Evidence: High Possible Benefits: High Safety: Very High
TABLE OF CONTENTS
What is cranberry?
Vaccinium macrocarpon, also known as cranberry, is a popular type of berry sometimes sold as a supplement for its wide variety of health benefits. Along with other flavonoids and polyphenols, this berry contains high amounts of anthocyanins, which can reduce inflammation, boost antioxidant defenses, improve cognition, and more. This article is about the main benefits of cranberry, its potential side effects, the best time to take it, and more.
Possible benefits
All of the potential benefits mentioned below are dose-dependent. As with other fruits and plants in general, there is a sweet-spot dose that allows you to get most of the benefits without causing meaningful side effects or tolerance buildup in the body. We will discuss the best dosing protocol later in this article.
Major benefits
Reduced urinary tract infections – Cranberries can greatly reduce infections of the kidneys, bladder, or urethra with the exception of neurogenic bladder, a condition caused by a spinal cord injury.
Antioxidant properties – This berry contains a wide variety of anthocyanins and other flavonoids, many of which have strong antioxidant properties and can help reduce oxidative stress in the body.
Reduced DNA damage – 375+ mg of anthocyanins can notably and reliably slow down DNA damage (by about 20%).
Improved cognition – Anthocyanins and other compounds in the berry can improve memory and various other aspects of cognition. The improvements in memory are most notable and reliable. Most berries can also improve dopaminergic neurotransmission, hippocampal IGF-1 levels, long-term potentiation (LTP), neuroprotective functions, brain circulation, and brain-derived neurotrophic factor (BDNF) levels. These benefits almost certainly apply to cranberry, but more human studies are needed to prove this.
Minor benefits
Reduced inflammation – Many anthocyanins and polyphenols in cranberry are proven to reduce inflammation in the body through various mechanisms.
Improved immune health – Secondary to the antioxidant and anti-inflammatory properties, cranberry can improve innate and adaptive immune system health and function. This berry can also reduce the symptoms of various autoimmune conditions.
High micronutrient content – Berries are rich in most vitamins and minerals per calorie. However, you would need to eat very high quantities of berries (hundreds or thousands of grams daily) to get enough vitamins and minerals from berries alone. So instead of relying on this fruit to get enough micronutrients, think of this benefit as a bonus.
Reduced LDL oxidation – While cranberry doesn’t influence LDL or HDL cholesterol levels much if at all, it can reduce the oxidation of LDL by as much as 27%.
Improved mood and well-being – Eating berries for a few weeks was associated with increased well-being in older people. This benefit almost certainly applies to cranberry as well.
Improved vision – The anthocyanins in cranberry were shown in animal studies to increase resistance to screen-induced ocular fatigue and retinal photoreceptor cell resistance to blue light-induced damage. Human studies are needed to confirm these effects.
Increased healthspan and lifespan – While the relationship between cranberry and healthspan or longevity has yet to be studied directly, there are many mechanisms through which this berry might slow down aging and increase healthspan and longevity. Besides the benefits already mentioned, cranberry can support stem cell proliferation, the management of senescent cells, Nrf2, DNA repair enzymes, DNA structure, and more. All of these benefits are associated with healthy aging.
Improved insulin sensitivity – People with insulin resistance may experience a slight improvement.
Increased exercise performance – This fruit can slightly improve exercise performance and reduce biomarkers of muscle damage, such as creatine kinase, leading to faster muscle recovery.
Possible side effects
The side effects below are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.
Allergic reaction – While an allergy to this berry is rare, some people may experience an allergic reaction after ingesting the fruit. If you experience allergic symptoms like itching or swelling of the mouth, coughing, sneezing, rash, or other skin reactions because of the berry, it is probably best to stay away from it.
Toxicity – Anthocyanins, polyphenols, and other bioactive compounds in this berry have adaptogenic properties and act as mild stressors on the body. That is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, stressing the body too much can be counter-productive and cause multiple side effects, including mild toxicity. While acute toxicity is extremely rare, taking or eating large quantities of cranberry could lead to mild chronic toxicity and cause some health problems over time. To prevent chronic toxicity or the buildup of tolerance, staying below 500 grams of fresh berries, 100 grams of dried berries, or 1000 mg of anthocyanins in a day is best unless you have a great reason to consume more.
Contamination – If growing or storing conditions are not adequately controlled, cranberry can be contaminated with bacteria, molds, and other potentially harmful microorganisms. Many growers also use pesticides that can be unsafe. Choose the brand you get berries and berry powders from wisely. For berry powders and supplements, it is often best to use websites like Amazon, where thousands of users have reviewed and rated the products. You are less likely to buy something of lower quality there.
Who should not eat or take cranberry?
