CVD Risk Factors and Dietary Antioxidants

Reducing Risk Factors of CVD

CVD Risk Factors

• Definition: Cardiovascular disease (CVD) refers to conditions affecting the heart and blood vessels, commonly associated with:

  • Atherosclerosis: Formation of hard plaques in the artery lining.

  • Thrombosis: Formation of blood clots in arteries.

• Risk Factors: Factors linked to an increased risk of disease. Being exposed to a risk factor does not guarantee developing the disease (e.g., smokers have a higher risk but not guaranteed lung cancer).

• Types of Risk Factors:

  • Lifestyle Factors: Includes diet and alcohol consumption.

  • Environmental Factors: E.g., air pollution or exposure to harmful substances.

  • Genetic Predisposition: Inheritance of genes increasing disease risk.

  • Biological Factors: Age and biological sex.

• Interaction of Factors: Diseases, including CVD, are often caused by interactions among multiple factors. (E.g., a diet high in cholesterol, lack of exercise, and smoking contributes to artery damage.)

• Control Over Risk Factors: Lifestyle-related factors are to some extent controllable by individuals (e.g., diet, smoking, exercise), though some factors (e.g., genetics, age) are beyond control.

Lifestyle Factors Linked to CVD

• A table detailing various lifestyle risk factors and their contributions to the risk of developing CVD. These may include factors like obesity, sedentary lifestyle, and poor dietary choices.

Other Factors Linked to CVD

• A table examining additional risk factors not linked directly to lifestyle choices, potentially including genetic disorders, existing health conditions, and socio-economic status.

Dietary Antioxidants & CVD

Importance of Antioxidants

• Definition: Antioxidants are compounds that protect cells from damage caused by free radicals. Fruits and vegetables are rich in antioxidants and are considered beneficial to health.

  • Examples of Antioxidants:

  • Vitamin A: Found in orange vegetables (carrots, sweet potato).

  • Vitamin C: Found in citrus fruits.

  • Vitamin E: Found in leafy greens, nuts, and oils.

The Evidence for Antioxidants and CVD

• Positive associations between fruit/vegetable intake and lower heart disease risk due to antioxidants.

• Studies:

  • Finnish study (1984-1992) with 1,605 men:

  • 13.2% of men with low Vitamin C had a heart attack.

  • 3.8% with normal Vitamin C levels experienced the same.

  • Suggested a correlation between Vitamin C intake and heart health.

Inconclusive Evidence

• 2016 Meta-Analysis: Did not find a clear link between Vitamin C intake and heart disease risk. Suggested the potential for harm from antioxidant supplements.

Conflicting Evidence

• In research, conflicting evidence must be acknowledged, and the totality of evidence should be considered before drawing conclusions.

Core Practical 2: Investigating Vitamin C Content of Food & Drink

Vitamin C Overview

• Importance: Essential for connective tissue health.

• Chemical Name: Ascorbic acid; acts as a reducing agent, readily oxidized.

Detection Method

• Titration with DCPIP:

  • DCPIP (Dichlorophenolindophenol): A blue dye that turns colorless in the presence of Vitamin C.

  • Method:

  1. Prepare various concentrations of Vitamin C through serial dilution.

  2. Titrate Vitamin C solutions against DCPIP in a test tube until color change occurs.

  3. Record the volume of Vitamin C added for complete decolorization.

Apparatus Required

• Vitamin C solutions and 1% DCPIP solution. Distilled water, measuring cylinder, pipette, stopwatch, test tubes.

Test Procedure

1. Measure out 1 cm of DCPIP into a test tube.

2. Add vitamin C solution drop by drop to DCPIP, shaking constantly.

3. Note the number of drops needed to turn DCPIP colorless.

Results Analysis

• Higher concentrations of Vitamin C require fewer drops to decolorize DCPIP. Create a calibration curve plotting Vitamin C concentration versus required volume for decolorization.

Risk Assessment

• Note that DCPIP is an irritant; proper safeguards (e.g., goggles) must be in place.

Interpreting Data on Risk Factors

Analyzing Data on Illness and Mortality

• Correlation vs. Causation: Just because two variables are correlated does not mean one causes the other. Multiple factors can influence disease prevalence.

