(NaturalNews) Eating just two to three kiwifruits a day may significantly reduce your risk of heart disease, research suggests.
Although their name associates them with New Zealand, kiwifruits (or "kiwis") are actually native to China. They are small, oval fruits with a fuzzy, brown exterior and a fleshy (usually green) interior filled with black seeds. Although commonly eaten peeled, the entire fruit is edible. The outside is slightly tough, while the inside is sweet and creamy.
One of the more recent studies into the heart benefits of kiwifruit was conducted by researchers from Taipei Medical University in Taiwan and published in the International Journal of Food Sciences and Nutrition in 2009. The researchers assigned 30 women and 13 men suffering from high cholesterol (hyperlipidemia) to eat two kiwifruit per day for eight weeks. Based on tests conducted at the beginning and end of the study, the researchers found that kiwifruit consumption significantly increased blood levels of vitamin C, vitamin E and HDL ("good") cholesterol, while lowering the LDL ("bad") cholesterol to HDL cholesterol and the total cholesterol to HDL cholesterol ratios.
The researchers concluded that for patients with high cholesterol, regular kiwifruit consumption might significantly improve antioxidant status and reduce the risk of cardiovascular disease.
These results back up those from an earlier study, conducted by Norwegian researchers and published in 2004. In this study, researchers found that people who ate two to three kiwifruits per day lowered their triglyceride levels by 15 percent and their platelet aggregation levels by 18 percent. High triglyceride levels are significant risk factors for heart disease, while platelet aggregation measures how sticky the blood is, and high levels can lead to excessive blood clumping and increase the risk of cardiovascular events. The regular use of aspirin as a heart attack preventive centers on aspirin's reduction of platelet aggregation.
The researchers also found that kiwifruit consumption prevented plaque from building up on the artery walls.
Bursting with antioxidants
Researchers believe that kiwifruit's health-promoting properties can be largely attributed to its high concentration of antioxidants, including vitamins C and E. By removing free radicals from the blood, antioxidants help prevent cell damage that has been linked to cardiovascular disease, cancer, dementia and some symptoms of aging. Some of the antioxidants found in kiwifruit have, in fact, been specifically linked to lower rates of cancer and heart disease.
According to a study conducted by researchers from the U.S. Department of Agriculture's Arkansas Children's Nutrition Center in Little Rock, and published in the Journal of the American College of Nutrition in 2008, the body actually absorbs antioxidants more effectively from kiwifruit than from other antioxidant-rich fruits such as berries and pomegranates.
Not all of kiwifruit's health benefits come from antioxidants, however. The fruit is also high in potassium, which may help reduce blood pressure, and dietary fiber, which is also good for the heart. Kiwifruit are also rich in vitamin A.
Studies have also linked kiwifruit to other health benefits, including improved respiratory and immune health. On study, conducted on six- and seven-year-olds living in northern and central Italy, found that eating more kiwifruit was associated with lower rates of respiratory related diseases, difficult breathing, shortness of breath, wheezing and night coughs. A study published in Nutrition Research 2008 found that the strain known as golden kiwifruit boosted immune function and improved the body's response to infection.
Unifying these results, a 2012 study in the British Journal of Nutrition found that golden kiwifruit reduced both the severity and duration of upper respiratory infections in older adults.