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Evidence Based

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Fungal Infections: What Is the Strongest Candida Killer?

Written by Dr. Michael Ruscio, DC on May 26, 2022

Written by Dr. Michael Ruscio, DC on May 26, 2022 — Reviewed by Dr. Hannah Hamlin

All You Need to Know About Treating Candida Infections Effectively

• What Is Candida?|
• Pharmaceuticals Are the Strongest Candida Killers|
• Probiotics for Candida|
• The Role of Antimicrobials|
• Diet and Candida|
• Squashing Candida Myths|
• Overcoming Candida Infections|

If you have a candida diagnosis, you’ll want to get rid of this fungal infection as quickly as possible so you can start feeling better. 

The strongest candida killers are generally recognized to be antifungal drugs, such as fluconazole (brand name Diflucan), nystatin, and clotrimazole. 

However, this doesn’t necessarily mean drugs are the best long-term approach for fighting candida. Many patients do better with herbal antimicrobials, either in addition to or as an alternative to pharmaceutical treatment. 

Probiotics also have an important role to play in keeping the microbiome healthy, and thereby preventing the inappropriate growth of candida species.

In this article, we’ll take a comprehensive look at candida infections and at the treatments that can help to cure and prevent them.

What Is Candida?

Candida is a type of yeast (a fungus) that’s often a normal, harmless part of the human microbiome, but which can also cause an opportunistic infection called candidiasis, or thrush 1.

There are various types of candida, but Candida albicans is the most common type. 

The clinically accepted symptoms of Candida albicans infection are either a burning, itchy, genital yeast infection (including vaginal discharge in women), and/or thrush in the mouth 1.

However, candida may sometimes present as a cluster of symptoms, including a typical yellow/white plaque on the tongue, but also diarrhea, skin rashes, and sugar cravings.

Common reasons why Candida albicans may tip from being a normal, harmless inhabitant of the digestive tract into an opportunistic infection can include 1:

• Having a compromised immune system 
• Wearing ill-fitting dentures (causing oral thrush)
• Taking antibiotics or corticosteroids 
• Undergoing chemotherapy
• Having diabetes
• Being pregnant
• Taking oral contraceptives

Candida albicans can become more virulent because of its ability to form biofilms, tightly packed communities of microbial cells embedded in a web of substances that can grow on living surfaces (such as the mucosal membranes that line the intestinal and urinary tract). Someone who’s been colonized with mold may have both mold and candida together as a biofilm.

Candida biofilms can also form on inanimate surfaces, like medical implants 2.

Pharmaceuticals Are the Strongest Candida Killers

Prescription antifungals are the strongest candida killers and will generally be able to get rid of the infection quickly and efficiently 3. Fluconazole (brand name Diflucan) and nystatin are the two most commonly prescribed, but fluconazole is the more fail-safe of these two as it’s absorbed and acts systemically (via the bloodstream).

Nystatin isn’t absorbed in the digestive tract and can only exert its antifungal properties on the infected mucosal surfaces it comes into contact with. This means it must be thoroughly swished around in the mouth cavity before swallowing to ensure it’s an effective treatment for candida in the oral cavity, pharynx, or esophagus 4.

Downsides of Antifungal Drugs

For the most part, antifungals used to clear up an oral or vaginal candida infection will have few side effects. When they do occur, side effects will generally be minor digestive issues, including mouth irritation, nausea, vomiting, diarrhea, or stomach upset 5 6.

However, while antifungal medications are the strongest candida killers and don’t have many serious side effects, candida infection can recur once the antifungal is stopped. 

In one study, just 8% of women with vaginal thrush who were treated with Diflucan for six months had recurrences (compared with 64% of women given placebo). However, six months after treatment ended, 57% of the women treated with Diflucan had experienced further bouts of the condition 7.

Unfortunately, antibiotic and antifungal drug resistance (which is when these disease-causing organisms become immune to the effects of the drugs designed to kill them) is more likely to occur when antifungal medicines are used for a long time 8.

A better approach may therefore be to try to make changes to the overall balance of microorganisms in your gut, so that candida infections are less likely to recur. 

For this you should consider probiotics and herbal antimicrobials, supported with a healthy diet.

Probiotics for Candida

Probiotics are supplements of friendly gut bacteria that can help displace pathogens and create a healthier balance of microbes (including bacteria, fungi, and yeast) throughout the digestive tract. They may not be the strongest candida killers, but several studies show they may have a positive impact on candida infections. For example:

• Three separate systematic reviews and meta-analyses have demonstrated that probiotics help protect against candida infection in the mouth, and/or reduce oral candida numbers. Probiotics appeared to be particularly effective at reducing candida in those who wore dentures 9 10 11.
• One of the reviewed studies showed that those who applied probiotics topically to the region of the mouth in contact with their dentures for five weeks had only a 16.7% Candida detection rate, compared to a 92% rate in the placebo group. Another showed that taking daily probiotic lozenges reduced the prevalence of oral candida by 50% 9.
• Probiotics may also enhance the ability of antifungals to treat vaginal candida infection. In a randomized clinical trial of women who took fluconazole, those also given probiotics for four weeks had significantly less vaginal discharge than the placebo group. Probiotic users also had reduced vaginal itching, and weren’t as likely to experience pain during sex or urination 12.
• Probiotics have also been used as successfully as the antifungal drug nystatin to prevent candida colonization in premature (very low birth weight) infants 13 14 15 16.

