The food we eat influences the scent we naturally emit. Many people notice a shift in their personal odor after consuming certain meals, leading to speculation about which dietary components are responsible. This common observation highlights a biological reality: the body processes everything ingested, and the breakdown products of various foods often affect an individual’s scent signature. Understanding this diet-odor relationship requires looking closely at how the human metabolic system handles specific chemical compounds found in everyday ingredients.
Addressing the Specific Claim About Tomatoes
The claim that tomatoes cause unpleasant body odor is supported by a proposed mechanism in scientific literature. A study suggested a direct link between consuming tomatoes and the development of underarm odor. The proposed culprit is a group of compounds called terpenes, which are present in high concentrations in tomatoes, particularly in their skins and the antioxidant lycopene.
After consumption, these terpenes are metabolized and excreted through the apocrine glands, which are the sweat glands located primarily in the armpits. These glands produce a fatty secretion that is naturally odorless until it interacts with bacteria on the skin surface. The presence of these excreted terpenes may enhance or alter the resulting odor, potentially making it more noticeable.
How Dietary Compounds Influence Body Odor
The influence of diet on smell begins with digestion, where food is broken down into smaller, absorbable molecules. The body’s ability to fully metabolize these molecules determines whether they are used for energy or excreted. When the body cannot fully process certain compounds, they are released as volatile organic compounds (VOCs) through breath, urine, and sweat.
This excretion route is relevant for body odor when VOCs are released through the skin’s apocrine glands. Bacteria on the skin’s surface consume these compounds, chemically converting them into smaller, pungent molecules. For example, odorless secretions can be converted into short-chain fatty acids like isovaleric acid, known for its strong, cheesy or sweaty smell.
The liver plays a significant role in this process, as it breaks down many foreign or difficult-to-process compounds. If the liver’s metabolic capacity is overwhelmed, or if an individual lacks the specific enzymes needed, the compound is more likely to be excreted through the breath and sweat. Highly odorous compounds often contain sulfur, which the body must convert into less odorous forms before disposal. When this conversion is incomplete, volatile sulfur compounds are released, contributing a strong, often rotten or garlicky smell.
Other Foods Known to Alter Personal Scent
Foods containing chemical components that readily convert into odorous VOCs are known to alter personal scent. Allium vegetables, including garlic and onions, are primary examples due to their high concentration of sulfur compounds. These sulfur-rich molecules are absorbed into the bloodstream and released through the lungs and skin, causing both bad breath and a distinct body scent.
Cruciferous vegetables, such as cabbage, broccoli, and cauliflower, also contain sulfur-containing glucosinolates. When digested, these compounds break down into volatile, sulfurous metabolites that are easily secreted through sweat. Similarly, spices like curry and fenugreek contain potent aromatic terpenes that are absorbed and excreted through the sweat glands, leading to a noticeable change in smell that can linger for days.
Red meat is associated with a less pleasant body odor profile, though the mechanism differs. The body takes longer to digest red meat compared to plant-based foods. This extended digestive time leaves residues in the gut that are acted upon by intestinal bacteria, which produce compounds contributing to a more intense scent released through the skin.