The tomato, or solanum lycopersicum is one of the most abundant yet overlooked plant foods that have the ability to ward off disease. In 2017 alone, about 162 million tonnes of tomato were produced worldwide as they form a staple part of many diets and cuisines spanning from Asia to the Americas. Tomatoes are of particular value because of their high levels of phytochemicals. The phytochemicals which tomatoes are specifically high in are vitamin C, folic acid, potassium and carotenoids – the most important of which is lycopene. These caretonoids are essentially what give each fruit and vegetable their distinctive color which in the case of the tomato is its bright red color. Lycopene, the tomatoes’ most prominent carotenoid has demonstrated its ability to prevent the development of diseases such as cardiovascular disease, osteoporosis, diabetes, neurodegenerative disorders and most notably of late, cancer.
Carotenoids and Lycopene
Carotenoids and lycopenes work through many ways, however their primary mechanism is as anti-oxidants. Antioxidants essentially scavenge the body of harmful substances called free-radicals which cause and are precursors to numerous chronic diseases. By capturing these ‘reactive oxygen species’, lycopene inhibits further damage to DNA strands, proteins and fats that lead to the negative attributions of the ageing process. As well as its antioxidant properties lycopene also works in four other ways.
- Lycopene assists in cell communication at areas called ‘gap junctions’ – junctions which are vital for cells to know when to stop growing, something pivotal for preventing tumor and cancer development.
- Lycopene works as a regulatory agent for the endocrine system (our glands) and in this way controls hormonal and other chemical activity in the body.
- Lycopene affects the immune system in such a way that it helps rid the body of harmful substances, such as early cancer cells and invasive microorganisms.
- Lycopene also is involved in cell reproduction and thereby can prevent the development of cancer cells themselves.
Since tomato and lycopene consumption was first established as having a correlation with decreased cancer risk there have been numerous studies demonstrating such. One study involved investigating 1,806 prostate cancer cases and 12,005 controls and formulating an index by using the three most important dietary factors associated with prostate cancer. The study found that increased consumption of tomatoes (as well as other plant based foods) led to decreased risk and a general protective effect against prostate cancer.
Another well known study used men with recently diagnosed prostate tumors who were given 15mg of lycopene twice daily for three weeks before the surgical removal of the tumor. In the lycopene group, the tumors were found to be less invasive and significantly smaller than in those in the control. The tumors were also classified as being lower-grade and levels of a tumor marker called PSA or prostate specific antigen, fell in the supplemented patients whereas in the control group the figure actually rose. Other human studies have also validated this study coming up with similar results.
Breast and Cervical Cancer
Today, breast cancer is in fact the most common form of cancer affecting women and the most prevalent cause of death amongst female cancer patients. Researchers and scientists have estimated that 40% of all breast cancer cases could however be prevented merely by including more plant-based foods in ones diet. Alongside broccoli, onions, carrots, garlic, chilli peppers and various fruits, the tomato is one of the most potent in its anti-cancerous effects. One study highlighted that breast cancer cells treated with lycopene resulted in the improvement of DNA repair, reduction and deceleration of cancer cell replication and increased death of cancer cells. Lycopene has also shown to reduce the amount of oxidative stress in the breast tissue itself and also stimulating the natural anti-oxidant enzymes in this tissue.
Lycopene has also been indicated in reducing women’s risk of developing cervical cancer as well as women studies have shown that women with the highest concentrations of lycopene in their blood had a 56% reduction in chances of having persistent infection with human papillomavirus – the primary cause for cervical malignancy.
Lung and Colon Cancer
Lycopene has also proved promising in the prevention of lung cancer as lung tissue has high oxidative stress exposure when we breathe. This carotenoid has been shown to reduce DNA damage in lung cells that could otherwise lead to cancer. Another study highlighted that those individuals with the highest concentration of lycopene in their blood were 28% less likely to develop lung cancer.
Prevention of colon cancer too has been associated with lycopene intake. It has been clearly demonstrated that supplementation of lycopene 30mg/day in individuals with a family history of colon cancer decreases IGF-1 concentrations which could potentially stimulate cancer cell growth in the region. This effect through supplementation could similarly achieved by simply consuming more cooked tomatoes or tomato based products as just one glass of tomato juice (250ml) contains 25mg of lycopene!
Probably one of the most important things to note when looking to naturally increase your lycopene intake is that eating raw tomatoes is ineffective at boosting serum levels of lycopene by itself. This is simply because the fibre content of the tomato interferes with lycopene bioavailability and absorption in the human body. So, the best way of getting the most out of your tomatoes is to cook them in some way or buy them in processed form. Pasta sauces, tomato based curries, and even juicing are all excellent ideas and, in addition adding things like chilli sauces, ketchup, or more general tomato sauces to your foods will certainly bring the figure up. Some examples: 125ml (or ½ cup) of pasta sauce provides 27mg of lycopene, 2 tablespoons of chili sauce provides on average 6.7mg of lycopene and 2 tablespoons of tomato paste provides 13.8mg. On the other hand 1 medium raw tomato consumed whole will provide a mere 3.7mg of lycopene as your body will not absorb it all.
With all the research and studies conducted, it is a sure bet to say that eating more cooked tomatoes is one of the best ways of preventing disease. However remember, a plant based diet involving a vast array of fruits and vegetables is also generally superior for disease prevention. This comes as good news to all the vegetarians out there, however the most important thing to remember is that the preparation of the vegetable or fruit is what is vital in getting the benefits from it. Studies have also shown that supplementation of lycopene is also a viable method, however if you’re not keen on spending more money for something which you can buy at your local grocery store or supermarket, then start using more tomatoes in the kitchen!
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