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Does a low-fat diet help prevent breast cancer?
No. Studies show no evidence that reducing dietary fat decreases a woman’s risk of developing postmenopausal breast cancer within the subsequent 14 years (strength of recommendation [SOR]: B, based on large heterogeneous prospective cohort studies and appropriate meta-analyses of these studies). Overall, evidence is insufficient to recommend for or against reduction in dietary fat to reduce risk of breast cancer for women, although recommendations for prudent fat intake may be justified on other grounds.
Losing weight is still a good strategy
Kathryn Kolasa, PhD, RD, LDN
East Carolina University, Greenville, NC
Women at risk for breast cancer—and cancer survivors—want to know about lifestyle changes that can reduce their risks for cancer or recurrence. There is growing evidence that obesity plays a role in cancer development and promotion.
A low-fat diet has been demonstrated as a successful strategy for weight loss. However, for most women, making these changes can be difficult without extensive instruction, support, and motivation. Limiting sweetened beverages, increasing consumption of fruits and vegetables, and limiting fat intake are 3 strategies women can use to achieve a healthy weight. If this turns out to reduce their risk of breast cancer, so much the better!
Evidence summary
Our Medline search retrieved 1114 English-language studies published from 1960 through October 2006. We limited this set to randomized controlled trials and cohort studies, leaving 212 articles. We then excluded articles that had small sample sizes, did not follow subjects for at least 5 years, did not include original data, included men, did not give prevalence or incidence rate of breast cancer in the subjects, or did not discuss diet assessment tools. Of the remaining articles, we selected the 11 best studies to include in the review.
Early studies evaluating national average dietary fat intake and breast cancer incidence rates showed an almost linear relationship between increased dietary fat and increased breast cancer incidence.1 However, increased fat intake occurs primarily in industrialized nations, providing multiple possible confounders for increased rates of breast cancer, such as pollutants and increased consumption of preservatives, pesticides, and other chemicals.
Case-control studies have shown some minimally increased risk related to dietary fat consumption, but there is concern about recall bias in these studies.2 Since the late 1970s, 7 large, well-designed prospective cohort studies have examined the possible relationship between dietary fat and breast cancer.1 The findings have been somewhat contradictory, with some studies showing statistically significant associations toward increased risk with higher fat intake.3-5
Since the late 1990s, several meta-analyses, a systematic review of these cohort studies, and the Women’s Health Initiative Randomized Controlled Diet Initiative have largely concluded that there is no difference in breast cancer incidence between women with a low-fat diet (<20% of total calories from fat) and women with average or high-fat diets (>40% total calories from fat).1,3,6,7
The meta-analysis performed by Boyd et al did find a statistically significant difference, with relative risks ranging from 1.11 for overall to 1.19 for high-saturated-fat diets.8 The upper limit of all confidence intervals was no higher than 1.35, however, suggesting a lack of clinical significance. The best-designed studies also evaluated dietary composition with regard to key types of fat (saturated, mono- and poly-unsaturated; animal vs vegetable vs marine) and found no significant differences based on type of fat consumed.1
Preliminary evidence indicates that lowering dietary fat consumption may help with secondary prevention of breast cancer, but no large studies have been performed to date.9 Recently, a nested study within the Women’s Intervention Nutrition Study did show that women with breast cancer who decreased their fat intake to a median of 33 g/day had a hazard ratio of 0.76 for relapse over 60 months (compared with controls who ate a median of 51 g/day).10
Recommendations from others
There are no evidence-based or specific recommendations for the primary prevention of postmenopausal breast cancer for women through dietary fat reduction. In particular, neither the American Academy of Family Physicians, American College of Surgeons, National Institutes of Health, American College of Obstetricians and Gynecologists, American College of Physicians, US Preventive Services Task Force, or the Centers for Disease Control and Prevention provide any guidelines on dietary fat restriction for primary prevention of postmenopausal breast cancer.
The American Heart Association does have guidelines for coronary artery disease prevention for women, which include a low-fat diet.11 The USPSTF has no specific guidelines regarding dietary fat consumption for the general population.
1. Willett WC. Diet and breast cancer. J Intern Med 2001;249:395-411.
2. Bingham SA, Luben R, Welch A, Wareham N, Khaw KT, Day N. Are imprecise methods obscuring a relation between fat and breast cancer?. Lancet 2003;362:212-214.
3. Mattisson I, Wirfalt E, Wallstrom P, Gullberg B, Olsson H, Berglund G. High fat and alcohol intakes are risk factors of postmenopausal breast cancer: a prospective study from the Malmo diet and cancer cohort. Int J Cancer 2004;110:589-597.
4. Sieri S, Krogh V, Muti P, et al. Fat and Protein Intake and subsequent Breast Cancer risk in Postmenopausal Women. Nutr Cancer 2004;42:10-17.
5. Velie E, Kulldorff M, Schairer C, Block G, Albanes D, Schatzkin A. Dietary fat, fat subtypes, and breast cancer in postmenopausal women: a prospective cohort study. J Natl Cancer Inst 2000;92:833-839.
6. Holmes MD, Hunter DJ, Colditz GA, et al. Association of dietary intake of fat and fatty acids with risk of breast cancer. JAMA 1999;281:914-920.
