Lifestyle Strategies to Maintain Bone Density During Aging

Berries with Greek Yogurt

My Fall

About six weeks ago, I took a hard fall when I tripped on a curb. Initially I couldn't walk without limping, and for several weeks my right hip and upper thigh really hurt, particularly when transferring in and out of bed. I also had extremely limited range of motion; I couldn't lift my leg more than an inch above the ground. An X ray and MRI revealed a hairline fracture of the right hip and adductor (groin) strain. This was my first fracture in 48 years of living. The X ray also indicated that I had arthritis throughout my hip region. 

Because the hairline fracture occurred as a result of falling from standing height, the doctor had me undergo a bone mineral density (BMD) scan to rule out potential osteoporosis. The results for all areas (spine and bilateral hips) were consistent with osteopenia, or low bone mass that is not severe enough to meet the criteria for osteoporosis.  Since I usually feel very healthy and energetic and am often mistaken for being several years younger than my age, I was surprised and a little unsettled to be diagnosed with osteoarthritis and osteopenia -- diseases that are most often associated with the elderly. We generally pay attention to weight, muscle tone, and other aspects of appearance but don't always consider what's happening on the inside, which is even more important. It's often not apparent that someone has bone or joint problems until disease is fairly advanced. And osteopenia isn't uncommon among women in their 40s and becomes more prevalent with age.

Osteopenia and Osteoporosis Classification and Risk Factors

According to World Health Organization criteria, osteopenia is defined as a BMD hip or spine T-score between -1.0 and -2.5 in postmenopausal women (indicating it is 1 to 2.5 standard deviations below the peak bone mass of a 30-year-old). Anything above -2.5 is considered osteoporosis. Both conditions increase the risk of fracture, poor healing, and immobility. For pre-menopausal women, many doctors prefer to use Z-scores, which report how BMD compares to average women of the same age. With the exception of one spine measurement, my Z-scores were all within the acceptable average range for my age. However, many older, postmenopausal women have better BMD than I do, and mine is obviously lower than I'd like it to be.

Risk factors for low bone density:

• Female gender
• Family history of osteoporosis
• Thin, small frame, and/or BMI <19
• Caucasian or Asian ethnicity
• History of anorexia nervosa 
• History of yo-yo dieting
• Amenorrhea or early menopause 
• Sedentary lifestyle
• Low estrogen levels
• Inadequate intake of protein, calcium, vitamin D, and other nutrients
• Smoking
• Heavy alcohol consumption

I have (or had in the past) most of the risk factors above, with the exception of history of anorexia nervosa, smoking or alcohol consumption, and I'm not sure about family history of osteoporosis.  One of the biggest contributors was likely hormonal dysfunction for many years, including two episodes of amenorrhea, culminating in a partial hysterectomy in 1999. I'm sure crash-dieting and constantly fluctuating 30 pounds or so during my teens also played a role.

Peak bone mass is achieved between childhood and about 25-30 years of age. After that time, everyone experiences some bone loss, but the extent to which it happens is highly variable. Unfortunately, many teens and young adults don't eat and exercise in a way that allows them to build a solid amount of bone that can withstand small losses over the subsequent decades. Weight reduction itself typically results in some loss of bone as well as muscle. Researchers report that losing weight results in a loss of 0.5-4% of bone mass, with the greatest percentage occurring in women over 45, those who weigh less than 132 pounds, those who restrict calories to very low levels, and those who lose a large amount of weight in a short period of time (1). 

Optimizing Bone Mineral Density as We Age

The loss of estrogen that occurs in the years leading up to menopause can exacerbate bone loss. However, at this point most doctors agree that hormone replacement therapy (HRT) should be initiated at the smallest effective dose when necessary. Every woman is different and should speak to her doctor about whether and when to initiate HRT, bioidentical or otherwise, and weighing the risks vs. benefits.

After talking it over with with my amazing integrative medicine MD, who ran several lab tests to rule out any underlying issues, I've decided to hold off on starting HRT right now while we continue to monitor my lab values and symptoms (although I will likely start in the near future because my estrogen levels have been low for a while). Fortunately, there are things that can be done to slow and possibly even reverse bone loss without initiating HRT prematurely or resorting to bisphosphonate medications such as Boniva, Fosamax, and Actonel.

