Nutritional Imbalances

Dr Viv Rolfe

Alternative formats and large print versionsof these handouts are available upon request.

Outline• Nutrition authorities in the UK

• A balanced diet versus the UK diet

• Health impact of common nutritional imbalances (e.g. salt, sugar/fat, vitamins, and fibre)

• Lipid metabolism, saturated and unsaturated fats and role of HDL, LDL and VLDL in health

• Other issues (food allergy, food additives, genetically modified (GM) foodstuffs)

Why is knowledge of nutrition important to nursing?

• Many diseases are caused by poor nutrition.

• Many diseases can be managed by nutrition, and it can influence the recovery after surgery.

• Others?

UK Nutrition Authorities

Department of Health - Health and social care policy including the NHS.

BNF British Nutrition Foundation (1967) - -nutrition research & health promotion charity.

FSA Food Standards Agency (2000) -(previously MAFF) – independent food safetywatchdog.

SACN – scientific advisory committee on nutritionIndependent advisory board on nutrition and diet consistingof top academics and researchers.

www.foodstandards.gov.uk

•The FSA enforce the 1990 Food Safety Act 1990(food safety, quality, labelling)

E.g. ensure ORGANIC products are genuine.

www.nutrition.org.uk

•Info on nutrients, diseases and recommendations for different life stages.

What is a balanced diet versus

the average UK diet?

© British Nutrition Foundation 2003

BNF Recommendations for a Healthy Diet

© British Nutrition Foundation 2003

UK Diet - higher or lower?

Not enough Not enough

OKTooHigh Too

High

FSA 2001 UK Diet Survey

• Survey of 2000 men and women (16-64) asking how much food do they eat in g per week.

• Not enough fibre and pulses and pasta.

• Too much fat, sugar and salt.

• Particularly a concern in low income areas.

Health risks associated with nutrition imbalance

SaltSugarFibre

Vitamins

High fat

Health risks

• Cancer and cardiovascular disease (CVD) are the main cause (60%) of deaths in the UK and poor diet is a risk factor.

• Treating diet-related disease costs the NHS £2 billion each year

extra visits to GPtreatmentshospital visits

From www.bhf.org.uk(British heart foundation)

Salt

• 2001 FSA research foundwe eat on average of 9gof salt per day (9 heaped tspns)- should be 6g.

Why is dietary salt so high?What are the problems associated with it?Who is more prone to problems?

Write down answers

•75% of our salt intake is from processed foods and junk!

•Reducing salt intake can help reduce hypertensionwhich leads to to stroke, heart attack or kidney problems.

•Hypertension (systolic >140 and diastolic >90 mmHg)

•Older people at risk due to changes in elasticity of bloodvessels so are more prone to hypertension.

Salt – discussion results

Gov. aim to reduceNational blood pressureaverages.

So, 3 years after this research we are nowadvised to lower our salt levels.

www.salt.gov.uk

Sugar/Fat

• Sugar and fat intake isdeclining, but is still too high.

• The intake of saturated fatsis still too high.

• Intake of omega 3/6 oils istoo low.

Sugar/Fat

• Why is saturated fatintake high?

• What health risks are associatedwith high dietary sugar/fat levels?

Write down answers

•Junk food and processed (supermarket) foods are high in fat (particularly saturated). This makes the food palatable and tasty!

•Sugar is high in cereals, fizzy drinks and squash, often particularly targeted at children.

•Health consequences include

•Obesity•CVD•Diabetes•Stroke

Discussion results

Obesity Epidemic

From www.bhf.org.uk (British heart foundation)

http://www.bbc.co.uk/health/healthy_living/your_weight/bmiimperial_index.shtml

Obesity – BMI >30

Societal CausesEating more ready made meals(faster life styles)

The junk food revolution

Lack of awareness of dietaryrequirements

Unfortunately, junk food isoften cheaper

How much salt and fat?

50g fat

6g salt

Health Risks

• CVD and stroke

• Some cancers

• Type 2 diabetes

• Osteoarthritis due to strain on joints

• Effect on mental well being

• All increasing in children.

Cardiovascular disease CVD

• CVD = heart disease and stroke.• 250,000+ UK deaths per year.• Risk factors high fat/sugar, high salt,

smoking, alcohol and lack of exercise.

Heart Disease Pathogenesis

High levels of fat

Circulation

Can result in heart attack.

atherosclerosis

Fragment of fattyplaque blocks the

cerebral artery causingstroke

Stroke

Fat and Cholesterol

• Cholesterol is made by the liver and is a main component of plasmamembranes and steroid hormones.

• Cholesterol is also contained in foods – particularly saturated fats (eggs, meat).

• Saturated fat is made soluble for transport in the blood by combining with lipoproteins.

Importance of Lipoproteins3 types

1. High density (HDL) - the good guys which transports cholesterol from body cells to the liver for elimination.

2. Low density (LDL) – combines with cholesterol and deposits it, eg in arteries.

3. Very low density (VLDL) – involved in development of fatty plaques.

Ratios of lipoproteins in the blood is used to assess the risk of CVD.

Impact on Children

• 1 in 5 children are obese (7% of 4 yr olds)

• 1 in 20 are overweight

• Children are getting “adult” diseases like CVD and type 2 diabetes.

Why?

• Why is obesity increasing in children?

Diabetes Mellitus

• Excess blood glucose.

– Type 1 – natural onset in childhood – requires daily injections of insulin.

– Type 2 – maturity onset diabetes linked to obesity. The body stops reacting to insulin.

• Permanent disease associated with blood vessel damage, CVD and blindness.

Health risks associated with nutrition imbalance

SaltSugarFibre

Vitamins

High fat

•UK intake of fruit has increased, but not vegetables.

•Why is fibre important?•What diseases are associated with low fibre?

Fibre

Beneficial Effects of Fibre• Insoluble fibre – eg bran, bulk out the

intestines and help regulate transit.• Soluble fibre – eg oats, fruit and veg,

are fermented by the gut bacteria and can help reduce blood cholesterol and help with diabetes.

• Fibre contains ANTIOXIDANTS which are beneficial in protecting against cancer.

Health Risks of Low Fibre

• Short term – constipation.• Diverticulitis – small pouches form

in the colon which become inflamed.

• Bowel cancer – associated with low fibre intake, and increasingly common in younger people.

Outline

• Nutrition authorities in the UK• A balanced diet versus the UK diet

• Identify possible nutritional imbalances (e.g. salt, sugar/fat, vitamins, and fibre) and their impact on health.

• Lipid metabolism, saturated and unsaturated fats and role of HDL, LDL and VLDL in health.

• Raise current issues such as food allergy, food additives, food intolerance and genetically modified (GM) foodstuffs.

Other Topical Issues

• What else has been in the news?

• Go to the Food Standards Agency site for topical information.

Food allergyThe immune system reacts to food, causing vomiting and diarrhoea, and non-gastrointestinal conditions such as rashes, swelling and breathing problems. Can be very rapid onset and very severe.

Adverse Reactions

Food aversionSomeone has a dislike to a type of food eg SWEDE.

Food intoleranceA reaction to food causing symptoms such as vomiting and diarrhoea, but with no immune system involvement, e.g. lactulose intolerance (deficiency of LACTULASE).

GM Food Debate

PROs

Maize, soya, rice

Increase yield

Increase resistance to pests

Enhance nutritional properties

Remove harmful trace elements We have eaten animal/plant DNAfor years but there is a fear with eatingGM foods - Frankenstein foods

GM foods resistant to antibiotics may transferthe risk to us

We don’t know what we are eating– need for clearer labelling

CONs