Lycopene: Properties and Benefits

Lycopene is a fat soluble substance that belongs to the carotenoids. It is a pigment that gives the red and pink color to various vegetables and fruits. However, red color is not always due to lycopene e.g. Strawberries and cherries do not contain it and owe it to other phytochemicals (flavonoids, anthocyanins, etc.).

The most important source of lycopene are processed tomato products such as juice, puree, ketchup and spaghetti sauce because they provide the highest bioavailability. 85% of the intake comes from tomatoes but is also found in other foods such as watermelon, pink guava, pink grapefruit, papaya, sweet red peppers, peach, apricot and melon.

Antioxidant properties

Lycopene became known when research showed it to be a potent antioxidant. Studies in the test tube have found that it neutralizes certain free oxygen radicals such as the HO-, O2 · -, RO-O ·, and singlet oxygen. It has more antioxidant activity than vitamin E and glutathione. It is 10 times more potent than tocopherol [1], 100 times more than vitamin E (tocopherols and tocotrienols together), and 125 times more potent than glutathione.

The impressive properties of lycopene have led researchers to look for the potential benefits to human health. Studies in the test tube and in animals have shown that this carotenoid can protect against damage caused by pesticides, herbicides, sodium glutamate and certain types of fungi.

In addition to its antioxidant activity, lycopene can provide benefits through other mechanisms, such as cellular communication and its interference with hormonal, immune and metabolic mechanisms.

Can it protect against cancers?

Studies in the test tube show that this carotenoid can slow the growth of breast and prostate cancer [2] by limiting the growth of tumors. Observational studies have linked high carotenoid intake, including lycopene, with a 32-50% reduced risk of lung and prostate cancer. Animal studies also indicate that lycopene may inhibit the growth of kidney cancer cells. Humans have shown that its higher blood concentration is associated with a lower risk of some cancers.

The 23-year Health Professionals Follow-Up Study, which included more than 46,000 men, found that those who consumed at least two rich portions of tomato sauce a week had a 30% lower risk of developing prostate cancer than those who consumed less than one serving of tomato per month [3]. However, a review of 26 studies involving more than 550,000 people showed more moderate results. High intake was associated with a 9% lower chance of developing prostate cancer. A daily intake of 9-21 mg daily appeared to be the most beneficial [4].

A recent study in mice showed that those infected with a liver carcinogen were protected when their diet contained tomato powder. In humans, this was equivalent to eating two to three tomatoes a day or serving a tomato sauce usually placed over pasta.

Can it promote cardiovascular health?

Lycopene, as an antioxidant, can theoretically help prevent atherosclerosis by reducing LDL cholesterol oxidation. It is sure to lower LDL cholesterol. 25 ml daily can reduce ‘bad’ cholesterol by up to 10%. A decade-long study showed that diets rich in this nutrient were associated with a 17-26% lower risk of heart disease while a review found that high blood concentration resulted in a lower risk of stroke by 31% [5, 6].

The protective effects appear to be greater in individuals who have low levels of antioxidants in their blood or high levels of oxidative stress, e.g. in the elderly, smokers, diabetics and heart patients.

Can it protect against sunburn?

It seems to offer some protection from the damaging effects of the sun. In a 12-week study, daily intake of 8-16 mg of lycopene, either from foods or supplements, helped reduce the intensity of skin redness by 40-50% after exposure to UV rays.

Can it help your eyesight?

It can prevent or delay the formation of cataracts and reduce the risk of macular degeneration, the leading cause of blindness in the elderly [7].

Can it reduce the pain?

Some evidence suggests that it may be neuroprotective. It helps reduce neuropathic pain, which is caused by damage to nerves and tissues.

Can it contribute to stronger bones?

Its antioxidant action can slow down the death of bone cells and enhance bone architecture by helping to keep bones healthy. One study found that two glasses of tomato juice a day, containing 15 mg of lycopene, were sufficient to strengthen the fragile bone.

Can it help fertility?

Researchers at the University of Sheffield in a double-randomized 12-week study gave lactolycopene supplementation, which is more easily absorbed by the human body – containing 14 mg of lycopene – and found a dramatic improvement in their sperm morphology [8]. 

Does it lower blood pressure?

Eating more than 12 mg daily has been shown to lower blood pressure, especially in people with hypertension.

Depression

The more tomatoes we consume, the lower the risk of depression, according to a study by Chinese and Japanese researchers.

Foods and bioavailability

The following is a list of foods with lycopene content per 100 grams [9]. Note that the tomato content depends on the variety, geographical location, climatic conditions, cultivation method and degree of ripening. Ripe tomatoes are more concentrated than unripe.

Dried tomatoes: 45.9 mg

Tomato puree: 21.8 mg

Pink guava: 5.2 mg

Watermelon: 4.5 mg

Fresh tomato: 3.0 mg

Canned tomatoes: 2.7 mg

Papaya: 1.8 mg

Pink grapefruit: 1.1 mg

Cooked sweet peppers: 0.5 mg

Unfortunately, the human digestive tract absorbs a small amount of lycopene. A study by Plant & Food Research in collaboration with the University of Lincoln found that 75% of its total antioxidants are released from raw tomatoes but only 4% for lycopene.

The absorption by the small intestine depends on two important factors: how the tomato products are processed – especially if they are heated – and how much fat is consumed with lycopene. Heating the tomato helps release it from plant tissues while fat helps absorb it as it is a fat-soluble ingredient. Consumption of olive oil, along with foods containing carotenoids, increase their absorption. Absorption is enhanced when the tomato and its products contain the peel as well. One study found that adding avocados to tomato sauce increased the absorption of lycopene by 4.4 times, while other carotenoids were absorbed even more.

On the other hand, iron reduces absorption. When the researchers gave tomato juice with iron sulfate as a supplement, they observed a 50% reduction in absorption.

How much do we need?

There is currently no official recommended daily dosage, however, some studies show that intakes between 8-21 mg daily are the most beneficial. Other studies suggest lower daily intake, between 5-7 mg.

One question is whether there can be side effects due to high lycopene intake. Regarding intake from food, there is a small possibility to do this, given the low bioavailability. However, there could be side effects from receiving too much through dietary supplements. Supplements may not be suitable for pregnant women and those taking certain classes of medicines [10 11]. Lycopene can interact with some medicines, including blood thinners and blood pressure lowerers.

Find at Vita4you.gr a great variety of lycopene supplements.

Bibliography

1.https://www.ncbi.nlm.nih.gov/pubmed/11744404

2.https://www.ncbi.nlm.nih.gov/pubmed/12424325/

3.https://www.ncbi.nlm.nih.gov/pubmed/26817504

4.https://www.ncbi.nlm.nih.gov/pubmed/26287411

5.https://www.ncbi.nlm.nih.gov/pubmed/23317928/

6.https://www.ncbi.nlm.nih.gov/pubmed/24848940/

7.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3738980/

8.https://link.springer.com/article/10.1007/s00394-019-02091-5

9.https://www.myfooddata.com/articles/high-lycopene-foods.php

10.https://medlineplus.gov/druginfo/natural/554.html#Safety

11.https://www.ncbi.nlm.nih.gov/pubmed/19527386/