3. Garlic and onion
Garlic and onion both have sulfur-containing compounds, too. “When you chew them, the sulfur compounds release gas that mixes with bacteria in your mouth that also expels gas, leading to bad breath,” Oliver says. Unfortunately, that smell can linger. “As digestion occurs, their byproducts are absorbed into the bloodstream and carried to the lungs to be exhaled via breath,” Dresser says.