  • Describing Data: Identify trends and state findings with supporting numbers (e.g., highest relative risk in oldest age groups).

  • Drawing Conclusions: Note relationships indicated by data without overstepping to causation.

Validating Data

• Sample Size: Larger sizes generally yield more valid results; sample must represent the broader population.

• Control Variables: Understanding experimental design helps validate findings. Bias must also be avoided in research.

  • Example Data: Non-smokers at 0 cigarettes/day risk = 1.0; 20+ cigarettes/day risk = 1.31.

Worked Example: Data Application

• Assess relative risk findings in relation to smoking and CVD, addressing validity concerns regarding sample size and control variables.

  • Conclusion Statement: Correlation exists between smoking exposure and increased CVD risk but lack sufficient evidence for direct causation.

  • Need for Additional Studies: Repetition and evidence from multiple sources increase confidence in findings.

Designing Studies into Effects of Risk Factors

Characteristics of a Good Study

• Sample Selection: It must be representative; random selection helps avoid bias.

• Controlling Variables: Ensure that only one independent variable is tested while controlling others.

• Repetition and Reproducibility: Findings should be consistent across repetitions.

• Bias Avoidance: Data collection and analysis must be unbiased and transparent.

Example of Experimental Design

• In drug trials, control groups receive a placebo to gauge the impact of new medication accurately. Repeating studies enhances reliability.

Perception of Risk vs Actual Risk

Definitions and Implications

• Risk Definition: The statistical probability that a harmful event occurs, supported by research.

• Perceptions of Risk: Varied perception due to multiple factors:

  • Overestimation Factors: Misleading media, personal experiences, lack of familiarity with events.

  • Underestimation Factors: Lack of information or personal experience, non-immediate harm, etc.

Statistics

• Example statistics contrasting risks:

  • Global annual risk for road accidents: 1 in 1,547.

  • Global annual risk for flight-related deaths: 1 in 4.5-5.5 million.

Data on Cholesterol & Lipoproteins

Definition and Role of Cholesterol

• Cholesterol is vital for cell membrane structure and function, lipid transport via lipoproteins.

• Lipoproteins split into:

  • HDLs (High-Density Lipoproteins): Transport cholesterol to the liver, lowering blood levels of LDLs and helping in the removal of atherosclerotic plaques.

  • LDLs (Low-Density Lipoproteins): Transports cholesterol to body tissues, higher levels contribute to plaque formation in arteries.

Cholesterol Impact on CVD

• Good vs. Bad Cholesterol: Ideally maintaining a LDL:HDL ratio of 3:1, while a ratio >5:1 suggests increased risk of heart disease.

• Influencing factors beyond diet, including genetic/metabolism patterns.

Evaluating Data from Health Risk Studies

• Emphasis on sample size, representative characteristics, control groups, and validating statistical significance in findings.

Data on Effect of Diet Measurements to Reduce CVD Risk

Diet and CVD

• Many studies link high saturated fat diets with an increased CVD risk, while some remain inconclusive.

• Public health education focusing on label awareness and healthy choices.

Identifying Obesity

• Metrics: Waist-to-hip ratio (women <0.86; men <1.0) and Body Mass Index (BMI).

• BMI Categorization:

  • Underweight: BMI <18.5.

  • Normal: 18.5 - 24.9.

  • Overweight: 25 - 29.9.

  • Obese: 30 or higher.

Public Health Initiatives

• Anti-smoking campaigns, availability of cessation resources, exercise encouragement in educational settings.

Treatments for CVD - Benefits & Risks

Treatment Options

• Various Treatments:

  • Antihypertensives: Reduce blood pressure, lower heart rate, dilate blood vessels.

  • Statins: Reduce LDL cholesterol, decrease inflammation.

  • Anticoagulants: Lower blood clotting risk.

  • Platelet Inhibitors: Prevent platelet aggregation, reducing clot formation.

Summary of Benefits and Risks

Conclusion

• While pharmacological therapies for CVD can yield benefits, careful monitoring of side effects and lifestyle management remains essential as part of comprehensive patient care.