Onions and garlic
Onions and Garlic

Dietitian, Juliette Kellow looks at a new study which showed that eating more onions and garlic lowered the risk of developing cancer.

Eat to Beat Cancer

By Dietitian, Juliette Kellow BSc RD

Onions and garlic are the perfect addition to casseroles, stews, soups and pasta dishes, but new research shows that these foods add far more to meals than just flavour.

Scientists from Italy used data from eight Italian and Swiss case-control studies to look at the effect eating onions and garlic has on the risk of developing different types of cancer. Case-control studies use people who already have a disease and look back to see if these people have any characteristics that differ from those who don’t have the disease.

The researchers found that older adults who ate the largest amounts of onions and garlic had the lowest risks of cancer as follows:

Type of cancer % reduction in cancer risk
  Onions Garlic
Oral cavity and pharynx 84 39
Oesophagus (gullet) 88 57
Bowel 56 26
Larynx 83 44
Breast 25 10
Ovaries 73 22
Prostate 71 19
Kidney cells 38 31

According to Dr Carlotta Galeone, the lead author of the study, it’s still not exactly clear whether it’s specifically onions and garlic that lower the risk of cancer, or whether it’s because onion and garlic lovers have an overall diet that protects against cancer.

The researches believe it’s a good idea to liven up meals with these veggies, in addition to including plenty of other vegetables.

WLR says…

It’s well known that including plenty of fruit and vegetables in our daily diets can help to reduce the risk of cancer – that’s one of the reasons health experts recommend eating five servings a day. Including just 80g of onion (around half a medium onion) in a dish will provide one of these five servings.

The exact way in which onions and garlic may help to reduce the risk of cancer still needs more investigation. Both are rich in sulphur-containing compounds that give them their pungent odour and may contribute to lowering the risk of cancer.

Onions are packed with plant chemicals called flavonoids, especially one called quercetin, that’s been linked to reducing heart disease. In fact, onions have been singled out as one of the few vegetables and fruits that contribute to the significant reduction of heart disease.

An analysis of seven large studies, involving more than 10,000 people, found that those people whose diets most frequently included onions, tea, apples and broccoli – the richest sources of flavonoids – had a 20 percent reduction in the risk of heart disease.

It’s worth remembering that both onions and garlic are a good choice for spicing up meals without adding too many calories or a lot of fat or salt. Garlic is virtually free from calories as it’s used in such small amounts. Meanwhile, there’s around 20 calories in one small onion, 55 calories in a medium-sized one and 86 calories in a large one.

For the best health benefits though, choose your onions carefully as different varieties contain different amounts of beneficial properties. In general, red onions contain more quercetin than white or spring onions, while spring onions are richer in other antioxidants such as lutein and zeaxanthin. The most pungent onions tend to contain more antioxidants. In other words, the more they make your eyes water, the more likely your onion is to be loaded with health-promoting nutrients!

Onion Nutrition

Onion, Raw, Average.

Percent Calories From:

Carbohydrate 76.3%
Protein 17.6%
Fat 6.1%
Alcohol 0%

Nutrition Data Per 100g

Calories (kcal) 30.6
Carbohydrate (g) 6
Sugars (g) 4.2
Protein (g) 1.3
Fat (g) 0.2
Sauturates (g) 0
Fibre (g) 1.4
Sodium (g) 0
Alcohol (g) 0
Fruit & Veg 1.3


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