None listed
Conditions
Brief summary
Protein and calcium are essential nutrients for older adults to help maintain muscle and bone mass, but these nutrients are often not consumed in recommended amounts. Milk is an excellent source of both protein and calcium, along with other important nutrients. Milk avoidance is often associated with poor nutrition in older adults. Older adults may avoid milk due to gastrointestinal discomfort after consuming milk, which may be caused by age-related changes in gastrointestinal function. Women may be more susceptible to these effects. However, milk from different ruminant species (for example, cow, sheep, or goat) may have different effects on gastrointestinal comfort. For instance, although cow milk is most often consumed in NZ, goat and sheep milk may be better tolerated due to different protein structures that may be easier to digest than cow milk protein. Most studies examining differences in the type of milk on nutrition intake and gastrointestinal comfort have included younger people, and are of short duration. Therefore, the aim of this study is to compare the effects of consuming different types of milk (goat, sheep, cow) on nutrition intake and gastrointestinal comfort of older adults, over 12 weeks. This research will help determine whether healthy older adults in NZ and worldwide can drink alternatives to cow milk, such as goat and sheep milk, to meet their protein, energy, vitamin, and mineral requirements with greater ease of digestion and reduced gastrointestinal discomfort.
Interventions
The intervention will consist of two servings of cow, goat, or sheep milk powder per day for 12 weeks (40 people in each group). The milk powder will be made up with water to mimic the nutritional content of fresh milk: 40 g cow milk powder with 160 mL water; 35 g sheep milk powder with 215 mL water; 30 g goat milk powder with 200 mL water. The drinks will be consumed with breakfast and lunch.
The study duration is a nominal total of 14 weeks, with a 2-week lead-in phase and 12-week interventio
The intervention will consist of two servings of cow, goat, or sheep milk powder per day for 12 weeks (40 people in each group). The milk powder will be made up with water to mimic the nutritional content of fresh milk: 40 g cow milk powder with 160 mL water; 35 g sheep milk powder with 215 mL water; 30 g goat milk powder with 200 mL water. The drinks will be consumed with breakfast and lunch. The study duration is a nominal total of 14 weeks, with a 2-week lead-in phase and 12-week intervention phase. During the 2-week lead-in phase (and throughout the duration of the intervention), participants will record their bowel habits every day, on an app designed for this study, and will complete weekly questionnaires about their digestive symptoms, mood (anxiety, depression), and sleep quality using validated questionnaires. On the 2nd week of the lead-in phase, participants will complete a non-consecutive 3-day diet, wear an actigraphy accelerometer for 7-days to measure activity levels, and undergo a Dual-energy X-ray Absorptiometry (DXA) scan to measure body composition. The day before their baseline visit, participants will collect a faecal sample, and will fast overnight for 9 hours. At the baseline clinic (beginning of the intervention phase), participants will provide a blood sample, have height, weight and waist circumference measured, and undergo functional tests (hand grip strength and a walk test). They will also complete a set of questionnaires about their mental health. At the clinic, a sub-group of participants from each milk group will consume double the amount of the milk powder that they have been assigned (80 g cow milk powder; 70 g sheep milk powder; 60 g goat milk powder). The powders will be made up to 350 mL with water. The participants will consume the milk within 10 minutes. After finishing the milk, they will provide blood samples hourly over 5-hours. During this time they will complete questionnaires on digestive comfort and appetite. This sub-group assessment will be undertaken once at baseline and again at follow-up (week 12). The double-amount of powder consumed during the clinic will replace the participant's regular intervention (two daily serves of milk powder with breakfast and lunch) for the first and last days of the intervention period. The first 25 people in each group who consent to participating in the sub study will be enrolled. Participants will be given four weeks supply of milk powder to take home. At weeks 4 and 8, participants will return any unused milk powder, and be provided with their next 4-week supply. Compliance will be monitored by checklist, and by weighing left-over milk powder. Participants will also have their waist circumference and body weight measured at the clinics. At the final follow-up visit, participants will repeat all of the aforementioned baseline visit procedures. The week prior to their follow-up visit, they will complete the same set of questionnaires, 3-day diet record, actigraphy, DXA scan, and collect a faecal sample. At the follow-up clinic visit, they will have their weight and waist circumference measured, and provide a fasted blood sample. The participants in the sub study will provide blood samples before and hourly, up to 5 hours, after consuming their milk. All participants will receive their reimbursement ($200 grocery voucher). Attendance of clinic visits and completion of questionnaires and study tests (accelerometery, DXA, functional tests, blood tests) will be assessed to measure the adherence of participants.
Sponsors
Riddet Institute
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
60 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
Women who live independently and are free from serious medical illness such as cancer, uncontrolled diabetes or cardiovascular disease, with a Body Mass Index between 18.5 to 30 kg/m2, and do not undertake more than 2 hours of structured exercise each day.
Exclusion criteria
•Inability to give informed consent •Taken antibiotics within the month before starting the study •Use of certain prescribed medication or recreational drugs within the last three months that could affect the gastrointestinal tract: opioids, non-steroidal anti-inflammatory drugs, proton pump inhibitors, laxatives, prebiotic or probiotic supplements. •Medical history of gastrointestinal surgery or disorders (inflammatory bowel disease, ulcerative colitis, coeliac disease, Crohn's disease), cardiorespiratory problems, uncontrolled diabetes mellitus, bleeding disorders, sleep disorders, psychiatric conditions (major depressive disorder, schizophrenia, bipolar disorder, post-traumatic stress disorder) •Alarm features associated with significant gastrointestinal or other disorders, such as burning pain in the epigastrium which increases during the night and wakes up the patient; frequent vomiting; loss of appetite; lower gastrointestinal bleeding; odynophagia; dysphagia; palpable abdominal mass; lymphadenopathy; jaundice. •Significant dietary changes within the month before starting the trial (i.e., being on a controlled diet or dietary weight loss regimen) •Dairy intolerance of, or ruminant milk allergy •High habitual milk intake (> 500 mL per day on average) •Malnutrition Screening Tool (MST) score of 2 or more points •Cigarette smoking or other use of tobacco or nicotine-containing products •Excessive alcohol intake >20g of pure alcohol (2 drinks)/d on average (>21 standard drinks a week) •Inability or unwillingness to comply with the study procedures
Outcome results
None listed