Are You Experiencing Breast Pain On Keto? [Learn Why]

A bit of a taboo subject, but one that must be addressed none the less, is the topic of breasts.

Sore breasts for that matter. 

Many women starting a ketogenic diet have major issues with sore breasts, sore nipples, and just extreme breast pain in general, but what is causing it? 

Can keto cause breast pain? There are various reasons why you may experience breast pain after starting keto, including hormonal changes, irritation or injury, a nutrient deficiency, and blocked lymph glands.

In this article, I'll address all the different reasons why you may suddenly be experiencing breast pain and soreness after starting a ketogenic diet, the various causes, solutions, and more.

Can keto cause breast pain pinterest

Breast Pain On A Low Carb Diet

Experiencing sore breasts may be typical for you and many women, especially right before that time of the month.

However, for some reason, you may be noticing more extreme breast pain, soreness, and possibly even increased breast size (swollen breasts).

This breast pain may is referred to as mastalgia, which is generally classified as either being cyclical (mensural or hormonal related) or non-cyclical (non-hormonal related).

To provide you a bit of relief, the likelihood of breast pain being related to cancer is slim. Breast pain is rarely associated with cancer, and it likely would not involve both breasts experiencing pain and soreness. 1 2

If the increased irritation occurred only after starting a ketogenic diet, it might be attributed to one of the following factors:

  1. Hormonal changes (cyclical)
  2. Irritation or an injury to the area (non-cyclical)
  3. Nutrient deficiency
  4. Blocked lymph glands

A High Fat Diet And Cyclical Breast Pain 

The majority of breast pain women experience is cyclical. Meaning, the pain will vary depending on the changes in hormonal levels you experience each month and the sensitivity to specific hormones.

Specifically, these hormones:

  • Estrogen
  • Progesterone
  • Prolactin

During each mensural cycle, especially during the reproductive years, fluid may be retained before your period starts. The fluid you retain may lead your breasts to become swollen, “heavy,” and painful. 

However, this extra fluid typically, and the resulting pain goes away 7 to 10 days after menstruation starts. Generally, you'll experience soreness and pain right before your period, but it typically subsides afterward.

In terms of a high-fat diet, it was first hypothesized that higher fat intake was associated with higher levels of reproductive hormones and thus an increased risk of breast cancer, but no evidence was found. The exact opposite was shown. 

In this study, as women increased fat intake in their diet, levels of six different hormones declined. 

Most women who adopt a ketogenic or high-fat diet do so intending to lose weight. 

If you're experiencing changes in your PMS and period symptoms after losing weight, try waiting for a few cycles to see if it returns to normal. 

 If you notice that the pain coincides with your monthly cycle affects the entire breast area, you may be suffering cyclical (hormone-related) breast pain. 

Keto And Sore Nipples Or Isolated Non-Cyclical Pain

Keto and sore nipples

If cyclical pain is related to hormones, non-cyclical pain is the exact opposite (non-hormone related). 

Non-cyclical breast pain is not related to your menstrual cycle at all. Meaning, it tends to be in one specific area and doesn't vary with your menstrual cycle.

The cause of non-cyclical breast pain may be due to irritation or an injury (trauma) to the breast. 

Also, arthritic pain in and around the chest cavity and neck can radiate pain down to the breasts, which may be mistaken for breast pain. 

Because the pain is non-hormonal, it can be more challenging to pinpoint the exact origin of the pain and appropriate treatment. 

Your healthcare provider will generally perform a physical examination, but may also order a mammogram. In rare cases, a biopsy of the area may be necessary.

In some cases, the pain may be caused by a cyst, in which the cyst will then be aspirated to remove the liquid contents. 

 If you notice that the pain doesn't coincide with your monthly cycle and/or is only located in one specific area of your breasts and not the entire area, you may be suffering from non-cyclical (non-hormone) breast pain. 

