Grapefruit and Cholesterol
The benefits of grapefruit against excess cholesterol have been confirmed by Jonathan Goldwasser’s team at the Center for Engineering in Medicine in Boston, Massachusetts. According to his work, naringenin – a flavonoid, a substance that has strong antioxidant properties – is at the origin of its cholesterol-lowering activity. And it would work like several classes of medications currently prescribed to control cholesterol levels in the blood. According to the researchers, it could, therefore, be used as a dietary supplement and “find its place naturally in the routine treatment of hyperlipidemia”. An idea that they present as “attractive”, this product “nontoxic and inexpensive” has, in addition, anti-inflammatory effects.
Properties naringenin in grapefruit against high cholesterol
The hypocholesterolemic properties of naringenin, which is responsible for the bitter taste of grapefruit, have already been demonstrated in animal models, but also in a small clinical study cited by researchers: in about thirty hypercholesterolemic patients, this substance has reduced by 17% LDL-cholesterol (the “bad” cholesterol). This decline is certainly lower than that obtained by current treatments, but it is significant. In trying to identify its mechanism of action, they saw that naringenin was acting on targets identical to those of fibrates (which lower the level of fat in the blood) and statins (against cholesterol).
According to research carried out by a group of scientists from the Brock University of Canada and published in Biochemical and Biophysical Research Communications, it is suggested that:
– Naringenin stimulates the liver to destroy the excess fats present in the body, which causes a reduction in the concentration of LDL cholesterol. In addition, the high fiber content of grapefruit traps and helps eliminate excess cholesterol consumed through food.
– It thins the blood and increases anticoagulant activity by reducing the likelihood of cardiovascular diseases.
– It increases the antioxidant activity in the blood, avoiding the synthesis of free radicals and the formation of atheromas in the arterial walls.
– Naringenin also increases the entrance of fats to the cells to be burned and converted into energy.
– It increases sensitivity to insulin, which adds other health benefits such as controlling blood sugar levels. Through this mechanism, the formation of endogenous cholesterol from other substances such as glucose is also avoided.
Naringenin can also be found in orange, tangerine, and lemon, although it is in grapefruit, and specifically in red grapefruit (it is characterized by having yellow skin and red pulp) where it is in higher concentration.
How to take grapefruit to decrease cholesterol?
Being a natural remedy and not a medication there are no standardized amounts that offer the same benefits to all people but as a general rule, it can be said that drinking the juice of a grapefruit per day should be enough to reduce cholesterol levels. If your cholesterol is very high you can increase the amount and drink the juice of two grapefruits, but it is always advisable to start with a grapefruit a day.
Juice or fruit? Fresh grapefruits of any color contain about the same amount of vitamin C as their juice. In both forms, they are excellent sources of this vitamin that would contribute 66% to 77% of the antioxidant potential of grapefruit juice. However, by consuming the fruit, you will take advantage of its richness in the soluble dietary fiber pectin which is found mainly in the white layer that is just under the skin of the fruit. Pectin naturally lowers cholesterol and promotes digestive health. Therefore, it would be better to eat grapefruit instead of just drinking the juice to maximize is cholesterol-reducing potential.
Other benefits of grapefruit
– Cancer (prevention)
Several studies have shown that the consumption of citrus fruit, including grapefruit, is linked to the prevention of certain types of cancer, such as esophageal cancer, stomach cancer, cancer of the colon, mouth, and pharynx. According to one of these studies, moderate consumption of citrus fruit (ie 1 to 4 servings per week) would reduce the risk of cancers affecting the digestive tract and the upper respiratory system. With specific regard to pancreatic cancer, studies, however, remain controversial.
– Cancer (slow progression)
Antioxidant compounds in citrus fruits (limonoids) have demonstrated anti-cancer effects in vitro and in animals. They could decrease the proliferation of cancer cells of the breast, stomach, lung, mouth, and colon.
– Glycemia and weight loss
In obese individuals with Metabolic Syndrome, eating grapefruit (half a day before each meal for 12 weeks) resulted in significant weight loss compared to a control group (1.6 kg vs. 0.3 kg). It also significantly reduced their insulin resistance. In diabetic animals, naringin supplementation (a flavonoid grapefruit) allowed significantly reduce the glucose blood. This compound may play a role in preventing hyperglycemia.
Several studies have shown that grapefruit flavonoids have anti-inflammatory properties. They would inhibit the synthesis and activity of mediators involved in inflammation (arachidonic acid derivatives, E2, F2 prostaglandins and A2 thromboxanes).
Watch out for drug interactions!
Grapefruit is an excellent food for your health, but if you are on medication it would be prudent to inform you of a possible interaction. It seems that the naringin in grapefruit neutralizes an enzyme that helps metabolize certain drugs. When the drug is not metabolized quickly, a larger amount is absorbed into the body, which multiplies the effects. The naringin would not be present in any other fruit, at least not in the same proportions. The list of drugs affected by grapefruit is constantly growing, so it is safer, when you are on medication, to seek advice from your pharmacist or in case of doubt to avoid the consumption of grapefruit.