Vegetable intake keeps your heart healthy, says study

Washington DC: Turns out, if everyone on the planet ate a healthy fiber-rich diet which includes vegetables, there wouldn't be many instances of heart disease.

A new research at the Medical University of Warsaw found that low-dose treatment with trimethylamine N-oxide (TMAO) reduced heart thickening (cardiac fibrosis) and markers of heart failure in an animal model of hypertension. The study is published in the American Journal of Physiology-Heart and Circulatory Physiology.

Elevated levels of TMAO--a compound linked with the consumption of fish, seafood and a primarily vegetarian diet--may reduce hypertension-related heart disease symptoms.

TMAO levels in the blood significantly increase after eating TMAO-rich food such as fish and vegetables. In addition, the liver produces TMAO from trimethylamine (TMA), a substance made by gut bacteria. The cause of high TMAO levels in the blood and the compound's effects on the heart and circulatory system are unclear, and earlier research has been contradictory. It was previously thought that TMAO blood plasma levels--and heart disease risk--rise after the consumption of red meat and eggs.

The researchers studied the effect of TMAO on rats that have a genetic tendency to develop high blood pressure (spontaneously hypertensive rats). One group of hypertensive rats was given low-dose TMAO supplements in their drinking water, and another group received plain water. They were compared to a control group of rats that do not have the same genetic predisposition and received plain water. The dosage of TMAO was designed to increase blood TMAO levels approximately four times higher than what the body normally produces. The rats were given TMAO therapy for either 12 weeks or 56 weeks and were assessed for heart and kidney damage and high blood pressure.

TMAO treatment did not affect the development of high blood pressure in any of the spontaneously hypertensive rats. However, the condition of the animals given the compound was better than expected, even after more than a year of low-dose TMAO treatment. "A new finding of our study is that [a] four- to five-fold increase in plasma TMAO does not exert negative effects on the circulatory system. In contrast, a low-dose TMAO treatment is associated with reduced cardiac fibrosis and [markers of] failing heart in spontaneously hypertensive rats," the researchers wrote.