Explain what is meant by the term 'risk factor' and identify and describe four nutrition-related risk factors. For each of these four risk factors, identify and describe one disease or health condition for which it is a risk factor, and discuss the reason(s) or possible reason(s) why it is a risk factor for this disease or health condition.
A risk factor is a characteristic, behaviour or condition that increases your susceptibility of contracting a disease or infection. They can be categorised as biomedical, environmental, behavioural, genetic or demographic. (Australian Institute of Health and Welfare, 2005) Biomedical risk factors include factors that are influenced by a combination of genetics and lifestyle factors for example overweight and obesity. Environmental risk factors are extremely broad including social, economical, cultural and political factors as well as physical, chemical and biological factors. Some diseases are entirely a result of an individual's genetic make-up for example Down syndrome. These are genetic risk factors whereas demographic risk factors include age, sex and population subgroups. Unlike these, behavioural risk factors are factors that can be reduced or eliminated through lifestyle or behaviour changes for example physical inactivity or poor diet and nutrition. These preventative risk factors are responsible for a large proportion of the total burden of disease in Australia and are therefore examined intensively. It is considered extremely important by health professionals that individuals consume a healthy, balanced diet. Across the lifespan a nutritious diet is extremely important for several reasons including optimal growth and development, repair of bodily tissue as well as the prevention against life-threatening diseases. Over time a poor diet has the potential to have devastating effects. A diet that lacks sufficient calcium can lead to osteoporosis later in life, whereas a diet lacking fibre can increase your likelihood of contracting colorectal cancer. During pregnancy if the mother's diet has a low consumption of folic acid it can have devastating health effects on the unborn. The effects of consuming too much of a nutrient is too significant. A diet high in saturated fat can lead to many diseases such as cardiovascular disease.
Calcium is considered to be the most abundant mineral in the body. It has several important functions.
Its main function is supporting the structure of bones and teeth. It is also required for muscle contraction, blood vessel contraction and expansion, the secretion of hormones and enzymes and needed so that communication can occur throughout the body via messages being sent through the nervous system. Daily foods such as milk, yoghurt and cheese are rich sources of calcium. Non dairy sources include green leafy vegetables such as broccoli. The recommended daily intake varies across the lifespan. Young children have high calcium needs as their skeletal tissue is constantly growing. They require around 1,000mg per day. A teenager's recommended daily intake is around 1,300mg per day as puberty prompts a growth spurt. During adulthood women and men both need around 1,000mg per day. There is an increase in the requirement as we age, women over the age of 50 years and men over the age of 70years have a recommended dietary intake of 1,300mg per day. An increase occurs because as we age the skeleton loses calcium. Women lose more calcium from their bones as a result of menopause although both sexes lose bone mass as they age and therefore need an adequate amount of calcium in their diet to counterbalance these losses. (Better Health Channel, 2010)
Osteoporosis is a disease that occurs when bones lose minerals, such as calcium more quickly than the body can replace them. This leads to a loss of bone density and consequently increases the risk of the bone seriously fracturing, even with a minor bump. Osteoporosis is often called the 'silent disease' as it tends to have no signs or symptoms until the fracture occurs. Fractures can lead to chronic pain, disability and decrease of independence and even premature death. Calcium throughout the life is critically important in preventing osteoporosis. An increase in calcium is required as we age to compensate for the gradual losses. Also from before the onset of puberty to around the mid-20's, the skeleton increases its bone mass. If the skeleton is strengthened with enough calcium during this period, osteoporosis later in life is thought to be less likely. (National Institutes of Health, 2009)
Folic acid is part of one of the B group vitamins necessary for healthy growth and development. Folic acid is found in foods such as cereals, grains, fruits and green leafy vegetables such as spinach. It is responsible for formation of red blood cells, DNA synthesis and for protein metabolism. Every individual needs folic acid in their diet, however the recommended daily intake varies from 0.2mg for the general population and 0.4-0.5mg for pregnant women. This increase is because folic acid is also extremely important for the development of the nervous system and for preventing neural tube defects (NTDs) in babies. Approximately one in every six hundred pregnancies in Victoria is affected by a neural tube defect. Neural tube defects include anencephaly, encephalocoele and spina bifida. Anencephaly is a fatal condition, where the upper end of the neural tube doesn't close and the brain therefore fails to completely develop. Encephalocoele is a rare condition where the brain or surrounding membranes protrude through a defect in the skull. Spina bifida is the most common which results in life after birth. It occurs when the lower part of the neural tube doesn't develop fully leaving the spinal cord exposed or covered only by skin. It generally results in an individual having a wide range of physical disabilities such as paralysis of legs. The National Health and Medical Research Council (NHMRC) and the Federal Government have both acknowledged the relationship between an increased intake of folic acid and the prevention against neural tubal defects. The Research suggests that reaching the recommended daily folic acid intake when pregnant can prevent seven out of ten births affected by neural tube defect. (State Government of Victoria, Australia, Department of Health, 2006)