7. Low-Fat Dietary Pattern and risk of Breast Cancer, Colorectal Cancer, and Cardiovascular Disease: The Women’s Health Initiative randomized Controlled Dietary Modification Trial. Available at: www.whi.org/findings/dm/dm.php. Accessed on June 14, 2007.
8. Boyd NF, Stone J, Vogt KN, Connelly BS, Martin LJ, Minkin S. Dietary fat and breast cancer risk revisited: a meta-analysis of the published literature. Br J Cancer 2003;89:1672-1685.
9. Rock CL. Diet and breast cancer: can dietary factors influence survival? J Mammary Gland Biol Neoplasia 2003;8:119-132.
10. Rowan T, Chlebowski GL, Blackburn CA, et al. Dietary Fat Reduction and Breast Cancer Outcome: Interim Efficacy Results From the Women’s Intervention Nutrition Study. J Natl Cancer Inst 2006;98:1767-1776.
11. Mosca L, Appel LJ, Benjamin EJ, et al. Evidence-based guidelines for cardiovascular disease prevention in women. Circulation 2004;109:672-693.
No. Studies show no evidence that reducing dietary fat decreases a woman’s risk of developing postmenopausal breast cancer within the subsequent 14 years (strength of recommendation [SOR]: B, based on large heterogeneous prospective cohort studies and appropriate meta-analyses of these studies). Overall, evidence is insufficient to recommend for or against reduction in dietary fat to reduce risk of breast cancer for women, although recommendations for prudent fat intake may be justified on other grounds.
Losing weight is still a good strategy
Kathryn Kolasa, PhD, RD, LDN
East Carolina University, Greenville, NC
Women at risk for breast cancer—and cancer survivors—want to know about lifestyle changes that can reduce their risks for cancer or recurrence. There is growing evidence that obesity plays a role in cancer development and promotion.
A low-fat diet has been demonstrated as a successful strategy for weight loss. However, for most women, making these changes can be difficult without extensive instruction, support, and motivation. Limiting sweetened beverages, increasing consumption of fruits and vegetables, and limiting fat intake are 3 strategies women can use to achieve a healthy weight. If this turns out to reduce their risk of breast cancer, so much the better!
Evidence summary
Our Medline search retrieved 1114 English-language studies published from 1960 through October 2006. We limited this set to randomized controlled trials and cohort studies, leaving 212 articles. We then excluded articles that had small sample sizes, did not follow subjects for at least 5 years, did not include original data, included men, did not give prevalence or incidence rate of breast cancer in the subjects, or did not discuss diet assessment tools. Of the remaining articles, we selected the 11 best studies to include in the review.
Early studies evaluating national average dietary fat intake and breast cancer incidence rates showed an almost linear relationship between increased dietary fat and increased breast cancer incidence.1 However, increased fat intake occurs primarily in industrialized nations, providing multiple possible confounders for increased rates of breast cancer, such as pollutants and increased consumption of preservatives, pesticides, and other chemicals.
Case-control studies have shown some minimally increased risk related to dietary fat consumption, but there is concern about recall bias in these studies.2 Since the late 1970s, 7 large, well-designed prospective cohort studies have examined the possible relationship between dietary fat and breast cancer.1 The findings have been somewhat contradictory, with some studies showing statistically significant associations toward increased risk with higher fat intake.3-5
Since the late 1990s, several meta-analyses, a systematic review of these cohort studies, and the Women’s Health Initiative Randomized Controlled Diet Initiative have largely concluded that there is no difference in breast cancer incidence between women with a low-fat diet (<20% of total calories from fat) and women with average or high-fat diets (>40% total calories from fat).1,3,6,7
The meta-analysis performed by Boyd et al did find a statistically significant difference, with relative risks ranging from 1.11 for overall to 1.19 for high-saturated-fat diets.8 The upper limit of all confidence intervals was no higher than 1.35, however, suggesting a lack of clinical significance. The best-designed studies also evaluated dietary composition with regard to key types of fat (saturated, mono- and poly-unsaturated; animal vs vegetable vs marine) and found no significant differences based on type of fat consumed.1
Preliminary evidence indicates that lowering dietary fat consumption may help with secondary prevention of breast cancer, but no large studies have been performed to date.9 Recently, a nested study within the Women’s Intervention Nutrition Study did show that women with breast cancer who decreased their fat intake to a median of 33 g/day had a hazard ratio of 0.76 for relapse over 60 months (compared with controls who ate a median of 51 g/day).10
Recommendations from others
There are no evidence-based or specific recommendations for the primary prevention of postmenopausal breast cancer for women through dietary fat reduction. In particular, neither the American Academy of Family Physicians, American College of Surgeons, National Institutes of Health, American College of Obstetricians and Gynecologists, American College of Physicians, US Preventive Services Task Force, or the Centers for Disease Control and Prevention provide any guidelines on dietary fat restriction for primary prevention of postmenopausal breast cancer.
The American Heart Association does have guidelines for coronary artery disease prevention for women, which include a low-fat diet.11 The USPSTF has no specific guidelines regarding dietary fat consumption for the general population.
