Yes. Most diseases are the result of a malfunctioning immune system. When the immune system is stimulated, for example, the body produces excessive IgE antibodies that will trigger allergic reactions such as skin allergies and hay fever. When the immune system is weak or not strong enough, it succumbs easily to cancer or infectious diseases, for example, SARS and other viral and bacterial infections. Rheumatoid arthritis, systemic lupus erythematosus and other chronic diseases are autoimmune diseases caused by the immune system's inability to distinguish self from non-self.

Wholesome foods refer to natural foods that have not been chemically processed or refined.

The American Cancer Society reports that calcium-rich foods may reduce risk of colorectal cancer and even modestly reduce the formation of colorectal adenomas (polyps). It advises adults to consume recommended calcium levels through wholesome foods such as soy, leafy vegetables and green foods rather than calcium supplements. The recommended daily intake of calcium is 1,000 mg for people aged 19 to 50 years and 1,200 mg for people over 50.

Experts recommend five to nine servings or 400 grams of a variety of fruits and vegetables, and not more than 80 to 90 grams of meat each day.

Studies by the World Health Organization (WHO) have shown that the greater the consumption of fruits and vegetables, the lower the risk of diseases like cancer, heart disease, osteoporosis, diabetes and stroke.

Each plant contains different types of antioxidants, phytochemicals and polysaccharides. Eating five servings of one type of fruit or vegetable cannot supply your body with all the essential nutrients.

It is important to try and keep meat consumption below the recommended 80 to 90 grams as research has pointed to dangerous effects of consuming too much red meat. Experts advise that it is better to eat fish than red meat.

Consumption of animal products causes the body to secrete prostaglandin II, which can suppress immune function and increase the probability of cancer. Thus, Nutritional Immunology only encourages the consumption of immunity-enhancing, plant-based foods.

All nutrients needed to support and enhance our immune functions are readily found in plant foods.

The American Cancer Society cautions against consuming foods preserved through the use of salt as these may increase cancer risk. The American Heart Association reports that too much salt can lead to high blood pressure which can, in turn, lead to complications like stroke and heart disease. It suggests moderating daily salt intake to less than 3,000 milligrams or about one and a half teaspoons.

Cooking and heating is actually necessary to remove harmful germs from meat and milk. However, some research suggests that frying, broiling or grilling meats at very high temperatures creates chemicals that may increase cancer risk. Some experts say that the process of pasteurizing milk not only removes germs but also destroys milk's natural enzymes by altering its delicate proteins, causing human-like chronic illnesses and stillbirth in lab animals.

Yes. Different phytochemicals, present in different plant foods, have varying ways in which they strengthen the immune system. Eating a wide range of nutrient-rich botanical foods greatly benefits the body.

No. Phytochemicals can only be obtained from plant sources.

Polysaccharides are long chain sugars commonly found in mushrooms and their mycelium. Polysaccharides are highly beneficial to the health of the immune system.

Polysaccharides are found in both plants and animals but those present in plants, such as mushroom polysaccharides, are in a purer state and have no known side effects.

Research has shown that the polysaccharides in certain mushrooms have the ability to inhibit tumor growth by activating immune cells. Polysaccharides can enhance and balance immune function by increasing the production of natural killer cells, interferon and interleukin to remove cancer cells. Polysaccharide-rich mushrooms are also widely used to prevent viral infections.

No, it is important that we take polysaccharides in the correct proportion. For example, Lentinan, a Shiitake mushroom polysaccharide, is ineffective against cancer when taken in excess. But, taken in the right amount, polysaccharides can boost the immune functions and help the body ward off tumor growth.

Beta-carotene is an antioxidant chemically related to vitamin A. As beta-carotene is found in fruits and vegetables that are deemed to have anti-cancer properties, many assume that ingesting beta-carotene supplements can reduce cancer risk.

In the past, three major clinical trials were conducted by giving cigarette smokers high doses of synthetic beta-carotene supplements to prevent lung cancer and other cancers. Two studies showed that synthetic beta-carotene supplements actually increased occurrence of lung cancer among the smokers while the third study showed neither harm nor benefit from beta-carotene supplements. Hence, researchers say that eating beta-carotene-rich fruits and vegetables has health benefits, but taking too many beta-carotene supplements may be harmful, especially to smokers.

Till today, there is no conclusive research to prove that tea reduces cancer risk. Some researchers have suggested that tea leaves can protect against cancer due to their antioxidants. Tests conducted on lab animals have shown that some types of tea leaves (including green tea leaves) can reduce cancer risk. Major clinical studies, however, reveal mixed results.

Tea leaves contain caffeine, which slows the body's DNA repair mechanism. For example, oolong tea, jasmine tea, red tea and green tea, which are all made using the Camellia leaf, are high in caffeine. Camellia leaf contains 3.5% caffeine by weight while coffee beans contain 2.2% caffeine by weight. Research has shown that a high intake of caffeine is linked with heart disease, insomnia, decreased fertility and even cancers like bladder cancer.

Different nutrients prevent different ways in which cancer occurs. Cancer can occur through a variety of means. A cancer may be caused by free radicals. In this case, we need an abundance of antioxidants to help prevent free radical attacks.

Cancer may also be caused by animal hormones, pollution and suppressed immune function. Phytochemicals have been found to prevent cancer by targeting such mechanisms. We constantly come into contact with cancer-causing chemicals, radiation and viral infections. Polysaccharides not only prevent cancer but they also destroy existing cancer cells and viruses by increasing the production of interleukin and interferon and by boosting overall cellular immunity.

Cancer is caused when cells mutate. This risk can either be acquired or hereditary. Nutrition cannot change our genes. But by eating healthily, we can prevent a lot of genetic illnesses from being triggered and also, through a healthy lifestyle, help control the illness or reduce the symptoms. The American Cancer Society advises that certain nutrients may protect our cells from mutating or becoming damaged. Physical activity and weight control may also delay or prevent the development of cancer in people with increased genetic risk. A great deal of research is being done to see in what other ways cancer can be prevented.

No. Healthy plant foods boost our immune system and make us better equipped to control the growth of cancer and infections. In fact, when people starve, bacteria and cancer grow even faster because their immune system is not functioning properly and therefore, unable to stop the spread of invaders or mutated cells throughout the body.

The American Cancer Society suggests that drinking water and other liquids may reduce the risk of bladder cancer. This is because water dilutes the concentration of carcinogens and shortens the time in which they are in contact with the bladder lining. Although drinking eight cups of water daily is recommended, researchers report in the American Journal of Physiology that the actual requirement for each individual may differ. Too much of water may become burdensome and lead to water intoxication where the kidney cannot keep pace with the fluid intake.

Nutritional Immunology emphasizes that a balanced diet, regular exercise, adequate rest and appropriate stress management are key to a healthier lifestyle.