Tomatoes - The Cancer Fighting Ingredient in Your Kitchen

Lycopene? Antioxidants? Cancer fighting compounds? Yep– all that is actually hiding in your marinara! But what do these terms actually mean? They aren’t just nutrition buzzwords, but important biomolecules that can have measurable effects on your body. Tomatoes are not only refreshing snacks, but they can help give your body a powerful cellular boost. In this post, we’ll explore the science behind lycopene’s incredible benefits and share delicious recipes that help take advantage of the superpowers hiding in your caprese. 

While you may think of tomatoes as a vegetable, they are scientifically defined as fruits, because they develop from a flower and have seeds. But in the kitchen, they are commonly treated as a vegetable because they are savory, not sweet (Metri, n.d.). The flavor of tomatoes can also differ across tomato breeds. For example, beefsteak tomatoes tend to be very juicy due to their 95% water content. In comparison, the roma tomato is much smaller, and is only 70% water (Zhang et al., 2023). Depending on the dish, the type of tomato you choose can have significant effects on the flavors. 

ANATOMY

The anatomy of a tomato is also very important to the overall flavor. The exocarp is the taut outer skin of the tomato, mostly made of cutin (a protective, waterproof, substance). As the fruit continues to grow, antioxidants increase in the exocarp. The mesocarp is the middle layer of the tomato, containing the tomato’s plumbing system that connects to the plant’s stem. This is how the plant moves water around the tomato. The endocarp is the inner layer responsible for the structure of the fruit. The shape of the endocarp is what determines how the fruit continues to grow inside. And what about those pesky seeds? The seeds are held in small chambers called locules. The number of chambers varies based on the type of tomato and overall shape (Nezhdanova et al., 2021). Each of these factors is crucial in order to grow a healthy, delicious tomato. Without the exocarp, the nutrients in the plant would be significantly depleted. Without the mesocarp, that juicy flavor we all love wouldn’t be possible, since the fruit wouldn’t get any water. And without the endocarp, the tomato’s structural integrity would be compromised. 

But how does lycopene play into all of this? What even is lycopene? Lycopene is a carotenoid– a type of antioxidant–  responsible for giving most tomatoes their rich red color (WebMD, n.d.). While it might sound like just another scientific term, lycopene plays a surprisingly powerful role in protecting your health in three key ways. 

Firstly, it’s shown to help reduce cancer risk by acting at the cellular level, halting unhealthy cells from multiplying. Let’s break it down. Lycopene plays a key role in the cell cycle, the process by which cells grow and divide. The cell cycle consists of four major phases: the growth phase, the synthesis phase, another growth phase, and mitosis (where the cell finally splits). The first growth phase, also referred to as G1, is where the cell carries out its normal functions and prepares for DNA replication (Alberts et al., 2002). Lycopene helps induce cell cycle arrest, which is a process that prevents cells from growing and replicating. Since cancer is caused by cells dividing uncontrollably, preventing this proliferation early helps to catch cancer cells before they grow into tumors (Trejo-Solís et al., 2013).

Think of it as a TSA officer at the airport. The body naturally has “checkpoints” to move from one phase to the next, like a baggage scanner. But the scanner can’t always catch everything, so the TSA officers act as added security. Lycopene decreases the number of proteins that move cells from one phase to the next, slowing cell cycle progression. And while we all hate standing in the security line, that added layer of security is what keeps harmful cells from slipping through.  In addition, lycopene increases proteins that promote apoptosis, which is a cell’s internal “self-destruct” feature. But why doesn’t it kill normal, healthy cells? Good question. Lycopene primarily targets cancer cells or damaged cells, as they tend to have imbalances that make them more sensitive to the apoptosis signal. In doing so, unhealthy cells die, while your regular, healthy cells continue to thrive (Trejo-Solís et al., 2013). 

