Complementary Health Approaches

Research on Conditions Affecting Older Adults

The National Institutes of Health (NIH) funds research into the safety and effectiveness of complementary health approaches. Much of this research involves diseases and conditions that are common among older adults.

An important focus of current research is how complementary health approaches may help manage disease symptoms and improve patients’ quality of life.

For example, studies have shown that some complementary health approaches may help cancer patients cope with their disease or its treatment. Both acupuncture and the herb ginger may help to control nausea related to chemotherapy, and mindfulness meditation may help cancer patients relieve stress and anxiety.

Basic and Clinical Research

NIH research on complementary health approaches includes both basic research (laboratory and animal studies) and clinical research (studies in people). Both types of research are important. Basic research investigates effects in the body, and studies in people show whether a complementary health approach is effective and safe.

Here are some examples of NIH-sponsored research projects on complementary health approaches for diseases or conditions common among older adults.

Cognitive Decline and Alzheimer’s Disease

  • The Ginkgo Evaluation of Memory (GEM) study, a 6-year trial of the herb Ginkgo biloba in more than 3,000 older adults, showed that ginkgo did not prevent Alzheimer’s disease or other types of dementia or slow cognitive decline.
  • Older people who were participating in an NIH study to evaluate the effects of supplements of omega-3 fatty acids and the carotenoids lutein/zeaxanthin on eye health were invited to participate in cognitive tests as well. During the 5-year study, neither of the supplements had a significant effect on cognitive function.
  • A study in older women showed that those with higher dietary intakes of monounsaturated fatty acids (the kind found in olive oil) had slower cognitive decline. Other types of fatty acids were not associated with faster or slower cognitive decline in this study.
  • NIH-sponsored studies currently in progress are investigating the possible value of mindfulness meditation in older adults who have both cognitive impairment and anxiety or depression.

Heart Disease and Other Circulatory Problems

  • Results from a large NIH-sponsored study suggest that chelation therapy may have modest benefits in some patients with heart disease. However, the only people who significantly benefited were those who also had diabetes. There are still many unanswered questions about chelation therapy, and the current evidence is not sufficient to support its use in everyday medical practice.
  • Studies in people with heart failure have shown that practicing tai chi may relieve some of their sleep problems and improve their mood and quality of life.
  • A study in middle-aged and older adults showed that flaxseed, which is rich in an omega-3 fatty acid called alpha-linolenic acid, may improve some risk factors for heart disease.
  • A study in postmenopausal women indicated that soy protein supplements containing isoflavones did not reduce the buildup of plaque in the arteries.
  • A study that tested three garlic preparations found that none of them reduced levels of low-density lipoprotein cholesterol (the “bad” cholesterol that is associated with an increased risk of heart disease).


  • An NIH-sponsored study showed that practicing yoga reduced fatigue in women who have been treated for breast cancer.
  • Massage therapy may have short-term benefits in relieving pain and improving mood in patients with advanced cancer, according to the results of an NIH-sponsored study.
  • A large study of vitamin E and selenium supplementation in older men, called SELECT (for Selenium and Vitamin E Cancer Prevention Trial), found that the two types of supplements, taken alone or together, did not reduce the risk of prostate cancer. In fact, men who took vitamin E alone had a higher rate of prostate cancer than those who took a placebo (pills containing only inactive substances). There was no increase in prostate cancer when vitamin E and selenium were taken together.
  • An analysis of data from the GEM study (a large trial of the herb Ginkgo biloba in older adults) found no evidence that the herb reduces the risk of cancer.
  • A study in patients with lung cancer who were being treated with radiation and chemotherapy found that adding shark cartilage to their treatment did not help them live longer.


  • A major NIH-sponsored trial of glucosamine and chondroitin in people with knee osteoarthritis, called GAIT (for Glucosamine/Chondroitin Arthritis Intervention Trial) showed that these supplements did not relieve pain or slow joint damage in the overall group of study participants. However, a subgroup of participants with moderate-to-severe pain did have significant pain relief when they took both supplements in combination.
  • A preliminary study of massage for knee osteoarthritis pain showed that a 60-minute “dose” of Swedish massage therapy once a week worked well.
  • A small study found that practicing tai chi helped older adults with knee osteoarthritis by reducing pain, enhancing physical function, and improving health-related quality of life. A second, larger study found that tai chi was as helpful as physical therapy for knee osteoarthritis pain.

Prostate Enlargement

  • Two NIH-sponsored studies found that saw palmetto was no more effective than a placebo (pills containing only inactive substances) in relieving urinary tract symptoms associated with prostate enlargement in older men. One of these studies used doses of saw palmetto up to three times what men usually take. No harmful side effects of saw palmetto were identified in these studies.


  • Older people who participated in a 16-week tai chi program developed better immunity after receiving the shingles vaccine than those who received the same vaccine but participated in a health education program instead of tai chi.

Menopause Symptoms

NIH has sponsored a number of studies of complementary health approaches for menopause symptoms:

  • One study showed that hypnosis significantly reduced the frequency and severity of hot flashes in postmenopausal women.
  • Another study found no evidence that the herbs black cohosh and red clover were better than a placebo (an inactive substance) in treating the hot flashes and night sweats that often accompany menopause.
  • A study of herbal remedies for menopause found that black cohosh and combination herbal supplements that included black cohosh along with other herbs did not reduce the number of hot flashes or night sweats in menopausal women.
  • A study of acupuncture showed that it reduced the severity and frequency of hot flashes and other menopause symptoms, when compared to usual care, and that the benefits persisted for at least 6 months after the completion of a series of acupuncture treatments.

Age-Related Macular Degeneration

  • A large NIH-sponsored study found that supplementation with a combination of antioxidants (vitamins C and E and beta carotene) and zinc helped to prevent age-related macular degeneration (AMD) from progressing from the intermediate stage to the advanced stage. AMD is an eye disease that can cause vision loss among older adults.
  • A follow up study on supplements and AMD found that adding omega-3 fatty acids (fish oil) to the supplement combination did not improve results. The study also identified some modifications that can be made in the supplement formula to decrease the likelihood of side effects.

Sleep Problems in Older Adults

  • An NIH-sponsored study showed that classes in tai chi chih (a Westernized version of tai chi) were more helpful than health education classes in improving sleep quality in healthy older adults with moderate sleep problems.
  • Results of a small study suggest that melatonin supplements may improve sleep in people with high blood pressure who take beta-blockers—a type of drug that sometimes causes difficulty sleeping.
  • Mindfulness meditation may be helpful for insomnia, according to a small NIH-funded study, but it’s uncertain whether this method is as effective as standard treatments such as cognitive-behavior therapy.

Hepatitis C

  • An NIH-sponsored study showed that silymarin (an extract from the herb milk thistle) was no more effective than a placebo (an inactive substance) in reducing liver damage from hepatitis C, even when given in doses larger than those that people usually take.

For More Information

You can learn more about NIH-sponsored research on complementary health approaches for conditions common among older adults by visiting the Research page and the Aging page on the National Center for Complementary and Integrative Health (NCCIH) Web site.

See NCCIH’s A to Z list of health topics to learn more about what science has shown about complementary approaches for a particular condition. You can look up the condition that interests you and find evidence-based information on complementary approaches that have been studied for that condition.