When it comes to vaginal tissue, maintaining an optimal pH is important for preventing infections, discomfort, and unpleasant smells. So let's dive into what a healthy vaginal pH is and what can mess with it.
What is a healthy vaginal pH?
The term pH is used to describe how acidic or basic something is. The pH scale is between 0 and 14. The lower the number, the more acidic, and the higher the number, the more basic (also referred to as alkaline). For example, tomato juice has a pH of 4. Water is neutral with a pH of 7, and the pH of baking soda, which is basic, is 9.
pH levels vary throughout the body, for example, a low pH is necessary for optimal digestion in your stomach, making it more acidic, whereas other parts of the body would be better with a neutral or even a higher pH.
When it comes to vaginal health, we want a more acidic pH. A normal vaginal pH is between 3.8 and 4.51. If your vaginal pH is too high, your risk of getting a vaginal infection or imbalance increases, like BV (bacterial vaginosis) and yeast infections, which can lead to an unpleasant smell, discharge, and uncomfortable itching.
What affects vaginal pH?
The most important determinant of our vaginal pH is our vaginal microbiome2. Remember, our microbiome constitutes all of the healthy bacteria that cover all aspects of our body, including our digestive system, skin, and, yes, our vaginal area as well.
Like the microbiome in our digestive system, sinuses, and skin, the vaginal microbiome is the first line of defense against infections. Disruption in the normal microbiome3 results in an elevated pH and an increased risk of STDs (sexually transmitted diseases) and, when pregnant, premature delivery, and pregnancy loss.
The most important group of healthful bacteria in our vaginal area is the Lactobacillus species. The Lactobacillus bacteria in the vaginal area secrete lactic acid and hydrogen peroxide, which create a more acidic pH. As a result, a deficiency of Lactobacillus in the vaginal area leads to an increase in vaginal pH and an increase in the risk of vaginal infections4.
What can you do to maintain a healthy vaginal pH?
Don't douche. The vagina cleans itself naturally. The process of "washing" your vaginal area with products claiming to make you smell better can actually do the opposite. This is because douching can wash away good bacteria and change the pH, increasing your risk of infection in the long run.
Don't leave your tampons in too long. When you are having your monthly cycle, the blood in the vaginal area naturally increases the vaginal pH. If you keep the blood around too long, as can happen when you don't change your tampon frequently enough, your pH will increase and, as a result, allows the unhealthy bugs to overgrow. In general, change your tampon every four to six hours.
Avoid unnecessary antibiotics. When you take antibiotics for anything, like a sinus infection, for example, it, unfortunately, kills off some of those healthful Lactobacillus species in your vaginal area, too. This results in a higher pH and increased risk for overgrowth of yeast and unhealthful bacteria in your vaginal area. While antibiotics are important, in some cases, they are actually unnecessary. Many upper respiratory infections, including sinus infections, are viral, and your body can naturally fight them off with proper rest and hydration. Check with your doctor and make sure an antibiotic is necessary before you take one.
Does lubricant negatively affect your vaginal pH and bacteria?
In short: It depends. Unfortunately, many lubricants5 can disrupt the natural balance of healthful bacteria in the vaginal area and negatively affect your vaginal pH. There is definitely a need for more options and good research in this area.
Probably the best lubricant to use at this time, that has not been shown to damage the good bacteria in the vaginal area, is olive oil. But this can damage latex condoms, so best to avoid when using condoms to prevent sexually transmitted diseases or pregnancy.
Can diet help?
We know that diet affects our gut microbiota, and we think that our gut may be an extra-vaginal reservoir for all of those good Lactobacillus bacteria that make up a healthy vagina. As a result, reach for a high-fiber, low-glycemic-load, nutrient-dense diet that is helpful for feeding the healthy bacteria in the gut and vaginal tissue.
What does this mean? Whole foods, lots of healthy vegetables, fruits, beans, ground flaxseeds, and nuts all can provide the food to help the good healthy bacteria in the body grow. Fermented foods that are rich in Lactobacillus are also helpful. These include unsweetened yogurt, sauerkraut, kimchi, and miso. In addition, you want to avoid a high-sugar diet that can feed the wrong yeast and bacteria in your body.
Should I take a probiotic for my vaginal microbiome?
I often prescribe probiotics for my patients when they have signs of an imbalanced vaginal microbiome, such as frequent vaginal bacterial or yeast infections. Look for one that is rich in Lactobacillus. I often recommend formulations that contain Lactobacillus reuteri and Lactobacillus rhamnosus. These strains of good bacteria have been shown to support vaginal health6. The research in this area is young, and I am sure we will learn even more about how to replenish the healthy microbes in the future.
Elizabeth Boham, M.D., M.S., R.D. is board certified in family medicine from Albany Medical College, and is Institute for Functional Medicine certified. She is also the medical director of The UltraWellness Center.
Boham lives in Valatie, NY, and lectures on a variety of topics, including women’s health and breast cancer prevention, insulin resistance, heart health, weight control, and allergies. She is on the faculty of the Institute for Functional Medicine.