Grapefruit is known for its slightly sweet and slightly bitter taste, and is loved by many. But are grapefruit a good fruit to eat if you live with diabetes?
Grapefruit has unique and sometimes negative interactions with at least 85 different drugs, including common diabetes medications such as Metformin and statins.
This article will explore the health benefits of grapefruit, the pros and cons of eating them, and how (and if!) you should incorporate them into your diet.
What is a grapefruit?
Grapefruit is actually a natural hybrid of the Jamaican sweet orange and the Indonesian pomelo, making them a delicious food to eat for breakfast, with lunch, or as a dessert or quick vegan snack that doesn’t require temperature control.
What are the health benefits of grapefruit?
Full of vitamins and minerals
Grapefruit, like all citrus fruits, comes with an excellent source of Vitamins C (with nearly an entire day’s worth of Vitamin C in one grapefruit!) and A, Vitamin B6, Potassium, and even Magnesium.
They also include plenty of antioxidants that can help the body’s immune system fight off colds and viruses.
The typical grapefruit has just 100 calories, 25 carbohydrates, and over 4 grams of fiber, making it a filling snack any time of day.
Low glycemic index
Grapefruit is low on the glycemic index, coming in at 25. This means that eating grapefruit won’t spike your blood sugar quickly, and can be fairly easy to dose insulin for.
A 2013 study even found that eating grapefruit is significantly associated with a reduced risk of developing type 2 diabetes.
Grapefruit can also be an excellent food to eat if you’re looking to lose weight, as it’s low in calories and high in filling fiber and water.
Reduced stroke risk
Eating flavonoids, compounds found in citrus fruits such as oranges, grapefruit, and lemons, has been shown to significantly lower the risk of ischemic stroke amongst women.
In the study, conducted by the American Heart Association, the risk of stroke was 19% lower among women who consumed the highest amount of citrus fruits, like grapefruit, in their diet!
The potassium found in grapefruit also contributes to lower blood pressure, reducing both the risk of stroke and heart disease, which is important for people with diabetes, as those are both complications of the disease.
Cancer prevention
Eating a diet high in antioxidants can help fight the formation of free radicals, which can cause cancer.
Grapefruit is full of Vitamin C, an important antioxidant for cancer prevention, with just one full grapefruit containing an average of 68.8 mg.
The daily recommended amount of Vitamin C for women is 70 mg and for men is 90 mg.
Grapefruit, along with the tomato, is also an excellent source of Lycopene, which has been shown to prevent prostate cancer.
Gut health
Grapefruit is rich in healthy fiber, which can keep you regular and help with digestion. One standard-sized grapefruit has 4 grams of fiber.
The daily recommended amount of fiber for women is between 21-25 grams per day, and men should aim for between 30-38 grams per day.
So one grapefruit can meet between 10-19% of one’s daily fiber needs.
Eating enough fiber can prevent constipation, and may even help prevent gastrointestinal cancers, including colorectal cancer.
The downside of eating grapefruit
Grapefruit seems like the perfect food, right? Well, grapefruit isn’t an appropriate food for everyone.
The following are the issues you need to be aware of when deciding whether or not to incorporate grapefruit into your diet.
Potentially dangerous drug interactions
Grapefruit is unique in that it has an enzyme-binding ability. This means that it may cause certain medications to pass from the GI tract into the bloodstream faster than normal, raising the amount of medication in your bloodstream, which can be potentially dangerous.
According to the FDA, it is particularly important to talk to your doctor before eating grapefruit if you are on any of the following prescription medications:
- Statins (used to lower cholesterol)
- Corticosteroids (to treat Crohn’s disease or ulcerative colitis)
- Certain psychiatric drugs (SSRIs used to treat depression)
- Calcium channel blockers (used to lower blood pressure)
- Antihistamines (used to treat allergies)
- Drugs that treat abnormal heart rhythms
- Immunosuppressive drugs
Not every drug in the categories above interacts with grapefruit. Interaction with grapefruit juice is drug-specific, not drug category-specific.
Work with your doctor if you are unsure of any drug interactions you may experience if you wish to include grapefruit in your diet.
Grapefruit and Metformin
Metformin isn’t broken down by enzymes in the same way as the drugs listed above, so the absorption of Metformin isn’t directly affected by eating grapefruit.
A 2009 study in rats showed some evidence that combining grapefruit and Metformin could lead to enhanced Metformin accumulation in the liver and cause increased lactic acid production, leading to a higher risk of lactic acidosis.
However, the same effect has never been observed in humans and it’s therefore generally considered safe to eat grapefruit while taking Metformin.
For more information about the possible side effects of taking Metformin, read our comprehensive guide “Metformin Side Effects: What You Need to Know”.
Skin cancer
Some studies have shown a correlation between a very high intake of citrus fruits and malignant melanoma.
This particular longitudinal study took place over 26 years and found that people who consumed the highest amounts of citrus juices had a higher incidence of malignant melanoma, although further studies are encouraged to strengthen the link between the two.
Kidney complications and potassium intake
If you live with kidney disease, or are even struggling with a kidney infection, you may want to limit the amount of grapefruit you eat.
Kidney damage makes clearing excess potassium from the blood harder to achieve, and grapefruit’s high levels of potassium may make this even more complicated.
Extremely high levels of potassium in the blood can be deadly.
Consult your physician/dietitian if you have kidney disease to understand how much potassium is safe for you to consume each day.
Pairing sweet with bitter
Grapefruit is a notoriously bitter fruit. This is great, because it’s both lower in carbohydrates than many other fruits and also contains a high amount of fiber, making it a great snack for people with diabetes.
However, all that bitterness may come with a cost. Grapefruit is typically eaten with sugar sprinkled on top, which can add significantly to the amount of carbohydrates one has to take insulin for and can even put you at risk of experiencing hyperglycemia (high blood sugar).
Be aware of what you’re eating your grapefruit with, and make sure to always account for that when carbohydrate counting and measuring out diabetes medications, like insulin.
Balancing grapefruit in your diet
Grapefruit, while a relatively lower carbohydrate fruit with a lower glycemic index (25), can be a healthy snack for many people, it also contains virtually zero fat and zero grams of protein. This can cause a blood sugar spike in some people.
Eating grapefruit with other foods containing both protein and fat can help balance out a meal. Think grapefruit with pan-fried eggs (protein and fat), or unsweetened, full-fat Greek yogurt (protein and fat).
Additionally, the high acidity of grapefruit may cause acid reflux and heartburn in some people and may degrade tooth enamel, causing sensitivity and potential for decay.
Conclusion
Grapefruit’s relatively low-carbohydrate, high-fiber content and lower glycemic index make it a suitable snack for people with diabetes. It is high in many vitamins, minerals, and antioxidants, and can improve blood pressure, heart health, is great for gut health, and may even help prevent certain cancers.
However, some studies have found that it can increase the incidence of melanoma, it may not be suitable for people with compromised immune kidney function, and may interact with certain prescription medications you take.
Check with your doctor if you’re unsure of any drug interactions you may experience if you eat grapefruit.
Grapefruit can also exacerbate acid reflux and heartburn conditions, and its acidity can erode tooth enamel.
Moderation is key, so if you choose to incorporate grapefruit into your diet, work with your care team to find a balanced way to add this fruit into your life, while keeping both your diabetes and overall health goals in mind.
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