Vegetarian diets can vary widely from person to person and can be healthy or unhealthy, just like diets that include animal products. A study of middle-aged women reveals those with a vegetarian diet had a 33% higher risk of hip fracture compared to regular meat-eaters (1). This study is one of very few studies to compare risk of hip fracture in vegetarians and meat-eaters where the occurrence of hip fracture was confirmed from hospital records.
According to the study lead author James Webster, from the School of Food Science and Nutrition at the University of Leeds, “Our study highlights potential concerns regarding risk of hip fracture in women who have a vegetarian diet. However, it is not warning people to abandon vegetarian diets. As with any diet, it is important to understand personal circumstances and what nutrients are needed for a balanced healthy lifestyle.”
It is concerning that vegetarian diets often have lower intakes of nutrients that are linked with bone and muscle health. The nutrients of concern in the diet of vegetarians include vitamin B(12), vitamin D, ω-3 fatty acids, calcium, iron, and zinc. Although a vegetarian diet can meet current recommendations for all of these nutrients, the use of supplements and fortified foods provides a useful shield against deficiency. A vegetarian diet usually provides a low intake of saturated fat and cholesterol and a high intake of dietary fiber and many health-promoting phytochemicals. This is achieved by an increased consumption of fruits, vegetables, whole-grains, legumes, nuts, and various soy products (2).
Low intake of these nutrients can lead to lower bone mineral density and muscle mass, which can make you more susceptible to hip fracture risk. This makes it especially important to better understand factors driving the increased risk in vegetarians, whether it be particular nutrient deficiencies or weight management, so that we can help people to make healthy choices.
While studies have shown the many health benefits of vegetarian eating, merely removing animal products from your diet doesn’t automatically ensure good health.
As with any eating plan, it’s important to know some basic nutrition information. Eating vegetarian makes it easier to avoid foods high in saturated fat and cholesterol, and ensure lots of fruits and vegetables.
Key nutrients to look out for when following a Vegetarian Diet:
Vitamin B12: To get the full benefit of a vegan diet, vegans should do one of the following (4):
- Eat fortified foods two or three times a day to get at least three micrograms (mcg or µg) of B12 a day
- OR Take one B12 supplement daily providing at least 10 micrograms
- OR Take a weekly B12 supplement providing at least 2000 micrograms.
Omega-3 fatty acids are readily available in a wide variety of plant foods. Sources include walnuts, flaxseeds, chia seeds, hemp seeds, edamame, seaweed, and algae. Other green leafy vegetables and beans also contain small amounts(5).
Vitamin D: This vitamin is important for good bone health. Our bodies make vitamin D when we’re exposed to sunlight. Spending some time outdoors every day without sunscreen and, during the winter months, eating vitamin D-fortified foods or taking a supplement is a good idea for everyone.
Protein: Proteins are the building blocks of the body and an important part of our diet. A balanced diet should include a daily intake of around 0.75grams of protein for every kilo of body weight. There are many protein rich foods for vegetarians, rivalling the protein content of meat products. Almonds, black beans, brown rice, cashews, garbanzo beans (chickpeas), kidney beans, lentils, lima beans, peanut butter, pinto beans, quinoa, seitan (a wheat-based mock meat), soybeans, soy milk, sunflower seeds, textured vegetable protein (TVP), and tofu are all protein-rich plant foods (6).
Iron: Those who follow a plant-based diet may have lower iron stores than omnivores. Make sure that you’re eating foods that contain substantial amounts of iron (7). Some of the best plant sources of iron include:
- Legumes: lentils, soybeans, tofu, tempeh, lima beans
- Grains: quinoa, fortified cereals, brown rice, oatmeal
- Nuts and seeds: pumpkin, squash, pine, pistacio, sunflower, cashews, unhulled sesame
- Vegetables: tomato sauce, swiss chard, collard greens
- Other: blackstrap molasses, prune juice
Calcium: Calcium is an important nutrient to consider when on a vegan diet. Although there’s calcium in plant-based foods, it may be difficult to eat and absorb enough for optimal nutrition What most people don’t know is that our risk of osteoporosis can be lowered by reducing sodium intake, eating more fruits and vegetables, exercising, and getting enough vitamin D from sunlight or fortified food sources. Almonds, black beans, broccoli, calcium-fortified orange juice, collard greens, great northern beans, kale, kidney beans, mustard greens, navy beans, pinto beans, sesame seeds, soybeans, soy milk, textured vegetable protein (TVP), and tofu are all excellent cholesterol-free calcium sources (8).
Plant-based diets growing in popularity
Vegetarian diets have gained popularity in recent years. U.S. retail sales of plant-based foods continue to increase, growing 6.2% in 2021 over a record year of growth in 2020 and bringing the total plant-based market value to an all-time high of $7.4 billion (3). The spike in popularity is largely due to weight issues many people had during lockdown, says Neal Barnard, MD, president of the Physicians Committee for Responsible Medicine and an adjunct professor at George Washington University School of Medicine. “Many people gained weight during the pandemic,” he says. They were stuck at home with the refrigerator or pantry nearby. For some, weight gain led to change. “They were looking to get healthy. In addition, they had time to read and look at health information, which they might have been neglecting before,” Barnard says
There is also a worldwide call for reducing the consumption of animal products in an effort to tackle climate change and eliminate inhumane livestock animal farms and processing methods.
Understanding hip fracture risk in vegetarians is therefore becoming increasingly important to public health. Hip fracture has become a global health issue with high economic costs that causes loss of independence, reduces quality of life, and increases risk of other health issues.
Plant-based diets have been linked with poor bone health, but there has been a lack of evidence on the links to hip fracture risk. This study is an important step in understanding the potential risk plant-based diets could present over the long-term and what can be done to mitigate those risks.
Effect of low BMI
The research team found that the average BMI among vegetarians was slightly lower than the average among the regular meat eaters. Previous research has shown a link between low BMI and a high risk of hip fracture.
Lower BMI can indicate people are underweight, which can mean poorer bone and muscle health, and higher risk of hip fracture. Further investigation is needed to determine if low BMI is the reason for the observed higher risk in vegetarians.
Study co-author, Dr Darren Greenwood, a biostatistician in the School of Medicine at Leeds, said: “This study is just part of the wider picture of diet and healthy bones and muscles in older age.
Further research is needed to confirm whether there could be similar results in men, to explore the role of body weight, and to identify the reasons for different outcomes in vegetarians and meat-eaters.
by Dick Benson