- A plant-based or vegan diet has known health benefits, but it may also adversely affect bone strength.
- A new study investigated the role strength training plays in the bone health of people who follow a vegan diet.
- The researchers found that vegans who regularly performed resistance exercises had better bone micro-structure than vegans who did not engage in resistance training.
- Study findings suggest that people who adhere to a vegan or plant-based diet should perform resistance training regularly to preserve bone strength.
A vegan or plant-based diet is a dietary lifestyle that avoids all animal-based foods, including meat, dairy, eggs, and often honey.
Plant-based or plant-forward diets are rising in popularity, particularly veganism. A 2018 news report estimates the number of people in the United States identifying as vegan increased by 600% between 2014 and 2017. What’s more, the Good Food Institute reports that plant-based food sales increased from $4.9 billion in 2018 to $7.0 billion in 2020.
Following a plant-based diet has some known health benefits. A 2019 research review shows that a vegan diet can have positive effects on energy metabolism, weight status, and systemic inflammation.
Despite the benefits of going plant-based, there may be drawbacks. A 2020 study found that non-meat eaters and vegans are more likely to experience bone fractures, particularly in the hip. Experts believe this may be related to the nutritional profile of a plant-only diet.
But new research published in the Journal of Clinical Endocrinology & Metabolism shows that resistance training may be key to maintaining bone strength in people who follow a plant-based diet, even more so than nutrient intake.
Bone health and resistance training
In the study, Austrian researchers assessed the microarchitecture of the trabecular bone and cortical bone of the radius and tibia in vegans and in those who followed an omnivore diet for at least 5 years. They then examined the relationships between these bone microstructures and nutrition and physical exercise.
The scientists who conducted the study recruited 88 male and female participants for the research. They divided them into two groups — vegans and omnivores.
Both groups filled out questionnaires regarding what types of athletic activities they participated in regularly. Those who reported regular resistance training at least once a week — using free weights, machines, or bodyweight exercises — were placed in a subgroup. People who did not engage in resistance training were assigned to another subgroup.
The researchers assessed the study participant’s bone microarchitecture using high-resolution peripheral quantitative computed tomography (HR-pQCT). They also looked at nutrient intake and serum markers for bone turnover.
After analyzing the data, scientists discovered that study participants in the vegan group who didn’t participate in regular resistance training had significantly diminished bone microarchitecture compared to non-resistance training omnivores.
However, the scientists found little or no bone structure differences among omnivores and vegans who regularly participated in resistance training exercises.
Stronger bones among vegans who resistance trained
The researchers also noted that bone structures differed between resistance training and non-resistance training individuals, and found more significant variations among the vegan participants.
In addition, study results showed that vegans and omnivores who only engaged in aerobic exercise or performed no physical activity had similar bone microarchitecture.
Moreover, investigators discovered that bone micro-structure was not influenced by how long a person had followed a vegan diet.
“Vegan participants who did resistance training exercises such as using machines, free weights, or bodyweight resistance exercises at least once a week had stronger bones than those who did not,” study co-author Dr. Christian Muschitz, associate professor at the Medical University of Vienna and head of the Metabolic Bone Diseases Unit at St. Vincent Hospital told Healthline.
“People who adhere to a vegan lifestyle should perform resistance training on a regular basis to preserve bone strength.”
Role of nutrition in a vegan diet
In addition to resistance training, nutrition can play a role in the bone health of people following a plant-based diet.
Study authors report that protein, vitamin B12, calcium, and vitamin D intake were adequate and similar between the resistance and non-resistance training vegan groups.
However, they suggest that vegans consider supplementing with vitamin B12 and ensure they are getting enough plant-based protein in their diet to prevent bone loss.
- vitamin A (carrots, winter squash)
- vitamin K (green leafy veggies)
- magnesium (chickpeas, spinach)
- phosphorus (beans, lentils, almonds)
“Fortunately, these nutrients are typically very easy to consume when enjoying a vegan diet,” she said.
Blake pointed out that other nutrients known to promote bone growth, including vitamin D and calcium, may be missing in a diet that does not contain foods from animal sources.
Still, it’s possible to obtain these nutrients on a plant-based diet.
“One of the best plant-based sources of these two nutrients is fortified soymilk,” Blake said. “Keep in mind that not all plant-based milk will provide adequate sources of vitamin and calcium unless they are fortified.”
Strength training for vegan bone health
The Austrian study suggests that resistance exercises are essential for bone health in people following a vegan diet. Kelsey Butler, MSc, a registered dietitian and nutritionist, agrees.
“Weight-bearing and resistance exercises are the most beneficial, as they help to build and maintain bone density,” she told Healthline.
“Examples of weight-bearing exercises include walking, running, jogging, and stair climbing. Resistance exercises like lifting weights or using resistance bands can also help to build bone density.”
Butler said that adding balance exercises to maintain coordination and muscle strength can also help prevent falls and bone fractures.
Although not specific to vegans, the Physical Activity Guidelines for Americans recommends that adults should perform moderate-intensity muscle-strengthening exercises that involve all major muscle groups 2 or more days a week.
Vegan diets may benefit health when the appropriate balance of nutrients is consumed from whole foods. But if meals are not well planned, this dietary lifestyle can sometimes lack adequate nutrients for bone health.
According to the new research, people who follow a plant-based diet may have diminished bone strength compared to those who eat both plant and animal-based food. However, the scientists found that regular resistance training may offset those differences.
Although superior nutrition is essential, scientists recommend that people who follow a plant-based diet should consider incorporating regular resistance training into their lifestyle to maintain bone health and strength.