No. Studies show no evidence that reducing dietary fat decreases a woman’s risk of developing postmenopausal breast cancer within the subsequent 14 years (strength of recommendation [SOR]: B, based on large heterogeneous prospective cohort studies and appropriate meta-analyses of these studies). Overall, evidence is insufficient to recommend for or against reduction in dietary fat to reduce risk of breast cancer for women, although recommendations for prudent fat intake may be justified on other grounds.
Losing weight is still a good strategy
Kathryn Kolasa, PhD, RD, LDN
East Carolina University, Greenville, NC
Women at risk for breast cancer—and cancer survivors—want to know about lifestyle changes that can reduce their risks for cancer or recurrence. There is growing evidence that obesity plays a role in cancer development and promotion.
A low-fat diet has been demonstrated as a successful strategy for weight loss. However, for most women, making these changes can be difficult without extensive instruction, support, and motivation. Limiting sweetened beverages, increasing consumption of fruits and vegetables, and limiting fat intake are 3 strategies women can use to achieve a healthy weight. If this turns out to reduce their risk of breast cancer, so much the better!
Evidence summary
Our Medline search retrieved 1114 English-language studies published from 1960 through October 2006. We limited this set to randomized controlled trials and cohort studies, leaving 212 articles. We then excluded articles that had small sample sizes, did not follow subjects for at least 5 years, did not include original data, included men, did not give prevalence or incidence rate of breast cancer in the subjects, or did not discuss diet assessment tools. Of the remaining articles, we selected the 11 best studies to include in the review.
Early studies evaluating national average dietary fat intake and breast cancer incidence rates showed an almost linear relationship between increased dietary fat and increased breast cancer incidence.1 However, increased fat intake occurs primarily in industrialized nations, providing multiple possible confounders for increased rates of breast cancer, such as pollutants and increased consumption of preservatives, pesticides, and other chemicals.
Case-control studies have shown some minimally increased risk related to dietary fat consumption, but there is concern about recall bias in these studies.2 Since the late 1970s, 7 large, well-designed prospective cohort studies have examined the possible relationship between dietary fat and breast cancer.1 The findings have been somewhat contradictory, with some studies showing statistically significant associations toward increased risk with higher fat intake.3-5
Since the late 1990s, several meta-analyses, a systematic review of these cohort studies, and the Women’s Health Initiative Randomized Controlled Diet Initiative have largely concluded that there is no difference in breast cancer incidence between women with a low-fat diet (<20% of total calories from fat) and women with average or high-fat diets (>40% total calories from fat).1,3,6,7
The meta-analysis performed by Boyd et al did find a statistically significant difference, with relative risks ranging from 1.11 for overall to 1.19 for high-saturated-fat diets.8 The upper limit of all confidence intervals was no higher than 1.35, however, suggesting a lack of clinical significance. The best-designed studies also evaluated dietary composition with regard to key types of fat (saturated, mono- and poly-unsaturated; animal vs vegetable vs marine) and found no significant differences based on type of fat consumed.1
Preliminary evidence indicates that lowering dietary fat consumption may help with secondary prevention of breast cancer, but no large studies have been performed to date.9 Recently, a nested study within the Women’s Intervention Nutrition Study did show that women with breast cancer who decreased their fat intake to a median of 33 g/day had a hazard ratio of 0.76 for relapse over 60 months (compared with controls who ate a median of 51 g/day).10
Recommendations from others
There are no evidence-based or specific recommendations for the primary prevention of postmenopausal breast cancer for women through dietary fat reduction. In particular, neither the American Academy of Family Physicians, American College of Surgeons, National Institutes of Health, American College of Obstetricians and Gynecologists, American College of Physicians, US Preventive Services Task Force, or the Centers for Disease Control and Prevention provide any guidelines on dietary fat restriction for primary prevention of postmenopausal breast cancer.
The American Heart Association does have guidelines for coronary artery disease prevention for women, which include a low-fat diet.11 The USPSTF has no specific guidelines regarding dietary fat consumption for the general population.
1. Willett WC. Diet and breast cancer. J Intern Med 2001;249:395-411.
2. Bingham SA, Luben R, Welch A, Wareham N, Khaw KT, Day N. Are imprecise methods obscuring a relation between fat and breast cancer?. Lancet 2003;362:212-214.
3. Mattisson I, Wirfalt E, Wallstrom P, Gullberg B, Olsson H, Berglund G. High fat and alcohol intakes are risk factors of postmenopausal breast cancer: a prospective study from the Malmo diet and cancer cohort. Int J Cancer 2004;110:589-597.
4. Sieri S, Krogh V, Muti P, et al. Fat and Protein Intake and subsequent Breast Cancer risk in Postmenopausal Women. Nutr Cancer 2004;42:10-17.
5. Velie E, Kulldorff M, Schairer C, Block G, Albanes D, Schatzkin A. Dietary fat, fat subtypes, and breast cancer in postmenopausal women: a prospective cohort study. J Natl Cancer Inst 2000;92:833-839.
6. Holmes MD, Hunter DJ, Colditz GA, et al. Association of dietary intake of fat and fatty acids with risk of breast cancer. JAMA 1999;281:914-920.
