Whole milk may worsen symptoms of heartburn in some people. The calcium and protein content, minus the fat, in skim milk may offer relief to some.

Heartburn, also called acid reflux, is a common symptom of gastroesophageal reflux disease (GERD), which affects about 20% of the U.S. population.

It happens when your stomach’s contents, including gastric acid, move back up to your esophagus, giving you a burning feeling in your chest.

Some people claim that cow’s milk is a natural remedy for heartburn, while others say it worsens the condition.

There is some evidence showing that milk‘s calcium and protein content may help relieve heartburn.

Calcium may offer some benefits

Calcium carbonate is frequently used as a calcium supplement and as an antacid due to its acid-neutralizing effect.

One cup (245 ml) of cow’s milk provides 21–23% of the Daily Value (DV) for calcium, depending on whether it’s whole or low fat.

Because of its high calcium content, some claim that it’s a natural heartburn remedy.

In fact, a 2019 study of 11,690 people determined that a high intake of dietary calcium was associated with a reduced risk of reflux in men.

Calcium is also an essential mineral for muscle tone.

People with GERD tend to have a weakened lower esophageal sphincter (LES), the muscle that usually prevents your stomach’s contents from coming back up.

A 2004 study of 18 people with heartburn found that taking calcium carbonate increased 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.

Protein may be helpful

Milk is also an excellent source of protein, providing about 8 grams per 1 cup (245 ml).

A 2017 study of 217 people with heartburn found that those who consumed more protein during an evening snack were less likely to have symptoms.

Researchers believe protein may help treat heartburn because it stimulates gastrin secretion.

Gastrin is a hormone that also increases LES contraction and promotes the emptying of your stomach’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.

Therefore, it’s unclear whether the protein in milk prevents or worsens heartburn.

One cup (245 ml) of whole milk packs 8 grams of fat, and research shows that fatty foods are a common trigger for heartburn.

High fat foods relax the LES muscles, making it easier for the stomach’s contents to reflux back up.

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 — an issue that’s already common among people with heartburn.

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.

If you don’t want to give up drinking milk, you can go for a reduced-fat option. This can contain 0–2.5 grams of fat, depending on whether skimmed or low fat.

Everybody is different, and drinking milk may or may not worsen your heartburn.

Some suggest switching to goat or almond milk for heartburn relief. Nevertheless, there is not enough scientific evidence to support these recommendations.

On one hand, goat’s milk may be better tolerated by people who are allergic to cow’s milk, and research suggests that it may have anti-inflammatory properties that could benefit your overall health.

However, it’s slightly higher in fat, which may worsen your symptoms. One cup (245 ml) of goat’s milk packs 10 grams of fat, compared with 8 grams for the same whole cow’s milk serving.

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, everything under 6.9 is acidic, and everything over 7.1 is alkaline.

While cow’s milk has a pH of 6.8, almond milk has one of 8.4. Thus, some believe it may help neutralize stomach acids, but further research is needed to confirm this claim.

While these two alternatives may be better digested than cow’s milk, due to the lack of scientific evidence, you may need to test whether you tolerate one better.

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 try low fat or skim or even switch to a milk substitute if you feel it suits you better.