Abstract
—Holger Cramer, PhD, Editor-in-Chief, Journal of Integrative and Complementary Medicine
Meditation for the Primary and Secondary Prevention of Cardiovascular Disease
Because stress is a risk factor for cardiovascular disease (CVD), and meditation may help relieve stress, it is possible that meditation may help prevent new or worsening CVD. This Cochrane review assessed whether mindfulness-based interventions (MBI) or transcendental meditation (TM) are effective for the primary or secondary prevention of CVD. Reviewers found 81 randomized controlled trials (6971 participants with or at high risk of CVD) comparing MBI or TM with no active treatment or another non-pharmacological treatment such as education. Reviewers concluded that compared with no active treatment both MBI and TM may reduce blood pressure and improve anxiety and depression, while MBI may also reduce stress and improve well-being. The effect of MBI and TM on CVD events is uncertain. Compared with other treatments, TM probably lowers systolic blood pressure but does not improve depression, and MBI probably reduces stress but not depression or anxiety. One small study of MBI reported two adverse events, which were not considered serious and other studies did not report on adverse events. Several currently ongoing studies may provide more certainty about the safety and effectiveness of MBI for CVD prevention.
Massage for Neck Pain
Massage therapy is an accessible and relatively inexpensive therapy sometimes used for relief of neck pain. Cochrane reviewers found 33 randomized controlled trials (1994 participants) assessing the effects of massage upon acute, sub-acute, or chronic neck pain. Studies compared massage with no treatment (eight studies), to a placebo or sham (10 studies), or compared massage plus another treatment to the other treatment alone (15 studies). Reviewers found that compared with no treatment, massage probably results in a large reduction in pain and a slight improvement in function at 12 weeks. However, compared with a placebo or sham, massage may have little or no effect on pain or function at 12 weeks. Similarly, when added to another treatment, massage may have little or no effect upon pain at 12 weeks. No difference in risk of mild adverse events was seen between treatments. The reviewers noted that most studies lacked complete information on the characteristics and dosage of the massage therapy and that trials may not reflect clinical practice. The effectiveness of massage for neck pain is currently unclear and better designed, conducted, and reported trials are needed.
Prebiotics for Induction and Maintenance of Remission in Ulcerative Colitis
It is thought that prebiotics might be helpful in relieving symptoms of ulcerative colitis (UC). Cochrane reviewers sought randomized trials comparing prebiotics to placebo or to other treatments for UC and found nine studies (445 participants). Based on one good-quality study, they concluded that for people in remission from UC there may be no difference between prebiotics and placebo for preventing relapse and there may be more side effects with prebiotics. Other studies compared prebiotics to placebo for improving UC symptoms, or compared different doses of prebiotics, compared prebiotics to probiotics, or tested combining prebiotics with anti-inflammatory drugs or probiotics. The studies were small and had problems in how they were conducted, and no conclusions could be made. Considering the clinical and methodological heterogeneity of the evidence, the reviewers stated that the effectiveness of prebiotics is not known and suggested that before further research consensus should be sought on the most promising prebiotics, and the doses and treatment combinations most suitable for testing.
Antioxidant Supplementation for Sickle Cell Disease
Sickle cell disease (SCD) is a group of genetic disorders that affects hemoglobin. This Cochrane review tested whether dietary antioxidant supplements may address oxidative stress in people with SCD and reduce the frequency of SCD crises, reduce pain, and improve quality of life. Reviewers found 26 studies (1609 adult and child participants) testing 11 different antioxidants against placebo. Based on eight studies with relevant outcomes for the review, the reviewers concluded that zinc and N‐acetylcysteine may have little or no effect on the number of SCD crises. Zinc may slightly improve hemoglobin levels but L‐arginine may have little or no effect.
Calcium Supplementation for People with Overweight or Obesity
Low calcium intake has been associated with higher body weight. If supplementation with calcium can slightly lower body weight in people with overweight and obesity, this could be significant on a population level. Cochrane reviewers found 18 studies (1873 participants) comparing calcium to placebo or controlled low-dose calcium for weight loss in people with overweight or obesity. Most participants were women. Calcium doses ranged from 0.162 to 1.5 g/day. Reviewers concluded that there may be little or no difference in overall body weight with calcium compared with placebo or control, but there may be a small decrease in body fat mass and there is probably a small decrease in waist circumference and body mass index. Few people reported adverse events, and there may be no increase in harms with calcium. When studies testing 1 g/day or more were looked at separately, a slight decrease in overall body weight was seen, but more research is needed to confirm this. Further studies should be done to improve the certainty of the evidence on calcium and to explore the effects of calcium supplementation in children, men, and older people.
Zinc for Prevention and Treatment of the Common Cold
Zinc supplements are sometimes used to prevent or treat the common cold, and there are plausible mechanisms for the effects of zinc upon the immune system or directly against cold viruses. Cochrane reviewers sought randomized controlled trials testing zinc against placebo for the prevention or treatment of the common cold. They found 34 studies (8526 participants); 15 studies tested zinc for preventing colds, and 19 studies tested zinc for treating colds. Reviewers concluded that taking zinc may not reduce the risk of developing a cold. Zinc may also not shorten the length or lessen the severity of a cold that develops after taking zinc. Reviewers found that when zinc is used as treatment for a cold, taking zinc may shorten the length of the cold by about 2 days, but the certainty of this finding is limited by heterogeneity between studies. Treatment with zinc may increase the risk of nonserious adverse events such as stomach upset. While zinc may help shorten the duration of the common cold, additional good-quality studies are needed to examine different types and doses of zinc and to increase the certainty of the evidence.