Fight Cancer by boosting immunity through nutrition

Immunology is the branch of biomedicine, concerned with the structure and function of the immune system. Immunologists study, how the immune system defends the body against attack from micro-organisms and parasites, how it discriminates between self and non-self, how it deals with foreign molecules, and how it recognizes and deals with neoplastic and virally transformed cells, as well as transplanted organs, cells, and proteins. They are also concerned with what happens when the immune system acts against self.

We cannot survive without well-functioning of immune system within our body. The benefits to us are impressively wide ranging if the immune system is working in a balanced effective way. The guidance about boosting immunity through nutrition has become increasingly important in the modern world.

Our bodies are constantly assaulted not only invaders such as bacteria, protozoa and viruses, but also by ever-increasing quantities of toxins from environmental pollution. Additional common factors known to put a strain on the immune system include physical and emotional stress, a poor diet deficient in the nutrients that boost the immune system, over-reliance on conventional medicines such as antibiotics for recurrent infection, and lack of exercise (1).

The good news is that we can turn this negative situation around by taking positive steps that have a tremendous effect in stimulating our own, in-built defense mechanisms. By taking the empowering steps of getting physically fitter, learning effective stress-reduction techniques, boosting our diets with powerful immune-system nutrients, and learning about appropriate use of nutritional supplements that help our bodies deal with environmental toxins, we can feel ourselves playing a major role in enabling our bodies to reach a state of optimum health(1).

The outcome of a cancer diagnosis can vary enormously, depending on how quickly the diagnosis is made, where the cancer is located, and on more general aspects such as inherited factors and quality of lifestyle. In fact, the immune system regularly eliminates potentially cancerous cells as they are produced. Cancer occurs when abnormal cells multiply in the bodies at such a rate that the immune system cannot control them (1).

Normal cell division goes on all the time in the body. Sometimes a dividing cell is produced that has failed to be correctly genetically coded. If this mutant cell is left free to multiply rapidly it has a strong chance of developing into cancer. If we are in good health and our immune system is working efficiently, our bodies have the potential to deal with such potentially cancerous cells. On the other hand, mutant cells have an elusive and resilient quality, sometimes developing a surface protective barrier in order to try to evade destruction by killer T-cells (1).

Several factors have been identified as influencing the risk of being vulnerable to developing cancer. They are:

Genetic inheritance:-

If women have close female relatives ( mother, sisters or aunts) who have suffered from breast or ovarian cancer they are four time more likely that an average woman to be vulnerable to these cancers.

Lifestyle:-

Genetic inheritance cannot be altered, but positive changes can be made to lifestyle, eliminating as many as possible of the negative aspects that can leave us more vulnerable to developing serious illness. Basic protective measures include:

• Cutting down alcohol intake.
• Giving up smoking and avoiding passive smoking wherever possible.
• Cutting down on intakes of dietary fats such as margarine, butter, cheese and cream.
• Avoiding exposure to radiation or too much sunbathing.
• Avoiding contact with certain chemicals such as the benzopyrenes used in dry cleaning.

Emotional well-being:-

Our emotion can play a significant role in promoting optimum immune-system functioning or undermining the body's defenses. Emotions that appear to play a powerful negative role in suppressing health and vitality include repressed anger, unexpressed grief and protracted depression. This appears to be due to the way in which extended psychological stress and unopposed negative emotions lead to a depressed functioning of the immune system, while positive, pleasurable experience appear to do the reverse. So now it's official: uplifting, pleasurable experience are good for our health (1).

Diet

Nutritionists are now very much eager to discover many diets which can fight to evil cancer by boosting our immunity.

Tomatoes, watermelons, guavas, strawberry and grape fruit are rich in the carotenoid lycopene. This is a fat soluble nutrient which appears to have a powerful action on the immune system which may protect against cancer. Because of olive oil's fat soluble nature, adding a little cold-pressed olive oil to tomatoes before eating them appears to allow the body a greater uptake of the lycopene in the tomatoes (1).

