Question 1

Which of the following micronutrients would impair immunity if they were deficient in the diet?

Accepted Answer

Iron is required for the production of white blood cells, which are involved in the immune response. Vitamin D helps to activate immune cells and deficiencies have been linked to increased susceptibility to infections. Protein is needed to produce immune cells and antibodies. Therefore, deficiency in any of these micronutrients can impair the immune system.

Question 2

Nutrient deficiencies could affect immune function by direct and/or indirect means.

Accepted Answer

Nutrient deficiencies can directly impact the function of immune cells, such as T cells and B cells, by limiting their development and function. Indirectly, nutrient deficiencies can impact immune function by disrupting the overall health and function of the body, making it more susceptible to infections and illness.

Question 3

Why does carbohydrate feeding during exercise attenuate some aspects of exercise-induced immunodepression?

Accepted Answer

Carbohydrate feeding during exercise helps maintain blood glucose levels, which in turn reduces the secretion of stress hormones like cortisol. Elevated cortisol levels can suppress the immune system, so by keeping these levels lower, carbohydrate intake can help attenuate exercise-induced immunodepression.

Question 4

Which of the following vitamins can be synthesised from the action of sunlight on the skin?

Accepted Answer

Vitamin D can be synthesised from the action of sunlight on the skin. The other vitamins listed cannot be synthesised from sunlight.

Question 5

Echinacea is a plant-derived flavonoid compound that stimulates acquired immune function.

Accepted Answer

Echinacea is not a flavonoid compound; it is a genus of herbaceous plants that are used in herbal medicine believed to stimulate the immune system, but it is not classified as a flavonoid. Flavonoids are a diverse group of plant metabolites with various biological activities, distinct from Echinacea.

Question 6

Which of the following is a strain of live bacteria that can influence immune function when ingested regularly?

Accepted Answer

Prebiotics are non-digestible food ingredients that promote the growth of beneficial microorganisms in the intestines, while Xenobiotics are foreign compounds that are not produced by the body or consumed in the diet. β-glucan is a fiber found in foods like oats and barley and can help support immune function but is not a live bacteria strain. Colostrum is a substance produced by mammals prior to milk production, and while it contains immune-boosting properties, it is not a strain of live bacteria. Therefore, the best choice is C, probiotics, which are live bacteria that can improve immune function when ingested regularly.

Question 7

Which of the following amino acids is important for lymphocyte proliferation and has been shown to decrease in concentration in blood after prolonged exercise?

Accepted Answer

Glutamine is important for lymphocyte proliferation and can be depleted during prolonged exercise, which can impair the immune system. Alanine, glycine, glutamate, and tryptophan do not have as significant of a role in lymphocyte proliferation.

Question 8

Regular ingestion of high doses of some antioxidant vitamins can attenuate cortisol responses to exercise.

Accepted Answer

Studies have shown that regular ingestion of high doses of antioxidant vitamins such as vitamin C and E can reduce the cortisol response to exercise. However, it is important to note that some cortisol response is necessary for optimal exercise adaptation, so a complete inhibition of cortisol response may not be beneficial for exercise performance.

Question 9

Decreases in soluble immune factors, such as immunoglobulins, complement proteins and lysozyme, can occur with inadequate nutrition.

Accepted Answer

Soluble immune factors, such as immunoglobulins, complement proteins, and lysozyme, are important components of our immune system. These factors are produced by different cells in our body, and their production and function can be negatively affected by inadequate nutrition. For example, protein-energy malnutrition is known to reduce the production of certain immunoglobulins, such as IgA, which can increase the risk of infections. Similarly, deficiencies in specific micronutrients, such as vitamin E, vitamin C, and zinc, can impair the function of different immune cells and reduce the levels of complement proteins and lysozyme.

Question 10

Ingestion of excessive amounts of some minerals, such as iron, does not impair any aspect of immune function.

Accepted Answer

Ingestion of excessive amounts of certain minerals, including iron, can have negative effects on the immune system and impair immune function. Iron overload, for example, has been associated with increased susceptibility to infections and impaired function of immune cells.

Quiz 9: Exercise, Nutrition and Immune Function