Carbohydrates: "Low-carb diets are bad for your bones." I've seen this  charge expressed more than once, and for the most part, I disagree. Bone density is influenced by many factors -- including overall diet composition (macronutrients, micronutrients, energy content), exercise, and genetic differences -- but doesn't seem related to the amount of carbohydrate consumed. More than a decade ago a paper was published in which the authors stated low-carbohydrate diets may increase the risk for osteoporosis because they're low in calcium, fruits, and vegetables (2). However, this certainly isn't true in my own case (where Greek yogurt, sardines, vegetables, avocado, and berries are staple foods), and for others following a well-balanced, carbohydrate-restricted way of eating. The authors provided no evidence for low-carbohydrate diets having a detrimental effect on BMD, and I haven't been able to find any either. 

Protein: In the past, concerns were raised that diets high in protein could have a negative impact on bone health by increasing the amount of calcium released from bone and lost in the urine. However, a review of several studies of high-protein diets demonstrated they don't cause loss of calcium when alkaline foods like fruits and vegetables are included (3), and  older women in particular appear to have better bone density at higher intakes of animal protein (4). Research suggests low-protein diets compromise calcium absorption and bone health (5), while diets containing a higher percentage of calories from protein appear to reduce the amount of bone lost during calorie restriction (6).  

Collagen Hydrolysate: The primary component of bone is collagen. Collagen hydrolysate (gelatin) is derived from animal bones and has been used for nearly 1000 years as a remedy for joint pain. Most studies have looked at its effects on osteoarthritis, several of which have been favorable (7).  However, there  may also be potential benefits on bone. A 1996 study found that women given gelatin in addition to calcitonin (a hormone involved in calcium regulation) had a reduction in bone collagen breakdown (8).

Calcium: Calcium is arguably the most important mineral for bone health, and we need to consume it in dietary form on a daily basis to help maintain the stores in our skeleton. There are many factors that affect absorption of dietary calcium, including the amount consumed; at higher intakes, a smaller percentage of calcium is absorbed, yet when small amounts are ingested, the rate of absorption increases. Although high intake of dietary fiber can reduce the amount of calcium the body absorbs, consuming plenty of fat in addition to fiber has been found to improve absorption  (9,10). In addition, it appears that the type of fiber is a consideration, with wheat bran binding to calcium and reducing its absorption to a much greater extent than the  fiber found in fruits, vegetables, nuts, and seeds (11).

Vitamin D: Serum vitamin D levels greatly affect the calcium absorption, and achieving a level of at least 30 ng/ml (80 mmol/L) is crucial for bone health (12).  Some people are able to do this via sun exposure and foods high in vitamin D such as fatty fish, liver, and cheese, but others require supplemental vitamin D3*.

Vitamin K2: There are two forms of vitamin K: vitamin K1 (phylloquinone) and vitamin K2 (menaquinones). Vitamin K1 is found in leafy green produce and is involved with blood clotting. Vitamin K2  helps to maintain BMD by encouraging calcium to remain within the bones and teeth. A small amount can be synthesized by gut bacteria. It's also found in several dietary forms, but the two most common are MK-4 and MK-7. MK-4 exists in small amounts in animal products such as liver, eggs and meat, while fermented foods such as cheese, sauerkraut, and especially a soybean product known as  "natto" contain MK-7. Research indicates that the MK-7 form may be preferable for raising serum vitamin K levels (13). In several small clinical trials, researchers reported that supplemental K2 improves spinal bone density and reduces the risk of fractures in postmenopausal women with osteoporosis, and its beneficial effects on bone appear to extend to healthy older women as well (14)*.

Omega-3 Fatty Acids:  Higher intake of 0mega-3  polyunsaturated fatty acids (PUFAs) and a lower ratio of omega-6 to omega-3 PUFA has been associated with better BMD in a number of studies (15).  Although the long-chain omega-3 fats found in fish (EPA and DHA) have demonstrated beneficial effects on bone health, one randomized clinical trial found that plant sources of dietary omega-3 PUFAs may also help to preserve bone density by decreasing the rate of resorption, the breakdown that occurs when bone is broken down and calcium and other minerals are released into the bloodstream (16). 

