Food · Vegetables · 茄果
Tomato
植物学上是水果 · 几乎全是水, 低热量 · 番茄红素: 反直觉地煮过 + 一点油吸收更好 · 生的赢维 C · 健康声明别夸大
Story path
- 1What is tomato · botanically a fruitWhat is tomato · botanically a fruit
- 2Macros & micros · almost all water · vitamin C / potassiumMacros & micros · almost all water · vitamin C / potassium
- 3Lycopene · cooking boosts uptakeLycopene · cooking boosts uptake
- 4Key knowledge · lycopene & health · how solidKey knowledge · lycopene & health · how solid
Chapter 1
What is tomato · botanically a fruit
What is tomato · botanically a fruit
In the kitchen tomato is a vegetable; botanically it is a fruit — it develops from the flower's ovary and holds seeds. But it is not sweet and shows up in savory dishes, so the table treats it as a vegetable (the U.S. Supreme Court actually ruled it a vegetable by use in 1893).
Varieties differ: beefsteak is juicy and good raw; roma is dense and low-water, the workhorse for paste and cans; cherry is small and sweet, often denser in carotenoids. A deeper red usually signals more lycopene — the pigment that headlines the scenes below.
Varieties differ: beefsteak is juicy and good raw; roma is dense and low-water, the workhorse for paste and cans; cherry is small and sweet, often denser in carotenoids. A deeper red usually signals more lycopene — the pigment that headlines the scenes below.
Chapter 2
Macros & micros · almost all water · vitamin C / potassium
Macros & micros · almost all water · vitamin C / potassium
Tomato is a textbook low-calorie, high-water food: raw, per 100 g about 18 kcal, over 94% water, roughly 3.9 g carbohydrate (about 1.2 g fiber), under 1 g protein, and almost no fat. It gives fullness and volume with almost no calorie cost.
Its highlights are water-soluble nutrients: vitamin C (vitamin-c, a medium tomato covers ~10-20% of the daily reference) · potassium (potassium-sodium, most diets run high in sodium and short on potassium) · folate (folate).
One honest caveat: vitamin C and folate are heat-sensitive and long cooking loses some. So raw tomato has the edge on vitamin C, while the lycopene in the next scene is the opposite, where heat helps. For one tomato, the best way to eat it is not the same for every nutrient.
Processing rewrites the table: tomato paste evaporates the water, so per 100 g its calories, sugar, and lycopene all concentrate several-fold.
Its highlights are water-soluble nutrients: vitamin C (vitamin-c, a medium tomato covers ~10-20% of the daily reference) · potassium (potassium-sodium, most diets run high in sodium and short on potassium) · folate (folate).
One honest caveat: vitamin C and folate are heat-sensitive and long cooking loses some. So raw tomato has the edge on vitamin C, while the lycopene in the next scene is the opposite, where heat helps. For one tomato, the best way to eat it is not the same for every nutrient.
Processing rewrites the table: tomato paste evaporates the water, so per 100 g its calories, sugar, and lycopene all concentrate several-fold.
Chapter 3
Lycopene · cooking boosts uptake
Lycopene · cooking boosts uptake
This is the scene to remember, and the most counterintuitive one. Lycopene is the carotenoid that makes tomato red, a strong antioxidant. The twist: cooked tomato often delivers lycopene that the body absorbs more easily than from raw.
Two reasons. First, lycopene is locked inside plant cell walls and structures, so raw it is hard to release; heat breaks the cell walls and frees it. Second, lycopene is fat-soluble, so a little oil (olive oil, a pasta sauce) markedly raises the fraction that reaches the blood.
So from a lycopene standpoint, tomato paste, canned tomato, and a cooked tomato soup often beat a slice of raw tomato for uptake. A spoon of paste packs several times the lycopene density of fresh fruit.
This doesn't mean raw tomato is bad: raw wins on vitamin C, cooked wins on lycopene, and each has its place. The classic tomato-and-egg stir-fry quietly gets it right: the oil helps lycopene, the egg supplies protein, and the heat releases lycopene.
Two reasons. First, lycopene is locked inside plant cell walls and structures, so raw it is hard to release; heat breaks the cell walls and frees it. Second, lycopene is fat-soluble, so a little oil (olive oil, a pasta sauce) markedly raises the fraction that reaches the blood.
So from a lycopene standpoint, tomato paste, canned tomato, and a cooked tomato soup often beat a slice of raw tomato for uptake. A spoon of paste packs several times the lycopene density of fresh fruit.
This doesn't mean raw tomato is bad: raw wins on vitamin C, cooked wins on lycopene, and each has its place. The classic tomato-and-egg stir-fry quietly gets it right: the oil helps lycopene, the egg supplies protein, and the heat releases lycopene.
Chapter 4
Key knowledge · lycopene & health · how solid
Key knowledge · lycopene & health · how solid
You've probably heard tomato 'prevents prostate cancer' or 'protects the heart'. This scene says it plainly: there is some evidence in these directions, but nowhere near solid enough to claim tomato prevents disease, and we won't overstate it.
On prostate, some observational studies find people who eat more tomato and have higher blood lycopene have slightly lower risk; but observational studies show association, not proof that lycopene itself is responsible. Controlled trials using purified lycopene supplements have given inconsistent results. After reviewing the evidence the U.S. FDA allowed only a very limited, heavily qualified claim — which itself signals the evidence is weak.
Cardiovascular is similar: diets rich in tomato and lycopene (often healthier diets overall) track with lower cardiovascular risk, but it's hard to assign the credit to lycopene alone.
The reasonable takeaway: treating tomato as a fine everyday part of a healthy diet makes sense; relying on lycopene supplements to prevent cancer or heart disease is not supported. General education only, not medical advice.
On prostate, some observational studies find people who eat more tomato and have higher blood lycopene have slightly lower risk; but observational studies show association, not proof that lycopene itself is responsible. Controlled trials using purified lycopene supplements have given inconsistent results. After reviewing the evidence the U.S. FDA allowed only a very limited, heavily qualified claim — which itself signals the evidence is weak.
Cardiovascular is similar: diets rich in tomato and lycopene (often healthier diets overall) track with lower cardiovascular risk, but it's hard to assign the credit to lycopene alone.
The reasonable takeaway: treating tomato as a fine everyday part of a healthy diet makes sense; relying on lycopene supplements to prevent cancer or heart disease is not supported. General education only, not medical advice.