Tomato: benefits, lycopene and how to make the most of it

What does tomato provide?

Per 100 g, raw tomato provides 19 kcal, 93.9 g of water, 3.5 g of carbohydrates and 1.1 g of fibre [1]. According to the Spanish Food Composition Database, it also contains 236 mg of potassium and 19 mg of vitamin C [1].

Botanically, it is a fruit because it grows from a flower and contains seeds. In cooking, it works as a vegetable because it is less sweet than dessert fruit. This means it contributes to the recommended three daily servings of vegetables [3]. A medium tomato in a salad already makes up a good part of one serving.

It does not provide as much vitamin C as an orange. Even so, because it is eaten often and usually raw, its contribution adds up over the week.

Its red colour comes from lycopene, a pigment in the carotenoid family, which gives colour to many fruits and vegetables. It acts as an antioxidant, meaning it helps slow one type of cell damage. Watermelon, pink grapefruit and papaya also contain it.

Does cooked tomato contain more lycopene?

In practice, lycopene in cooked tomato is absorbed more easily than lycopene in raw tomato [2]. Heat and chopping break down the tomato’s cell walls and release the pigment. Excessive heating can degrade some of it, so a gently cooked sofrito or sauce is enough [2].

Lycopene dissolves in fat. That is why it is absorbed better when a dish contains some oil [2]. Any fat will do for this purpose; at home, we use extra virgin olive oil because it is the fat we recommend for cooking and dressing food.

Raw tomato counts too. You also absorb lycopene from a salad dressed with oil, and retain more vitamin C, some of which is lost with heat.

What about prostate cancer?

This is one of the questions people ask most often about tomatoes. Some observational studies, which look at what people eat and which illnesses develop later, find lower rates of prostate cancer among those who consume more lycopene [4]. This type of study does not prove that tomato is the cause.

The World Cancer Research Fund, which reviews all the available evidence, downgraded this association in 2018 to “limited, no conclusion” [5]. Tomato is a good everyday food, but no food replaces the check-ups recommended by your doctor.

Can tomato cause problems if you have reflux or gastritis?

For some people, yes. Tomato is acidic and, for people with reflux, it may increase heartburn, especially in concentrated sauces or at dinner. That is why it appears among the foods the US reflux guideline suggests avoiding if they worsen symptoms [6]. The same guideline acknowledges that the evidence supporting this list is limited [6].

In practice, you can try it and see. If tomato gives you heartburn, leave it out for one or two weeks and then try it again. If you suspect other foods, reintroduce them one at a time. If the heartburn returns, try a smaller amount or avoid having it at dinner. If it does not bother you, there is no reason to remove it. Avoiding it as a precaution means missing out on a nutritious and versatile food.

If you have frequent heartburn or diagnosed gastritis, you can find the full guidance in our reflux diet guide.

Fried tomato and jarred sauces: how to choose

Many fried tomato products and jarred sauces contain added sugar and salt. You do not need to avoid them, but it is worth choosing by checking the label. European regulations require ingredients to be listed in descending order by weight and sugars and salt to be declared per 100 g [7]. This lets you compare two jars in the supermarket aisle.

• Check the order of the ingredients. Tomato should come first; ideally, sugar should not be listed.
• Compare sugars per 100 g. If choosing between two jars, pick the one with less.
• Compare salt per 100 g too. Prepared sauces can contain quite a lot.
• Choose plain chopped tomatoes. They contain tomato and little else, so you can season them yourself.

Sugar added by the manufacturer counts as free sugar. It is advisable to keep free sugars below 10% of daily energy intake, with 5% as a desirable target [8]. Homemade sofrito made with chopped tomatoes, onion and oil can replace a jarred version, and you can freeze it in portions.

Which tomato to choose for each dish

Tomatoes grown outdoors are in season from June to September, when they have the most flavour. For the rest of the year, greenhouse and canned tomatoes are good alternatives. Each variety works better in certain preparations.

• For salads, use oxheart, pink or Raf tomatoes, sliced and dressed with oil.
• For sauces and sofrito, use pear tomatoes, which are fleshy and contain little water.
• For spreading on bread, use hanging tomatoes, which are very juicy.
• For snacking or taking with you, use cherry tomatoes, whole and uncut.
• For the pantry, choose chopped or whole canned tomatoes.

Two simple tomato recipes

The quantities are for one serving. Both use homemade sofrito, which you can prepare in advance.

Spiral pasta with tomato and herbs

• 60–80 g dry spiral pasta, preferably wholemeal
• Homemade tomato sofrito, to taste
• 1 teaspoon aromatic herbs (parsley, tarragon, chives, chervil)

Cook the pasta according to the packet instructions. Heat the sofrito in a frying pan, add the drained pasta and finish with the herbs. Serve with a salad and a source of protein, such as egg, pulses or fish.

Cod in tomato sauce

• 1 fresh or desalted cod loin
• Homemade tomato and onion sofrito
• 1 tablespoon extra virgin olive oil
• Oregano

Heat the oil in a frying pan, add the sofrito and cook for about 3 minutes. Add the cod loin skin-side down and cook over a low heat. Cover it with more sauce and, once cooked through, finish with oregano. Leave it to rest for a few minutes before serving.

If you are looking for ways to spread tomato and other vegetables across the week, this healthy weekly menu that is easy to prepare includes a shopping list.

What we hear about tomatoes in consultations

Three ideas come up often, and all three are easy to address.

“Fried tomato makes you gain weight.” Homemade fried tomato is tomato cooked with oil, and the oil is what adds calories. A tablespoon in the dish is enough to help absorb lycopene [2], so there is no need for the sauce to be swimming in oil.

“Only raw tomato counts, because cooking destroys the vitamins.” Cooking reduces some vitamin C, but makes lycopene more available [2]. Alternating raw and cooked tomato lets you get the benefits of both.

“Canned tomatoes are less nutritious.” Canned chopped tomatoes are cooked and retain their lycopene [2]. What varies from one jar to another is the amount of added salt and sugar.