Fruits and Vegetables: A recent study investigated the effects of various fruits and vegetables on bone health. Subjects were randomized into three groups. Group A consumed several servings of generic fruits, vegetables, and herbs, including apples, bananas, eggplant, cauliflower, and basil. Group B consumed the  "Scarborough Fair" diet, which included high amounts of specific produce and herbs containing phytochemicals with known benefits on bone turnover (resorption and new bone formation): Chinese cabbage, bok choy, lettuce, arugula, broccoli, tomatoes, mushrooms, cucumber, leeks, green beans, prunes, citrus fruits, garlic, and -- naturally -- parsley, sage, rosemary, and thyme. Group C subjects served as the controls and continued following their customary diet. While both Group A and Group B experienced a decline in urinary calcium losses, only Group B showed improvement in markers of bone turnover (17). Onion consumption alone is associated with improved bone density in women over 50, with those consuming the highest amounts significantly reducing their risk of hip fracture (18).

Weight Bearing and Resistance Exercise: The 12-month BEST (Bone, Estrogen, Strength Training) study investigated changes in bone mineral density between women who participated in 60-minute sessions focused primarily on weight-bearing and resistance-training exercise and a control group who did not. The researchers found significant gains in muscle strength and BMD for the intervention group and a loss of bone density in the non-exercisers. This was independent of hormone replacement therapy (HRT), which enhanced bone density and muscle strength in both groups (19). The most effective type of exercise for preserving and improving BMD in both pre- and postmenopausal women appears to be a combination of resistance training with weights and weight-bearing exercise like walking, running, or step aerobics  (20, 21), tailored to the individual's limitations and abilities. For postmenopausal women, a combination of tai chi and green tea (very high in polyphenols, a type of phytochemical) was found to improve markers of bone turnover and increase muscle strength (22).


Take-Home Points and Resources

1. Make sure you're consuming adequate calories, protein, fats, vitamins, and minerals, particularly during weight loss. No starvation diets or overly-restrictive eating plans. 

2. Consume adequate calcium. Excellent low-carb sources include plain Greek yogurt, cheese, broccoli, and leafy greens.

3.  Supplement with vitamin D3 and vitamin K2, as needed* .

Dr. Spencer Nadolsky and his brother Dr. Karl Nadolsky of Docs Who Lift have a great new combination supplement in an olive oil base.

4. Eat fatty fish (salmon, herring, sardines) at least three times a week. These fish provide long-chain omega-3 PUFAs, calcium (if the bones are consumed), and vitamin D.

5.  Eat several servings of produce and herbs every day, especially those listed in the "Scarborough Fair" diet and other brightly- and deeply-colored vegetables.

6. Gelatin might have a beneficial effect on bones, but there's not a lot of research in this area. It does appear to support joint health, so consider adding a tablespoon to your hot beverage in the morning. You can also get gelatin in bone broth or these low-carb, sugar-free recipes using gelatin: 

Healthy Low-Carb Marshmallows from KetoDiet
Strawberry Gelatin Tulsi Bites from Holistically Engineered
Sugar-Free Gummy Bears from Low Carb Yum

7. Lift weights and perform weight-bearing exercise several times a week*.

I advise working with a personal trainer to design the safest, most effective workout. This is something I'm currently exploring.

Recommended reading for strength training with heavy weights: "Training" section in the article Menopause and Fitness, with contributions from Dr. Karl Nadolsky and Dr. Spencer Nadolsky.

Recommended  DVDs  from Ellen Barrett focusing on weight-bearing exercise, light weights, cardio, and flexibility: 

Grace + Gusto
Fusion Flow 
Slim Sculpt (light weights)
Skinny Sculpt (light weights)
Barefoot Cardio
Super Fast Body Blast
Sleek Sculpt Express (light weights)
Stretch Sculpt (light weights)
Power Fusion
Fat Burning Fusion


While there's nothing we can do to change our genetics or our past eating and exercise history, there are plenty of steps we can take to prevent osteoporosis in the future, and  it's never too early or too late to start. I'm committed to doing all of the above in order to improve the health of my bones and reduce the risk of fractures as I age.  And, of course, I'm going to be more careful when navigating curbs.

