Peanuts for Cardiometabolic, Brain, and Intestinal Health

In the US, 37.1 million adults have diabetes mellitus and 96 million have prediabetes. Type 2 diabetes mellitus (T2DM) accounts for 95% of the cases and results in many public health complications that increase economic burden and reduce productivity and quality of life. Eight out of 10 people with T2DM die from cardiovascular disease, while those with T2DM also face a 50% higher risk of developing dementia compared to healthy individuals. Also, studies indicate that intestinal health significantly influences the development of T2DM. Of note, the burden of T2DM is particularly pronounced in non-Hispanic Black and Hispanic populations compared to the non-Hispanic White population. Prevention and treatment of T2DM focus on lifestyle changes including dietary modifications. Plant-based foods, including peanuts and peanut products, have been increasingly recognized for their importance in the prevention and management of prediabetes and T2DM due to their unique nutritional profile, including their favorable fatty acid composition, fiber content, and bioactive compounds. While emerging evidence indicates that peanut improves cardiometabolic, cognitive and intestinal health, no studies have collectively and comprehensively evaluated the effects of peanut or peanut product consumption on the cardiometabolic, cognitive, and intestinal health of individuals with prediabetes or T2DM. Thus, this study aims to investigate whether adults with prediabetes consuming 43 g of peanut butter (1 snack cup) 3 x/week, 42 g of dry roasted peanuts (1/3 of a cup) 3x/week, or 56 g of peanut flour 1x/week for six months will have 1) reduced levels of serum HbA1c, fasting glucose (FBG), insulin, HOMA-IR (homeostatic model assessment of insulin resistance) and improved lipid profile, 2) reduced blood pressure, improved endothelial function, arterial stiffness and microvascular function, 3) Improved gut microbiota composition and reduced intestinal permeability, 4) improved cognitive function (verbal memory and executive functions [inhibition, working memory, cognitive flexibility]) and brain health metrics as assessed by neuroimaging, and 5) reduced serum markers of oxidative stress and inflammation. The effectiveness of the intervention on the abovementioned outcomes among races including non-Hispanic Black (NHBA), non-Hispanic White (NHWA), non-Hispanic Asian (NHAA) and Hispanic (HA) adults will also be compared. Lastly, whether changes in cardiometabolic and cognitive outcomes are associated with changes in intestinal microbiota outcomes and whether changes in cardiometabolic outcomes are associated with changes in cognitive function parameters will be explored.

Inclusion criteria

• men and women
• 20-59 years of age
• BMI: 24.5 - 35.5 kg/m^2
• Prediabetes (fasting blood glucose levels 100-125 mg/dL and/or HbA1c between 5.7-6.4%)
• Ability to give consent

Exclusion criteria

• Allergies to peanuts and peanut products
• Use of insulin, antidiabetic, antibiotics, and anti-inflammatory drugs
• Active cancer, gastrointestinal, renal, cardiovascular, thyroid, and neurological diseases or severe head injury
• Smoking
• Consumes greater than 2 alcoholic beverages per day
• Consumes antioxidant, probiotic, and prebiotic supplements
• Pregnant or Lactating
• Actively participating in a weight loss program

MRI Exclusion Criteria:

• Certain neurological disorders (e.g., uncontrolled seizure disorders)
• Braces on their teeth, a cardiac pacemaker; hearing aid; other metal in the body or eyes (which may include certain metallic-embedded tattoos), including but not limited to pins, screws, shrapnel, plates, dentures or other metal objects