Cardiovascular (CV) Risk
Conditions
Keywords
dairy, diet, nutrition, LDL-cholesterol, cardiovascular disease
Brief summary
The purpose of this study is to find out if full-fat dairy and low-fat dairy have similar effects on risk factors for heart disease and diabetes. During the study, participants will consume two types of dairy products: low-fat dairy (milk, yogurt, and cheese) and full-fat dairy (milk, yogurt, and cheese). Each type of dairy will be consumed for 6 weeks with a ≥4-week break between. Measures will be taken to evaluate blood cholesterol, blood sugar, body weight, inflammation, blood pressure, heart health and dietary intake at the beginning and end of each 6 week period.
Detailed description
The overarching goal of this clinical trial is to characterize and compare the effect of full-fat dairy to low-fat dairy on low density lipoprotein cholesterol (LDL-C) and other cardiometabolic disease (CMD) risk factors in healthy adults and those at risk for CMD. This goal will be achieved with the following objectives: 1. Characterize the effect of full-fat dairy compared to low-fat dairy on LDL-C and other CMD risk factors in healthy adults and adults at risk for CMD after 6 weeks. 2. Compare the effect of full-fat dairy to low-fat dairy in healthy adults vs. adults at risk for CMD after 6 weeks. This clinical trial will test two hypotheses: 1) intake of 3 cup-equivalents/day of full-fat dairy (milk, yogurt & cheese) has equivalent effects on LDL-C and other CMD risk factors to 3 cup-equivalents/day of low-fat dairy (milk, yogurt & cheese) in adults with normal BMI and optimal/near optimal LDL-C, and in adults with overweight/obesity and elevated LDL-C after 6 weeks; 2) the effect of full-fat dairy on LDL-C and other CMD risk factors, compared to low-fat dairy, is equivalent in adults with normal BMI and optimal/near optimal LDL-C compared to adults with overweight/obesity and elevated LDL-C after 6 weeks. This trial is expected to demonstrate equivalent effects of full-fat and low-fat dairy on LDL-C and other CMD risk factors in both healthy and at-risk adults. This is a randomized clinical trial with 2 groups of adults. Group 1 will include adults with normal BMI (18.5 -24.9 kg/m2) and optimal/near optimal LDL-C (≤ 129 mg/dL). Group 2 will include adults with overweight/obesity (25-39.9 kg/m2) and elevated LDL-C (130-190 mg/dL). Within each group, subjects will undergo two 6-week dietary conditions in random sequence order, separated by a 4-week washout: 1) 3 cup-equivalents/day of full-fat dairy; 2) 3 cup-equivalents/day of low-fat dairy. Outcomes will be assessed at the start and end of each period.
Interventions
OTHERFull-fat dairy
3 cup-equivalents/day of full-fat dairy (milk, yogurt \& cheese)
OTHERLow-fat dairy
3 cup-equivalents/day of low-fat dairy (milk, yogurt \& cheese)
Sponsors
Penn State University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
25 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* BMI 18.5 to 39.9 kg/m2 * LDL-C ≤190 mg/dL assessed by the Modified Sampson-NIH Equation * Currently consume milk, yogurt, and/or cheese daily * Willing to eat 3 servings of dairy (milk, yogurt, cheese) for two 6-week periods during the study
Exclusion criteria
* Hemoglobin \<13.2 g/dL for men or \< 11.7 g/dL for women at screening * Fasting triglycerides \>350 mg/dL at screening * ≥10% change in body weight within the 6 months prior to enrollment * Blood pressure \>140/90 mmHg at screening * Fasting glucose ≥126 mg/dL * Type 1 or type 2 diabetes * Takes any (prescription or over-the-counter) anti-hypertensive, lipid-lowering, glucose-lowering or anti-inflammatory drugs, or drugs that alter body weight * Intake of supplements that affect the outcomes of interest (i.e., lipids, blood pressure, glucose, body weight, inflammation and microbiome) and are unwilling to cease during the study period. * Unwilling to refrain from starting to take any