When it comes to bone health and diet, most people think of calcium and vitamin D. And while these two nutrients are key to building and maintaining bone density combined with smart lifestyle choices like physical activity, there is emerging evidence that phytonutrients derived from a plant-foods, are also important to bone health.
According to the Surgeon General’s report on bone health, an estimated 10 million Americans over age 50 have osteoporosis, while another 34 million are at risk.1 A healthy skeletal system is essential to overall health and quality of life. Osteoporosis prevention begins at an early age as peak bone mass happens in the first three decades of life. During mid-life, the best defense against thinning bones is avoiding premature bone loss.
Fortunately, there are several ways adults of all ages can intervene to protect their bones including avoiding smoking, limiting alcohol intake, and engaging in activities such as jogging or weightlifting, which cause muscles and bones to work against gravity. Next to regular physical activity, nutrition is equally important to building and maintaining strong bones throughout life.
Adequate intakes of calcium and vitamin D are considered mainstays of sound bone health and osteoporosis prevention. For calcium, the adequate intake levels established by the Institute of Medicine (IOM) are 1,000 mg/day for adults up to 50 years old, and 1,200 mg/day for adults over 50 years of age. While dairy products like yogurt, cheese, and milk are good sources of calcium, plant-based sources such as tofu are also a smart dietary addition for calcium. Just one-half cup of firm tofu made with calcium sulfate offers 20 percent of the daily value of calcium.2 Plus, tofu is a lower calorie, lean protein source, and very versatile in the kitchen.
For vitamin D, the adequate intake level for adults up to 50 years old is 200 IU, for 51 to 70 years old it is 400 IU, and 600 IU for those over 70 years old. Vitamin D is not naturally present in very many foods. For this reason, it is not surprising that recent research shows over three out of four Americans fall short in healthy intakes of vitamin D.3
Key food sources include fish like salmon and tuna, as well as fortified dairy and some fortified cereals. In 2008, scientists at the Agricultural Research Service teamed up with industry and created an excellent plant-based source of vitamin D in the form of mushrooms. Thanks to UV-B light, the kind found in sunshine, some brands of mushrooms are now grown in specific conditions that result in 100 percent of the recommended intake of vitamin D in one 3-ounce serving (about one half cup).4 It should be noted that emerging research now points to potential benefits of daily intakes of vitamin D above this range for adults. The reader is advised to keep a watch for an uptick in daily vitamin D intake recommendations.
Beyond the two key nutrients of calcium and vitamin D for bone health, perhaps the next big nutritional player is vitamin K found in leafy greens like spinach, kale, and collard greens. It turns out that eating those leafy greens, along with the full spectrum of colorful fruit and vegetables may be the overarching critical step to promoting better bone health.
Mounting research on plant-based diets, often eaten more typically in Asian nations, suggests phytonutrients, plant-derived nutrients that do not include vitamins and minerals, may be beneficial to bone health.5 Population-based research shows that high fruit and vegetable intake may protect bone mineral density, thereby keeping bones from becoming weak or brittle.6 A subtle shift away from animal-based proteins towards plant-based proteins may also help promote better bone health.7
There are literally thousands of phytonutrients, and scientists are discovering more everyday. In fact, one orange is believed to have over 170 phytonutrients. Recent data from America’s Phytonutrient Report: Quantifying the Gap indicate that based on the five color groupings of phytonutrients, on average, eight out of 10 Americans (76 percent) have a "phytonutrient gap."8 Using government datasets on what Americans eat, the “gap” is defined as the percentage of American adults with phytonutrient intakes less than levels
identified as a “prudent intake.” In the report, the “prudent intake” was identified as the median intake of phytonutrients by the subpopulation of adults who meet recommended daily intakes of fruits and vegetables (“meeters”).9
Based on America’s Phytonutrient Report: Quantifying the Gap, Americans are falling short in virtually every color category of phytonutrients:
• 69 percent fall short in green
• 74 percent fall short in red
• 83 percent fall short in white
• 76 percent fall short in purple/blue
• 80 percent fall short in yellow/orange
For bone, the phytonutrients of interest span all fruit and vegetable color categories:
•Green – EGCG, lutein/zeaxanthin, and isoflavones
•Red – lycopene
•White – quercetin
•Yellow/orange – beta-carotene, hesperitin, beta-cryptoxanthin
Therefore, for better bone health, it is advisable to eat a wide variety of fruits and vegetables on a daily basis. A simple, actionable goal is to eat two servings from each of the five color categories every day for a total of 10 servings. Newly analyzed data on American’s who meet their fruit and vegetable intakes (“meeters”) suggest they not only get the benefits of higher levels of phytonutrients, they also have higher mean intakes of the big two — calcium and vitamin D.10 Roughly 50 percent of “meeters” have average calcium intakes of 1,000 mg/day or more, versus only about 25 percent of “non-meeters.” Likewise, roughly 50 percent of “meeters” have intakes of vitamin D of 200 IU/day or higher, versus just slightly more than 25 percent of "non-meeters."
All totaled, these results based on two-day average intakes suggest that adults who meet their recommended fruit and vegetable intakes get the broader benefit of higher overall phytonutrient consumption, and have higher intakes of calcium and vitamin D compared to adults who fail to meet recommended fruit and vegetable intakes.
Overall, consuming a wide variety of phytonutrient-rich whole fruits and vegetables is the primary goal. Further steps to improve bone status include avoiding smoking, limiting alcohol intake, and increasing regular exercise especially weight-bearing activities such as jogging or weightlifting. Natural plant-based supplements which contain extracted and concentrated phytonutrients are also an option for those wishing to fill their “phytonutrient gap.”
3 Adit Ginde, M.D., M.P.H., assistant professor, surgery, University of Colorado Denver School of Medicine; Heike A. Bischoff-Ferrari, Dr.P.H., assistant professor, University of Zurich, University Hospital, Zurich, Switzerland; Michael F. Holick, M.D., Ph.D., director, Vitamin D Laboratory, Boston University; March 23, 2009, Archives of Internal Medicine.
5 Anderson JJB. Plant-based diets and bone health: nutritional implications. American Journal of Clinical Nutrition. 1999;70: 539S-542S.
6 Tucker TL, Chen H, Hannan MT, Cupples LA, Wilson PWF, Felson D, Kiel DP. Bone mineral density and dietary patterns in older adults: the Framingham Osteoporosis Study. American Journal of Clinical Nutrition. 2002;76:245-252.
7 Sellmeyer DE, Stone KL, Sebastian A, Cummings SR. A high ratio of dietary animal to vegetable protein increases the rate of bone loss and the risk of fracture in postmenopausal women. American Journal of Clinical Nutrition 2001;73:118-22.
8 America’s Phytonutrient Report: Quantifying the Gap. Available via: http://www.amway.com/en/nutrition-wellness/nutrilite-experience#/section/phytonutrients/modal/content_list/id/phytonutrients_report/ . Accessed 1 March 2010.
9 U.S. Department of Agriculture (USDA). Available via: www.mypramid.gov. Accessed 1 March 2010.
10 Estimates of calcium and vitamin D were developed from an analysis of dietary recall data from NHANES, surveys designed to assess the health and nutritional status of the U.S. population, and nutrient concentration data from the United States Department of Agriculture (USDA). The analysis was completed by Exponent for Nutrilite on February 19, 2010.
This research was provided by Nutrilite.