Nutritionist Lao Gu points out that watermelons have a high water content and lack lipids, making it difficult for the body to absorb lycopene; tomatoes, on the other hand, can have their lycopene absorption rate improved by heating or crushing, making the nutrients easier to utilize.

Watermelon also contains lycopene, but why do health studies almost exclusively focus on tomatoes? Nutritionist Lao Gu shares that clinical studies show that most research related to cardiovascular health, prostate health, or antioxidant indicators uses tomatoes, not watermelon, as the source of lycopene. This is because watermelon has a high water content and lacks lipids, making lycopene difficult for the body to absorb. Tomatoes, on the other hand, can have their lycopene absorption rate improved by heating or crushing, making the nutrients more readily utilized.

Lao Gu shared this in a post on his Facebook page, “Lao Gu Nutrition and Science,” explaining that this isn’t because watermelon is bad, but rather because the “absorption efficiency” of the two is vastly different! Watermelon does contain a considerable amount of lycopene and naturally possesses a more easily absorbed cis form. However, watermelon is almost entirely composed of water and lacks the lipids needed to absorb fat-soluble phytochemicals, as well as other phytochemicals that aid in absorption. Without lipids, lycopene struggles to form absorbable microparticles in the intestines.

Mr. Gu further explained that, in other words, while watermelon has a superior natural lycopene content and structure, the amount actually absorbed into the bloodstream and utilized by the body is limited. In contrast, tomatoes have the advantage of “processability” and “synergistic effects.” Heating or crushing can convert all-trans lycopene into the more easily absorbed cis form; the absorption rate of cooked tomatoes can increase by 2-4 times.

At the same time, tomatoes also contain polyphenols, flavonoids, and other carotenoids, which can promote absorption and create “overall food benefits,” something that single lycopene supplements or watermelon cannot easily replace. In recent years, health research results have indeed consistently shown that tomatoes are the primary source of lycopene. This is perhaps because they provide stable, culinary options and possess the necessary conditions to support phytochemicals. Combined, these factors make them easier for the body to absorb and exert their nutritional benefits.

Mr. Gu added that this certainly doesn’t mean watermelon is bad; it’s just that it’s not the main player in this “lycopene absorption rate race,” nothing more.