Fruits & Vegetables May Help Prevent Hip Fracture
Take Home Points:
- Bone loss during aging is a significant health concern as it places individuals at increased risk of fractures.
- Dietary factors have been associated with varying risks of fracture and research continues to focus on which specific foods and quantities may be associated with fracture risk reduction.
- Byberg et al., 2014 found that low intakes of fruit and vegetables (less than 1 serving) were associated with increases of hip fracture compared to 3-5 servings.
- Numerous studies performed since 2014 have also found significant associations between increased fruit & vegetable intake and fracture risk reduction.
- Although associations are not proof of causation the current body of literature suggests that fruit and vegetable intake may reduce fracture risk in the elderly.
During aging and in elderly populations it is very common for bone loss to place individuals at risk for one or more fractures. Mild loss of bone is refereed to as osteopenia, whereas severe loss of bone is known as osteoporosis. Bone fracture risk is higher for those with osteoporosis and a great deal of research is being conducted to diagnose, prevent, and treat fractures in the elderly. What you eat may be able to improve or maintain bone structure during aging.
In an article by Byberg and others (2014) in the Journal of Bone and Mineral Research, fruit and vegetable intake was analyzed in men and women to determine if there were statistical associations between intake levels and incidence of hip fracture. The rationale was that daily intake of at least 5 servings of fruits and vegetables is associated with reduced risk of disease (e.g., diabetes, cardiovascular disease). Further, prior studies have indicated fruit and vegetable intake was associated with increased bone mineral density (which is linked to reduced fracture risk). Some studies also exist linking fruits and vegetables to reduced forearm fractures, but the specific foods and doses could not be linked to the reduction in fracture risk. Therefore, in the Byberg et. Al 2014 study, the authors sought to clarify the relationship between fruit and vegetable intake and hip fracture risk.
The study indicated that, in both men and women, low intakes of fruit and vegetables (less than 1 serving) were associated with increases of hip fracture compared to 3-5 servings. Over 5 servings of fruits and vegetables did not appear associated with any increased reduction in hip fracture. So, there appears to be a limit to the power fruits and vegetables; you can’t reduce your fracture risk to zero by increasing your intake beyond 5 servings a day. As with all questionnaire-based studies, this study is limited by the ability of the participants to accurately recall the details of their past eating habits. The study also doesn’t address the mechanism by which fruits and vegetables might protect against hip fractures, though the authors speculate it may be tied to the roles these foods might play in reducing oxidative stress and inflammation, and increasing intestinal calcium absorption. Nevertheless, the findings are of note given the study’s large sample size and detailed data set.
New Studies Since 2014
There have been several studies examining the relationship between fruits & vegetable intake and fracture risk since the publication of the Byberg study. A meta-analysis in 2016 found larger intakes of vegetables (but not fruit) were associated with reduced incidence of hip fractures. In the 2016 CHANCES study of over 100,000 individuals results indicated that those individuals who consumed <1 serving per day of fruits and vegetables had a 39% greater chance of hip fracture risk than those with a moderate intake (2-5 servings/day). However, high levels of fruit and vegetable intake (>5 servings per day) did not reduce risk further. These results closely match those of the Byberg study mentioned above.
Data from the Rotterdam study also found associations between increased fruit and vegetable intake and lower risk of hip fracture. A study of women 70 years or older took baseline data on fruit and vegetable consumption and then followed participants for 14 years. The results found that those hospitalized with hip fractures were more likely to have consumed lower intakes of fruits and vegetables. Finally, a 2019 meta-analysis of randomized controlled trials and cohort studies (10 studies in total) found that increasing fruit and vegetable intake by at least one serving per day was associated with a reduction in any type of fracture.
As you can see above, evidence over the years continues to support significant associations between increased fruit & vegetable intake and reduced risk of fractures. The relationship may not be directly causative, but with such a large body of evidence, causation is likely.
Appendix: Additional Study Details from Byberg et al., 2014
- Swedish men (40,644) and women (34,947) free of cancer and cardiovascular disease (age 45-83 years old) were studied.
- Fruit and vegetable consumption was recorded based on surveys given to participants asking them how often, on average, they had consumed each food during the previous year.
- Responses were converted to average daily intakes based on age and sex-specific portion sizes.
- There were 14 vegetable entries tracked (carrot, beetroot, broccoli, cabbage, cauliflower, lettuce, onion, garlic, peas, pea soup, pepper, spinach, tomato, and “other” vegetables) and 5 fruit entries tracked (apple, banana, berry, orange/citrus, and “other” fruits).
- The outcome measure was a participant’s first incidence of a hip fracture.
- Information on prevalent diseases, body composition, size, medication, smoking and various other variables were incorporated in the statistical design as covariates.
- Depending on the specific analysis used, 5 or between 3 and 5 servings of fruits and vegetables per day was used as the reference point.
- Cox’s proportional hazards regression models were used for assessing the association between fruits and vegetables and hip fracture.
The Results in Detail:
- The was an inverse association between fruit and vegetable intake and hip fracture such that less than or equal to 1 serving a day was associated with an almost 50% increased rate of fracture, as compared to 3-5 servings per day.
- Compared with 5 servings a day, lower intakes of fruits and vegetables were associated with higher rates of hip fracture.
- Intakes above 5 servings per day did not appear associated with any increased benefit to hip fracture incidence.
- There was no interaction between fruit and vegetable intake and possible co-variants like potassium, magnesium, calcium, or body mass index (BMI). So, these factors were likely not underlying the observed association between fruit & vegetable intake and fracture risk.
- Fruit and vegetable consumption was self-reported by the participants (not monitored by the investigators).
- Only certain covariates (education, physical activity, smoking) were considered and other factors not considered may be contributing to the observed relationship between fruit and vegetable intake and reduced hip fracture incidence.
- This study does not point to causation, only association between fruit & vegetable intake and reduced hip fracture incidence.