Soy And Fish Oil May Help Prevent Heart Attacks
http://www.sciencedaily.com/releases/2005/05/050506141828.htm
NORTHBROOK, IL (April 11, 2005) -- Taking daily supplements of fish
or soy oil may improve cardiac function and protect against heart attacks
in the short-term. Study results published in the April issue of CHEST,
the peer-reviewed journal of the American College of Chest Physicians,
are the first to show that soy oil increases heart rate variability
(HRV), a measure of cardiac autonomic function.
"Our findings contradict the current belief in the medical community
that increasing the intake of omega-3 fatty acids produces only long-term
cardiac benefits," said the study's lead author, Fernando Holguin,
MD, Emory University School of Medicine, Atlanta, GA. "In fact,
our study group showed improvements in heart function in as little as
two weeks."
Researchers from Atlanta, GA, Boston, MA, and Cuernavaca, Mexico, took
the HRV of 58 elderly patients every other day for two months to establish
an HRV baseline for each participant. For 11 weeks, half of the study
participants took a daily 2 g supplement of fish oil, which contains
marine-derived omega-3 fatty acids, and the other half took a daily
2 g supplement of soy oil, which contains plant-derived omega-3 fatty
acids. The omega-3 fatty acids improve heart function by providing greater
variability between beats, therefore reducing the risk of arrhythmia
and/or sudden death. Heart rate variability is measured by high-frequency
(HF) and low-frequency (LF) domain components and standard deviation
of normal RR intervals (SDNN). Those who received fish oil experienced
a significant increase in total HF and LF domain components and SDNN.
Patients who received soy oil experienced a marginally significant increase
in HF and LF domain components and a significant increase in SDNN.
"Reduced HRV predicts mortality and arrhythmic complications in
patients who have had a heart attack, as well as those who are considered
healthy," said Dr. Holguin. "Taking a daily supplement of
fish or soy oil may help reduce the risk of suffering an adverse cardiovascular
event, such as arrhythmia or sudden death, specially in persons with
known cardiovascular disease or at increased risk for it, such as those
with lipid disorders, advanced age, hypertension, a history of smoking,
and family history of heart disease."
Researchers also discovered that while patients in both groups experienced
a significant increase in HRV, those who took the fish oil supplements
achieved a greater increase in a shorter time period. Patients who received
fish oil experienced increased HRV within the first 2.7 weeks, whereas
it took 8.1 weeks for a significant increase in HRV to be seen in the
group taking soy oil. None of the study participants experienced significant
negative side effects, but 41% of participants in the fish oil group
reported belching, compared to 16% in the soy oil group.
"Studies like this demonstrate that there are additional approaches
we can take to protect ourselves from heart attacks," said Paul
A. Kvale, MD, FCCP, President of the American College of Chest Physicians.
"It's exciting to see the potential for omega-3 fatty acids in
improving heart function when it complements a healthy lifestyle of
exercising, maintaining a healthy weight, and getting eight hours of
sleep."