Greek Yogurt Consumption for Bone Development in Athletes

Overseen by Panagiota Klentrou, PhD

Age: < 65

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Recruiting

Sponsor: Brock University

Disqualifiers: Injury, Dairy allergy, Lactose intolerance, others

No Placebo Group

Trial Summary

What is the purpose of this trial?

Physical activity and dairy consumption during growth and development are each known to improve peak bone mass in young adults. Peak bone mass, the maximum amount of bone a person will have in their lifetime, is typically reached in the early 20's in females and late 20's in males. However, evidence suggests that young people do not consume enough dairy to maximize their bone mass. The resulting effect in peak bone mass can be troublesome, particularly for athletes, such as volleyball players. This study aims to determine whether increased dairy consumption combined with training can have an additive effect on the physiology of young competitive athletes. Specifically, we will examine whether Greek yogurt consumption will lead to beneficial changes in bone metabolism and inflammation, in adolescent and young adult, male and female athletes, similar to those observed with whey protein supplementation. Many athletes choose exclusively protein supplementation and miss out on other nutrients vital for healthy growth and development. By examining the benefits of Greek yogurt across different athlete age groups and sexes, this work will help reshape the attitudes, beliefs, and behaviours surrounding diet of young athletes.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of increased Greek yogurt consumption for bone development in athletes?

Research shows that consuming Greek yogurt along with exercise can increase bone formation in young adult males, suggesting it may help support bone health. Greek yogurt contains protein and calcium, which are important for bone strength, and it was found to positively affect bone turnover when combined with high-impact exercise. ^{1 2 3 4 5}

Is Greek yogurt safe for human consumption?

Research shows that Greek yogurt is generally safe for human consumption. Studies involving Greek yogurt consumption in athletes have not reported any significant safety concerns, and it is considered a nutritious food that supports bone health. ^{1 2 3 6 7}

How does Greek yogurt consumption differ from other treatments for bone development in athletes?

Greek yogurt is unique because it combines protein and calcium, which are essential for bone health, and is consumed as a food rather than a supplement or medication. It has been shown to increase bone formation when combined with exercise, making it a novel dietary approach to support bone health in athletes. ^{1 2 8 9 10}

Research Team

Panagiota Klentrou, PhD

Principal Investigator

Brock University

Eligibility Criteria

This trial is for young competitive athletes who are looking to improve their bone health. Participants should be actively engaged in sports and not have any allergies to dairy, lactose intolerance, or injuries that prevent them from practicing.

Inclusion Criteria

Competitive youth or varsity athletes

Exclusion Criteria

Allergy to dairy foods/dairy protein

I have an injury.

I am diagnosed with lactose intolerance.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

Control Condition

Participants follow their typical diet and training protocols while completing food records for baseline assessment

8 weeks

Weekly virtual check-ins

Intervention Condition

Participants consume Greek yogurt or whey protein while maintaining their habitual diet and training

16 weeks

Weekly virtual check-ins and dietary logging

Follow-up

Participants are monitored for changes in bone metabolism and inflammation markers

4 weeks

2 visits (in-person)

Treatment Details

Interventions

• Increased Greek Yogurt Consumption (Other)

Trial Overview The study is testing if eating more Greek yogurt can help with bone development and reduce inflammation in youth and young adult athletes. It compares the effects of Greek yogurt consumption to whey protein supplementation during athletic training.

Participant Groups

Group I: Whey protein intervention group (WP) Experimental Treatment 1 Intervention

Participants in the WP group will follow a similar consumption schedule but will be instructed by the RD to consume two servings/day (preferably morning and night) each of 2/3 of a scoop of commercially available WP powder (flavoured, \~29 g, 120 calories, 19 g protein, 112.5 g calcium; e.g., PURE Whey Protein, Walmart) for a total of 16 weeks. The WP scoop will be dissolved in water (e.g., 1 g of WP isolate to 10 mL of water, as recommended by the manufacturer). This protein dose is similar to the previous dose in young swimmers and comparable to other studies in adults. Athletes will be provided with appropriately marked scoops (corresponding to 2/3 of the manufacturer scoop) to measure their single servings. Each athlete will receive two large containers (2 x 907 g = 1814 g per week) at the beginning of each week, which will be enough to cover the two daily servings of 29 g (i.e., 58 g/day).

