Health and Fitness News and Notes

Eating substantial amounts of fruits and vegetables may lower the risk for breast cancer, a new study has found, and some kinds may be more effective than others.

Researchers used well-validated nutrition questionnaires to examine the association of diet with the risk of invasive breast cancer in 182,145 women. They followed them with periodic examinations for an average of 24 years, during which there were 10,911 cases of invasive breast cancer. The study is in The International Journal of Cancer.

After controlling for many health, diet and behavioral variables, the scientists found that compared with having less than 2 1/2 servings (about one cup) of fruits and vegetables a day, having 5 1/2 servings or more was associated with an 11 percent lower breast cancer risk. The effect was especially significant with the most aggressive types of breast cancer.

The researchers found that cruciferous vegetables like cauliflower, Brussels sprouts and kale were especially strongly associated with reduced risk, as were yellow or orange vegetables including carrots, winter squash, yams and sweet potatoes.

Anyone traveling to a national park in the hope of enjoying some fresh air may be disappointed.

A study published in Science Advances looked at air pollution levels in Yellowstone, Grand Canyon, Yosemite, Glacier and 29 other parks, and it found that they differed little from those in the country’s 20 largest metropolitan areas.

The study focused on ozone levels, which are used in national parks to notify visitors of air quality conditions. Using data gathered from 1990 to 2014, they estimated annual trends in eight-hour ozone concentrations in each park, the same standard used by the Environmental Protection Agency.

They also counted the number of days in a year when ozone concentrations reached 70 parts per billion, a level the agency considers unhealthy for children and older people, and for anyone with lung disease.

Summertime ozone levels and number of unhealthy days in parks and cities were almost identical. In Sequoia National Park, the most polluted in the country, unhealthy days surpassed those in Los Angeles in all but two years since 1996.

Herbs, acupuncture and other so-called complementary treatments for cancer may not be completely innocuous.

A new study has found that many cancer patients treat these nostrums not as a supplement to conventional treatment but as an alternative. This, the researchers say, can be dangerous.

The observational analysis, in JAMA Oncology, used data on 258 complementary medicine users and 1,032 people in a control group. Complementary therapies included herbs, vitamins, traditional Chinese medicine, homeopathy, naturopathy, yoga, acupuncture and others.

People who used complementary treatments were more often women, younger, privately insured and of higher socioeconomic status. They did not delay the start of conventional treatment any longer than others, but they had higher rates of refusal of surgery, chemotherapy, radiation and hormone treatments. They also had lower five-year survival rates and more than double the risk of death. The complementary treatments did no harm when conventional treatment was carried out simultaneously.