Lycopene is a powerful natural antioxidant, which is not destroyed by cooking. It prevents damage to the cell from naturally produced toxic free radicals. These free radicals are responsible to produce cancer. By binding free radicals, lycopene has a protective, anti-cancer effect, particularly against cancer of prostate, breast and skin.

A few studies have shown that tomato seeds contain a chemical called oxalate, which can combine with calcium (diet or supplements) and precipitate in the urine as kidney stones in susceptible people. It is better to remove the seeds. Or, drink lemon juice. The citric acid in the lime prevents the oxalate from precipitating.

Grapes appear to have an important role in protecting against cancer because of the presence of an important phytochemical called reservatrol. They are also sources of selenium and quercetin. For maximum benefits, choose red or purple grapes in preference to green as they appear to have a higher antioxidant yield (1).

Cruciferous vegetables such as broccoli, cauliflower, cabbage and watercress have important role in protecting against cancer of the colon, breast and intestinal polyps. The phytochemicals found in broccoli appear to have a positive effect in switching off cancer cells and allowing the body to eliminate them. The sulphoraphane that broccoli also contains appears to support helper T-cells in identifying cancer cells so that they can be dealt with as speedily possible (1).

Garlic appears to have an amazingly wide beneficial effect on the immune system. Research suggests that the protective and health promoting effects of garlic may be linked to its allicin content, although garlic also contains a wide range of compounds which appear to have a part to play in the well-being of the mind and the body. The sulfur compounds in garlic are considered to be the main source of its immune system-boosting effect, because of the way in which they support the action of killer cells. Taking garlic regularly is thought to enhance the immune system's potential for eliminating cancer cells and bacterial and viral infections (1).

Shiitake mushrooms are rich in a broad spectrum of phytochemicals, including the amino acids leucine, lysine and threonine, as well as calcium, phosphorus and vitamin D. In addition, they appear to have a powerful immune system booster in the form of lentinan. It appears to have an impact in helping keep tumors at bay, thus possibly reducing the risk of cancer (1).

It is well known that citrus fruits such as lemons and grapes contain lots of vitamin C. less well-known, perhaps, is the fact that there are alternative sources of this essential nutrient and supporter of the immune system available in other fruit and vegetables, including kiwifruit, dark red or purple berries such as blueberries, tomatoes, peppers and dark green vegetables (1).

Selenium's role as a powerful antioxidant has been well established. It appears to provide significant protection against heart disease and cancer, while also providing an all-round immunity boost. This generally beneficial action appears to be linked to the way in which selenium, a mineral, is very effective free radical scavenger, while also giving extra support in mobilizing T-cells and killer cells in fighting bacterial and viral infections. Brazil nuts are an excellent dietary source of selenium: just one or two eaten each day provide the basic daily requirement (1).

Co-Enzyme Q10 has a powerful immune-boosting effect which increases antibody production, and is antiviral, antibacterial and antitumor agent. Possible dietary sources include oily fish such as mackerel and sardines, offal and peanuts. A dose of approximately 30 mg/day is recommended for its immune-boosting effect (1).

If the body does not have enough vitamin B6 at its disposal, the thymus gland will reduce in size and there will be a corresponding drop in the quantity of thymulin generated. The T-cells will not act as efficiently as they should, along with B-cell and antibody activity. Levels of interleukin-2 will also be negatively affected, and the consequent counterproductive effect on killer cells will leave the body vulnerable to infections and tumors. Dietary sources of B vitamins include a wide range of foods: fish, poultry, whole grains, nuts and seeds, soya beans, red meat, green and leafy vegetables, potatoes (1).

Fruit and vegetables are essential source of dietary fiber, which plays an important role in protecting against chronic digestive problems such as constipation. It is thought that the high fiber content of a healthy vegetarian diet may be one of the important factors in vegetarian having a substantially reduced risk of dying of cancer. It has been estimated that this may be approximately 40 per cent lower than non-vegetarian (1).

