- What is anastrozole?
- What is anastrozole used for?
- How does anastrozole work?
- What happens if a man takes anastrozole?
- 14 foods to avoid while taking anastrozole
- 11 foods to eat while taking anastrozole
- Other things to avoid while taking anastrozole
- What do I need to know before taking anastrozole?
- Should anastrozole be taken with food?
- What is the best time to take anastrozole?
- Any other safety concerns?
- How to reduce the side effects of anastrozole
- How long can you stay on anastrozole?
The effectiveness of medications depends on the diet we eat, when we take them, and many other factors.
If you’re going to be taking anastrozole, you’re probably wondering how to modify your diet and what foods you should eat and avoid.
Read on to learn more about the anastrozole diet and other useful info about this medication.
What is anastrozole?
Anastrozole is a hormone treatment mainly prescribed to women who develop breast cancer after menopause. Sold under the brand name Arimidex, anastrozole was patented in 1987 and received FDA approval in 1995. It is also available as a generic medication.
Numbers show that in 2019 alone, doctors issued around 3,338,664 anastrozole prescriptions, meaning it’s the 176th most commonly prescribed drug in the United States.
Anastrozole is available in the form of 1mg tablets. No other forms and strengths are available or approved by the FDA.
What is anastrozole used for?
Anastrozole is formulated and approved primarily to treat breast cancer in postmenopausal women. Doctors may prescribe it to women whose breast cancer has progressed despite taking tamoxifen (Soltamox, Nolvadex). More precisely, the drug is prescribed for women with hormone-dependent breast cancer, where estrogen dominance plays a role.
Like all medications, anastrozole has off-label use as a treatment for male hypogonadism or low testosterone levels. Other off-label uses of anastrozole include breast cancer prevention, treatment of ovarian cancer, uterine cancer, endometrial cancer, and endometriosis.
While the medication is mainly prescribed for women, men can also use it under some circumstances.
How does anastrozole work?
Anastrozole belongs to a class of medications called non-steroidal aromatase inhibitors. It works by reducing the levels of estrogen in the body. As a result, the medication can delay growth or prevent types of breast cancer that rely on estrogen to grow. Anastrozole reduces estrogen levels by preventing estrogen synthesis from your adrenal glands.
It inhibits the aromatase enzyme, whose main job is to convert androgens (testosterone and androstenedione) into estrogens. Plus, anastrozole is selective. That means it only acts on blood estradiol and doesn’t impact the formation of aldosterone or adrenal corticosteroids.
By reducing estrogen levels, anastrozole could also increase testosterone or prevent it from dropping beyond normal levels.
What happens if a man takes anastrozole?
Although anastrozole isn’t approved for men, one of its off-label uses is for managing low testosterone levels. Indeed, evidence confirms that anastrozole increased testosterone levels and reduced estradiol levels in participants with mild hypogonadism (1).
This medication can also prevent gynecomastia (increased breast size) in men taking anabolic steroids. These steroids may increase breast size due to elevated estrogen levels, but anastrozole is formulated to reduce estrogen.
14 foods to avoid while taking anastrozole
When taking anastrozole, it’s important to reduce or avoid intake of some foods which could decrease its effects.
Some foods you may want to avoid while taking anastrozole include:
Some people may experience redness and hot flashes when drinking alcohol while taking anastrozole. That’s why it is useful to avoid alcohol when taking this medication.
It’s also useful to mention that studies confirm alcohol consumption may act through increased aromatase activity.
Alcohol consumption may aggravate the side effects of anastrozole and make it more difficult for this medication to function since anastrozole works to block aromatase.
2) Lemons, limes, oranges, tangerines, and other citrus fruits and juices
Citrus fruits and juices, including grapefruit, can interfere with medications. Citrus fruits contain a compound that blocks the normal breakdown of medication and thereby reduces its efficacy.
While the effects may vary from one person to another, one shouldn’t take these interactions lightly, especially when it comes to grapefruit. Additionally, citrus fruits are acidic, meaning they may aggravate diarrhea, a side effect of anastrozole.