* Check with your doctor before beginning an exercise program or taking any of the supplements listed above, and make sure to have routine monitoring of serum vitamin D levels if you are supplementing.


References:

1. Shapses SA, et al. Bone, Body Weight, and Weight Reduction: What Are the Concerns? J Nutr. 2006;136(6):1453-1456
2. Bilsborough SA, et al. Low-carbohydrate diets: what are the potential short- and long-term health implications? Asia Pac J Clin Nutr. 2003;12(4):396-404
3.Barzel US, et al. Excess dietary protein can adversely affect bone. J Nutr.1988;128:1051–1053    
4. Promislow JH, et al. Protein consumption and bone mineral density in the elderly: the Rancho Bernardo Study. Am J Epidemiol. 2002 Apr 1;155(7):636-44 
5. Kerstetter JE, et al. Low protein intake: the impact on calcium and bone homeostasis in humans. J Nutr. 2003 Mar;133(3);855S-861S.
6. Sukumar D, et al. Areal and Volumetric Bone Mineral Density and Geometry at Two Levels of Protein Intake During Caloric Restriction: A Randomized, Controlled Trial. J Bone Miner Res. 2011;26(6):1339-1348
7. Moskowitz RW. Role of collagen hydrolysate in bone and joint disease. Semin Arthritis Rheum. 2000 Oct;30(2):87-99 
8. Adam M, et al. Postmenopausal osteoporosis. Treatment with calcitonin and a diet rich in cartilage proteins. Cas Le`k ces. 1996;135:74-8
9. Ramsubeik R, et al. Factors Associated with Calcium Absorption in Postmenopausal Women: A Post-Hoc Analysis of Dual Isotope Studies. J Acad Nutr Diet. 114.5 (2014): 761–767
10. Wolf RL, et al.  Factors associated with calcium absorption efficiency in pre- and perimenopausal women Am J Clin Nutr 2000 Aug;72(2): 466-71
11. Weaver CM, et al. Wheat bran abolishes the inverse relationship between calcium load size and absorption fraction in women.  J Nutr 1996 Jan;126(1):303-7
12. Beto JA. The Role of Calcium in Human Aging. Clin Nutr Res. 2015;4(1):1-8
13. Sato T, et al. Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutr J. 2012;11:93
14. Iwamoto J, et al. Vitamin K2 Therapy for Postmenopausal Osteoporosis. Nutrients. 2014;6(5):1971-1980
15. Molfino A, et al. The role for dietary omega-3 fatty acids supplementation in older adults. Nutrients 2014 Oct 3;6(10):4058-73  
16. Griel AE, et al. An increase in dietary n-3 fatty acids decreases a marker of bone resorption in humans. Nutr J. 2007;6:2
17. Gunn CA, et al. Increased Intake of Selected Vegetables, Herbs and Fruit May Reduce Bone Turnover in Post-Menopausal Women. Nutrients 7.4 (2015): 2499–2517
18. Matheson EM, et al. The association between onion consumption and bone density in perimenopausal and postmenopausal non-Hispanic white women 50 years and older. Menopause. 2009 Jul-Aug;16(4):756-9
19.Metcalfe L, et al. Post-menopausal Women and Exercise for Prevention of Osteoporosis. American College of Sports and Medicine Journal May/June 2001
20. Martyn-St James M, et al. Effects of different impact exercise modalities on bone mineral density in premenopausal women: a meta-analysis. J Bone Miner Metab. May 2010;28(3):251-67
21. Moreira LF, et al. Physical exercise and osteoporosis: effects of different types of exercises on bone and physical function of postmenopausal women. Arq Bras Endocrinol Metabol. 2014 58(5): 514-522.  
22. Shen CL, et al. Effect of green tea and Tai Chi on bone health in postmenopausal osteopenic women: a 6-month randomized placebo-controlled trial. Osteoporos. 2012;23(5):1541-1552

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