Precision Nutrition Strategies for Improving the Quality of Life of Pre-senior and Senior Populations

The number and proportion of people aged 60 years old and over is increasing worldwide. Ageing is characterized by a progressive loss of physiological integrity, leading to impaired function and increased vulnerability to death. This deterioration is the primary risk factor for major chronic diseases including diabetes, cardiovascular disease, and neurodegenerative disorders.

The incidence of chronic conditions frequently rises sharply with age, after long exposure to unhealthful lifestyles involving the consumption of unhealthy diets and physical inactivity. Consequently, integrated dietary strategies and actions are required to promote healthy ageing and target major causes of morbidity and mortality in senior populations.

The promising field of precision nutrition is rising as a therapeutic approach that aims to design tailored dietary interventions to prevent and manage chronic diseases. Indeed, precision nutrition approaches contemplate the interindividual heterogeneity caused by genetic/epigenetic dissimilarities, individual facets such as age and gender, the lifestyle and environmental exposome diversity, microbiome variations, and singular behavioral/psychological features.

On the other hand, the inclusion of potentially bioactive compounds and functional foods as promoters of healthy aging within personalised dietary patterns could be an effective strategy to delay the aging process and age-related chronic diseases.

One of the main limitations of a dietary prescription is the lack of compliance, due to the complexity of the prescription itself and/or the lack of commitment of the individual. The inclusion of digital tools to empower and motivate individuals and to support them in the management of the dietary strategy could overcome this limitation.

With this background, the general objective of this investigation is to design precision nutritional strategies based on the inclusion of functional foods and digital tools for preventing age-related chronic diseases in pre-senior and senior populations. Additionally, this study proposes alternative tools for cognitive assessments increasing the accessibility to cognitive assessment tools for this population as well as an innovative digital tool for cognitive stimulation which is personalized, monitored, and evidence-based.

This study is designed as a 12-week, randomized parallel intervention trial, with two arms: 1) Control group, who follows a control diet based on the current dietary guidelines of the Spanish Society of Community Nutrition (SENC) using the Healthy Eating Plate method (Harvard), and 2) Nutriprecision Group, which were instructed to follow the Nutriprecision diet based on the inclusion of digital tools and functional foods, whose postprandial effects were previously evaluated by randomized, cross-over, double-blind studies in senior subjects in the Centre for Nutrition Research (UNAV) and IMDEA-ALIMENTACIÓN. The incremental area under the curve (iAUC) for glucose and insulin was calculated for all designed foods and was compared with their reference products. Additionally, lipid profile and satiety were measured at fasting and at 15, 30, 45, 60, 90, and 120 min after starting the food intake. In all these studies, the reference and test foods were administered once in random order, with a wash-out period between 7 days and 14 days among assays.

This multi-centric study was carried out in the Nutrition Intervention Unit of the Centre for Nutrition Research in the University of Navarra and the Nutritional and Clinical Trials Unit in IMDEA-ALIMENTACIÓN by qualified professionals (nurse, doctor-dietician, dieticians, pharmacists).

A total of five visits had been established along with the 12-weeks trial: 1) study information and screening; 2) day 0: start of the intervention; 3) day 28: group session (control group)/follow-up visit (Nutriprecision group); 4) day 56: group session (control group)/follow-up visit (Nutriprecision group) and 5) day 84: end of the intervention.

At the start and finish days of the study, participants visited the Nutrition Intervention Unit or the Clinical Trials Unit in a fasting state. Participants were instructed to collect the first-morning urine sample. Additionally, volunteers from the University of Navarra self-collected fecal samples at baseline using OMNIgene.GUT kits from DNA Genotek. Volunteers were also informed of a digital-based procedure for cognitive assessment and other digital tools available depending on the assigned intervention (experimental VS control).

Blood samples were drawn by venipuncture after a 12 h overnight fast in a clinical setting. After 10 minutes of rest and having answered the Mini Nutritional Assessment (MNA) and the Mini-Mental State Examination (MMSE) questionnaires, blood pressure was measured. Later, anthropometric measurements and body composition analysis were performed. Global cognitive performance was also assessed by the Guttmann NeuroPersonalTrainer platform. The duration of these visits was approximately 1 hour.

On the 28th and 56th study days, participants assigned to the control group attended online group sessions and received intensive education and advice to increase the adherence to the dietary strategy. Sessions consisted of informative talks about the prescribed dietary pattern, food label use, seasonal shopping lists, meal plans and recipes, physical activity and exercise recommendations, sleep habits, etc. Contrary, participants allocated to the Nutriprecision group attended in person visits with the dieticians, to evaluate the adherence to the assigned nutritional treatment. Additionally, anthropometric, body composition, and blood pressure measurements were assessed. Participants were also asked to fill different questionnaires about health status (SF-36 Health Survey), gastrointestinal symptoms (gastrointestinal symptoms rating scale, GSRT), dietary assessment (7-day recall), Mediterranean diet adherence (14-Item Mediterranean Diet Assessment Tool), physical activity (International Physical Activity Questionnaire, IPAQ) and drug therapy modifications. Moreover, the Nutriprecision group were asked to collect a sensory perception questionnaire and a food consumption record of the precision foods administered.

Eligibility Criteria:
Inclusion Criteria:

* Men and women aged 50-80 years
* BMI \>27 kg/m2
* One or more of the following risk factors:

  * Glucose ≥100 to ≤125 mg/dL or type 2 diabetes (independently of antidiabetic medication)
  * Hypertension (systolic blood pressure ≥140 mmHg or diastolic blood pressure ≥90 mmHg or under antihypertensive medication)
  * LDL-cholesterol ≥160 mg/dL independently of lipid-lowering therapy
  * HDL-cholesterol ≤40 mg/dL (men)/≤50 mg/dL (women), independently of lipid-lowering therapy
  * Triglycerides ≥160 mg/dL independently of lipid-lowering therapy
  * Waist Circumference ˃95 cm (men)/\>82 cm (women), independently of lipid-lowering therapy
  * Sedentary behavior (AHA)\*

Exclusion Criteria:

* Relevant functional or structural digestive abnormalities (malformations, angiodysplasia, active peptic ulcers, chronic inflammatory diseases, or malabsorption)
* Endocrine disorders (hyperthyroidism or uncontrolled hypothyroidism)
* Undergone surgical interventions with permanent sequelae (gastroduodenostomy)
* Pharmacological treatments with immunosuppressants, cytotoxic agents, systemic corticosteroids, or other drugs that could potentially cause hepatic steatosis or alteration of liver tests
* Active cancer in the last five years or under therapy
* Weight loss ≥3 kg in the last three months
* Instable drug therapy in the last three months
* Severe psychiatric disorders
* No autonomy
* Inability to follow the diet (food allergies, intolerances)
* Difficulties to follow scheduled visits

  * AHA Recommendations for Physical Activity in Adults: at least 150 minutes per week of moderate-intensity aerobic activity or 75 minutes per week of vigorous aerobic activity, or a combination of both, preferably spread throughout the week.