Heartburn, also called acid reflux, is a common symptom of gastroesophageal reflux disease (GERD), which affects about 20% of the U.S. population (1).
It happens when your stomachâ€™s contents, including gastric acid, move back up to your esophagus, giving you a burning feeling in your chest (2).
Some people claim that cowâ€™s milk is a natural remedy for heartburn, while others say it worsens the condition.
This article analyzes whether milk relieves heartburn.
Can drinking milk relieve heartburn?
There is some evidence showing that milkâ€˜s calcium and protein content may help relieve heartburn.
Calcium may offer some benefits
Calcium carbonate is frequently used as a calcium supplement, but also as an antacid due to its acid-neutralizing effect.
One cup (245 ml) of cowâ€™s milk provides 21â€“23% of the Daily Value (DV) for calcium depending on whether itâ€™s whole or low-fat (3, 4).
Because of its high calcium content, some claim that itâ€™s a natural heartburn remedy.
In fact, a study in 11,690 people determined that high intake of dietary calcium was associated with a reduced risk of reflux in men (5, 6).
Calcium is also an essential mineral for muscle tone.
People with GERD tend to have a weakened lower esophageal sphincter (LES), the muscle that would usually prevent your stomachâ€™s contents from coming back up.
A study in 18 people with heartburn found that taking calcium carbonate caused an increase in LES muscle tone in 50% of cases. These results suggest that taking this supplement to improve muscle function may be another way to prevent heartburn (7).
Protein may be helpful
Milk is an excellent source of protein, providing about 8 grams per 1 cup (245 ml) (3, 4).
A study in 217 people with heartburn found that those who consumed more protein were less likely to have symptoms (8).
Researchers believe that protein may help in treating heartburn because it stimulates gastrin secretion.
Gastrin is a hormone that also increases LES contraction and promotes the emptying of your stomachâ€™s contents, also known as gastric emptying. This means that less food is available to move back up.
However, gastrin is also involved in the secretion of stomach acid, which may end up increasing the burning feeling in your chest (9).
Therefore, itâ€™s unclear whether the protein in milk prevents or worsens heartburn.
Milk is rich in calcium and protein, which may have beneficial effects that help relieve heartburn.
Could make heartburn worse
One cup (245 ml) of whole milk packs 8 grams of fat, and studies show that fatty foods are a common trigger for heartburn (3, 8, 10).
High-fat foods relax the LES muscles, making it easier for your stomachâ€™s contents to reflux back up (11).
Also, since fats take longer to digest than proteins and carbs, they delay gastric emptying. This means that the stomach empties its contents at a slower rate â€” an issue thatâ€™s already common among people with heartburn (12, 13).
Delayed gastric emptying has been associated with increased esophageal exposure to gastric acid and a higher volume of food available to move backward to the esophagus. These factors would make heartburn worse (14).
If you donâ€™t want to give up drinking milk, you can go for a reduced-fat option. This can contain 0â€“2.5 grams of fat, depending on whether itâ€™s skimmed or low- fat (4, 15).
Milkâ€™s fat content may make heartburn worse, as it relaxes the LES and delays gastric emptying.
Are substitutes better?
Everybody is different, and drinking milk may or may not worsen your heartburn.
Some people suggest switching to goatâ€™s milk or almond milk for heartburn relief. Nevertheless, there is not enough scientific evidence to support these recommendations.
On one hand, goatâ€™s milk is associated with better digestibility than cowâ€™s milk, and studies show that it has anti-inflammatory and anti-allergic properties, which may be beneficial for your overall health (16, 17, 18).
However, itâ€™s slightly higher in fat, which may worsen your symptoms. One cup (245 ml) of goatâ€™s milk packs 11 grams of fat, compared with 8 grams for the same serving of whole cowâ€™s milk (19).
On the other hand, almond milk is believed to reduce heartburn symptoms due to its alkaline nature.
The acidity or alkalinity of a food is measured by its pH level, which can range from 0 to 14. A pH of 7 is considered neutral while everything under 6.9 is acidic, and everything over 7.1 is alkaline.
While cowâ€™s milk has a pH of 6.8, almond milk has one of 8.4. Thus, some believe that it may help neutralize stomach acids, but further research is needed to confirm this claim (20).
While these two alternatives may be better digested than cowâ€™s milk, due to the lack of scientific evidence you may need to test for yourself whether you tolerate one better than the other.
Some people suggest switching from cowâ€™s milk to a substitute to reduce heartburn. However, there is not enough research to support this recommendation.
The bottom line
Milk has its pros and cons when it comes to relieving heartburn.
While protein and calcium from skimmed milk may buffer stomach acids, full-fat milk may increase heartburn symptoms.
Nevertheless, you can give low-fat or skim a try, or even switch to a milk substitute if you feel it would suit you better.