Dr. Kundu, T.K (The Telegraph, India Edition, 11th Nov 2012) and his research team have identified a compound in pomegranate peel that can stem the spread of cancers. They are working in the Institute named Jawaharlal Nehru Centre for Advanced Scientific Research in India. The skin of this fruit contains a compound called ellagic acid, which hampers the function of an enzyme that is implicated in cancer manifestation. It has been known for a while that an enzyme called CARM-1 is up-regulated in some types of breast cancer and prostate cancer. They wanted to identify a compound that would target this specific function of the enzyme which helps in tumor growth. They won an award instituted in India by Pharmaceutical named Merck Millipore Limited for isolating this promising anti-cancer molecule from the peel of the pomegranate. Dr. Kundu said that enzyme CARM-1, among other things, play an important role in stem cell differentiation. So they assumed that it may have a role in the differentiation of cancer stem cells i.e. stem cells from which cancer cells originate-as well. What is important is that cancer stem cells do not respond to conventional chemotherapy drugs. When we give normal chemotherapeutic drugs, cancer stem cells do not die. What dies are the differentiated cancer cells.
They also found that curcumin is an active ingredient of turmeric which interferes with cellular processes in an oral cancer tissue in such a way that the tissue undergoes a programmed cell death.
The Neem Leaf Glycoprotein (NLGP) is found to restrict the growth of cancer. Unlike the chemotherapy, this compound does not kill tumors but helps increase the proliferation of immune cells (2). He explained that the immune system is normally very powerful and is capable of warding off diseases, including cancers, but when cancer occurs, a biochemical cycle is set in motion, allowing cancer cells to multiply unabated. The cycle makes sure that the immune cells are deprived of a key amino acid called trytophan. Trytophan, absorbed from cereals, legumes, fruits and meat that we eat, is not only essential for normal growth, but vital for the cells to maintain their viability. T-cells, the body's first line of defense against hostile invaders, depend on it for their immune response. If they don't get enough tryptophan, the T-cells die and the invaders remain undetected. On the other hand, in cancer cells tryptophan undergo a cascade of chemical transformations, because of the handiwork of an enzyme called indoleamine 2,3 dioxygenase (IDO). IDO depletes trytophane and thus starves T-cells of tryptophan. This is where the neem compounds kick in, the NLGP reduces the concentration of IDO and, as a result, there is an increase in the tryptophan available to T-cells. This in turn makes them efficient in attacking cancer cells.
[6]Gingerol a pharmacologically important bioactive component of ginger, which is extracted from roots of ginger plant, can kill cancer cells. Through experiments on clusters of cervical cancer cells maintained in laboratory vials, Khuda-Bukhsh (3) and his colleagues have determined the genetic switches that gingerol turns on or off to kill tumor cells. Their experiments suggest that gingerol initiates a cascade of reactions inside cancer cells that leads to the release of an enzyme called caspase within cancer cells, which directs the cells to self-destruct through a process called apoptosis. This work raises the possibility that ginger in diet might have chemo-preventive effects –but even this will need more studies.
A compound sulforaphane, contained in certain leafy vegetables, boosts the activity of certain phase II enzymes, which form part of the body's cancer-fighting machinery.  Three day old broccoli sprouts contain major amount of glucoraphanine – the precursors of sulforaphane (4). Isothiocyanates present in broccoli prevent breast cancer in human females (5)
Some foods do contain anticancer compound. These so-called phytonutrients include resveratrol in grapes and red wine, curcumin in turmeric, and many others. Some of these molecules, including sulforaphane and genistein (an isoflavone found in soybeans), are now on way to becoming pharmaceutical agents in cancer prevention (4). A daily dose of resveratrol of 40 mg/kg achieved long term survival of glioma cases(6). Anthocyanins, a class of flavoniod, from cranberries and other berries inhibited proliferation of three different cancer cell lines (7). Highest consumer of tomatoes, which contain lycopene, reduces to male prostate cancer by 10-20% (4). Curcumin of turmeric play a distinct role in the reduction of colon cancer (8). Tanaka et al (9) reported that twelve-month consumption of garlic extract reduced total size of colorectal polyps was one-third those of controls.
