Increased fruit and vegetable consumption may decrease the risk of fractures in men and women over 50

Brondani JE, Comim FV, Flores LM, et al. Fruit and vegetable intake and bones: A systematic review and meta-analysis PLOS ONE. 2019;14: e0217223.

Review question

Does regular consumption of fruits and vegetables have a significant effect on bone fractures, bone mineral density (BMD), or bone markers in men and women 50 years old or over?

Background

Globally, over 200 million people have osteoporosis, a disease that decreases the strength of bones and contributes to fractures. The incidence of fractures due to osteoporosis is increasing. The availability of nutrients that are important to the skeleton, such as calcium, vitamin D, and protein, are impacted by diet and lifestyle. However, uncertainty still remains around the role that fruits and vegetables play in maintaining bone health, with past research on this topic yielding mixed results.     

How the review was done

This is a systematic review of five randomized controlled trials (RCTs) and eight cohort studies published between 1999 and 2017, including a total of 274,337 participants. Ten studies were included in a meta-analysis.

Key features of the studies:

• Participants were men and women aged 50 years old and over.
• Participants in the cohort studies consumed their regular diets (some of which were rich in fruits and vegetables). Participants in the RCTs were either provided with or prescribed a certain amount of fruits and vegetables to consume, enrolled in a behavioural program to increase fruit/vegetable intake, or used tripotassium citrate tablets.
• Researchers measured: fractures at any site, hip fracture, bone mineral density (BMD), and bone makers (e.g., C-terminal telopeptide aka CTx – indicates the breakdown and absorption of bone as part of the bone growth process).  
• Within the RCTs specifically, results were compared to people in control groups who were either not receiving any intervention at all, receiving placebo tripotassium citrate tablets but no diet advice, or receiving a specific but smaller amount of fruits and vegetables to consume vs. those in the intervention group.

What the researchers found

Researchers found that increasing fruit and vegetable consumption may be associated with a small but not unimportant decrease in the risk of hip fractures and fractures at any site. It should be noted that the outcome of fractures at any site was informed by only two studies, and therefore should be interpreted with caution. Results for the association between bone mineral density and fruit and vegetable consumption were mixed, with a trend towards no a significant association. In terms of the bone marker CTx, there was no association between it and fruit and vegetable consumption. The majority of the studies were of high quality. More research, which includes diverse populations, more participants, and different measurement tools is needed, to further establish these results.

Conclusion

Increasing fruit and vegetable consumption may be associated with a decreased risk in bone fractures.