Jan 20, 2013

Just eating Berries (Anthocyanins) is not enough to prevent heart attack: NHS-2.

Recently published nurse health study-2 (NHS-2) in Circulation 2013;127:188-196, doi:10.1161/CIRCULATIONAHA.112.122408  says anthocyanins decrease incidence of MI (myocardial infarction) in young females.

In this study 93,600 young females aged 24-42 were followed for 18 years. Subjects who had  IHD, CVA, peripheral artery disease and cancer at baseline were excluded. 405 MI were recorded during 18 years follow-up. An inverse association between higher intake of anthocyanins and risk of MI was observed (hazard ratio, 0.68; 95% confidence interval, 0.49–0.96;P=0.03,)
Anthocyanins are type of  Flavonoids , are present in strawberry and  Vaccinium species, such as blueberry, cranberry, and bilberry; Rubus berries, including black raspberry, red raspberry, and blackberry; blackcurrant, cherry, eggplant peel, black rice, 

Flavonoids improve endothelial function by
·        Antiinflmatory effects
·        Inhibiting LDL-C oxidation and endothelial NADPH oxidase
·        Modulating nitric oxide synthase activity/expression, and augmenting nitric oxide status
·        They stabilize the plaque

In the present study other Flavonoids benfit was not much. May be because other Flavonoids were not taken in needed quantity to reduce MI.

The occurrence of MI in young and middle-aged women is more often in non-obstructive coronary artery lesion, which may differ from those in older women and men.
·        In young women ulceration rupture of non-obstructive coronary artery with thrombus  is important cause of MI
·        Spasm of non-obstructive lesion also important mechanism of MI in young women.

Due to difference in causation of MI in young women as compared to men and older women, anthocyanins supplementation in men and older women may give different results. In a study in women with wide age range with anrthrocynines, greatest reduction of Blood pressure was seen younger women as compared to older women

In present study women who took more anthocyanins led healthier life as compared to women who did not, i.e.  They were nonsmoker, ate less fat, regularly exercised, and consumed moderate alcohol. Although benfit was present after correction for these covariates but it was less.

Combined intake of blue and strawberries more than three serving per week as compared to one serving per month, MI hazard ration was 0.66 (95% CI 0.40-1.08; p=0.09).

Lichtenstein told to hearttwire,

So just eating anthocyanins is not enough to reduce MI risk even in young women. Along with berry fruits, regular exercise, less fat, not smoking and moderation alcohol are also needed good benfit.