found no association in men who were current smokers and women who were never smokers. (Mori N et al, J Nutr. 2017)
Vitamin C Intake may Reduce Lung Cancer Risk
A meta-analysis done by the researchers from the Tongji University School of Medicine, China based on 18 articles reporting 21 studies involving 8938 lung cancer cases, obtained through literature search in PubMed, Web of Knowledge and Wan Fang Med Online through December of 2013, found that higher intake of vitamin C (found in citrus fruits) might have a protective effect against lung cancer, especially in the United States. (Jie Luo et al, Sci Rep., 2014)
Apple Intake may Reduce the Risk
Researchers from the University of Perugia in Italy evaluated data from 23 case-control and 21 cohort/population-based study obtained through literature search in PubMed, Web of Science and Embase databases and found that compared to those who did not consume or rarely consumed apples, people with highest apple intake in both case-control and cohort studies were associated with a 25% and 11% reduced risk of lung cancers respectively. (Roberto Fabiani et al, Public Health Nutr., 2016)
Raw Garlic Consumption may Reduce the Risk
A case–control study conducted between 2005 and 2007 in Taiyuan, China evaluated data obtained through face-to-face interviews with 399 lung cancer cases and 466 healthy controls and found that, in Chinese population, compared to those who did not take raw garlic, ones with high raw garlic intake may be associated with a reduced risk of lung cancer with a dose-response pattern. (Ajay A Myneni et al, Cancer Epidemiol Biomarkers Prev., 2016)
Another similar study also found a protective association between intake of raw garlic and lung cancer with a dose-response pattern (Zi-Yi Jin et al, Cancer Prev Res (Phila)., 2013)
Yogurt Consumption may Reduce the Risk
A pooled analysis of 10 cohorts was done based on studies that were conducted in the United States, Europe, and Asia, between November 2017 and February 2019, involving 6,27,988 men, with an average age of 57.9 years and 8,17,862 women, with an average age of 54.8 years and a total of 18,822 incident lung cancer cases reported during a mean follow-up of 8.6 years. (Jae Jeong Yang et al, JAMA Oncol., 2019)
The study found that both fiber and yogurt (probiotic food) consumption may reduce the risk of lung cancer with the associations more significant in people who never smoked and were consistent across sex and race/ethnicity. It was also found that a high yogurt consumption as part of diet by the group with the highest intake of fiber, synergistically resulted in more than 30% reduced risk of lung cancer compared to those with the least intake of fiber who also didn’t consume yogurt.
Foods to include in the Diet for Lung Cancer Patients
Oral Glutamine Supplementation may Reduce Radiation-Induced Esophagitis in Non-Small Cell Lung Cancer Patients
A clinical trial conducted at Far Eastern Memorial Hospital, Taiwan, on 60 non-small cell lung cancer (NSCLC) patients who received platinum based regimens and radiotherapy concurrently, with or without oral glutamine supplementation for 1 year found that glutamine supplementation decreased the incidence of grade 2/3 acute radiation-induced esophagitis (inflammation of the esophagus) and weight loss to 6.7% and 20% compared to 53.4% and 73.3%, respectively in patients who didn’t receive glutamine. (Chang SC et al, Medicine (Baltimore)., 2019)
Folic Acid and Vitamin B12 Supplements along with Pemetrexed may Reduce Treatment-Induced Blood Toxicity in Lung Cancer Patients
A clinical trial done by the researchers from the Postgraduate Institute of Medical Education and Research in India on 161 non-squamous non-small cell lung cancer (NSCLC) patients found that supplementing Folic acid and Vitamin B12 along with Pemetrexed reduced Treatment-related hematologic/blood toxicity without impacting the chemo efficacy. (Singh N et al, Cancer., 2019)
Astragalus Polysaccharide combined with Vinorelbine and Cisplatin Treatment may Improve Quality of Life of Lung Cancer Patients
Researchers from the Third Affiliated Hospital of Harbin Medical University, China carried out a study involving 136 advanced non-small cell lung cancer (NSCLC) patients and found improvements in the overall quality of life (improved by around 11.7%), physical functioning, fatigue, nausea & vomiting, pain, and loss of appetite in patients who received Astragalus polysaccharide injection along with vinorelbine and cisplatin (VC) chemotherapy, as compared with those who received only vinorelbine and cisplatin treatment. (Li Guo et al, Med Oncol., 2012)