7. Low-Fat Dietary Pattern and risk of Breast Cancer, Colorectal Cancer, and Cardiovascular Disease: The Women’s Health Initiative randomized Controlled Dietary Modification Trial. Available at: www.whi.org/findings/dm/dm.php. Accessed on June 14, 2007.
8. Boyd NF, Stone J, Vogt KN, Connelly BS, Martin LJ, Minkin S. Dietary fat and breast cancer risk revisited: a meta-analysis of the published literature. Br J Cancer 2003;89:1672-1685.
9. Rock CL. Diet and breast cancer: can dietary factors influence survival? J Mammary Gland Biol Neoplasia 2003;8:119-132.
10. Rowan T, Chlebowski GL, Blackburn CA, et al. Dietary Fat Reduction and Breast Cancer Outcome: Interim Efficacy Results From the Women’s Intervention Nutrition Study. J Natl Cancer Inst 2006;98:1767-1776.
11. Mosca L, Appel LJ, Benjamin EJ, et al. Evidence-based guidelines for cardiovascular disease prevention in women. Circulation 2004;109:672-693.
1. Willett WC. Diet and breast cancer. J Intern Med 2001;249:395-411.
2. Bingham SA, Luben R, Welch A, Wareham N, Khaw KT, Day N. Are imprecise methods obscuring a relation between fat and breast cancer?. Lancet 2003;362:212-214.
3. Mattisson I, Wirfalt E, Wallstrom P, Gullberg B, Olsson H, Berglund G. High fat and alcohol intakes are risk factors of postmenopausal breast cancer: a prospective study from the Malmo diet and cancer cohort. Int J Cancer 2004;110:589-597.
4. Sieri S, Krogh V, Muti P, et al. Fat and Protein Intake and subsequent Breast Cancer risk in Postmenopausal Women. Nutr Cancer 2004;42:10-17.
5. Velie E, Kulldorff M, Schairer C, Block G, Albanes D, Schatzkin A. Dietary fat, fat subtypes, and breast cancer in postmenopausal women: a prospective cohort study. J Natl Cancer Inst 2000;92:833-839.
6. Holmes MD, Hunter DJ, Colditz GA, et al. Association of dietary intake of fat and fatty acids with risk of breast cancer. JAMA 1999;281:914-920.
7. Low-Fat Dietary Pattern and risk of Breast Cancer, Colorectal Cancer, and Cardiovascular Disease: The Women’s Health Initiative randomized Controlled Dietary Modification Trial. Available at: www.whi.org/findings/dm/dm.php. Accessed on June 14, 2007.
8. Boyd NF, Stone J, Vogt KN, Connelly BS, Martin LJ, Minkin S. Dietary fat and breast cancer risk revisited: a meta-analysis of the published literature. Br J Cancer 2003;89:1672-1685.
9. Rock CL. Diet and breast cancer: can dietary factors influence survival? J Mammary Gland Biol Neoplasia 2003;8:119-132.
10. Rowan T, Chlebowski GL, Blackburn CA, et al. Dietary Fat Reduction and Breast Cancer Outcome: Interim Efficacy Results From the Women’s Intervention Nutrition Study. J Natl Cancer Inst 2006;98:1767-1776.
11. Mosca L, Appel LJ, Benjamin EJ, et al. Evidence-based guidelines for cardiovascular disease prevention in women. Circulation 2004;109:672-693.
Evidence-based answers from the Family Physicians Inquiries Network
Are any alternative therapies effective in treating asthma?
Yes, some are. Acupuncture relieves subjective symptoms of asthma and reduces medication use in mild to moderate asthma (strength of recommendation [SOR]: A, based on systematic review of randomized controlled trials [RCTs] of variable quality). Herbal medications, such as Ginkgo biloba, appear to improve lung function, while herbs such as Tylophora indica and Tsumura saiboku-to may decrease asthma symptoms (SOR: B, based on systematic review of RCTs with poor methodology). No evidence, however, supports the use of room air ionizers, manual therapy, homeopathy, or mind-body therapy for treatment of asthma (SOR: A, based on systematic reviews and meta-analyses of RCTs and individual RCTs).
Though this research is interesting, we should adhere to current guidelines
Vincent Lo, MD
San Joaquin General Hospital, French Camp, Calif
Guidelines for the diagnosis and management of asthma are widely disseminated by the National Asthma Education and Prevention Program through its Expert Panel Reports (updated in 2002).1 Nevertheless, nearly 500,000 hospitalizations, 2 million emergency department visits, and 5000 deaths were reported annually in the US among those who have asthma.2 Furthermore, a significant difference in asthma prevalence, health care use, and mortality was found among different ethnic groups.1
Poor patient understanding of asthma control, nonadherence to medication regimens, cultural beliefs, and disparity of access to the health care system, together with physicians’ lack of close monitoring and inadequate compliance with national asthma guidelines, contribute to suboptimal control of chronic asthma. Family physicians must guide and empower their patients with the knowledge and responsibility of how to manage their asthma. For now, we should adhere to current national guidelines of management of asthma and avoid routine recommendation of any complimentary alternative treatments.