3) Beef and lamb
These meats may increase aromatase and promote estrogen dominance. This effect is the opposite of the anastrozole’s mechanism of action.
Additionally, meats may contain hormones and hormone-like compounds whose main goal was to promote the growth of the animal.
While estrogen levels in meats are lower than those in birth control pills, lifetime exposure to the hormone isn’t something a person should ignore.
For that reason, it is useful to avoid or reduce the intake of beef and lamb and make sure meat derives from safe sources that don’t use hormones.
4) Sunflower oil
This is a rich source of Omega-6 fatty acids, which are associated with estrogen dominance. Estrogen dominance prevents anastrozole, as an aromatase inhibitor, from working properly.
It’s also possible for sunflower seeds to contain cadmium, a heavy metal. By mimicking estrogen, cadmium could contribute to estrogen dominance as well.
This heavy metal can increase the risk of breast cancer, and it participates in its pathogenesis.
5) Corn oil
Like sunflower oil, it is high in Omega-6 fatty acids, which may contribute to estrogen dominance and thereby could potentially prevent aromatase inhibitors from exhibiting their full effects.
6) Soybean oil
Due to the high Omega-6 fatty acid content, which is associated with estrogen dominance, it’s a good idea to reduce the intake of soybean oil.
7) Safflower oil
Just like previous oils on this list, safflower oil is a rich source of Omega-6 fatty acids. Since these fats are linked to estrogen dominance, they induce effects that are entirely opposite from what aromatase inhibitors are formulated to accomplish.
It’s also useful to mention that safflower oil contains compounds that act as phytoestrogens i.e., plant versions of the hormone estrogen.
8) Soy protein isolate
A protein that comes from soybeans. This type of plant-derived protein contains phytoestrogens i.e., compounds that mimic the effects of the hormone estrogen.
Research on this subject is limited, but persons with current hormone imbalances may want to consult a doctor before consuming high amounts of soy protein isolate.
Also, some people are intolerant or sensitive to soy. In that case, they may experience digestive issues such as diarrhea.
Anastrozole may also cause diarrhea in some people. That means consuming this protein while being intolerant to soy could worsen diarrhea that occurs as a side effect of this medication.
9) Chamomile tea
It can affect the absorption of some oral medications and interfere with their effects. For that reason, people who are taking medications for breast cancer, as a hormone replacement therapy, or oral contraceptives may want to consult a doctor before using chamomile.
At this point, there is no research on the impact of chamomile tea on anastrozole, but it is better to be safe since chamomile tea can interfere with other breast cancer drugs, such as tamoxifen.
10) Raw fruit and vegetables
Raw fruits and vegetables may increase the risk of diarrhea. Around 4-5% who are taking aromatase inhibitors experience diarrhea as a side effect.
Intake of raw fruit and vegetables can worsen diarrhea and contribute to dehydration. This is a risk that people with compromised immunity shouldn’t take lightly.
Raw fruit and vegetables can cause diarrhea due to high levels of fructose (which can have a laxative effect) and fiber, which causes loose stools when eaten too much.
Not only does diarrhea increase the risk of dehydration, but it also reduces the effectiveness of oral medications.
11) Processed food
This is high in calories and low in nutritional value. Consumption of processed food can contribute to estrogen dominance.
At the same time, this type of food tends to increase blood pressure, which may intensify hot flashes.
This is important because hot flashes are among the most common side effects of anastrozole.
Eating processed foods can worsen other side effects of this medication as well, such as fatigue, because they can also deplete a person’s energy levels.
12) Foods rich in saturated fats
They increase levels of both HDL (good) and LDL (bad) cholesterol. However, anastrozole does the same.
Evidence confirms anastrozole can raise the concentration of both good and bad cholesterol, thereby contributing to abnormal lipid metabolism.
Eating foods high in saturated fat while taking anastrozole could have a major impact on your cholesterol. This is why you may want to reduce your intake of these foods or consult a healthcare provider.
Since difficulty sleeping is a common side effect of anastrozole, it may be useful to reduce the intake of caffeine, a known stimulant.
