By Sam Blanchard
Chopping up spinach and putting it in a smoothie is the healthiest way to eat it, research suggests.
Cooking the leafy vegetable breaks down its antioxidants, while mixing it raw with yoghurt or milk helps to release the powerful nutrient lutein.
Boiling or frying spinach are sure-fire ways of destroying lutein, a study found.
Lutein helps lower the risk of heart attacks and prevents eye damage, previous research suggests. Reseachers from Linköping University in Sweden tested different ways of cooking supermarket-bought baby spinach to see how its nutritional content changed.
They measured the lutein levels regularly and concluded the leaves are best chopped up and consumed raw alongside dairy.
‘Best is not to heat the spinach at all,’ PhD researcher and study author Rosanna Chung said.
‘And even better is to make a smoothie and add fat from dairy products, such as cream, milk or yoghurt.’
She explained: ‘When the spinach is chopped into small pieces, more lutein is released from the leaves and the fat increases the solubility of the lutein in the fluid.’ The more lutein dissolved into a smoothie, the more it can be absorbed by the body, the scientists suggested.
Whereas cooking spinach for a long time at a high heat – such as in a lasagne or frying it – is the most damaging way to prepare the green vegetable.
A meal cooked at a lower heat, like a stew, retains more of the vitamin, with heating spinach in a microwave also potentially being a healthier option, the study suggests.
Study author Professor Lena Jonasson, from the department of medical and health sciences, said: ‘What is unique about this study is that we have used preparation methods that are often used when cooking food at home.
‘And we have compared several temperatures and heating times.
‘We have also investigated methods of preparation in which the spinach is eaten cold, such as in salads and smoothies.’
The research was published in the journal Food Chemistry.
Lutein has been shown to help reduce chronic swelling in the blood vessels of people with coronary artery disease, which can lower their risk of a heart attack.
It is also referred to as the ‘eye vitamin’ because lutein it is thought to protect against damage from sunlight.
Many also take lutein supplements in a bid to reduce their risk of heart disease, colon or breast cancers, and type 2 diabetes, according to WebMD.
Revealed: The 36 Nutrients That Help You Live Longer, How They Benefit Your Health And What To Eat To Get Them
Protects against: Blindness, certain cancers, acne and osteoporosis
Found in: Liver, fish oils, milk, eggs, and orange vegetables, such as sweet potatoes and carrots
Vitamin B1 (Thiamine)
Protects against: Nerve, muscle and heart damage
Found in: Beef, liver, nuts, oats, oranges, pork, eggs, seeds and peas
Vitamin B2 (Riboflavin)
Protects against: Cataracts, heart disease and migraines
Found in: Red meat, almonds, dairy, eggs, fish and green leafy vegetables, such as kale and spinach
Protects against: Heart disease, stroke and Alzheimer’s
Found in: Pork, poultry, fish, bread, eggs and vegetables
Protects against: Anaemia
Found in: Animals products, including meat, poultry, fish, eggs and dairy; as well as fortified cereals
Protects against: Multiple sclerosis
Found in: Egg yolks, almonds, cauliflower, cheese, mushrooms, sweet potatoes and spinach
Protects against: Heart disease, osteoporosis, anameia and scurvy
Found in: All fruit and vegetables, particularly broccoli, Brussels sprouts and cauliflower
Protects against: Liver, brain, muscle and nervous system damage
Found in: Liver, salmon, chickpeas, eggs and turkey
Protects against: Skin, heart and eye damage
Found in: Vegetable oils, nuts, seeds and green leafy vegetables
Protects against: Spina bifida in newborns when taken in early pregnancy, certain cancers and anaemia
Found in: Green leafy vegetables, citrus fruits, beans, and fortified breads and cereals
Protects against: Heart disease, brain damage and arthritis
Found in: Liver, chicken, tuna, turkey, salmon, anchovies, pork and beef
Vitamin B5 (Pantothenate)
Protects against: ADHD, arthritis, allergies, hair loss, asthma and colitis
Found in: Mushrooms, fish, avocados, eggs, chicken, beef, pork and sunflower seeds
Protects against: Bone damage, certain cancers and diabetes
Found in: Dairy, green leafy vegetables, soya beans, tofu, fish where you eat the bones; such as sardines, and fortified products; like bread and soya drinks
Protects against: Dangerous blood pressure levels and poor nerve signalling
Found in: Salt, seaweed, rye, tomatoes, lettuce, celery and olives
Protects against: Diabetes
Found in: Vegetables, whole grains, beef, poultry and dairy
Protects against: Nerve damage
Found in: Fish, nuts, cereals and green leafy vegetables
Protects against: Nerve cell damage
Found in: Shellfish, whole grains, beans, nuts, potatoes, kidneys and liver
Protects against: Bone damage and immune dysfunction
Found in: Seaweed, cod, dairy, shrimp, tuna, eggs and prunes
Protects against: Low levels of oxygen in the body
Found in: Red meat, shellfish, spinach, liver, lentils, pumpkin seeds, quinoa and turkey
Protects against: Oesophageal cancer, liver disease, yeast infections and allergies
Found in: Peas, lentils, kidney beans, nuts, soy, dairy, eggs and whole grains
Protects against: Arthritis, osteoporosis and cognitive decline
Found in: Milk, meat, beans, lentils and nuts
Protects against: Stroke, osteoporosis and kidney stones
Found in: Squash, sweet potato, yoghurt and halibut
Protects against: Muscle and nerve damage
Found in: Salt, and smoked and cured meats
Protects against: Bacterial infections and acne
Found in: Seafood, eggs, liver, kidneys, nuts and dairy
Protects against: Bleeding, immune dysfunction and thyroid problems
Found in: Seafood, meat, poultry, eggs, beans, lentils, nuts and seeds
Protects against: Heart disease, osteoporosis and cognitive decline
Found in: Parsley, spinach, grapes and eggs
Protects against: Heart disease, Alzheimer’s, stroke and certain cancers
Found in: Brazil nuts, sunflower seeds, chicken, eggs and sardines
Protects against: Rickets (known as osteomalacia in adults), certain cancers, heart disease, diabetes and cognitive decline
Found in: Sunlight and oily fish, such as salmon, sardines and mackerel
Omega-3 fatty acids
Protect against: Heart disease, Alzheimer’s, Parkinson’s, schizophrenia, bipolar and depression
Found in: Oily fish
Protects against: Cancer, particularly lung; heart disease and stroke
Found in: Fruit, vegetables, whole grains, nuts and seeds
Protects against: Cognitive decline
Found in: Liver, peanuts, red meat, poultry, fish, pasta, noodles and rice
Protects against: Heart disease, cognitive decline, diabetes and mitochondrial diseases, which can cause brain damage.
Mitochondria are the ‘energy powerhouses’ of cells
Found in: Fish and other seafood, seaweed, eggs and the dark meat of poultry
Protects against: Heart disease, and brain and eye damage
Found in: Mushrooms, meat, poultry and red kidney beans
Protects against: Diabetes, cognitive decline and general inflammation
Found in: Fruit and vegetables
Protects against: Multiple sclerosis, schizophrenia, ADHD, autism and bipolar
Found in: Tomatoes, wheat, coconut water and dairy
Carotenoids are antioxidants produced by plants. The following make up 95 per cent of those in the human body:
Alpha and beta carotene
Protect against: Blindness, cognitive decline, heart disease, various cancers, high blood pressure, hearing loss, inflammation and immune system damage
Found in: Fruit and vegetables