Eating a known amount of phytonutrient doesn't guarantee that a predictable amount of the cancer-fighting molecule will enter the blood stream. Differences here can be traced to variations in the genes involved in the digestive processes, because human genomes vary one to another (4). The glutathione S-transferase M1 gene ( GSTM1) influences the speed at which the body metabolizes sulforaphane and expels it in the urine (4). GSTM1 is the best studied of the genes that influence phytonutrient metabolism, but it is just one of a rapidly growing list. For example, people who carry two copies of a particular variant of the UGT1A1 gene make about 30% to 40% less than normal of a type of phase II enzyme. One study has shown that people with this genotype derive more cancer-protecting benefit from eating cabbage- and carrot-family vegetables—possibly because phytonutrients in these foods boost UGT1A1 activity closer to normal (10).
Due to variations of human micro biomes, gut micro biota reflect a complex interplay of diet and genetics. For example, vegetarians are more likely to produce equol than non-vegetarians, which some scientists believe is one of the more beneficial forms of isoflavone. A less active molecule O-desmethylangolensin produced by different micobioms in gut of 80% to 90% human population (4).
Cancers and its treatment may lead to a decrease in nutrient intake of sufficient magnitude to cause weight loss and alteration of intermediary metabolism. The prevalence of this problem is difficult to estimate because of variations in the definition of cancer cachexia, but most patients with advanced cancer experience weight loss and decreased appetite. A variety of both tumor-derived factors (e.g., bombesin, adrenocorticotropic hormone) and host-derived factors (e.g., tumor necrosis factor, interleukins 1 and 6, growth hormone) contribute to the altered metabolism, and a vicious cycle is established in which protein catabolism, glucose intolerance, and lipolysis cannot reversed by the provision of calories. It remains controversial how to assess nutritional status and when and how to intervene. Efforts to make the assessment objective have included the use of a prognostic nutritional index based on level of albumin, triceps skin fold thickness, transferring levels, and delayed-type hyper-sensitivity skin testing. However, a simpler approach has been to define the threshold for nutritional intervention as >10% unexplained body weight loss, serum transferring levels <1500 mg/L (150 mg/dL), and serum albumin <34g/L (3.4 g/dL). The decision is important because it appears that cancer therapy is substantially more toxic and less effective in the face of malnutrition. Nevertheless, it remains unclear whether nutritional intervention can alter the natural history. Unless some pathology is affecting the absorptive function of the gastrointestinal tract, enteral nutrition provided orally or by tube feeding is preferred over parenteral supplementation. However, the risks associated with the tube may outweigh the benefits. Megestrol acetate, a progestational agent, has been advocated as a pharmacologic intervention to improve nutritional status. Research in this area may provide more tools in the future as cytokine-mediated mechanisms are further elucidated (11).
To prevent cancer- rather than treat it- is not a new idea. In fact, over the past few decades a new specialty known as ‘chemoprevention' has grown up around the concept. Finding the right food to help reduce our chances of cancer can be a maze. But ongoing studies and a little inventive cooking might point us in the right direction. Many studies in the past couple of decades have examined the dietary factors on cancer risk. It is very essential to choose the right food for boosting immunity against cancer.
References:

1. MacEoin. B. In: boost your immune system naturally. Ed Carlton Books Limited. London. (2011).
2. Roy .S et al. Human Immunology, 74:1015-1023 (2013).
3. Chakraborty. D. et al.  European Journal of Pharmacology, 694: 20-29 (2012).
4. Deweerdt, S, Nature. 471: S22-S24 (2011).
5. Ambrosome, C.B et al, J.Nutr. 134:1134-1138 (2004)  
6. Tseng.S. et al Clin.Cancer.Res. 10:2190-2202 (2004).
7. Ferguson, P.J. et al, J. Nutr. 134:1529-1535 (2004).
8. Cruz-Correa, M. et al. Gastroenterol. Hepatol. 4:1035-1038 (2006).
9. Tanaka, S et al. J. Nutr. 136: 8215-8265 (2006).
10. Navarro, S. L et al. Cancer Prev. Res. 2:345-352 (2009).
11. Longo.DL. In: Harrison's Hematology and Oncology, ed. Longo. DL. McGraw Hill, New York,  pP, 330 (2010).