Plus, caffeine can increase the severity of hot flashes, which is also a common adverse reaction of anastrozole.
14) Sugar-laden products
Like processed foods, they are high in calories and low in nutrients. Eating sugar-laden products can contribute to difficulty sleeping, fatigue, and hot flashes, all of which are also side effects of this medication.
Due to its effect on insulin, sugar can also contribute to hormonal imbalances, which is something that people taking anastrozole may want to avoid.
While high intake of sugar is prevalent today, especially in Western Diet, it’s not healthy due to its effect on weight and potential to wreak havoc on one’s health.
11 foods to eat while taking anastrozole
Some foods can help lower estrogen levels and thereby enhance the effects of anastrozole. The foods to eat while taking anastrozole are listed below.
1) Omega-3 fatty acids
Omega-3 fatty acids, found in salmon and other fatty fish, are well-known for their outstanding health potential. They exhibit anti-inflammatory effects, improve heart health, strengthen our immune system, and so much more. Omega-3s also support hormonal balance.
Plus, they are a good source of lignans, compounds with a weak estrogenic effect. When a weak estrogen-like compound replaces the body’s strong estrogen in breast cell receptors, it can act as anti-estrogen. That means Omega-3s could work against breast cancer.
2) Fiber-rich foods
A fiber-rich diet can help reduce estrogen levels and exhibit protective effects against cancers linked to estrogen dominance. It works by reducing the absorption of estrogen in the colon and allows the body to eliminate it through feces.
Strive to enrich your diet with whole grains, fruits, and vegetables. Cruciferous vegetables are good sources of fiber that also help with high estrogen levels.
These vegetables contain indole-3-carbinol, which holds anti-estrogen potential. They can reduce estrogen production in men and even decrease prostate cancer risk.
NOTE: if you have diarrhea, you may want to stick to bland, low-fiber foods, which can relieve this side effect.
Not only are they delicious, but pomegranates fit perfectly into an anastrozole diet. They can decrease the activity of 17-beta-estradiol, a type of estrogen associated with breast cancer, by up to 55% (3).
Some mushrooms can block aromatase and thereby reduce estrogen levels in the body. For that reason, they may help support the effects of anastrozole. This is particularly important for men whose testosterone levels are low.
5) Other diet changes
When modifying the anastrozole diet, it’s important to focus on making healthy choices by eating foods that exhibit favorable effects on hormones and strengthen the immune system. You may want to opt for the Mediterranean diet, one of the healthiest eating patterns in the world.
The Mediterranean diet is abundant in fruits and vegetables, healthy fats, nuts and seeds, and other healthy foods you should eat daily. Plus, it’s rich in protein. Studies show protein can reduce the concentration of endogenous estrogen in postmenopausal women (4).
Your anastrozole diet should be abundant in dark leafy greens, berries, fermented foods, beans, and other legumes, herbs, and spices (unless you are experiencing digestive difficulties). Also, make sure to drink enough water throughout the day. Just make sure the fruits and vegetables you eat aren’t raw.
Other things to avoid while taking anastrozole
When taking anastrozole, it’s crucial to adhere to your doctor’s instructions. Your healthcare provider will explain what to do or avoid when taking this medication.
For example, besides avoiding foods, you may also need to stop smoking. Avoiding cigarettes can help reduce side effects and improve the effectiveness of this medication.
You should also avoid taking other estrogen derivatives, such as estradiol, because they may decrease the effectiveness of anastrozole.
Another important thing to remember is that you should never tweak the dosage on your own. Avoid changing the dosage or combining anastrozole with other medications unless your doctor approves.
Before you start taking some other medication, you should check with your doctor first. That way, you can reduce the risk of interactions.
Avoid taking double doses if you happen to forget to take anastrozole. If you forget the medicine, take it as soon as you remember. But, if it’s almost the time for the next dose, then skip the missed dose entirely.
What do I need to know before taking anastrozole?
Before taking anastrozole, it’s useful to know the symptoms of an allergic reaction so that you can call the doctor if they occur.