Milk Thistle active Silibinin may Reduce Brain Edema in Lung Cancer Patients with Brain Metastasis
A small clinical study suggested that the use of milk thistle active silibinin-based nutraceutical named Legasil® may improve Brain Metastasis in NSCLC patients which progressed post treatment with radiotherapy and chemotherapy. The findings of these studies also suggested that silibinin administration may significantly reduce brain edema; however, these inhibitory effects of silibinin on brain metastasis may not impact the primary tumor outgrowth in lung cancer patients. (Bosch-Barrera J et al, Oncotarget., 2016)
Turkey Tail Mushroom Ingredient Polysaccharide krestin (PSK) may be beneficial in Lung Cancer Patients
Researchers from the Canadian College of Naturopathic Medicine and Ottawa Hospital Research Institute in Canada did a systematic review of Polysaccharide krestin (PSK), the key active ingredient of Turkey Tail mushroom based on 31 reports from 28 studies (6 randomized and 5 non-randomized controlled trials and 17 preclinical studies) obtained through literature search in PubMed, EMBASE, CINAHL, the Cochrane Library, AltHealth Watch, and the Library of Science and Technology till August 2014. (Heidi Fritz et al, Integr Cancer Ther., 2015)
The study found improvement in median survival and 1-, 2-, and 5-year survival in non-randomized controlled trial with PSK use and benefits in immune parameters and hematological/blood function, performance status and body weight, tumor-related symptoms such as fatigue and anorexia in lung cancer patients, as well as survival in randomized controlled trials.
Ganoderma Lucidum (Reishi Mushroom) polysaccharides may Improve Host Immune Functions in few Patients with Lung Cancer
Researchers from the Massey University conducted a clinical study on 36 patients with advanced lung cancer and found that only a subgroup of these cancer patients responded to Ganoderma Lucidum (Reishi Mushroom) polysaccharides in combination with chemotherapy/radiotherapy and showed certain improvements on host immune functions. Large well defined studies are needed to explore the efficacy and safety of Ganoderma Lucidum polysaccharides when used alone or in combination with chemotherapy/radiotherapy in these cancer patients. (Yihuai Gao et al, J Med Food., Summer 2005)
Vitamin D supplementation may Reduce Depression Symptoms in Metastatic Lung Cancer Patients
In a very recent study done by the researchers from the Memorial Sloan Kettering Cancer Center Department of Psychiatry and Behavioral Science in New York on 98 metastatic lung cancer patients, they found that Vitamin D deficiency may be associated with depression in these patients. Hence, Vitamin D supplementation may help in reducing depression and anxiety symptoms in cancer patients with Vitamin D deficiency. (Daniel C McFarland et al, BMJ Support Palliat Care., 2020)
Omega-3 Fatty Acid intake may Reduce Depression Symptoms in Newly diagnosed Lung Cancer Patients
Fatty fishes such as salmon and cod liver oil are rich in omega-3 fatty acids. Researchers from the National Cancer Center Research Institute East in Kashiwa, Japan carried out a clinical study on 771 Japanese Lung Cancer patients and found that total omega-3 fatty acid intake and alpha-linolenic acid may be associated with 45% and 50% reduced depression symptoms in lung cancer patients. (S Suzuki et al, Br J Cancer., 2004)
The studies suggest that diet including foods such as cruciferous vegetables, apples, garlic, Vitamin C rich foods such as citrus fruits and yogurt may help reduce the risk of lung cancer. Intake of Glutamine, Folic Acid, Vitamin B12, Astragalus, Silibinin, Turkey Tail Mushroom, Reishi Mushroom, Vitamin D and Omega3 supplements may also help in reducing specific treatment induced side-effects, improving quality of life or reducing depression and other symptoms in lung cancer patients. However, smoking, obesity, following high fat diet with foods containing saturated fats or trans-fats such as red meat, and consuming beta-carotene and retinol supplements by smokers may significantly increase the risk of lung cancer. Avoiding smoking, eating a healthy diet with the right foods in right proportions, being physically active and doing regular exercises are unavoidable to stay away from lung cancer.
Cancer patients often have to deal with different chemotherapy side effects which affect their quality of life and look out for alternative therapies for cancer. Taking the right nutrition and supplements based on scientific considerations (avoiding guesswork and random selection) is the best natural remedy for cancer and treatment related side-effects.