The Role of Herbal Antimicrobials

A number of herbal/botanical antimicrobials have been studied, and shown to be clinically effective against candida. For example: 

• Garlic supplements rich in allicin treated vaginal candida infection about as well as an antifungal drug 17.
• Curcumin (derived from turmeric) and its derivatives were effective at treating candida infection and sidestepping antifungal drug resistance 18.
• Capric acid or caprylic acid (derived from coconut oil) reduced candida in the digestive tracts of preterm infants 19.
• Propolis, a resin that honey bees collect from tree buds, was as effective as conventional antifungal drugs in treating denture stomatitis (typically caused by candida) 20.
• The herb Triphala churna effectively reduced candida counts on people’s dentures 21.

Other herbal antimicrobials that that have showed more general anti-candida effects in in vitro studies and literature reviews include:

• Peppermint essential oil 22
• Rose geranium 23
• Tea tree oil 23
• Persian lime 23
• Oregano oil (active ingredient carvacrol) 24
• Berberine 25
• Apple cider vinegar 26 27
• Artemisinin (sweet wormwood) 28
• Horsetail oil 29

In most cases the above would be used externally, but some can be taken internally. It’s important to check usage advice carefully.

Herbs Have a Safer Profile

Many people will get effective clearance of fungal infections by combining probiotics with multi-herb antimicrobial formulations.

More research is needed to confirm exactly which antimicrobials or combinations of antimicrobials are the most effective for candida infections. But it can be safely said that patients tend to prefer the side effect profiles of herbal antifungals to pharmaceutical drugs. This is supported both from systematic review evidence 20 and my experience with patients. 

Herbal compounds, such as oregano and peppermint oil, are also less likely to contribute to antifungal resistance than pharmaceutical drugs. This is because herbal compounds have a broad-acting pharmacology, enabling control of pharmaceutical-resistant organisms 30.

To put it another way, while bacteria and fungi may be able to develop resistance to pharmaceutical drugs that essentially act in one specific way, they’re less likely to develop resistance to herbal compounds, which act in multiple different ways.

Diet and Candida

Contrary to what you might have read, there’s very little evidence that a special, highly restrictive anti-candida diet or “candida cleanse” diet is needed to deal with candida infection. Nor can any specific diet cure candidiasis 31 32 33.

That said, a low-sugar, reduced-carbohydrate diet is commonly advocated for candida patients and there’s a lot of sense to this. Though research doesn’t clearly show that cutting down on sugars helps to clear candida, yeasts need sugar to thrive, so depriving them of this food source may limit their growth. 

In addition, it’s quite typical for sugar cravings to be part and parcel of many people’s candida experience, and therefore a diet that helps to smooth out blood sugar ups and down is likely important. 

Since there are multiple other general health benefits to reducing dietary sugar 34, it’s a sensible idea to try. However, being excessively strict isn’t necessary nor supported by the evidence.

For many people, the Paleo diet, which contains plenty of protein and vegetables and only a modest amount of processed foods and carbs (especially refined carbohydrates), is ideal for candida patients, as well as helping to manage blood sugar fluctuations. 

Could Vitamin D Help Candida?

One large study showed that vitamin D supplements reduced candida infections in critically ill kids taking broad-spectrum antibiotics 35. While we have no evidence to say that vitamin D can also benefit less-serious candida infections like vaginal yeast infection or oral thrush in adults, it might be worth making sure your levels of this nutrient are topped up with a daily supplement.

Squashing Candida Myths

While on the subject of candida and the strongest candida killers, it’s worth putting to rest the myth that it’s common for candida to get into the bloodstream and spread to other body organs 1. Invasive candidiasis, as it is known, certainly can occur, but is a very rare, life-threatening condition that only tends to occur in hospitalized individuals who are already very ill or highly immunocompromised.

In other words, having a thrush or candida infection can be uncomfortable and debilitating, but you don’t need to worry that you’ll become very sick 36.

The other popular idea that overgrowth of candida causes a vast array of symptoms is also unfounded. Despite a lot of research since the 1980s, it’s never been shown that candida yeast causes fatigue, insomnia, impotence, headaches, brain fog, joint pain, weight gain, or any of the other ailments it’s sometimes associated with 33 34 35 36 37.

Poor gut health caused by a general imbalance of gut microorganisms may certainly contribute to such symptoms, but candida is rarely the only or main culprit.

In fact, focusing just on candida can be a red herring, given that for most patients, gut issues tend to occur because of a more generalized dysbiosis, in which other microbes are also out of balance. A better approach for suspected candida is a more comprehensive overhaul of diet and lifestyle to get gut health in general back on track.

Overcoming Candida Infections

To fight candida and deal with the unpleasant symptoms of a candida infection, the strongest candida killer you can use is a prescription antifungal medicine such as Diflucan (fluconazole). To prevent recurrences and create an environment in your gut that is less prone to candida overgrowth and yeast overgrowth generally, a regimen of probiotics and herbal antimicrobials is also worth considering. 

If you’ve struggled with candida infections and feel you need more information on how to treat them, consider scheduling a virtual or in-person consultation at the Ruscio Institute for Functional Medicine clinic, or read more about my eight-step protocol for restoring your digestive system to health in Healthy Gut, Healthy You.

The Ruscio Institute has developed a range of high-quality formulations to help our patients and audience. If you’re interested in learning more about these products, please click here. Note that there are many other options available, and we encourage you to research which products may be right for you.