2013 Mar | The Mediterranean Diet, Green Tea, & Vitamin D

The Mediterranean Diet, Green Tea, & Vitamin D

Med Diet Offers Powerful Heart Protection

A widely covered study published in the New England Journal of Medicine offers the most compelling evidence yet that the Mediterranean style of eating is the way to go for better heart health (1).

The Med-style diet had already been shown to help protect people who have cardiovascular disease (CVD). The new study confirms that the diet also protects those at risk of developing it. The odds of having a heart attack, stroke, or dying from CVD fell by a meaningful 30% in those adopting the diet.

The study, which followed over 7,400 women and men, was stopped ahead of time when a clear-cut health disadvantage was seen for the control group on a low fat diet.

Moving Toward the Med Diet Isn’t Hard

None of the study participants were asked to curb calories, and the two Med diet groups – one that ate nuts daily and the other that consumed extra olive oil – had little trouble sticking with the diet. A diet that doesn’t require calorie restriction and that’s easy to follow is appealing.

The Med diet is rich in fresh fruits and veggies, seafood, whole-grains and mono-unsaturated fats (the type in olive oil). All groups in this study were able to cut back on meats, sweets, dairy and alcohol, but the main difference between interventions was that the Med diet group ate fewer carbs and more fats (mostly from olive oil), fruit, beans and nuts.

Can Green Tea Lower Breast Cancer Risk?

Although a number of population health studies support a link between green tea intake and the risk of breast cancer, there is a need for more randomized clinical trials to help clarify whether green tea has a role in preventing this cancer.

A new report (2) from the National Cancer Institute (NCI) sheds some light on how green tea might influence breast cancer risk. NCI researchers followed nearly

200 healthy pre- and post-menopausal, Japanese-American women to assess the effect of green tea on estrogen metabolism. While estrogen is essential, long-term exposure to this hormone increases the risk for breast cancer.

The researchers found that daily consumption of green tea was associated with lower levels of estrogen metabolites in the urine of postmenopausal women.

The polyphenols in green tea, according to the authors, may modify breast cancer risk by interacting with enzymes that metabolize estrogen.

While we await the results of further investigations, experts have concluded that drinking 3-5 cups of this tea daily is safe and healthful.

Vitamin D May Influence Risk of Dying

Vitamin D plays a role in many processes within the body including regulating inflammation, the immune system and the secretion of insulin. These wide-ranging effects have led researchers to explore the relationship of vitamin D to mortality.

In the most recent exploration3, researchers from Vanderbilt University and Meharry Medical College report that people with the highest blood levels of vitamin D were less likely to die earlier than those with the lowest blood levels.

Better vitamin D blood values were most protective against early death from circulatory disease, and lower risk for overall mortality was seen for values that were at least 35-40 ng/mL. Although poor vitamin D levels are most common among African Americans, the study’s findings held true for other ethnic groups as well.

References

  1. Estruch R et al. Primary prevention of cardiovascular disease with a Mediterranean diet. NEJM [Epub ahead of print Feb 25, 2013]
  2. Fuhrman BJ et al. Green tea intake is association with urinary estrogen profiles in Japanese-American women. Nutr J 12:25 [Epub ahead of print Feb 15, 2013].
  3. Signorello L et al. A prospective study of serum 25-hydroxyvitamin D levels and mortality among African Americans and non-African Americans. Am J Epidemiol 177:171-79, 2013.