Nutrafiles Consultant Abdul Qudoos discusses the attributes that make the tomato a first-class addition to any diet.

Tomato – The wonder berry

The tomato is technically classified as a berry, a subset of fruit, but it is considered a vegetable for culinary purposes because of its savoury flavour.

They were first cultivated in 700AD by Aztecs and Incas. French botanist Joseph Pitton de Tournefort provided the Latin botanical name, Lycopersicon esculentum, which translates to ‘wolfpeach’. The English word ‘tomato’ comes from the Spanish ‘tomate’. Native versions were small, like cherry tomatoes, and most likely yellow rather than red.

The high acidic content of the tomato makes it a prime candidate for canning, which is one of the main reasons it was canned more than any other fruit or vegetable by the end of the 19th century.

The tomato is also an excellent source of vitamin C (one medium tomato provides 40% of the RDA) and a good source of vitamin A (20% of the RDA). In addition, tomatoes are a very good source of fibre, which has been shown to reduce cholesterol, keep blood sugar levels low and help prevent colon cancer.

"The tomato is also an excellent source of vitamin C."

The fruit is rich in lycopene, a carotenoid that gives tomatoes their red colour. A powerful natural antioxidant, lycopene has been shown in epidemiological and experimental studies to protect against prostate cancer, breast cancer, atherosclerosis, and associated coronary artery disease. It reduces low-density lipoprotein oxidation and helps reduce cholesterol levels in the blood. In addition, preliminary research suggests lycopene may reduce the risk of macular degenerative disease, serum lipid oxidation, and cancers of the lung, bladder, cervix and skin. Lycopene has also been shown to improve the skin’s ability to protect against harmful UV rays.

Tomatoes and tomato sauces and puree are said to help lower urinary tract symptoms (benign prostatic hyperplasia) and may have anticancer properties.

Consuming tomatoes with a small amount of fat enables lycopene to be better absorbed. However, cooked tomatoes actually have higher concentrations of lycopene than raw one. Processed tomatoes, such as tomato paste, puree, sauce, ketchup, etc. contain more lycopene because cooking breaks down cell walls, releasing and concentrating carotenoids.

"Tomatoes and tomato sauces and puree are said to help lower urinary tract symptoms."

Under different food processing conditions, lycopene undergoes degradation via isomerisation and oxidation, which impact its bioactivity and reduce the functionality for health benefits. The degradation reactions of lycopene are influenced by factors such as reaction medium, temperature, physical state and environmental conditions. The most important factors during processing are heat, light and oxygen. When storing tomatoes, it is best not to refrigerate them as this will break down their natural flavours.

According to Dr. Edward Giovannucci, Harvard School of Public Health, Cambridge, Massachusetts: "A review of 72 different studies showed consistently that the more tomatoes and tomato products people eat, the lower their risks of many different kinds of cancer. The secret may lie in lycopene, the chemical that makes tomatoes red."

Among the studies he reviewed, 57 showed that the more tomatoes one ate, the lower the risk of cancer. "The evidence for benefit was strongest for cancers of the prostate, lung and stomach," Giovannucci reported.

"Eating tomatoes, especially cooked tomatoes, provides protection against prostate cancer."

"A meta-analysis of 21 studies published in Cancer Epidemiology Biomarkers and Prevention confirms that eating tomatoes, especially cooked tomatoes, provides protection against prostate cancer. When the data from all 21 studies was combined, men who ate the highest amounts of raw tomatoes were found to have an 11% reduction in risk for prostate cancer. Those eating the most cooked tomato products fared even better with a 19% reduction in prostate cancer risk.

"Research showing tomatoes’ cardiovascular benefit continues to accumulate. A study led by Dr. Howard Sesso and published in the American Journal of Clinical Nutrition further supports Dr. Sesso’s earlier studies, reported in the Journal of Nutrition, which found that women with the highest intake of lycopene-rich tomato-based foods had a significantly reduced risk of heart disease. This 4.8-year study, found that as the women’s blood levels of lycopene went up, their risk for cardiovascular disease dropped."