26 terms

Nutrition 1: Nutrition in Health and Disease

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Healthy diet
results in absence of illness or discomfort, fitness, longevity, optimum health
Under-nutrition
low food intake
Specific deficiencies
imbalanced nutrient intake
Overweight/obesity
BMI > 25/>30
Malnutrition
under-nutrition, specific deficiencies, overweight/obesity
Key variables that influence nutritional demands and the incidence and presence of diseases with a nutritional basis
stage of development (fetus->elderly), level of inflammatory stress, previous nutritional exposure in utero (fetal origins of adult disease), genotype
Defense for exposure to pathogens and toxins
immune system, antioxidant defenses, detoxification systems (efficiency declines with age -> activity of enzymes involved in xenobiotic detoxification systems declines with age)
Whole body protein synthesis
rate significantly declines from infancy to elderly -> impacts on speed of wound healing and recovery from infection
Level of inflammatory stress
interaction between nutritional status and effective operation of the immune system -> malnutrition leads to increased chances of dying from infection -> due to malfunctioning immune system -> inflammation plays significant role in morbidity and mortality in chronic diseases with a nutritional basis
Hypertension
does not involve the immune system (this could be false) but is influenced by nutrition
Chronic diseases
most involve immune system and mostly all are influenced by nutrition
Microbes
we are surrounded by these and our physiology is designed to resist them
Immune system
normal function is to detect and destroy pathogens, removing damaged tissue and bringing about wound healing
IL-1, IL-6, TNF-alpha
Effects of pro-inflammatory cytokines and inflammation in health and disease -> many types of injury produce a similar inflammation
Typical response of the body to infection or injury
immune system activation -> pro-inflammatory cytokines -> oxidants -> pathogen killing and tissue damage -> nutrients are released from host tissues (appetite loss) -> glutamine and glucose consumed by T and B cells (immuno-nutrition)
Glutamine
along with sulfur amino acids cause glutathione synthesis -> antioxidant defenses are strengthened to reduce tissue damage
TWEAK/Fn14 system
tissue remodeling
Feedback systems
IL10, heat shock proteins
Influence of infections and injury on metabolic rate
major injury (burns) or infection increase significantly, under-nutrition can decrease (weight loss >10% of body weight)
Body weight loss during fasting and following injury and infections of various intensity
although weight loss provides nutrition for the immune system during infection and injury -> there is a limit to weight loss and survival
Body cell mass
Survival curves of patients with HIV infection according to rate of loss of body protein content -> % of patients surviving decreases significantly with BCM <30% of body weight
Serum albumin
negative acute phase reactants -> when it is reduced when levels of inflammatory stress become raised -> One of the first indications that the immune system had a role in mortality from chronic diseases
HDL
as serum albumin it is a negative acute phase reactant and is reduced when inflammatory stress levels are increased
Monocytes
take up cholesterol and damaged lipoproteins -> die and deposit fat under lining of endothelial cells of the arteries -> all due to inflammation
Anti-inflammatory changes in lifestyle
Heart disease is caused by chronic inflammation and therefore this should be the focus
Inflammation (stimulated by pathogens, environmental factors and damaged tissue)
key task is to kill pathogens -> too much of this can cause mortality and morbidity -> can also cause insulin insensitivity (diabetes mellitus), hyperlipidemia, atherosclerosis (MI)