Thursday, September 17, 2009
To appreciate the possible benefits of antioxidants, you must first understand what an antioxidant is. An antioxidant is anything that slows down or stops oxidation, a chemical reaction involving the uptake of oxygen. For example, the rusting of iron is an oxidation process that results in oxygen being taken from the atmosphere and combined with other elements to form something new. In the context of human cells, many metabolic processes use oxygen and result in the release of new oxygen-containing molecules, such as hydrogen peroxide, that can subsequently damage cells and body tissues and cause disease. An antioxidant is anything that mops up these oxygen-containing "free radicals" and removes them before they can do any damage.
Antioxidants benefits that are being celebrated in popular culture and widely studied in scientific research are those associated with certain diseases. Free radicals are thought to play an important role in the development of heart disease, cancer, physical changes associated with aging, and other health problems. Attention is largely focused on identifying food sources of antioxidants and determining whether the benefits of antioxidants can be increased by supplements containing particular antioxidant molecules.
It turns out that anyone who has used vitamin and mineral supplements has already enjoyed antioxidants benefits without knowing anything about it - a number of the common vitamins and minerals are antioxidants and this characteristic is a large part of their demonstrated contribution to good health. Vitamins that have been particularly noted for their antioxidant properties include Vitamins A, C, and E. Zinc, selenium and calcium are some of the antioxidant minerals. Other common dietary sources of antioxidants include carotenoids (beta-carotene, lutein, lycopene and others), bioflavinoids and related compounds, phenolic acids and related compounds, and various other molecules. The benefits of antioxidants can be obtained from some hormones as well.
Among the identified and suggested antioxidants benefits are protection against cancer, good eye health with prevention of degenerative eye diseases such as age related macular degeneration, protection of the central nervous system, a stronger immune system, and cardiovascular health with increased protection against heart attacks and strokes. These benefits of antioxidants, however, are obtained by including a wide range of different healthy foods in the diet, rather than by taking high doses of one or two specific antioxidants. High doses of antioxidants, in fact, may do more harm than good.
If you want to enjoy the benefits of antioxidants, the best approach is probably the traditional one: eat a healthy diet rich in plant sources and combine this with a healthy active lifestyle. If you suspect that your diet is not what it should be, you might want to add a multivitamin and mineral supplement containing moderate and safe amounts of a variety of antioxidants. Discuss particular heath problems with your doctor.
Wednesday, September 2, 2009
Something we already know, but interesting.
By SHAHREEN ABEDIN Shahreen Abedin – Wed Sep 2, 3:40 am ET
In the longest-term study of its kind, researchers pitted two popular diets head to head - a low-fat American Heart Association–style diet and a carb-controlled Mediterranean diet, each combined with regular physical activity - in a population of overweight patients who had Type 2 diabetes.
Researchers found that over the four-year study, patients who adhered to the Mediterranean-style eating plan maintained lower blood-sugar levels for a longer time than those in the low-fat-diet group. On the basis of their findings, the study's authors suggest that some diabetes patients may be able to substitute diet and exercise for blood-sugar-lowering medications.
The study involved 215 overweight adults in Naples, Italy, who were newly diagnosed with Type 2 diabetes. Patients were randomly divided into two diet groups: the low-fat eaters were instructed to follow a regimen rich in whole grains, fruits and vegetables and low in additional fats, sweets and high-fat snacks; no more than 30% of daily calories were to come from fat and no more than 10% from saturated fat. The Mediterranean-diet group was taught to eat lots of fruits, vegetables, whole grains and healthy fats, including olive oil, with an emphasis on lean protein sources such as fish, chicken and nuts. Mediterranean dieters were instructed to limit carbohydrate intake to less than 50% of their daily calories. (Read "Study: Diabetes Linked to Cognitive Decline.")
All dieters were encouraged to exercise regularly and received regular nutrition counseling throughout the course of the study. Regardless of the specific eating plan, the study's participants were required to restrict their daily caloric intake: 1,800 calories maximum per day for men, and 1,500 calories daily for women - a significant reduction from what the average American eats daily (about 2,600 calories for men and 1,800 calories for women, according to government statistics).
By the end of the study, which was published in the Sept. 1 issue of the Annals of Internal Medicine, 56% of patients following the Mediterranean diet were able to control their blood sugar without medication, compared with 30% of those on the low-fat regimen. The Mediterranean dieters were also able to maintain slightly more weight loss than the low-fat group - 8.4 lb. vs. 7.1 lb. - and showed small improvements in triglyceride and HDL cholesterol (the good kind) levels, both risk factors for heart disease.
"A Mediterranean-style diet is a very important part in the treatment of diabetes. We knew that," says Dr. Loren Greene, a New York University Medical Center endocrinologist, who was not involved in the study. "But there just hasn't been a good study to confirm this before." Some past studies have suggested that eating fewer carbohydrates can help diabetes patients lower their blood sugar. Other research has shown that intake of monounsaturated fats like olive oil can improve patients' insulin sensitivity, allowing the body to naturally control blood sugar more effectively. (Read "Heart Risk for Diabetics May Be Exaggerated.")
The current study does not make clear, however, whether diet alone can reduce blood sugar enough to eliminate the use of diabetes medication or whether it is even advisable to forgo medication at all. Participants in the new study were kept off drugs when their A1C levels - a measurement that indicates a patient's blood-sugar levels over the previous three months - were below 7%, the standard cutoff for what is considered controlled blood sugar. But "we don't know for sure if people with A1C levels under 7% still need to be on drugs," says Greene. "The research just hasn't answered that question yet." Recent studies suggest that using blood-sugar-controlling medication even among the 57 million Americans who have prediabetes - meaning they have elevated, but not dangerously high blood sugar and are at very high risk of developing diabetes - may prevent the development of heart disease and stroke.
While diabetes doctors generally agree that the first line of defense against Type 2 diabetes should always be exercise and diet, many recommend also using drugs. For its part, the American Diabetes Association advises patients with Type 2 diabetes to make appropriate lifestyle changes and to start a drug regimen immediately upon diagnosis. Dr. R. Paul Robertson, a spokesperson for the organization, says that for people with diabetes, "the goal should not be to avoid drugs. It is to do everything you can to keep your sugar levels down."
Still, many doctors acknowledge patients' aversion to chronic drug-taking. "Almost universally, people don't want to take medicine if they can avoid it," says Greene. And physicians, including internist Dr. Christine Laine, who is the editor of the Annals of Internal Medicine, point out that the direct and indirect costs associated with taking a drug - even one as widely prescribed as the generic diabetes medication metformin - can serve as a barrier for many patients, especially among disadvantaged populations and those without health insurance.
Whether avoidance of medication in certain cases proves to be reasonable, for now it can at least be used as an effective incentive to improve lifestyle habits, says Greene: "If you are told, 'If you don't want to go on medicine, stick to this diet,' then that's a pretty valuable tool at least for patient compliance."