Nutrition Research

Culinary Herbs and Intestinal Permeability (CHIP) Study

Alexandra Vita, PhD, Ryan Bradley, ND, MPH, Heather Zwickey, PhD

This cross-sectional study aims to examine the relationship between the use of culinary herbs and spices, intestinal health, and inflammation. To do so, we will evaluate if associations between culinary herb-derived polyphenol consumption, the gut microbiome, and intestinal permeability biomarkers differ between healthy adults and adults with rheumatoid arthritis (RA).

Increasing evidence suggests that polyphenol consumption may exert a protective effect on intestinal barrier function through several microbiota-mediated mechanisms. Therefore, we hypothesize that intestinal dysbiosis, such as that which is experienced by many individuals with RA, may impact the beneficial bioactivity of these compounds. Further assessment of these relationships may have future implications for dietary recommendations in the context RA.

Food As Medicine Everyday Research (FAMER): Evaluating Physiological Changes Associated with a Shift Toward a Whole-Foods Diet

Principal Investigator: Kim Tippens ND, MSAOM, MPH

Clinical Investigator: Andrew Erlandsen, ND

Abstract: Diabetes and heart disease are serious public health problems affecting more adults each day. Pre-diabetes, or impaired glucose tolerance without a formal diagnosis of diabetes, is becoming more common in the United States.  Without adequate prevention, those with pre-diabetes are likely to develop type 2 diabetes within 10 years.  People with pre-diabetes are also at increased risk for developing cardiovascular disease.  Promoting changes in diet and physical activity are the key behavioral targets for preventing progression to type 2 diabetes.  Diabetes and CVD are highly co-morbid conditions that share a number of risk factors.  Dietary intake is one of the key behavioral risk factors for these and other chronic diseases.  As such, the United States Department of Agriculture (USDA), local governments, healthcare institutions, and community-based public health agencies have adopted health promotion and nutrition education programs to support health behavior change.  Structured community-based programs may provide the greatest impact in communities at high risk for behaviorally-mediated chronic diseases.  This study will measure the health impacts of a physician-led 12-week whole-foods nutrition education program among 60 Portland-area adults with or at risk for pre-diabetes.  This pre/post assessment will measure the degree of change in physiologic and behavioral outcomes.  We hypothesize that active participation in the FAME course will be associated with reductions in markers of diabetes and CVD risk, including hs-CRP, hemoglobin A1c, and lipids, which will be sustained after program completion.  We will assess whether a whole-foods nutrition curriculum increases vegetable and whole grain consumption using a validated food frequency questionnaire.

Impact of IgG Food Sensitivity Elimination Diet in an Overweight/Obese Population

Principal Investigator: Rachel Neuendorf, ND

Up to one-fifth of adults report having a food sensitivities or allergies. Symptoms of food intolerance are diverse and include skin rashes, abdominal complaints, fatigue, and mood changes. The gold standard test for food sensitivities is an elimination diet, which can be difficult to assess as reactions can take hours or days to appear. Using IgG antibody testing to identify food sensitivities could provide a more targeted elimination diet approach to relieving symptoms. Studies have shown that people with food sensitivities have an increased gut permeability which is likely caused by inflammation. Systemic inflammation present in people with an elevated BMI may increase the risk of food sensitivities via increased gut permeability and/or chronic impairment of immunological tolerance. An effective method to identify food sensitivities can help people develop an effective dietary plan to reduce sensitivities and improve quality of life.

This randomized, controlled trial assessed the effect of an elimination diet plus nutritional counseling on serum IgG titers after three months. Participants were randomized to either an intervention group or waitlist group for three months. Food IgG testing was performed and the intervention group was instructed to eliminate up to 10 foods, for which they had high titers of IgG. Participants in the intervention group communicated with health coaches for nutritional counseling for meal planning and adherence. The waitlist group did not receive their IgG testing results or health coaching.

The primary outcome was serum IgG titers for foods that were eliminated during the study based on elevated IgG titers at baseline. Secondary outcomes included quality of life and change in participant-identified symptom severity. IgG antibody concentrations decreased in 83% of the targeted foods in the treatment group and in 60% of the foods in the waitlist group, but this was not found to be a statistically significant difference. The only statistically significant finding in the study was that the intervention group reported improvement in sleep during the trial compared with the waitlist group.

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Effect of the Anti-Inflammatory Diet in People with Diabetes and Pre-Diabetes

Principal Investigators: Heather Zwickey, PhD and Patricia Elmer, PhD (NUNM), Annie Moore, MD (OHSU)

A collaboration between NUNM’s Helfgott Research Institute and Oregon Health and Science University (OHSU), this NIH-funded study examined the effects of the naturopathic anti-inflammatory (AI) diet in type 2 diabetics and pre-diabetics. Type 2 diabetics and pre-diabetics often have a mild inflammatory response with elevated levels of cytokines – proteins that stimulate an immune response. This study looked at the levels of inflammatory cytokines and other inflammatory markers in participants who consumed the AI diet or a diet based on American Diabetic Association (ADA) recommendations for six weeks.