Evidence summary
Although complementary and alternative medicine (CAM) therapies are widely used, the overall body of research into CAM for asthma is still small and of limited quality. Interpreting the research is hampered by lack of standardized therapeutic approaches, lack of accepted methods for appropriate trials, and the fact that many CAM treatments are used as part of a multi-pronged, individualized approach to treatment in actual practice. Our search found 4 good-quality systematic reviews of RCTs, 1 good-quality systematic review of randomized trials, and 1 small additional pilot RCT of various CAM treatments for asthma.
Acupuncture and herbals provide some benefit
While a Cochrane review of 11 RCTs with variable trial quality and a total of 324 participants found that acupuncture had no significant effect on pulmonary function or global assessment of well-being, the review noted that some studies reported significant positive changes in daily symptoms, reductions in medication use, and improved quality of life. This suggests that some patients with mild to moderate asthma may benefit from acupuncture.3 In 1 RCT, improvement in general well-being was reported by 79% of 38 patients receiving acupuncture compared with 47% of 18 patients in the control group.4
When it comes to herbal remedies, a good-quality systematic review5 of 17 trials, with overall poor methodological quality and a total of 1445 participants, reported significant improvements in clinically relevant measures with 6 different herbal medicines.
- Ginkgo biloba liquor increased forced expiratory volume in 1 second (FEV1) by 10% at 4 weeks and by a more clinically relevant 15% at 8 weeks (significantly greater than placebo, P<.05).
- Invigorating Kidney for Preventing Asthma (IKPA) tablets increased FEV1 by 30% at 3 months compared with 17% in controls (P<.05).
- Wenyang Tonglulo Mixture (WTM) improved FEV1 by 30% at 8 weeks compared with a 16% increase in the control group using oral salbutamol and inhaled beclomethasone (P<.05).
- Dried ivy extract, thought to work as both a secretolytic and bronchospasmolytic, reduced airway resistance in children by 23.6% compared with placebo (P=.036).
- Tylophora indica (a rare herb also known as Indian ipecac) provided significant improvement in nocturnal dyspnea when compared with controls (P<.01) in a study that relied on patients’ symptom diaries.
- Tsumura saiboku-to (TJ-96) provided patients in one RCT with significant, but unspecified, asthma symptom relief when compared with those in a control group (P<.01).5
Other therapies didn’t quite make the grade
Homeopathy. A Cochrane review of 6 RCTs of mixed quality, with a total of 556 patients, concluded the evidence is insufficient to evaluate the possible role of homeopathy for the treatment of asthma, due to heterogeneity of interventions, patient populations, and outcome assessments. Each study evaluated a different homeopathic remedy, making any overall assessment difficult.
The review notes there have been only limited attempts to study a complete “package of care,” which includes the in-depth, one-on-one consultation, treatment, and follow-up that characterizes most homeopathic treatment in practice.6
Room air ionizers. A Cochrane review of 6 good-quality trials with a total of 106 participants reported no significant effect of room air ionizers on pulmonary function measures, symptoms, or medication use.7
Manual therapy. A Cochrane review8 of 3 moderate- to poor-quality RCTs with 156 participants reported no significant effect of chiropractic spinal manipulation (2 trials) or massage therapy (1 trial) on lung function, asthma symptoms, or medication use.
Mind-body therapy. A pilot RCT9 with 33 adults found a nonsignificant reduction in medication use among the subjects practicing mental imagery, but no overall effect on lung function or quality-of-life measures.
Recommendations from others
The New Zealand Guideline Group (NZGG)10 gives a Grade B recommendation for Buteyko Breathing Techniques as an intervention that may be helpful in reducing acute exacerbation medication use and improving patient quality of life. However, the NZGG did not find other benefits to this intervention and noted that it might be costly for the patient to obtain training in these techniques. The NZGG further recommends as a good practice point that healthcare professionals be open to the use of CAM therapies and that such therapies be tried by patients who are interested in them, with monitoring and self-assessment to assist patients in determining which therapies are of value.
1. Guidelines for the diagnosis and management of asthma. Update on selected topics 2002. Available at: www.nhlbi.nih.gov/guidelines/asthma/index.htm. Accessed on March 30, 2007.
2. Mannino DM, Home DW, Akinbami LJ, Morrman JE, Guynn C, Redd SC. Surveillance of Asthma—1980–1999. MMWR Surveill Summ 2002;51:1-13.
3. McCarney RW, Brinkhaus B, Lasserson TJ, Linde K. Acupuncture for chronic asthma. Cochrane Database Syst Rev 2004;(1):CD000008.-
4. Joos S, Schott C, Zou H, Daniel V, Martin E. Immunomodulatory effects of acupuncture in the treatment of allergic asthma: a randomized controlled study. J Altern Complementary Med 2000;6:519-525.
5. Huntley A, Ernst E. Herbal medicines for asthma: a systemic review. Thorax 2000;55:925-929.
6. McCarney RW, Linde K, Lasserson TJ. Homeopathy for chronic asthma. Cochrane Database Syst Rev 2004;(1):CD000353.-
7. Blackhall K, Appleton S, Cates FJ. Ionisers for chronic asthma. Cochrane Database Syst Rev 2003;(3):CD002986.-
8. Hondras MA, Jones LK, Jones AP. Manual therapy for asthma. Cochrane Database Syst Rev 2005;(2):CD001002.-
9. Epstein GN, Halper JP, Barrett EA, et al. A pilot study of mind-body changes in adults with asthma who practice mental imagery. Alternative Therapies 2004;10:66-71.
