January/February 2018

Nutrition: Osteoporosis Patients With Comorbidities: All Foods Can Fit
By Beth Kitchin, PhD, RDN
Today's Geriatric Medicine
Vol. 11 No. 1 P. 30

Older patients rarely present at an outpatient clinic with a single disease or condition. As patient educators, we must recognize that patients who come to us for lifestyle and medication counseling often have real and perceived competing issues. When seeking counseling on bone health, patients with lactose intolerance, heart disease, hypertension, and diabetes are often concerned about dietary changes that may conflict with these health issues. However, data from well done studies support an "all foods (and supplements) can fit" approach to counseling osteoporosis patients with comorbidities.

Calcium Supplements and Heart Disease
Concerns about heart disease and calcium supplements are likely the result of media headlines about the European Prospective Investigation into Cancer and Nutrition (EPIC) study and the emergence of arteriole calcification as a measure of heart attack risk.1 Results of the EPIC study showed, as have other observational studies, that taking calcium supplements was related to a statistically significant increased risk of myocardial infarction.2 Dietary calcium was related to a 30% decreased risk of myocardial infarction.

When the study was published, media headlines proliferated with messages warning the public of the "dangers" of taking calcium supplements. However, valid criticisms of the study were largely ignored in media accounts and among consumers. Since the study was observational, causal conclusions are inappropriate, as confounders could explain the association. In the study cohort only 3.6% of the participants were taking calcium supplements, so this segment of the population was underrepresented. Finally, there were only seven documented heart attacks in the cohort, skewing the results. The Women's Health Trial, a large randomized controlled trial, did not show that calcium supplementation caused heart attacks, strokes, or cardiovascular disease (CVD).3 To address the issues of arterial calcification, cardiac CT was conducted in a subset of 754 women in the supplement group. They found no association between calcium supplement use and coronary artery score. Furthermore, in the women not taking adequate calcium at baseline, calcium supplement use statistically significantly reduced the risk of hip fracture.

Based on these data, we can reassure patients at risk for heart disease who cannot get the calcium they need through dietary sources that calcium supplementation is not only safe for them but also necessary for their bone health. However, it is prudent to recommend appropriate doses of calcium supplements after an accurate assessment of dietary intake and also avoiding excessively high doses. The Tolerable Upper Intake Level (UL) for calcium is 2,000 mg per day.4 Since there are no demonstrable benefits in exceeding 1,200 to 1,500 mg of total calcium per day, we should advise patients to stay well below the UL.

Some patients prefer to obtain some or all of their calcium through dietary sources. They may have experienced stomach upset from calcium supplements or had other negative experiences with them. For patients at high risk of kidney stones, dietary calcium is recommended because of its association with a lower risk of calcium oxalate stone formation. Some patients simply prefer a more natural approach to their bone health. However, they may have concerns about high calcium foods, in particular dairy foods, with regard to other health issues.

Dairy, Heart Disease, and Hypertension
In addition to taking calcium supplements, patients at risk for heart disease are also concerned about possible effects of dairy foods on blood lipids. Low-fat and fat-free dairy have always been reasonable options for heart patients who also have bone health concerns. However, recent data strongly suggest that even high-fat milk and cheese are heart-neutral options. A recent dose-response meta-analysis of prospective cohort studies found no associations between total dairy (both high-fat and low-fat) and mortality, coronary heart disease, or CVD.5 Total fermented dairy foods (including fermented cheeses, sour milk, and yogurt) were slightly inversely associated with mortality and CVD risk.

Patients are often particularly concerned about eating cheese and say they like cheese but can't eat it because of high cholesterol levels. While most observational studies show no or a negative correlation between cheese intake and risk of heart disease, one randomized dietary intervention showed that a relatively large intake of hard cheese actually lowered LDL cholesterol levels when compared with butter of equal fat content.6 Cheese and butter intake during the intervention were calculated to comprise 13% of the participants' caloric needs. For the participants in the medium-energy group, this amounted to approximately 5 oz of cheese per day. Cheese intake resulted in a 6.9% reduction in LDL cholesterol levels when compared with comparable butter intake and no difference in LDL cholesterol levels when compared with participants' habitual diets. The researchers speculated that the calcium, protein, or the fermentation could explain the study's findings.

For patients with hypertension, the Dietary Approaches to Stop Hypertension (DASH) diet with sodium restriction may be a dietary pattern that improves both bone health and blood pressure. The DASH diet is a plant-based diet that includes low-fat dairy foods. This dietary pattern has been shown to significantly reduce blood pressure.7 Researchers have also compared the DASH and the DASH with low sodium with a control group for bone turnover and calcium excretion.8 The DASH diet contained 1,250 mg of calcium primarily through dairy foods compared with 450 mg in the control group. It was also higher in potassium from dairy, fruits, and vegetables (4,700 mg vs 1,700 mg) and magnesium from nuts and seeds (500 mg vs 160 mg). After 30 days, several markers of bone turnover were reduced in the participants on the DASH diet compared with the controls. There were no differences between the two groups for calcium excretion. However, there was a significant decrease in calcium excretion with the reduction of sodium to 1,150 mg in both the control group and the DASH group.

