Antioxidants

The Heart-Brain Blood Supply

Just like every other organ and tissue in the body, the brain needs oxygen and nutrient-rich blood to function properly. Because the brain is so crucial to the bodys survival, it receives a disproportionate amount of blood. Though it takes up only about 2 percent of the bodys weight, the brain receives 15 to 20 percent of the bodys entire blood supply, and 25 percent of its oxygen supply. The body will deprive other parts of the body of blood to ensure that the brain has what it needs.

The heart feeds the brain by sending blood through vessels both on the surface of the brain and deep inside it. Two pairs of arteries branching out from the aorta-the internal carotid arteries and vertebral arteries-supply the brain with blood. Carotid arteries send blood to the front of the brain, and vertebral arteries send blood to the back of the brain.

Blood flow into the brains tissues is a bit different than it is in other parts of the body. Elsewhere in the body, nutrients, oxygen and waste products can move freely in and out of the capillaries. This is not true in the brain. The brain has its own checkpoint, the blood-brain barrier, a semi-permeable system that lets only certain substances pass into the brain. This barrier protects the brain against viruses, toxins, hormones, and other substances in the blood that might harm the brains delicate tissues.

Considering how essential nutrient-rich blood is to the brains function, any disruption in blood flow can pose a serious risk. A blockage in the brains blood supply from a clot either in the brain or from elsewhere in the body is called a stroke. A stroke deprives the affected part of the brain of oxygen. Without oxygen, the brains cells will die. If too many brain cells die, thought and virtually every other function will come to a halt. Two primary risk factors for stroke are high blood pressure and heart disease, which illustrates the close relationship between heart and brain health.

For more information on the connection between the heart and brain, purchase Heart-Brain Diet: Essential Nutrition for Healthy Longevity by Tufts Medical Report.

Q. How much green tea should one consume daily to get the benefits I...

A. Jeffrey Blumberg, PhD, director of Tufts HNRCA Antioxidants Research Laboratory, answers: The health benefits associated with drinking tea (green, oolong or black) are...

Cranberries: Theyre Not Just for Thanksgiving Anymore

If you think of cranberries as strictly Thanksgiving fare, you're missing out on the unique health benefits of this tart red fruit. "The profile of cranberries' biologically active constituents is distinct from that of other berry fruit," says Jeffrey B. Blumberg, PhD, director of Tufts' HNRCA Antioxidants Research Laboratory. Blumberg and colleagues recently authored a comprehensive review of cranberries' bioactive compounds and their effects on human health, published in Advances in Nutrition.

Q. Im thinking about taking a vitamin A supplement, but am confused by the...

If youre eating a balanced diet and have no special health concerns, you probably dont need extra vitamin A of any kind. According to the Office of Dietary Supplements of the National Institutes of Health, Vitamin A is available in multivitamins and as a stand-alone supplement, often in the form of retinyl acetate or retinyl palmitate [preformed vitamin A].

Antioxidants Vary in Green Tea

Green tea is touted for its health-promoting properties in large part because of its high levels of antioxidants called catechins, especially epigallocatechin gallate (EGCG).

Q. You recently covered a new green tea study that focused on protecting brain...

A.Jeffrey Blumberg, PhD, director of Tufts HNRCA Antioxidants Research Laboratory, responds: It is not possible to determine the green tea cups/day equivalent in that particular study because the authors disclosed the dose only as 0.05% standardized green tea extract without describing the standard. However, two observational studies of green tea and cognitive performance, published in the American Journal of Clinical Nutrition in 2006 and 2008, identified those drinking two or more cups per day and…

New Reasons to Pick Fruit Over Juice

Choosing whole fruit rather than fruit juice might significantly reduce your risk of developing type 2 diabetes, according to a new large study. And when it comes to picking fruit, some varieties-notably blueberries, grapes, apples and pears-are better than others in protecting you against diabetes.

Blueberries Found to Boost Blood-Vessel Function

A pair of randomized, controlled trials-considered the gold standard for scientific research-have linked eating blueberries to improved blood-vessel function. Jeremy Spencer, PhD, of the University of Reading in England, and colleagues reported in the American Journal of Clinical Nutrition: Our data suggest that consumption of blueberries at dietary intakes may have public health relevance in maintaining circulatory function.

Healthy Herbs Do More Than Just Spice Up Your Meals

Discover the nutritional benefits of these tasty plants.

Antioxidants Higher in Darker-Roasted Peanuts

Darker-roasted peanuts pack a greater antioxidant punch, according to Agricultural Research Service (ARS) scientists in North Carolina. The researchers measured antioxidant levels in peanuts roasted at 362 degrees from zero to 77 minutes. Longer, darker roasting was consistently associated with higher levels of both water- and oil-soluble antioxidants, which scientists attributed to greater concentrations of phenolic compounds and/or browning reaction products.