During the summer season, a number of diets flourish and all their benefits are emphasized. But in the long run, some diets are not necessarily good for the body. Several studies already point to the effects of a vegetarian diet on bones, despite their positive effects on other aspects of our health. Recently, British researchers in a large study of vegetarian women found that they have a 33% higher risk of hip fracture later in life than those who often eat meat. The main cause will be nutritional deficiencies, weakening the bones and muscles. Further research is needed to assess whether this also occurs in humans and so that more effective prevention strategies can be introduced.
A hip fracture actually corresponds to a fracture of the femoral neck, in other words, the upper end of the femur that supports the head of the femur. The head enters the pelvis at the level of the acetabulum, forming the hip joint or hip joint.
About 90% of hip fractures involve falls, more often in older people and women with weaker bones. But fractures can often make bones more brittle, which in turn increases the risk of falls and further weakness. Not to mention the fact that, on the one hand, after a hip fracture, the quality of life decreases, and on the other, mortality increases. The aging of the world’s population only increases the risks.
In addition, the number of vegetarians around the world is increasing every year, due in part to the many proven benefits against a number of chronic diseases, including diabetes, coronary heart disease, and cancer, as well as having a lower environmental impact than omnivorous diets. However, the relationship between fracture risk and a meat-free diet is still relatively unclear.
That’s why a team of researchers from the University of Leeds conducted a massive study of more than 26,000 British vegetarian women to see if there was a link between diet and hip fracture risk. Their results are published in the journal BMC Medicine.
Acute need for learning
In November 2021, the same research team, led by James Webster, a graduate student in the School of Nutritional Sciences, announced that it was starting a large study of several dietary factors associated with hip fracture risk in about 30,000 women. UK and using NHS data on hip fractures. This included evaluating the impact of consuming various animal products, fruits and vegetables, and following a vegetarian diet.
This study was taken for granted in the face of an unambiguous observation of lack of evidence and conclusive studies regarding the risk factors for hip fracture, affecting nearly 70,000 people in France every year. Hip fracture is the most common serious injury in adults, and current prevention recommendations mainly focus on calcium, vitamin D, and protein intake through diet and supplements. According to the authors, the lack of data hinders the development of dietary recommendations that could reduce the incidence of hip fractures.
Proven risk of fractures in vegetarians
The researchers relied on data from the UK Women’s Cohort Study, in which women track the relationship between nutrition and health. The files of 26,318 women aged 35 to 69 were analyzed. They were divided into the following categories: regular meat eaters (5 servings per week), occasional meat eaters (less than 5 servings per week), pescatarians (eat fish but no meat), or vegetarians (eat neither meat nor fish). Accidental hip fractures were identified by reference to hospital episode statistics for March 2019. Finally, Cox regression models were used to evaluate the association between each diet group and hip fracture risk.
The researchers found that 822 women, or 3%, suffered hip fractures over a period of about 22 years. About 28% of the affected women were vegetarians and 1% were vegans. According to these data, vegetarians had a 33% higher risk of this than those who ate meat at least five times a week.
However, there is no clear evidence of the effect of BMI (body mass index) in groups. Differences in risk remained after confounding factors were ruled out and were not explained by differences in intake of key bone-health-related nutrients between vegetarians and meat eaters, implying the potential importance of other factors that were not accounted for.
New diet line?
The authors note that while there is no clear evidence for an association between BMI and hip fracture risk, the lower mean BMI among vegetarians partly explains their higher risk. Indeed, possible mechanisms include the protective role of bone mass, fat mass, and muscle mass, each of which is inversely related to the risk of hip fracture. Lack of body fat can reduce cushioning at hip level during falls (e.g. a pillow without padding). Not to mention, higher body fat may also increase bone strength due to increased mechanical stress and higher estrogen production.
The second reason that researchers put forward, complementing the first, is the low intake of nutrients important for bone health, which are abundant in animal products. Specifically, vegetarians have lower levels of protein, which helps build muscle, and possible deficiencies in vitamins and minerals, such as calcium and vitamin B12, which help build strong bones.
Further research is needed to confirm this in other populations, such as males and non-Europeans, and to determine the factors responsible for the observed difference in risk. In particular, further research is recommended on the role of BMI and nutrients in animal products so that public health interventions can be developed to reduce the risk of hip fracture in vegetarians through dietary adjustments or weight control. .
However, the authors insist that vegetarians should not give up their diet due to the numerous benefits, particularly in terms of cardiovascular health, as well as in terms of animal welfare and environmental impact. However, they must be careful to maintain a healthy body weight and ensure adequate intake of protein and other nutrients important for bone health, including calcium and vitamin D.