The medicine may cause various side effects, which can be frustrating and overwhelming. Most of them go away on their own.
During the course of the treatment, the doctor will monitor your cholesterol levels, blood pressure, and bone density.
It’s also practical to know that people with kidney or liver disease aren’t generally good candidates for this medicine.
Should anastrozole be taken with food?
Anastrozole is okay to take with food or on an empty stomach. For some people, it’s more convenient to take it with food, whereas others may prefer it on an empty stomach.
If unsure, consult your healthcare provider regarding the best way to take this medicine. The most important thing is to adhere to dosage instructions. Make sure to take the medicine with a glass of water or juice.
What is the best time to take anastrozole?
There is no specific time of day considered best to take anastrozole. Patients can take it any time of day they like.
Ideally, you should take the medicine at whatever time of day is easiest for you to remember. For the best effects, you should take the drug at the same time every day.
That being said, for patients who experience hot flashes after taking anastrozole, you may want to take it at bedtime. On the flip side, patients who experience night sweats may want to take anastrozole in the morning.
Any other safety concerns?
Anastrozole may cause some unwanted effects. Not every person is bound to experience adverse reactions or have all side effects associated with the drug.
The most common side effects include:
- Bone pain
- Swollen feet and/or lower legs
- Fast or slow heartbeat
- Chest pain or discomfort
- Pounding in the ears
- Hot flashes or night sweats
Some less common anastrozole side effects include arm/back/jaw pain, cough, chills, sweating, sore throat, difficulty breathing, painful urination, increased blood pressure, drowsiness, vaginal bleeding, constipation, confusion, metallic taste, and reduced appetite. Patients on anastrozole may also experience vomiting, weight loss, and many other side effects.
Women are unlikely to take this medication before menopause. But, those who do take it shouldn’t do so when pregnant. Use adequate birth control and inform a healthcare provider right away if you get pregnant when taking this drug.
Patients who take anastrozole shouldn’t take it with tamoxifen.
Yet another important precaution is that anastrozole can induce an allergic reaction. Call a doctor if you experience symptoms such as hives, itching, hoarseness, difficulty swallowing, and swelling of the face, hands, or mouth.
Anastrozole may increase the risk of heart problems, including a heart attack in patients with a history of ischemic heart disease. Call a doctor if you have chest pain or difficulty breathing.
The medication may elevate fat or cholesterol levels in the blood.
Inform the doctor if you’re taking other medications such as those for asthma, appetite control, sinus problems, cold, and vitamin supplements. The doctor will inform you whether it’s safe to take anastrozole.
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How to reduce the side effects of anastrozole
Take anastrozole as directed by a healthcare provider. If nausea is the problem, taking the medicine after eating may help. Try staying in a cool environment to reduce hot flashes or night sweats, and take ibuprofen to manage headaches or other types of pain.
Keep your bones healthy by quitting smoking, eating a healthy diet, and exercising regularly.
Having small and frequent meals can help with appetite changes and unintentional weight loss.
Some side effects improve over time as the body adjusts to the medicine. Contact a healthcare provider if they are persistent.
How long can you stay on anastrozole?
Treatment with anastrozole usually lasts about five years, but this is usually for patients with breast cancer or breast cancer prevention.
Some studies have shown anastrozole treatment is safe and beneficial five years after the initial treatment, i.e., it may be safe to use for 10 or up to 12 years (5). The doctor is the one who instructs patients on how long to take the medication.
Anastrozole is a medication that doctors prescribe to treat breast cancer. It works by reducing estrogen levels. Men may also use it to reduce gynecomastia and manage low testosterone levels.
When taking this medication, a proper diet is necessary. Avoid foods that are bad for hormonal balance. Instead, enrich your diet with foods that support the effectiveness of this drug.
When tweaking your diet, it’s also necessary to consider side effects. For instance, if you are experiencing nausea, a fiber-rich diet isn’t a solution. Instead, you need to reduce fiber intake until the side effect resolves. When taking anastrozole, it’s crucial to avoid junk food and other unhealthy foods.