Effects of High Fruit, Vegetable, and Dairy Intake on Plasma Lipids and Blood Pressure in Healthy Individuals

Effects of a Modified Lower Carbohydrate, Higher Fat DASH Diet Plan on Plasma Lipids, Lipoprotein Particle Size, and Blood Pressure in Healthy Adults

The Dietary Approaches to Stop Hypertension (DASH) trial has been shown to reduce blood pressure and plasma total and LDL-cholesterol (C) compared to a Western diet, but shows no benefit on other blood lipid variables associated with cardiovascular disease (CVD) risk, namely HDL-cholesterol and triglycerides. The overall objective of this study is to determine whether modification of the DASH diet by substituting carbohydrate with fat will result in improvements in multiple biomarkers of CVD risk. Specifically, the investigators will test the hypotheses that modification of the DASH diet by reducing carbohydrate, primarily in the form of simple sugars and glycemic starches, and allowing for a more liberal intake of total and saturated fat, primarily from dairy foods, will: (1) improve lipoprotein markers of CVD risk (reduced total/HDL-C ratio, apolipoprotein B, small LDL particles, and increased HDL-C, apoAI, and large HDL particles); and (2) result in comparable reductions of systolic and diastolic blood pressure to those achieved with the standard DASH diet. The investigators will also assess the effects of the modified DASH diet on markers of insulin resistance and inflammation. Our main hypotheses will be tested by a controlled dietary intervention conducted in 40 healthy men and women who will be randomly allocated to consume, for 3 weeks each, a control Western diet, a standard DASH diet, and a modified low-carbohydrate DASH diet, separated by 2-week washout periods.

Inclusion Criteria:

• Age 22 years and older
• Average systolic blood pressure <160 mm Hg and diastolic blood pressure 80 - 95 mm Hg measured on 2 separate days
• Non-smoking
• Agrees to abstain from alcohol and dietary supplements during the study
• Willing to consume all study foods as instructed

Exclusion Criteria:

• History of coronary heart disease, cerebrovascular disease, peripheral vascular disease, bleeding disorder, liver or renal disease, diabetes, lung disease, HIV, or cancer (other than skin cancer) in the last 5 years.
• Taking hormones or drugs known to affect lipid metabolism or blood pressure.
• Body Mass Index (BMI) > 35
• Total- and LDL-cholesterol > 95th percentile for sex and age.
• Fasting triglycerides > 500 mg/dl.
• Fasting blood sugar (FBS) > 126 mg/dl.
• Abnormal thyroid stimulating hormone
• Not weight stable
• Pregnant or breast-feeding