Scientific Update
By Reed Mangels, PhD, RD
Lower Risk of Hip Fractures in Vegan Women Using Calcium and Vitamin D Supplements
A study from the United Kingdom reported that vegetarians had a 25% higher risk while vegans had more than twice the risk of hip fractures than did meat eaters.1 This study did not take into consideration use of calcium supplements or assess vitamin D intake.
Another recent study of more than 34,000 non-Hispanic white Seventh-day Adventists in the United States and Canada provided more information on hip fractures in vegetarians and vegans.2 Subjects were asked about their eating habits and their health and were observed for around eight years. Vegans were defined as those consuming animal products less than once a month; lacto-ovo vegetarians were defined as eating meat, fish, or poultry less than once a month. Subjects were at least 45 years old at the start of the study.
Vegan women had a markedly higher risk of fracturing a hip compared to nonvegetarian women. Lacto-ovo vegetarians, both women and men, and vegan men did not have a higher risk of hip fracture than did nonvegetarians. The researchers looked at use of calcium and vitamin D supplements. Vegan women who did not use calcium or vitamin D supplements had almost three times the risk of hip fracture compared to nonvegetarian women. Interestingly, vegan women who used calcium and vitamin D supplements did not have a higher risk of hip fractures.
Vegan women had an average dietary calcium intake of 774 milligrams per day, average supplemental calcium intake of 363 milligrams per day, and a total daily calcium intake averaging 1,137 milligrams of calcium. This appeared to be similar to or slightly less than the total calcium intake of vegan men and lacto-ovo vegetarian and nonvegetarian men and women. Calcium recommendations for adults age 45 and older are between 1,000 milligrams and 1,200 milligrams per day, depending on age and sex.
Vegan women had an average dietary vitamin D intake of 2.3 micrograms per day, an average intake of vitamin D from supplements of 5.5 micrograms per day, and a total daily vitamin D intake of 7.8 micrograms per day. Vegans, both men and women, had somewhat lower total daily vitamin D intakes compared to lacto-ovo vegetarians and nonvegetarians. The total average vitamin D intakes of all groups were below the recommended intake of 15 to 20 micrograms per day.
Sunlight exposure could have promoted vitamin D production, but this was not reported.
The reduction in hip fracture rates in those women taking calcium and vitamin D supplements supports the importance of getting adequate amounts of calcium and vitamin D to reduce the risk of having a hip fracture.
1 Tong TYN, Appleby PN, Armstrong MEG, et al. Vegetarian and vegan diets and risks of total and site-specific fractures: results from the prospective EPIC-Oxford study. BMC Med. 2020;18(1):353.
2 Thorpe DL, Beeson WL, Knutsen R, Fraser GE, Knutsen SF. Dietary patterns and hip fracture in the Adventist Health Study 2: combined vitamin D and calcium supplementation mitigate increased hip fracture risk among vegans. Am J Clin Nutr. 2021;114(2):488-495.
Nutritional Content of Plant Milks Varies
Does your plant milk supply calcium, vitamin B12, and vitamin D? Not everyone relies on plant milk to supply these nutrients; however, plant milks are often identified as an easy way to get significant amounts of these essentials.
A recently published study examined 148 different plant milks from stores in Europe, Australia, and the United States. The plant milks from the U.S., as opposed to those in other countries, were more likely to be fortified with calcium, vitamin D, and vitamin B12. An 8-ounce serving contained at least 20% of the Daily Value for these nutrients. A food that contains at least 20% of the Daily Value per serving for a nutrient is considered to be high in that nutrient. Of the plant milks examined in the U.S., 87% were fortified with calcium, and 82% contained vitamin D. Surprisingly, less than half (47%) supplied vitamin B12. If we look at the number of products that were examined in the U.S. that would be considered to be high in a nutrient, 73% were high in calcium, 47% were high in vitamin D, and 40% were high in vitamin B12. These results suggest that consumers cannot assume that the plant milk they purchase is a good source of key nutrients unless they have confirmed this by checking the Nutrition Facts label.
All the plant milks that were examined, except for those based on coconut, had very little saturated fat; more than 60% of the plant milks were low in sodium (less than 115 milligrams of sodium in an 8-ounce serving). More than half of the plant milks had low to moderate amounts of added sugar. The Nutrition Facts label lists added sugar, making it easy to select a milk with little or no added sugar.
If you are relying on a plant milk to supply calcium, vitamin D, and/or vitamin B12, be sure to check the Nutrition Facts label to see if the product you plan to purchase supplies these nutrients.
Craig WJ, Fresán U. International analysis of the nutritional content and a review of health benefits of non-dairy plant-based beverages. Nutrients. 2021;13(3):842.
Lower Risk of Type 2 Diabetes with Reduced Red Meat Consumption
Close to one in 10 American adults have been diagnosed with type 2 diabetes, formerly called adult-onset diabetes. In addition to health problems associated with type 2 diabetes, this condition can also lead to a higher risk of heart disease, eye problems, and kidney disease. A recent analysis assessed the effect of reducing red meat consumption and replacing the meat with other protein sources on the risk of developing type 2 diabetes. This study had more than 150,000 adult participants. From 1990 to 2013, they reported what they ate every four years and let researchers know if they had been diagnosed with type 2 diabetes.
Eating one fewer serving per day of red meat over a 4-year period and eating an additional serving of legumes was associated with an 11% lower risk of type 2 diabetes. Replacing a serving of red meat with a serving of nuts was associated with a 17% lower risk. Replacing processed red meat (bacon, hot dogs, etc.) with other foods had a stronger association with reduced risk of type 2 diabetes compared to replacing unprocessed red meat (beef, pork, lamb).
This study did not look at vegetarians; other studies have found a lower risk of type 2 diabetes in vegetarians.
According to the American Diabetes Association, on average, medical expenditures of people with diagnosed diabetes are approximately 2.3 times higher than they would be if people didn't have diabetes. Dietary changes that reduce the risk of diabetes could improve quality of life and potentially could reduce the cost of health care.
Würtz AML, Jakobsen MU, Bertoia ML, et al. Replacing the consumption of red meat with other major dietary protein sources and risk of type 2 diabetes mellitus: a prospective cohort study. Am J Clin Nutr. 2021;113(3):612-621.
Dietary Choices Affect Air Quality
About 15,900 deaths in the United States each year are attributed to air pollution related to food production; 80% of these deaths are estimated to be related to animal-based food production. There are numerous ways that food production contributes to air pollution.
Livestock waste (urine and feces) and fertilizer applications result in ammonia production. Ammonia is estimated to be associated with 69% of deaths related to air quality from food production. Particulate matter from dust from tillage, dust kicked up by livestock hooves, field burning, and emissions from agricultural equipment is estimated to be associated with 27% of food production air quality-related deaths.
Red meat production has the greatest impact on health damage related to air quality. The health effect of red meat production on air quality is estimated to be 10 times higher than that of nut and seed production and 15 times more than that of the production of other plant foods. Production of eggs, poultry, and dairy products all have a greater impact on deaths attributed to food production air quality than does production of plant foods.
Domingo NGG, Balasubramanian S, Thakrar SK, et al. Air quality-related health damages of food. Proc Natl Acad Sci U.S.A. 2021;118(20):e2013637118.