Lycopene also acts as an anticancer compound by depriving malignant cells of the blood and nutrients they need to proliferate. Angiogenesis refers to the process by which new blood vessels form. This is a key step in cancer growth, as malignant tumors hijack the body, forcing it to build new vessels and provide the tumor with its own direct blood supply. Tumors need their own blood supply to grow and spread, in turn causing more damage (Cleveland Clinic, n.d.). Lycopene blocks the angiogenesis signal by reducing VEGF levels, which is a protein that stimulates blood vessel formation. By blocking angiogenesis, lycopene basically starves tumors of their blood supply, limiting their ability to grow and spread. But here’s the cool part: it only targets the abnormal blood vessel growth that occurs in tumors, not the growth that our bodies need. It acts with precision without interfering with the body’s normal processes (Trejo-Solís et al., 2013).

But that’s not all.  Lycopene is also a powerful antioxidant that can protect our bodies from cardiovascular disease. While many know that cancer is a leading cause of death, you might not know that cardiovascular disease is as well  (Przybylska & Tokarczyk, 2022). In some countries, heart disease causes more deaths than cancer (Center for Disease Control and Prevention, n.d.). But why are heart problems so prevalent in our modern era? Increased oxidative stress can greatly affect cardiovascular health and plays a role in heart attacks and heart failure (Przybylska & Tokarczyk, 2022). Oxidative stress is caused when there are too many free radicals and not enough antioxidants to combat them. Free radicals are unstable compounds because they have an uneven number of electrons. Registered dietitian Anthony DiMarino, RD, says “Free radicals are missing an electron from their outer shell. That makes them unstable, so they go and steal an electron from the molecules in your skin cells, or from your blood cells or from wherever they can. That causes damage to surrounding cells” (Cleveland Clinic, 2022).

Antioxidants can help neutralize free radicals and prevent oxidative stress. Antioxidants are also unstable compounds, but unlike free radicals, they don’t take electrons from other cells. Instead, antioxidants neutralize these unstable compounds by benevolently giving up their own electrons, stabilizing both the free radicals and themselves. So why can’t we prevent free radicals from entering our body all together, therefore escaping oxidative stress? While free radicals can’t be avoided altogether, there are certain factors that have been proven to increase the amount of free radicals in the body. External pollution, smoking, excessive alcohol use and stress have been proven to increase the number of free radicals (Harvard Health Publishing, 2019).

While you can’t completely circumvent oxidative stress, it can be minimized by incorporating antioxidant-rich fruits and vegetables into your diet. Luckily, tomatoes are super rich in antioxidants, like lycopene (Cleveland Clinic, 2024). Lycopene is known to be one of the strongest antioxidants found in food, due to its molecular structure. Lycopene acts on free radicals like singlet oxygen (a highly reactive oxygen molecule), hydrogen peroxide, nitrogen dioxide, and others. But lycopene doesn’t just fight damage directly; it helps regenerate other antioxidants like vitamin C and E, turning them into an active form so they can continue their work on free radicals (Przybylska & Tokarczyk, 2022). So when you eat tomatoes, you’re not just getting a burst of flavor– you’re fueling your body’s defense system with one of nature’s most powerful antioxidants.

Now that we’ve unpeeled the science behind tomatoes, let's wrap it up. Tomatoes are more than just a summer staple– they’re packed with lycopene, a powerful compound that fights cancer and cardiovascular disease. Lycopene acts like a cellular security guard, halting the cell cycle to prevent cancer cells from multiplying. It also induces apoptosis, thus activating unhealthy cells’ internal “self destruct mode.” To prevent tumor growth, lycopene sends out an anti-angiogenesis signal that prevents tumors from acquiring their own blood supply, in turn starving the tumor of blood. And it’s role as a powerful antioxidant helps clear free radicals and regenerate other antioxidants to continue combating these unhealthy compounds. Beyond the health benefits, tomatoes are packed with a rich and juicy flavor thanks to their unique structure. Whether it’s the juicy mesocarp or protective exocarp, each part plays a role in the taste of your tomato. 

Phew! That was a lot, and I’m getting hungry. And now that we’ve learned how lycopene makes tomatoes a healthy and nutritious ingredient, let’s head to the kitchen and turn all this science into something that fits on my fork.