The AI diet is designed to reduce inflammation by eliminating inflammatory and allergenic foods, and promoting anti-inflammatory foods. Anti-inflammatory diets typically exclude foods such as wheat, corn, soy, dairy, beef, pork, nightshade vegetables, citrus fruits, processed oils, alcohol, caffeine and peanuts and emphasize fruits, vegetables, fish, whole grains and nuts. The excluded foods are thought to either stimulate an inflammatory response in the gastrointestinal tract, or act as an allergen in certain individuals.

Study results indicated that for patients with pre-diabetes and diabetes, both the AI diet and the diet based on recommendations from the ADA showed modest improvements in body weight and trends in benefits for inflammation and biomarkers associated with cardiovascular disease and diabetes. The study was not able to find a specific benefit of eliminating foods that have commonly been linked with inflammation. The data also suggests that any benefits in inflammation could be the result of weight loss rather than the specific elimination of inflammatory foods and/or inclusion of anti-inflammatory fats. As this was a small pilot study in a small number of participants, additional research is needed.

This research was funded by NIH-NCCAM, grant number R21AT002374.

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A Mixed-Method Evaluation of Local Community Health Education on Food Intake and Behavior Change

Principal Investigator:  Kim Tippens, ND, MSAOM, MPH
Student Investigator: Bob Graybill


Introduction: Cooking nutritious meals is an important part of maintaining health.  With levels of obesity, diabetes, and other preventable diseases rising, public health programs that focus on nutrition and cooking education are becoming more common.  It is important to understand the motivations and barriers of participants in these programs to support behavior change.

Methods: This study offers a mixed methods analysis of participants’ experiences with the Food as Medicine Everyday (FAME) classes taught in northwest Oregon from 2013-2015.  Surveys including the FAME Assessment Survey (FAS), designed for this class and the Patient Activation Measure (PAM) were collected at the beginning and the end of the 12-week class.  Semi-structured interviews were conducted with a sub-group of participants and analyzed using thematic analysis by the research team.

Results: Thirty-Four individuals completed the surveys.  Participants reported a significant decrease in eating at restaurants and an increase in cooking at home as well as an increase in total whole grain consumption.  Non-significant trends showed an increase in total vegetable consumption and decrease in refined grain consumption. There was also a small but significant increase in patient activation level, studied by the Patient Activation Measure survey (PAM).  Eight individuals completed the semi-structured interviews which gave insight into each participant’s motivations for health and food behavior changes and the barriers impeding these changes.  Primary motivators for food behavior change and taking the FAME class were health concerns and a desire to change food choices.  Chief barriers to behavior change included time management, organization, a lack of knowledge and self-reporting oneself as a poor cook.  These barriers can be mitigated and changes facilitated by the structure of the class and the importance of family, friends and peer participation.

Conclusions: According to the limited survey responses and the interviews, participants in the FAME classes successfully implement some targeted food behavior changes including cooking more at home, reducing meals out at restaurants and changing food choices  Further research is needed to determine exactly which food behaviors change.  Our findings underscore the importance of nutrition education and cooking programs that encourage partnering and family involvement and focus on not only food preparation but food selection and shopping.

Impact of a Short-Term Naturopathic Whole-Foods-Based Nutrition Education Intervention on Dietary Behavior and Diabetes Risk Markers

Principal Investigator:  Kim Tippens, ND, MSAOM, MPH
Student Investigator: Robert Graybill

Americans increasingly consume processed foods, which contain more sugar and fat than whole, unprocessed foods and less protein, fiber and micronutrients. Evidence demonstrates the increased risk of diabetes, chronic inflammation, and cardiovascular disease (CVD) is associated with intake of added sugars and highly processed oils.

This nonrandomized pilot study assessed the impact of a 12-week nutrition education course based on naturopathic principles and whole foods. Forty five adult participants with or at risk for prediabetes were assessed for changes in markers  of  diabetes  and  cardiovascular  disease  risk,  including  high-sensitivity C-reactive protein (hs-CRP), hemoglobin A1c (HbA1c), insulin, lipids and changes in dietary behaviors.

Pre-post intervention results showed decreases in blood glucose and hs-CRP. Daily servings of grains, dairy, and fat were also reduced. Decreases in blood glucose, hs-CRP, triglycerides, cholesterol, LDL, VLDL, and HbA1c were observed at 12-month follow-up. Both insulin and HDL were decreased from baseline and 12-week levels at the 6-month follow-up but increased from all earlier levels at 12 months. Daily servings of meat, dairy, and fat remained decreased at 6-month follow-up. Reduced grain consumption observed at 12-week and at 6-month follow-up was not sustained, and increased at 12 months, although still decreased from baseline.

Results suggest that this naturopathic nutrition education series may promote dietary behavior change with associated changes in clinical biomarkers. Larger controlled studies are needed to confirm these results.

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