Hiển thị các bài đăng có nhãn oxidative stress. Hiển thị tất cả bài đăng
Hiển thị các bài đăng có nhãn oxidative stress. Hiển thị tất cả bài đăng

Thứ Tư, 29 tháng 10, 2008

Fruit Juice May Be Superior Than Fruit To Prevent Heart Disease

Fruit and vegetables should form part of everyday’s diet if one wishes to prevent heart disease and maintain a healthy body. Yet, most of the health experts would advise us not to take fruit juice because it may cause a person to gain weight.

However, a recent study by French researchers from the Universite Montpellier reported in May 2008 that grapes, apples and their juices could prevent atherosclerosis being developed in hamsters eating a high-fat diet, high-cholesterol diet.

The term atherosclerosis refers to buildup of fatty plaque deposits in the arteries that can lead to heart attacks or stroke.

The study found that fruit juices had a more powerful anti-atherosclerotic effect than the fruit itself. This is probably the first time that processing fruits can have a major impact on its health benefits.

In the study, hamsters were fed with grapes, grape juice, apples, apple juices or water, along with a diet designed to promote atherosclerosis. The aim is to investigate how juice might influence the content of phenolic compounds, which are powerful antioxidants contained in fruits. Meanwhile, a control group of animals ate normal chow.

The hamsters, which were fed with fruits, had the amount equivalent to 3 apples or 3 bunches of grapes daily for a human, while the amount of juice given to another group of hamsters was equivalent to 4 glasses daily for a person weighing 70 kilos.

The researchers noted that apples and grapes had roughly the same phenol content but the purple grape juice had 2.5 times more phenols than apple juice.

When comparing with hamsters given water, those consumed fruit or fruit juice had lower cholesterol levels, less oxidative stress, and less fat accumulation in their aorta (the main vessel supplying oxygenated blood to the body). In terms of health effects, purple grape fruit rank high, followed by purple grapes, apple juices and apples.

According to the researchers, while the amounts of phenols contained in a food have a direct effect on its antioxidant properties, other antioxidant compounds in the fruits such as Vitamin C, carotenoids could also contribute to their effects. Such findings do provide encouragement that fruit and fruit juice may have significant clinical and public health relevance.

Thứ Ba, 21 tháng 10, 2008

How Would Hostility Raise Heart Disease Risk?

Before we get into the topic, we need to understand 3 terms: free radical, antioxidant and oxidative stress. Let us look at how they are related.

Technically, oxidative stress is a condition, which occurs when production of free radicals in the human body exceeds the body's ability to neutralize and eliminate them. Free radicals would start chain reactions that disturb the body’s ability to neutralize them, hence resulting in tissue or cell damage. Oxidative stress has been associated with heart disease, cancer and other illnesses.

Antioxidants could stop these chain reactions by removing free radical intermediates and inhibit other oxidation reactions by being oxidized themselves. Antioxidant vitamins like vitamin C and E can help counteract oxidative stress. On the other hand, activities like smoking and pollution can actually increase it.

A study has indicated that hostility could raise a person’s risk of heart disease by depleting the level of certain heart-healthy antioxidants.

The researchers from the University of Minneapolis, who carried out the study, suggested that antioxidants could help explain why hostile individuals are more likely to smoke and drink, and poor diet and smoking can deplete antioxidants.

In their study, the researchers investigated 3,579 men and women of the age between 18 and 30 years old who were participating in the so-called Cardiovascular Risk Development in Young Adults study. Their levels of several different carotenoids and tocopherols (vitamin E) were measured.

It was found that people having high levels of hostility at the beginning of the study were more likely to have lower levels of several types of carotenoids 7 years later, but hostility did not predict levels of tocopherols or lycopene. The increased risk was found to be, nevertheless, small but significant.

Lifestyle factors such as diet, smoking and drinking probably play a part in explaining why hostility reduces levels of antioxidants, but the researchers are not clear whether the differences are importantly related to the risk of coronary heart disease. Therefore, further study is necessary.