supplements, vitamins, nutritional products, or health foods that are not prescribed by a doctor for the duration of the study * History of liver, kidney, or autoimmune disease * Prior cardiovascular event (e.g., stroke, heart attack) * Current pregnancy or intention of pregnancy within the next 12 months * Lactation within the prior 6 months * Dairy allergy/intolerance/sensitivity/dislike * Antibiotic use within the prior four weeks * Oral steroid use within the prior four weeks * Use of tobacco or nicotine-containing products within the past 6 months * History of cancer at any site within the past 10 years (eligible if ≥10 years without recurrence) or non-melanoma skin cancer within the past 5 years (eligible if ≥5 years without recurrence) * Participation in another clinical trial within 60 days of baseline * Currently following a restricted or weight-loss diet * Prior bariatric surgery * Intake of \>14 alcoholic drinks/week and/or not willing to avoid alcohol consumption for 48 hours prior to test visits * Does not speak and/or understand English * Unwilling to refrain from donating blood and/or plasma during the study * Weight \<110 lb * Lactose intolerance or sensitivity * Unwilling to contact study staff before enrolling in other health-related research and avoid participating in any research that may interfere with this study * For individuals taking thyroid medication: abnormal thyroid stimulated hormone (TSH) concentration, or change in dose of thyroid medication within the last 6 months * Principal Investigator discretion related to the potential participant's ability to adhere to the study requirements, including being able to come to attend visits
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| LDL-cholesterol change | 6 weeks | Assessed from fasting blood draw expressed in mg/dL. LDL-cholesterol will be calculated via the Modified Sampson-NIH Equation. Change in LDL-cholesterol will be calculated as the mean of the end of intervention measures (i.e., mean of day 1 and day 2 values) minus the mean of the pre-intervention measures (i.e., mean of day 1 and day 2 values). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Apolipoprotein B change | 6 weeks | Assessed from fasting blood draw expressed in mg/dL. |
| Triglycerides change | 6 weeks | Assessed from fasting blood draw expressed in mg/dL. |
| Total cholesterol change | 6 weeks | Assessed from fasting blood draw expressed in mg/dL. |
| HDL-cholesterol change | 6 weeks | Assessed from fasting blood draw expressed in mg/dL. |
| non-HDL cholesterol change | 6 weeks | Assessed from fasting blood draw expressed in mg/dL. |
| Glucose change | 6 weeks | Assessed from fasting blood draw expressed in mg/dL. |
| Insulin change | 6 weeks | Assessed from fasting blood draw expressed in micro IU/ml. |
| Fructosamine change | 6 weeks | Assessed from fasting blood draw expressed in umol/L. |
| Homeostatic model of insulin resistance (HOMA-IR) change | 6 weeks | Calculated from insulin and glucose measured from a fasting blood sample. Calculated as (insulin × glucose) / 22.5 |
| C-reactive protein change | 6 weeks | Assessed from fasting blood draw expressed in mg/L. |
| Body weight change | 6 weeks | Measured in the fasting state using a calibrated electronic scale. |
| Brachial systolic and diastolic blood pressure change | 6 weeks | Measured in the fasting state using a SphymoCor Xcel (Atcor Medical) |
| Central systolic and diastolic blood pressure change | 6 weeks | Measured in the fasting state using a SphymoCor Xcel (Atcor Medical) |
| Carotid-femoral pulse wave velocity change | 6 weeks | Measured in the fasting state using a SphymoCor Xcel (Atcor Medical) |
| Diet quality change | 6 weeks | Healthy Eating Index-2020 assessed using 24-hour recalls |
Contacts
CONTACTKristina Petersen, PhD
CONTACTStacey Meily
PRINCIPAL_INVESTIGATORKristina Petersen, PhD
The Pennsylvania State University
Outcome results
None listed