A review of research published in May 2021 looked at 12 studies with more than 500,000 people who were followed for up to 25 years. It found those who ate the most plant foods were less likely to die from any cause over follow-up time periods that varied across the studies from five to 25 years, compared to those who ate the least.
Here are four versatile and tasty plant foods I have on my weekly grocery list, and the research showing why they're good for you.
Tomatoes
Tomatoes are berry fruit (not a vegetable). They're rich in vitamin C and lycopene, which is a carotenoid. Carotenoids are pigments produced by plants that give vegetables their bright colours.
A review of six trials asked people to consume tomato products equivalent to 1-1.5 large tomatoes or 1-1.5 cups of tomato juice daily for about six weeks.
The researchers found people who did this had reduced blood levels of triglycerides (a type of fat in your blood that increases heart-disease risk), as well as lower total and bad cholesterol levels, compared to those who didn't have any tomatoes. These people also had increased levels of good cholesterol.
Another review of 11 studies tested the effect of tomatoes and lycopene on blood pressure.
Researchers found consuming any tomato products led to a large decrease in systolic blood pressure (the first number that measures the pressure at which the heart pumps blood). However, there was no effect on the diastolic pressure (the second number which is the pressure in the heart when it relaxes).
In the group who had high blood pressure, to begin with, both systolic and diastolic blood pressure decreased after eating tomato products compared to placebos.
A review of studies included a total of 260,000 men and found those with the highest intakes of cooked tomatoes, tomato sauces and tomato-based foods (equivalent to around one cup per week) had a 15-20% lower risk of developing prostate cancer compared to those with the lowest tomato intakes. Keep in mind correlation doesn't necessarily mean causation, though.
Recipe tips: Keep canned tomatoes in the cupboard and add to pasta sauce, casseroles and soup. Make your own sauce by roasting tomatoes and red capsicum with a splash of olive oil and balsamic vinegar, then puree with a spoon of chilli paste or herbs of your choice. Keep in the fridge.
Pumpkin
Pumpkinis rich in beta-carotene, which is also a carotenoid (plant pigment). It gets converted into vitamin A in the body and is used in the production of antibodies that fight infection. It's also needed to maintain the integrity of cells in the eyes, skin, lungs and gut.
A review of studies that followed people over time looked at associations between what people ate, blood concentrations of beta-carotene and health outcomes.
People who had the highest intakes of foods rich in beta-carotene (such as pumpkin, carrots, sweet potato and leafy greens) had an 8-19% lower relative risk of having coronary heart disease, stroke, or dying from any cause in studies over 10 years or more compared to those with the lowest intakes.