You should probably avoid cranberry if you:
are allergic to this berry
experience a severe adverse reaction after eating the berry (though a mild adverse reaction is usually not a problem and can even be seen as positive as it is a sign that the adaptogenic molecules like anthocyanins are causing a hormetic response that allows the body to adapt and become more resilient)
Who will benefit the most?
You should consider taking the berry or adding it to your diet if you:
wish to improve your memory, focus, or other aspects of cognition
enjoy the taste of it
wish to improve general health
have a high budget for supplements and are willing to experiment with a variety of them (assuming you don’t fall into any of the categories that should avoid this fruit, cranberry appears safe and is unlikely to do more harm than good for most people)
How much cranberry should you take?
Because anthocyanins and other flavonoids and polyphenols in the berry are adaptogenic compounds, they act as mild hormetic stressors on the body, which allows your body to adapt and become more resilient to certain kinds of stressors in the long term. A higher dose of these compounds isn’t necessarily better because they may put too much stress on the system.
The sweet-spot dose typically ranges between 60-120 grams of fresh cranberryor 10-20 grams of dry berry or dry powder daily. If you buy an x:1 extract, divide the dry powder dosage by x. If you purchase an extract standardized for anthocyanins, the sweet spot dose of total anthocyanins is about 500-1000 mg.
The higher end of this range usually provides slightly more benefits in the short term. If you plan to take or eat this berry regularly for a longer time (multiple months or years), the lower end is probably a better way to go.
While this fruit could theoretically cause acute toxicity, you’d need to take an extremely high amount that would be way beyond what even the most potent extracts contain.
Like most other plants, it is best to cycle cranberry and take about two days off weekly to reset your tolerance to anthocyanins and other adaptogenic compounds in the berry. That will allow you to keep getting the benefits in the long term.
Best time to take cranberry
Anthocyanins and most other bioactive compounds in cranberry are water-soluble, so you don’t need to take the berries with food to absorb them well.
Whether you take the berries in the morning or the evening does not make much difference. Both options are fine so feel free to experiment.
Interactions
Grape seed extract These two can improve each other’s polyphenol bioavailability. The supplements also act synergistically in improving cognitive function and brain health.
Where to buy cranberry supplements?
In most countries, Amazon is the best option for ordering cranberry and other berry powders and supplements. They offer some very affordable products backed by many positive reviews. Also, you can choose from a wide range of brands without having to search through other markets on the Internet.
Some brands display the dosage per serving instead of per pill or capsule. Therefore, you may accidentally buy something less potent than you intended. Do not fall for this marketing trick.
FAQ
As for most other fruits and supplements, it is best to cycle cranberry and take a break from it for about two days per week to reset your tolerance back to baseline. You can also eat this berry only during its season and take a break from it for the rest of the year. Both of these strategies will keep your body sensitive to the fruit and allow you to keep getting the benefits in the long term.
The health difference between these two options typically isn’t too big. Fresh berries may have a slightly higher antioxidant content but supplements and dry powders don’t expire nearly as fast as fresh berries, don’t need to be stored in perfect conditions, and are often cheaper.
Generally not. If anything, frozen berries are better as they are frozen right after they get harvested. That means fewer antioxidants get lost during the transportation and storage of berries. Fruits sold as frozen also tend to be harvested when they are fully ripe whereas fruits sold fresh generally have to be harvested long before they ripen.
Yes. This berry will not worsen your sleep quality in any way. Whether you take it in the morning or the evening doesn’t matter much if at all.
Dry berry powders and supplements can expire but not nearly as fast as fresh berries. They can also lose potency over time but very slowly if you store them well. Keep the supplement in a cold, dark, and dry place. It should remain just as potent for many months or even years there.
This berry contains anthocyanins and other adaptogenic compounds that act as mild stressors on the body. That is usually a great thing as it allows your body to adapt to specific forms of stress and become more resilient. However, stressing the body too much can be counter-productive and cause mild toxicity over time. High doses can also make you develop tolerance much faster than lower doses, and they may be less effective at improving health in the long term.
While you could safely take higher doses, there is usually no point in eating more than 300 grams of fresh berries, 50 grams of dried berries, or taking 500 mg of anthocyanins daily. This amount should give you most of the benefits without meaningful side effects.
This berry contains many bioavailable compounds, and each has a different half-life. The half-life of anthocyanins in the body ranges anywhere from 0.5-96 hours. However, most of the effects of this fruit are cumulative, so they mostly happen in the long term rather than acutely. Therefore, the half-life of this berry isn’t very relevant in practice.
Small amounts of this berry should have little to no effect on fasting, but higher doses (100+ grams) may reduce or offset some benefits of the fast, especially the ones related to autophagy. That should only be a concern if you do prolonged water fasts. If you practice intermittent fasting, you don’t have to worry about eating berries during your fast unless you consume high quantities of them.
References
Most of the information in this guide is based on scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything you read in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.