Group II: Greek yogurt intervention group (GY) Experimental Treatment 1 Intervention

Participants in the GY group will be instructed by a registered dietician to consume 2 servings/day (preferably morning and night) of 175 g GY (0% MF, flavoured, 130 calories, 17 g protein, 225 g calcium; e.g., OIKOS High Protein GY) for a total of 16 weeks. For their convenience, the athletes will be provided with appropriate scoops to measure out 175 g of GY per serving of the larger 650 g commercially available, pre-packaged containers. Although it is recommended to consume the two servings morning and night, to increase ecological validity and strengthen the feasibility of the intervention, the timing of the servings will be flexible to facilitate the training and competition routines. For the same reasons, the athletes will be able to choose the flavour of their GY.

Who Is Running the Clinical Trial?

Brock University

Lead Sponsor

Trials

41

Recruited

6,500+

York University

Collaborator

Trials

64

Recruited

521,000+

Dr. Christopher Anzalone

York University

Chief Executive Officer since 2007

PhD in Biology from UCLA

Dr. Ray Pratt

York University

Chief Medical Officer since 2012

MD from Albert Einstein College of Medicine

Findings from Research

In a 12-week study with 30 untrained university-aged males, Greek yogurt (GY) consumption alongside a resistance training program significantly increased bone formation markers (P1NP) compared to a placebo, indicating its potential to enhance bone health.

GY also appeared to reduce bone resorption (CTX) after one week of training, suggesting that it may help maintain a healthier balance in bone turnover during exercise.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Consumption of Greek yogurt during 12 weeks of high-impact loading exercise increases bone formation in young, adult males - a secondary analysis from a randomized trial. Bridge, AD., Brown, J., Snider, H., et al.[2020]

In a study involving 13 female adolescent soccer players, Greek yogurt consumption during 5 days of intense training did not show significant effects on key bone biomarkers compared to a carbohydrate placebo.

While there was a notable decrease in undercarboxylated osteocalcin (unOC) after training in the Greek yogurt condition, overall, the findings suggest that high-impact training did not negatively affect bone metabolism, and Greek yogurt did not provide additional benefits over the carbohydrate control.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Circulating Levels of Bone Markers after Short-Term Intense Training with Increased Dairy Consumption in Adolescent Female Athletes. Klentrou, P., McKee, K., McKinlay, BJ., et al.[2023]

In a study of 46 young female endurance swimmers, those who consumed probiotic yogurt daily for 8 weeks experienced fewer respiratory infections and shorter durations of symptoms like dyspnea and ear pain compared to those who consumed regular yogurt.

While the improvement in swimming performance (measured by 400-m free swimming records) was not statistically significant, the reduction in upper respiratory tract infections suggests that probiotic yogurt may enhance overall health and potentially improve VO2max in athletes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of probiotic yogurt on performance, respiratory and digestive systems of young adult female endurance swimmers: a randomized controlled trial. Salarkia, N., Ghadamli, L., Zaeri, F., et al.[2022]

A study of 114 female collegiate athletes revealed that while they had a moderate understanding of osteoporosis (mean score of 7.1 out of 10), their dietary calcium knowledge and attitudes towards osteoporosis were less favorable, indicating a gap in effective health education.

Despite an average dairy intake of 2.4 servings per day, only 31% met the recommended intake of 3 or more servings, and there was no correlation between their knowledge of osteoporosis and their actual dairy consumption, suggesting that other factors may influence dietary habits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Osteoporosis knowledge, attitudes, and behaviors of female collegiate athletes. Turner, LW., Bass, MA.[2022]

Fortifying yogurt with vitamin D and calcium significantly increased serum vitamin D levels and decreased parathyroid hormone (PTH) levels in older women, indicating improved bone health over 84 days compared to non-fortified yogurt.

The fortified yogurt also led to a significant reduction in bone resorption markers, suggesting that it may help prevent bone loss and reduce the risk of fractures in aged women at risk for osteoporosis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fortification of Yogurts with Vitamin D and Calcium Enhances the Inhibition of Serum Parathyroid Hormone and Bone Resorption Markers: A Double Blind Randomized Controlled Trial in Women over 60 Living in a Community Dwelling Home. Bonjour, JP., Benoit, V., Atkin, S., et al.[2022]

Vitamin D-fortified yogurt significantly increases serum 25-hydroxy vitamin D levels by an average of 31.00 nmol/L compared to plain yogurt, based on a meta-analysis of 9 randomized controlled trials involving 665 participants over 8 to 16 weeks.

