If you're looking to treat irritable bowel syndrome (IBS) naturally, St. John's wort may not be your best bet. A recent study found that the herb was less effective than a placebo when it came to alleviating IBS symptoms such as stomach pain, diarrhea, constipation, and bloating.

The study included 70 IBS patients. For three months, half the participants received St. John's wort, while the other half received a placebo. After observing the patients' symptoms throughout the treatment period, researchers determined that the placebo group had a better response than study members taking St. John's wort.

A popular natural remedy for IBS, St. John's wort is thought to affect neurotransmitters found in the colon. In past studies, St. John's wort has been found to benefit people with depression, as well as individuals attempting to quit smoking.

Haphazard use of vitamin E may do more harm than good, according to a recent report on vitamin E supplementation and heart disease.

Sizing up data on more than 300,000 study subjects, investigators found that those who didn't take vitamin E supplements had more "quality-adjusted-life years" (QALY), a parameter used in medicine to measure the effect of medical interventions. "To explain the meaning of this parameter," said study co-researcher Dr. Ilya Pinchuk in a press release, "consider a participant who was healthy during the first 10 out of 20 years of the study, but then suffered a stroke and became dependent on others throughout the following 10 years. The QALY during the first 10 years of healthy life is 10, but after the stroke the quality of life is only half of what this person had before. Therefore, the second decade is considered the equivalent of merely 5 years of healthy life and in sum a person's QALY is 15."

The researchers also found that while some individuals may be harmed by vitamin E supplementation, others may benefit from taking vitamin E. The medical community's challenge is to now "establish selection criteria that will predict who is likely to benefit from vitamin E supplementation," the authors note in their report.

Natural chemicals found in pomegranates may help protect against certain forms of breast cancer, according to a new study. The study focused on ellagitannin, a type of phytochemical plentiful in pomegranate fruit.

In laboratory experiments, scientists found that a byproduct of ellagic acid (a compound derived from ellagitannin) significantly inhibited cell growth. According to the study's authors, this finding suggests that ellagitannin-derived compounds have the potential to prevent hormone-dependent breast cancer.

It's too soon to tell whether eating pomegranate could have cancer-fighting effect in humans, the study's authors note. However, past research shows that drinking pomegranate juice may provide other health benefits, such as keeping blood pressure in check.

Previously published preliminary research suggests that other natural substances (such as curcumin, resveratrol, and green tea may also help guard against breast cancer.

Practicing yoga may enhance your heart health, according to a newly published study.

For the study, researchers compared the electrocardiograms of 42 healthy, non-yoga-practicing adults to those of 42 experienced yoga practitioners. All study participants were male, aged 18 to 48.

Study results revealed that yoga practitioners appear to have higher heart rate variability, a measure of beat-to-beat changes in heart rate. In individuals with high heart rate variability, the study's authors explain, heart rate is steady but ready to respond to changes induced by factors such as eating or stress. Low heart rate variability, on the other hand, may be a marker of cardiac abnormalities.

In previous studies, scientists have found that yoga may decrease a number of cardiovascular disease risk factors (including high blood pressure), as well as aid in the management of cardiovascular disease.