10. New Zealand Guidelines Group (NZGG) The diagnosis and treatment of adult asthma. Best Practice Evidence-Based Guideline. Wellington, NZ: NZGG; 2007. Available at: www.nzgg.org.nz/guidelines/0003/Full_text_Guideline.pdf. Accessed on March 30, 2007.
Yes, some are. Acupuncture relieves subjective symptoms of asthma and reduces medication use in mild to moderate asthma (strength of recommendation [SOR]: A, based on systematic review of randomized controlled trials [RCTs] of variable quality). Herbal medications, such as Ginkgo biloba, appear to improve lung function, while herbs such as Tylophora indica and Tsumura saiboku-to may decrease asthma symptoms (SOR: B, based on systematic review of RCTs with poor methodology). No evidence, however, supports the use of room air ionizers, manual therapy, homeopathy, or mind-body therapy for treatment of asthma (SOR: A, based on systematic reviews and meta-analyses of RCTs and individual RCTs).
Though this research is interesting, we should adhere to current guidelines
Vincent Lo, MD
San Joaquin General Hospital, French Camp, Calif
Guidelines for the diagnosis and management of asthma are widely disseminated by the National Asthma Education and Prevention Program through its Expert Panel Reports (updated in 2002).1 Nevertheless, nearly 500,000 hospitalizations, 2 million emergency department visits, and 5000 deaths were reported annually in the US among those who have asthma.2 Furthermore, a significant difference in asthma prevalence, health care use, and mortality was found among different ethnic groups.1
Poor patient understanding of asthma control, nonadherence to medication regimens, cultural beliefs, and disparity of access to the health care system, together with physicians’ lack of close monitoring and inadequate compliance with national asthma guidelines, contribute to suboptimal control of chronic asthma. Family physicians must guide and empower their patients with the knowledge and responsibility of how to manage their asthma. For now, we should adhere to current national guidelines of management of asthma and avoid routine recommendation of any complimentary alternative treatments.
Evidence summary
Although complementary and alternative medicine (CAM) therapies are widely used, the overall body of research into CAM for asthma is still small and of limited quality. Interpreting the research is hampered by lack of standardized therapeutic approaches, lack of accepted methods for appropriate trials, and the fact that many CAM treatments are used as part of a multi-pronged, individualized approach to treatment in actual practice. Our search found 4 good-quality systematic reviews of RCTs, 1 good-quality systematic review of randomized trials, and 1 small additional pilot RCT of various CAM treatments for asthma.
Acupuncture and herbals provide some benefit
While a Cochrane review of 11 RCTs with variable trial quality and a total of 324 participants found that acupuncture had no significant effect on pulmonary function or global assessment of well-being, the review noted that some studies reported significant positive changes in daily symptoms, reductions in medication use, and improved quality of life. This suggests that some patients with mild to moderate asthma may benefit from acupuncture.3 In 1 RCT, improvement in general well-being was reported by 79% of 38 patients receiving acupuncture compared with 47% of 18 patients in the control group.4
When it comes to herbal remedies, a good-quality systematic review5 of 17 trials, with overall poor methodological quality and a total of 1445 participants, reported significant improvements in clinically relevant measures with 6 different herbal medicines.
- Ginkgo biloba liquor increased forced expiratory volume in 1 second (FEV1) by 10% at 4 weeks and by a more clinically relevant 15% at 8 weeks (significantly greater than placebo, P<.05).
- Invigorating Kidney for Preventing Asthma (IKPA) tablets increased FEV1 by 30% at 3 months compared with 17% in controls (P<.05).
- Wenyang Tonglulo Mixture (WTM) improved FEV1 by 30% at 8 weeks compared with a 16% increase in the control group using oral salbutamol and inhaled beclomethasone (P<.05).
- Dried ivy extract, thought to work as both a secretolytic and bronchospasmolytic, reduced airway resistance in children by 23.6% compared with placebo (P=.036).
- Tylophora indica (a rare herb also known as Indian ipecac) provided significant improvement in nocturnal dyspnea when compared with controls (P<.01) in a study that relied on patients’ symptom diaries.
- Tsumura saiboku-to (TJ-96) provided patients in one RCT with significant, but unspecified, asthma symptom relief when compared with those in a control group (P<.01).5
Other therapies didn’t quite make the grade
Homeopathy. A Cochrane review of 6 RCTs of mixed quality, with a total of 556 patients, concluded the evidence is insufficient to evaluate the possible role of homeopathy for the treatment of asthma, due to heterogeneity of interventions, patient populations, and outcome assessments. Each study evaluated a different homeopathic remedy, making any overall assessment difficult.
The review notes there have been only limited attempts to study a complete “package of care,” which includes the in-depth, one-on-one consultation, treatment, and follow-up that characterizes most homeopathic treatment in practice.6
Room air ionizers. A Cochrane review of 6 good-quality trials with a total of 106 participants reported no significant effect of room air ionizers on pulmonary function measures, symptoms, or medication use.7
Manual therapy. A Cochrane review8 of 3 moderate- to poor-quality RCTs with 156 participants reported no significant effect of chiropractic spinal manipulation (2 trials) or massage therapy (1 trial) on lung function, asthma symptoms, or medication use.