Other Reasons For Breast Pain On Keto

There are two other reasons you may be experiencing breast pain when starting a ketogenic diet; those are a nutrient deficiency and blocked lymph glands.

When switching to a ketogenic diet, many individuals stop eating all the processed foods they were used to consuming before switching to keto.

While as a whole, this is a great switch, many of those processed, pre-packed, and fast-foods were fortified with vitamins and minerals, especially iodine from iodized salt. 

Nutrient deficiency

Iodine insufficiency may lead to increased sensitivity of breast tissue to hormones, especially estrogen. 3 

A lack of iodine may also result in an increased risk of a thyroid disorder, though excess iodine may be hazardous as well. 4

 To know for sure whether you have an iodine deficiency, a urine or blood test must be used to measure iodine levels. 
Blood test for iodine

To help combat low levels of iodine, you can either start using iodized salt or take an iodine supplement to bring levels within normal levels. 

Iodine supplement I would recommend:

Otherwise, you can also try to get in iodine through iodine-rich keto-friendly sources such as: 5

  • Fish
  • Seaweed
  • Shrimp
  • Dairy products (cheese, heavy whipping cream, kefir, unsweetened yogurt) 

Blocked lymph glands

Each of your breasts contains vessels that carry fluid, known as a lymph. Lymph vessels drain fluid from tissues throughout the body and also allow immune cells to travel where needed. 6

When these lymph vessels become obstructed, lymphedema may occur, which results in swelling due to the blockage.

Treatments for lymphedema include:

  • Compression
  • Manual lymph drainage
  • Resistance or range of motion exercises

Below is a video of a lymphatic massage that you can try if you believe you are suffering from lymphatic obstruction.

Can Keto Diet Effect Breast Size?

When it comes to breast size and keto, there is nothing magic about keto that will affect breast size… 

And that's whether you're looking for them to grow or reduce in size.

 Unfortunately, due to the breasts having a significant proportion of fat, as women lose weight, they may also experience a reduction in breast size.  

While it is a necessary evil when it comes to weight loss, it must be a trade-off you're willing to accept if fat loss is of importance to you. 

Figure competitors and female bodybuilders often undergo breast enlargement due to having to get to very low levels of body fat to compete on stage. 


Experiencing more than swollen breasts, such as swollen hands and feet on keto?

How To Relief Breast Pain On Keto

There are numerous ways to help manage the breast pain associated with the reasons listed above. If the pain is interfering with your normal daily activities, you may want to consider some of the following:

  • Reducing stress as hormones respond greatly to stress
  • Stop smoking (if you do)
  • Anti-inflammatory medications, mainly if breast pain is being radiated from elsewhere into the breasts (ribs, chest wall, etc.)
  • Reduce caffeine intake as caffeine may stimulate breasts
  • Wear a well-fitted, supportive bra, especially if you're highly active in exercise or sports.

The Takeaway

A ketogenic diet can cause increased breast pain only if doing so results in a change in hormones, which weight loss, in general, may do for some women.

However, if you've also undergone a change in your physical activity to go along with your change in diet, or had a recent trauma in or around your breast area, you may be experiencing a non-cyclical (non-hormonal) related breast pain.

Lastly, you may have a lymphatic blockage preventing fluid from draining or a nutrient deficiency, particularly iodine, which your doctor may test for. 

Frequently Asked Questions

Can change in diet cause breast pain?

Yes, it's definitely possible that a change in diet can cause breast pain. If you're new diet includes more caffeine and includes foods that are high in a lot of salt, there's a possibility that it might be the reason why you're experiencing breast pain.

Does keto mess with female hormones?

According to some women that engage in the keto diet, they experience irregular periods. Others have experienced a complete stop in their cycle, which is known as amenorrhea.

Does keto mess with estrogen?

Being on the keto diet will alter a women's GnRH levels. A disruption in the GnRH levels cause a reduction in the level of estrogen. That can end up leading to amenorrhea.