By Claire Georgiou, Reboot Naturopath, B.HSc ND
Grapefruits are certainly known for their weight loss benefits and are commonly associated with weight loss diets. They find their way into many weight loss plans including ideas like half of a grapefruit with a boiled egg or the grapefruit diet which included a serving of grapefruit whole or as a juice with each meal to speed up the metabolism and kickstart the weight-loss process. Once considered a myth, it now has science backing up its true health benefits.
Grapefruit has a long list of health benefits and due to its ability to alter pathways in the liver it can also cause increased concentrations of some medications and should be consumed with caution or not at all (more on this later).
The nutritional content of a grapefruit is impressive with 1 grapefruit offering 85 calories, 2g of protein, 77mg of vitamin C, 30mcg of folate, 330mg of potassium, 28mg of calcium, 21mg of magnesium, 2.3g of soluble fiber, vitamin B1 and B6, along with a long list of specialized antioxidants and plant compounds that offer an array of health benefits. The pink and red varieties also contain carotenoids which includes lycopene and beta-carotene.
The benefits of grapefruits seems endless but here are some well-known benefits:
A study at the Nutrition and Medical Research Center at Scripps Clinic in San Diego included 100 obese people who were divided into 3 groups.
No other changes were made to their diets. The results showed that the grapefruit consumers lost an average of 3.3 – 3.6 pounds in the 12 weeks while the non-grapefruit group didn’t lose anything sufficient. They also found that the insulin levels were lower in the grapefruit groups which is associated with improved weight loss and improved blood sugar control which reduces the risk of diabetes and cardiovascular disease.
Another study involving 91 obese people showed that grapefruit consumption significantly reduced body weight by an average of 3.5lbs over 12 weeks with significant reduction in post insulin readings, some even lost 10 pounds. There were no other changes made.
Grapefruit contains specialized antioxidants such as naringenin, that has shown to improve insulin sensitivity and helps to maintain a healthy weight. Scientists found that naringenin makes the liver burn fat instead of storing it. It has been demonstrated that grapefruit helps to lower insulin levels and it was shown in one study that grapefruit worked just as well as metformin in lowering blood sugar levels with a 13% reduced fasting blood sugar level.
Animal studies indicate that consuming grapefruit juice with fatty meals reduces the weight gain that can be associated. There was an 18% reduction in weight gain compared to the group that consumed sweetened water, these results also included lowered blood pressure and insulin readings.
With the increased sensitivity to insulin and better blood sugar control the cells become more receptive and food is more efficiently burnt as fuel which also supports a more regulated appetite.
Consuming grapefruit regularly may be associated with better insulin sensitivity. When insulin is elevated it tends to utilize calories into stored fats and inhibits the body’s ability to burn fat so further perpetuates weight problems. This effect also has the added bonus of reducing the likelihood in the development of type 2 diabetes.
Due to the high soluble fiber of pectin in grapefruits, this type of fib0re is helpful for the elimination of cholesterol via the bowel. A study at the Hebrew University in Jerusalem showed that eating 1 red grapefruit daily after 30 days reduced LDL cholesterol by 20.3%, a yellow grapefruit lowered it by 10.7%, while eating no grapefruit made no changes. The triglycerides also decreased by 17.2% with the red grapefruit while it reduced by 5.6% for the yellow grapefruit.
Due to the antioxidant and the high potassium content, consuming grapefruit helps to support vascular dilation, modulates blood sugar levels, supports weight loss, and lowers LDL cholesterol and triglycerides which all works towards protecting your heart health.
Due to the sourness of grapefruit, it is believed to support bile production combined with the soluble fiber content, grapefruit can certainly get things going.
Due to the big boost in natural vitamin C and other antioxidants, this fruit offers health promoting benefits to the immune system in the fight against infections. One grapefruit offers more than 120% of your daily recommended vitamin C. There are other health benefits which include anti-cancer, reduced incidence of kidney stones, liver support and HCV prevention. Preliminary lab tests show that naringenin, a compound found in grapefruit, may curb the spread of the hepatitis C virus by 80%.
Grapefruit consumption has the potential to interact with many medications that could cause harm, so if you are taking any medications it is best to speak to your doctor before including grapefruit in your diet.
An article published in the Canadian Medical Association Journal highlights more than 85 possible medicines that can interact with grapefruit, with 43 of these having potentially serious consequences. Here is a list of medications where there is a potential interaction with grapefruit. These include high blood pressure medication, statins, some antibiotics, anti-clotting medications and more.
Here are some of my favourite grapefruit juices: