Diet and Vascular Health Study

Diet and Vascular Health Study

The aim of this study is to examine the effects of a diet rich in broccoli on cardiovascular disease risk using biochemical indicators such as blood lipid profiles, most notably cholesterol; markers of inflammation as well as established physiological measurements such as Pulse wave velocity (PWV), Augmentation index (AIx) and Ambulatory Blood Pressure Measurements (ABPM). Broccoli contains compounds known as glucosinolates which are metabolised to isothiocyanates when consumed. The major glucosinolate in broccoli is known as glucoraphanin which produces the isothiocyanate sulforaphane. The glucosinolates are thought to be the principal component in broccoli that may reduce CVD risk. The investigators will use a standard cultivar of broccoli and a cultivar that has enhanced levels of glucosinolates ('HG broccoli'). This broccoli has been used in previous intervention studies (e.g. ClinicalTrials.gov NCT00535977). Volunteers will be asked to consume 400g of standard broccoli, HG broccoli or peas each week over a 12 week period in a double blinded (for the broccoli) parallel study. The volunteers recruited will, according to the Joint British Societies (JBS 2) Guidelines on the prevention of cardiovascular disease (CVD) in clinical practise, have a 10-20% (mild to moderate) risk of developing cardiovascular disease or having a cardiovascular (CV) event in the next 10 years.

Inclusion Criteria:

• Men and women aged ≥ 50 years will be recruited onto the study using the JBS 2 cardiac risk assessor calculator (Copyright University of Manchester 1998): Scores of 10-20% will be acceptable for participation in the study.

• Total cholesterol ≥ 5.0mmol/L

• Blood pressure measurements

  • Systolic≥ 120mmHg
  • Diastolic ≥ 80mmHg
  • BMI ≥20
  • Smokers and Non Smokers

Exclusion Criteria:

• Diagnosed diabetics;
• Fasting glucose >6mmol/L;
• Blood pressure <90/50 or 95/55 if symptomatic; >160/100
• Chronic kidney disease;
• Those on any lipid lowering therapies like statins, bile acid sequestrants, cholesterol absorption inhibitors and nicotinic acid;
• Those who have suffered a cardiovascular event like stroke, myocardial infarction or trans ischemic attacks;
• Peripheral vascular disease including Claudication
• Consumption of fish oil supplements (unless volunteer is willing to discontinue their use 4 weeks prior to the start of the)
• Parallel participation in another research project which involves dietary intervention and/or sampling of biological fluids/materials
• Any person related or living with any member of the study team
• Participation in another research project which involves blood sampling within the last four months; Blood from both studies should not exceed 470mL
• BMI <20
• BMI >40
• Fasting total cholesterol > 8.0mmol/L
• Gastrointestinal disease (excluding hiatus hernia) unless symptomatic or study intervention/procedure is contraindicated
• Going on holiday for more than 7 days in any single period or within 2 weeks of their clinical appointment at the CRTU
• Currently suffering from or have suffered from any neck and throat injuries and surgery