In addition to boosting vitamin D levels, fortified yogurt also reduces parathyroid hormone levels and improves various health markers, including body weight, waist circumference, fasting glucose, and lipid profiles, making it a beneficial option for individuals with metabolic concerns.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Is vitamin D-fortified yogurt a value-added strategy for improving human health? A systematic review and meta-analysis of randomized trials. Gasparri, C., Perna, S., Spadaccini, D., et al.[2019]

A 10-week study involving 140 obese participants found that yogurt fortified with vitamin D significantly increased vitamin D levels compared to plain yogurt and probiotic yogurt, indicating that vitamin D-fortified yogurt is an effective option for addressing vitamin D deficiency.

The addition of probiotic bacteria (Lactobacillus acidophilus and Bifidobacterium lactis) did not enhance the vitamin D levels beyond what was achieved with vitamin D-fortified yogurt alone, suggesting that probiotics may not be necessary for improving vitamin D status.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effect of yogurt co-fortified with probiotic and vitamin D on lipid profile, anthropometric indices and serum 25-hydroxi vitamin D in obese adult: A Double-Blind Randomized- Controlled Trial. Hajipoor, S., Hekmatdoost, A., Rezaei, M., et al.[2021]

Collegiate male athletes consumed significantly more calcium (1,354 mg/day) than female athletes (898 mg/day), with female cross-country runners having the lowest intake at 605 mg/day, highlighting a gender disparity in calcium consumption.

Most athletes obtained their calcium primarily from dairy products and mixed dishes, but none of the groups used supplements to compensate for low dairy intake, indicating a potential risk for inadequate calcium levels, especially among female athletes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Food sources of calcium in a sample of African-American an Euro-American collegiate athletes. Leachman Slawson, D., McClanahan, BS., Clemens, LH., et al.[2022]

In a study of 4310 older adults, higher yogurt intake was linked to significant increases in bone mineral density (BMD) and better physical function, particularly in women, where BMD at the hip and femoral neck was 3.1-3.9% higher in those with the highest yogurt consumption.

Yogurt intake was associated with a reduced risk of osteopenia and osteoporosis, with females showing a 31% lower risk of osteopenia and a 39% lower risk of osteoporosis, while males had a 52% lower risk of osteoporosis, suggesting yogurt could be an effective dietary strategy for improving bone health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Greater yogurt consumption is associated with increased bone mineral density and physical function in older adults. Laird, E., Molloy, AM., McNulty, H., et al.[2018]

Fermented milk products like yogurt and soft cheese are rich in calcium, phosphorus, and protein, which are essential for bone growth and reducing bone loss.

These products may also contain prebiotics and probiotics that enhance calcium absorption and support bone metabolism, potentially leading to better bone health and increased compliance with dietary recommendations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Fermented Milk Products on Bone. Rizzoli, R., Biver, E.[2019]

References

1. Canada pubmed.ncbi.nlm.nih.gov

Consumption of Greek yogurt during 12 weeks of high-impact loading exercise increases bone formation in young, adult males - a secondary analysis from a randomized trial. [2020]

2. Switzerland pubmed.ncbi.nlm.nih.gov

Circulating Levels of Bone Markers after Short-Term Intense Training with Increased Dairy Consumption in Adolescent Female Athletes. [2023]

3. Iran pubmed.ncbi.nlm.nih.gov

Effects of probiotic yogurt on performance, respiratory and digestive systems of young adult female endurance swimmers: a randomized controlled trial. [2022]

4. United States pubmed.ncbi.nlm.nih.gov

Osteoporosis knowledge, attitudes, and behaviors of female collegiate athletes. [2022]

5. France pubmed.ncbi.nlm.nih.gov

Fortification of Yogurts with Vitamin D and Calcium Enhances the Inhibition of Serum Parathyroid Hormone and Bone Resorption Markers: A Double Blind Randomized Controlled Trial in Women over 60 Living in a Community Dwelling Home. [2022]

6. United States pubmed.ncbi.nlm.nih.gov

Is vitamin D-fortified yogurt a value-added strategy for improving human health? A systematic review and meta-analysis of randomized trials. [2019]

7. United States pubmed.ncbi.nlm.nih.gov

The effect of yogurt co-fortified with probiotic and vitamin D on lipid profile, anthropometric indices and serum 25-hydroxi vitamin D in obese adult: A Double-Blind Randomized- Controlled Trial. [2021]

8. United States pubmed.ncbi.nlm.nih.gov

Food sources of calcium in a sample of African-American an Euro-American collegiate athletes. [2022]

9. England pubmed.ncbi.nlm.nih.gov

Greater yogurt consumption is associated with increased bone mineral density and physical function in older adults. [2018]

10. United States pubmed.ncbi.nlm.nih.gov

Effects of Fermented Milk Products on Bone. [2019]