Mind-body therapy. A pilot RCT9 with 33 adults found a nonsignificant reduction in medication use among the subjects practicing mental imagery, but no overall effect on lung function or quality-of-life measures.
Recommendations from others
The New Zealand Guideline Group (NZGG)10 gives a Grade B recommendation for Buteyko Breathing Techniques as an intervention that may be helpful in reducing acute exacerbation medication use and improving patient quality of life. However, the NZGG did not find other benefits to this intervention and noted that it might be costly for the patient to obtain training in these techniques. The NZGG further recommends as a good practice point that healthcare professionals be open to the use of CAM therapies and that such therapies be tried by patients who are interested in them, with monitoring and self-assessment to assist patients in determining which therapies are of value.
Yes, some are. Acupuncture relieves subjective symptoms of asthma and reduces medication use in mild to moderate asthma (strength of recommendation [SOR]: A, based on systematic review of randomized controlled trials [RCTs] of variable quality). Herbal medications, such as Ginkgo biloba, appear to improve lung function, while herbs such as Tylophora indica and Tsumura saiboku-to may decrease asthma symptoms (SOR: B, based on systematic review of RCTs with poor methodology). No evidence, however, supports the use of room air ionizers, manual therapy, homeopathy, or mind-body therapy for treatment of asthma (SOR: A, based on systematic reviews and meta-analyses of RCTs and individual RCTs).
Though this research is interesting, we should adhere to current guidelines
Vincent Lo, MD
San Joaquin General Hospital, French Camp, Calif
Guidelines for the diagnosis and management of asthma are widely disseminated by the National Asthma Education and Prevention Program through its Expert Panel Reports (updated in 2002).1 Nevertheless, nearly 500,000 hospitalizations, 2 million emergency department visits, and 5000 deaths were reported annually in the US among those who have asthma.2 Furthermore, a significant difference in asthma prevalence, health care use, and mortality was found among different ethnic groups.1
Poor patient understanding of asthma control, nonadherence to medication regimens, cultural beliefs, and disparity of access to the health care system, together with physicians’ lack of close monitoring and inadequate compliance with national asthma guidelines, contribute to suboptimal control of chronic asthma. Family physicians must guide and empower their patients with the knowledge and responsibility of how to manage their asthma. For now, we should adhere to current national guidelines of management of asthma and avoid routine recommendation of any complimentary alternative treatments.
Evidence summary
Although complementary and alternative medicine (CAM) therapies are widely used, the overall body of research into CAM for asthma is still small and of limited quality. Interpreting the research is hampered by lack of standardized therapeutic approaches, lack of accepted methods for appropriate trials, and the fact that many CAM treatments are used as part of a multi-pronged, individualized approach to treatment in actual practice. Our search found 4 good-quality systematic reviews of RCTs, 1 good-quality systematic review of randomized trials, and 1 small additional pilot RCT of various CAM treatments for asthma.
Acupuncture and herbals provide some benefit
While a Cochrane review of 11 RCTs with variable trial quality and a total of 324 participants found that acupuncture had no significant effect on pulmonary function or global assessment of well-being, the review noted that some studies reported significant positive changes in daily symptoms, reductions in medication use, and improved quality of life. This suggests that some patients with mild to moderate asthma may benefit from acupuncture.3 In 1 RCT, improvement in general well-being was reported by 79% of 38 patients receiving acupuncture compared with 47% of 18 patients in the control group.4
When it comes to herbal remedies, a good-quality systematic review5 of 17 trials, with overall poor methodological quality and a total of 1445 participants, reported significant improvements in clinically relevant measures with 6 different herbal medicines.
- Ginkgo biloba liquor increased forced expiratory volume in 1 second (FEV1) by 10% at 4 weeks and by a more clinically relevant 15% at 8 weeks (significantly greater than placebo, P<.05).
- Invigorating Kidney for Preventing Asthma (IKPA) tablets increased FEV1 by 30% at 3 months compared with 17% in controls (P<.05).
- Wenyang Tonglulo Mixture (WTM) improved FEV1 by 30% at 8 weeks compared with a 16% increase in the control group using oral salbutamol and inhaled beclomethasone (P<.05).
- Dried ivy extract, thought to work as both a secretolytic and bronchospasmolytic, reduced airway resistance in children by 23.6% compared with placebo (P=.036).
- Tylophora indica (a rare herb also known as Indian ipecac) provided significant improvement in nocturnal dyspnea when compared with controls (P<.01) in a study that relied on patients’ symptom diaries.
- Tsumura saiboku-to (TJ-96) provided patients in one RCT with significant, but unspecified, asthma symptom relief when compared with those in a control group (P<.01).5
Other therapies didn’t quite make the grade
Homeopathy. A Cochrane review of 6 RCTs of mixed quality, with a total of 556 patients, concluded the evidence is insufficient to evaluate the possible role of homeopathy for the treatment of asthma, due to heterogeneity of interventions, patient populations, and outcome assessments. Each study evaluated a different homeopathic remedy, making any overall assessment difficult.