It is reasonable to advise patients who would like to use dairy foods as sources of calcium—particularly fermented dairy—that these foods are unlikely to have a negative effect on heart health. Additionally, reducing sodium may offer additional benefits for both blood pressure and bone health. However, reducing sodium to 1,150 mg per day may be challenging for many people. The DASH diet's high content of fruits and vegetables may have a very modest positive effect on bone health due to an alkaline effect on body pH.9 However, studies show inconsistent results with alkaline diets so suggesting them as an approach to managing osteoporosis is not recommended.10

Dairy and Obesity
Consumers often perceive dairy foods as fattening and counterproductive to weight management.11 However, there is little evidence that dairy foods contribute to obesity to a greater extent than any other food group. In fact, a 2016 prospective cohort study found an association between eating high-fat dairy foods and less weight gain over 11 years in middle-aged and elderly women.12 Low-fat dairy, dietary calcium, and calcium supplements were not associated with weight gain. However, this and other observational studies cannot establish a causal relationship between high-fat dairy and less weight gain. However, it is reasonable to assure patients who would like to add dairy foods to their diets that they are no more likely to cause weight gain than other foods, and that high-fat dairy foods are associated with better weight control as we age. Counseling should include helping patients monitor their weight with the addition of any foods to their dietary patterns.

Dairy and Lactose Intolerance
Some patients may express a desire to eat and drink more milk products but believe they suffer from lactose intolerance.13 Lower lactase levels leave undigested lactose in the gut. The large intestine attempts to ferment the undigested lactose resulting in gas, abdominal pain, bloating, and diarrhea. Patients may perceive themselves to be lactose intolerant due to their symptoms after eating or drinking dairy foods. However, a hydrogen breath test is recommended for an accurate diagnosis. If a patient wants to include dairy as a source of calcium but is lactose intolerant, there are many options.14 Drinking smaller amounts of milk throughout the day, lactose-free milk and other products that are treated with lactase, and filtered milk with a lower carbohydrate content such as Fairlife are often tolerated well. Some patients are able to tolerate yogurt, likely due to bacterial fermentation of lactose. Hard cheeses are low in lactose and may be well tolerated. Since every patient's symptoms and level of intolerance are different, keeping a food record and tracking symptoms can help the patient and the counselor to develop a workable plan.

For patients who don't care for drinking or eating dairy products, are vegan, or have severe symptoms with lactose intolerance (or a milk protein allergy), calcium-fortified products such as soymilk, almond milk, and calcium-added orange juice can help patients achieve adequate intakes of calcium. Always advise these patients to shake these products well before pouring, as the calcium may sink to the bottom of the container.

Conclusion
Patients often perceive nutritional recommendations for bone health to be at odds with their other diseases and conditions. Health care providers and nutrition counselors can help patients develop an evidence-based calcium regimen based on their personal needs, likes, dislikes, and desired lifestyle choices.

— Beth Kitchin, PhD, RDN, is an assistant professor in the University of Alabama at Birmingham (UAB) department of nutrition sciences, where she teaches undergraduate and graduate courses and directs the Nutrition Minor Program. She is also the patient educator at UAB's Osteoporosis Prevention and Treatment Clinic at the Kirklin Clinic and a weekly contributor on Birmingham's morning show Good Day Alabama. Follow her blog, The Kitchin Sink, at http://uabnutritiontrends.blogspot.com and on Twitter at @DrBethK.

References
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2. Li K, Kaaks R, Linseisen J, Rohrmann S. Associations of dietary calcium intake and calcium supplementation with myocardial infarction and stroke risk and overall cardiovascular mortality in the Heidelberg cohort of the European Prospective Investigation Into Cancer and Nutrition Study. Heart. 2012;98(12):920-925.

3. Prentice RL, Pettinger MB, Jackson RD, et al. Health risks and benefits from calcium supplementation: Women's Health Initiative clinical trial and cohort study. Osteoporosis Int. 2012;24(2):567-580.

4. Institute of Medicine of the National Academies. Dietary Reference Intakes for Calcium and Vitamin D. Washington D.C.: National Academic Press; 2011.

5. Guo J, Astrup A, Lovegrove JA, Gijsbers L, Givens DI, Soedamah-Muthu SS. Milk and dairy consumption and risk of cardiovascular diseases and all-cause mortality: dose-response meta-analysis of prospective cohort studies. Eur J Epidemiol. 2017;32(4):269-287.

6. Hjerpsted J, Leedo E, Tholstrup T. Cheese intake in large amounts lowers LDL-cholesterol concentrations compared with butter intake of equal fat content. Am J Clin Nutr. 2011;94(6):1479-1484.

7. Appel LJ, Moore TJ, Obarzanek E, et al. A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl J Med. 1997;336(16):1117-1124.

8. Lin PH, Ginty F, Appel LJ, et al. The DASH diet and sodium reduction improve markers of bone turnover and calcium metabolism in adults. J Nutr. 2003;133(10):3130-3136.

9. Levis S, Lagari VS. The role of diet in osteoporosis prevention and management. Curr Osteoporos Rep. 2012;10(4):296-302.

10. Hanley DA, Whiting SJ. Does a high dietary acid content cause bone loss, and can bone loss be prevented with an alkaline diet? J Clin Densitom. 2013;16(4):420-425.

11. Nolan-Clark DJ, Neale EP, Probst YC, Charlton KE, Tapsell LC. Consumers' salient beliefs regarding dairy products in the functional food era: a qualitative study using concepts from the theory of planned behavior. BMC Pub Health. 2011;11:843-850.

12. Rautiainen S, Wang L, Lee IM, Manson JE, Buring JE, Sesso HD. Dairy consumption in association with weight change and risk of becoming overweight or obese in middle-aged and older women: a prospective cohort study. Am J Clin Nutr. 2016;103:979-988.

13. Nicklas TA, Qu H, Hughes SO, et al. Self-perceived lactose intolerance results in lower intakes of calcium and dairy foods and is associated with hypertension and diabetes in adults. Am J Clin Nutr. 2011;94(1):191-198.

14. Suchy FJ, Brannon PM, Carpenter TO, et al. NIH consensus development conference statement: lactose intolerance and health. NIH Consens State Sci Statements. 2010;27(2):1-27.