In: Anatomy and Physiology
Nutrition is an important factor associated with risks for chronic diseases. For example, we know that some dietary factors promote disease while others are preventative. Choose one chronic disease – cardiovascular disease, hypertension, diabetes or cancer – and describe how nutrition can prevent or reduce the risk for that disease. Also, describe some nutritional behaviors that can increase the risk for your chosen disease.
Many predictors of coronary events are in some way attributable to lifestyle. These include cigarette smoking, weight, serum cholesterol and triglycerides, low HDL-cholesterol, blood pressure, physical activity, alcohol intake, and fruit and vegetable consumption. The most sensitive method of identifying those at risk is to use the total cholesterol concentration of more than 6.5 mmol/l, and more accurately the total cholesterol:HDL-cholesterol ratio and apply these to the Sheffield tables. The Sheffield tables and the New Zealand tables take into account the key variables in coronary artery risk: systolic hypertension, smoking, diabetes, total:HDL-cholesterol ratio, age and gender.
• Smoking: Coronary deaths occur twice as often in smokers
compared with non-smokers. Stopping smoking is possibly the most
important step in reducing the risk of CHD. Socio- economic factors
acting over the lifetime of the person affect health and the risk
of premature death.
• Obesity or waist:hip ratio (indicative of central obesity)
adversely affects the risk factors by significant amounts.
Cardiovascular mortality increases by 40% with a BMI between 24 and
30, and by 100% with a BMI over 30.
• Cholesterol reduction: using such a measurement as the serum
triglyceride has little predictive value. Every 1% decrease in
serum cholesterol is rewarded by a 1.5–2.5 % decrease in risk. This
is achieved by diet with a reduced fat intake, by using
polyunsaturated fatty acids and reducing weight to the ideal for
height. Eating oily fish two or three times a week is helpful. In
populations at risk of CHD, there is an individual variation in
response to changes in dietary fat. This is not due to variable
dietary compliance and may be determined by individual lipid
metabolic activi- ties, apolipoprotein concentrations and other
polygenic factors.
• Alcohol: small amounts are protective, but more than 25
units/week are harmful.
• Fruit and vegetables contain many positive addi- tions to a
healthy diet and are recommended.
• Food frequency: concentrations of cholesterol
and low-density lipoproteins are favourably affected by the
frequency of eating. Eating six times a day reduces by 5% on
average the serum cholesterol and LDLs. Serum cholesterol con-
centrations fall after the age of 70 years, but with- out reduction
in the rate of CHD.
• Blood pressure reduction: this may be helped by weight loss,
reducing salt intake, alcohol reduction and exercise, but most of
all by hypotensive therapy.
• Exercise: helps the general condition and aug- ments
lipid-reduction regimens. Maintaining or taking light or moderate
exercise reduces mor- tality and heart attacks in older men with or
with- out diagnosed cardiovascular disease.
• Educational status is important; studies have demonstrated that
less educated people in India have a higher prevalence of CHD,
hyper- tension and smoking.
Coronary heart disease (CHD) is associated with populations who eat a high saturated fat intake and in whom the serum lipids are increased. The CHD in such populations is, to a large extent, concentrated within genetically vulnerable families.