The review notes there have been only limited attempts to study a complete “package of care,” which includes the in-depth, one-on-one consultation, treatment, and follow-up that characterizes most homeopathic treatment in practice.6
Room air ionizers. A Cochrane review of 6 good-quality trials with a total of 106 participants reported no significant effect of room air ionizers on pulmonary function measures, symptoms, or medication use.7
Manual therapy. A Cochrane review8 of 3 moderate- to poor-quality RCTs with 156 participants reported no significant effect of chiropractic spinal manipulation (2 trials) or massage therapy (1 trial) on lung function, asthma symptoms, or medication use.
Mind-body therapy. A pilot RCT9 with 33 adults found a nonsignificant reduction in medication use among the subjects practicing mental imagery, but no overall effect on lung function or quality-of-life measures.
Recommendations from others
The New Zealand Guideline Group (NZGG)10 gives a Grade B recommendation for Buteyko Breathing Techniques as an intervention that may be helpful in reducing acute exacerbation medication use and improving patient quality of life. However, the NZGG did not find other benefits to this intervention and noted that it might be costly for the patient to obtain training in these techniques. The NZGG further recommends as a good practice point that healthcare professionals be open to the use of CAM therapies and that such therapies be tried by patients who are interested in them, with monitoring and self-assessment to assist patients in determining which therapies are of value.
1. Guidelines for the diagnosis and management of asthma. Update on selected topics 2002. Available at: www.nhlbi.nih.gov/guidelines/asthma/index.htm. Accessed on March 30, 2007.
2. Mannino DM, Home DW, Akinbami LJ, Morrman JE, Guynn C, Redd SC. Surveillance of Asthma—1980–1999. MMWR Surveill Summ 2002;51:1-13.
3. McCarney RW, Brinkhaus B, Lasserson TJ, Linde K. Acupuncture for chronic asthma. Cochrane Database Syst Rev 2004;(1):CD000008.-
4. Joos S, Schott C, Zou H, Daniel V, Martin E. Immunomodulatory effects of acupuncture in the treatment of allergic asthma: a randomized controlled study. J Altern Complementary Med 2000;6:519-525.
5. Huntley A, Ernst E. Herbal medicines for asthma: a systemic review. Thorax 2000;55:925-929.
6. McCarney RW, Linde K, Lasserson TJ. Homeopathy for chronic asthma. Cochrane Database Syst Rev 2004;(1):CD000353.-
7. Blackhall K, Appleton S, Cates FJ. Ionisers for chronic asthma. Cochrane Database Syst Rev 2003;(3):CD002986.-
8. Hondras MA, Jones LK, Jones AP. Manual therapy for asthma. Cochrane Database Syst Rev 2005;(2):CD001002.-
9. Epstein GN, Halper JP, Barrett EA, et al. A pilot study of mind-body changes in adults with asthma who practice mental imagery. Alternative Therapies 2004;10:66-71.
10. New Zealand Guidelines Group (NZGG) The diagnosis and treatment of adult asthma. Best Practice Evidence-Based Guideline. Wellington, NZ: NZGG; 2007. Available at: www.nzgg.org.nz/guidelines/0003/Full_text_Guideline.pdf. Accessed on March 30, 2007.
1. Guidelines for the diagnosis and management of asthma. Update on selected topics 2002. Available at: www.nhlbi.nih.gov/guidelines/asthma/index.htm. Accessed on March 30, 2007.
2. Mannino DM, Home DW, Akinbami LJ, Morrman JE, Guynn C, Redd SC. Surveillance of Asthma—1980–1999. MMWR Surveill Summ 2002;51:1-13.
3. McCarney RW, Brinkhaus B, Lasserson TJ, Linde K. Acupuncture for chronic asthma. Cochrane Database Syst Rev 2004;(1):CD000008.-
4. Joos S, Schott C, Zou H, Daniel V, Martin E. Immunomodulatory effects of acupuncture in the treatment of allergic asthma: a randomized controlled study. J Altern Complementary Med 2000;6:519-525.
5. Huntley A, Ernst E. Herbal medicines for asthma: a systemic review. Thorax 2000;55:925-929.
6. McCarney RW, Linde K, Lasserson TJ. Homeopathy for chronic asthma. Cochrane Database Syst Rev 2004;(1):CD000353.-
7. Blackhall K, Appleton S, Cates FJ. Ionisers for chronic asthma. Cochrane Database Syst Rev 2003;(3):CD002986.-
8. Hondras MA, Jones LK, Jones AP. Manual therapy for asthma. Cochrane Database Syst Rev 2005;(2):CD001002.-
9. Epstein GN, Halper JP, Barrett EA, et al. A pilot study of mind-body changes in adults with asthma who practice mental imagery. Alternative Therapies 2004;10:66-71.
10. New Zealand Guidelines Group (NZGG) The diagnosis and treatment of adult asthma. Best Practice Evidence-Based Guideline. Wellington, NZ: NZGG; 2007. Available at: www.nzgg.org.nz/guidelines/0003/Full_text_Guideline.pdf. Accessed on March 30, 2007.
Evidence-based answers from the Family Physicians Inquiries Network