A randomized, clinical trial to provide the first comprehensive investigation of the role of fatty acid desaturate (FADS) genetic determinants on PUFA biosynthesis and metabolism as well as levels of inflammatory markers in a controlled dietary environment using two (low and high linoleic acid) parallel diets.

Participants will be provided (weekly) with food items containing most of (>90%) the daily dietary fat (25-30% of daily calories) to be consumed. All study-supplied foods will be prepared by or acquired by the Wake Forest University Health Sciences (WFUHS) Clinical Research Unit (CRU) Metabolic Kitchen and distributed by the same. These foods will include smoothies (containing flaxseed oil common to both arms), and arm-dependent oil-based condiments (salad dressing, mayonnaise, and margarine) and prepared snack foods, each made with the arm-specific oil, as well as several packaged snacks and food items. Participants will be provided meal plans and recipes for home preparation of meals that will allow them to adhere to the target fatty acid contents of the two dietary arms. The goal of the dietary intervention is to provide participants with the daily fat content of their diet (25-30% of the daily calories) and to educate the participant to select and consume the balance of nutrients (60-75% of daily calories) derived from non-fat/low-fat containing foods.

Inclusion Criteria:

• Able to give informed consent
• Must agree to adhere to dietary intervention requirements during the entire 12-week study period
• Be willing to participate for the whole study
• Agree not to take any PUFA-based dietary supplements during the study
• Agree not to take interfering medications during the duration of the study
• Agree to allow samples to be stored for future use
• Self-identify as European American or African American

Exclusion Criteria:

• A diagnosis of diabetes, cancer, heart disease, arthrosclerosis, asthma, multiple sclerosis or chronic joint disease or the occurrence heart attack or vascular surgery within the past year, untreated high blood pressure or a history of stroke, having a pacemaker or a defibrillator
• use of tobacco products (smoked, smokeless, electronic) within the last six months
• Currently pregnant or lactating. Potential female subjects are asked in the telephone screening if they are pregnant or plan to become pregnant in the next year. Those answering in the affirmative are excluded. We will include in the Institutional Review Board (IRB) protocol and consent that subjects agree to use a reliable method of birth control during the time they are in the study.
• Having a current or recent history of eating disorders
• Having an allergy to safflower or, flaxseed or olive oils.
• fasting triglycerides (TG) greater than 150 mg/dl, as measured by Lab Corp at screening
• BP greater than 140/90 , as measured by a CRU nurse, at screening
• BMI equal to or greater than 30 or less than 19, as measured at screening
• fasting glucose greater than 125 mg/dl, as measured by Lab Corp at screening
• use of aspirin (>100 mg /day), NSAIDS or oral corticosteroids
• use of montelukast-type of allergy medications
• use of statins, niacin or fibrates or other lipid lowering medications
• use of botanical/fish (PUFA-containing) oil or dietary supplements for one month prior to joining the study .
• individuals not self-identifying as European American or African American
• individuals self-identifying as Hispanic
• Individuals of vulnerable populations, including children, will not be recruited for this study
• having an hsCRP measurement in excess of 3.0 at Visit 1