The 21 foods you should eat (at least) twice a week

Sweet potato is good for the immune system

It doesn’t take much to make your diet a little healthier. Some store cupboard standbys and foods that you already have in your fridge are surprisingly nutritious — and they don’t require any special preparation or effort. Here the food expert Ian Marber explains what you should be eating more of, and why.

Oats

Fibre is an often overlooked but essential part of a healthy diet and most of us still don’t get anywhere near the 30g a day we need. Eating 100g of oats provides you with about 11g of fibre, the benefits of which range from enhancing the number and variety of beneficial gut bacteria to helping to reduce the risk of bowel cancer. In addition, oats contain a specific type of soluble fibre called beta glucan, known to bind to cholesterol in the gut and prevent it from being reabsorbed. Just 3g of beta glucan daily can reduce overall cholesterol by 5-10 per cent in six weeks and can be achieved with a small bowl of porridge or three oatcakes.

Sweet potato

The orange flesh of the sweet potato is a good source of beta carotene, which is converted into vitamin A in the body. This is needed for the production of antibodies, contributing to a healthy immune system.

Sweet potato is also rich in potassium (as are white potatoes, but these only have negligible amounts of beta carotene). Together with sodium, potassium maintains the fluid levels in and around cells, which can be disturbed by excess sodium in the diet, contributing to a rise in blood pressure. A diet rich in potassium can offset this to some degree and also support kidney function. Potassium is also involved in regulating muscle contractions including the beating of the heart muscle.

Sardines are a rich source of calcium

Sardines

Sardines are a rich source of omega-3 fats, which have anti-inflammatory properties and can reduce blood pressure and raised cholesterol. They are also an important source of calcium, which we need for strong bones and to help the blood to clot normally. Eating 100g of tinned sardines provides 400mg of calcium — about half of the recommended daily intake — as well as 75 per cent of the daily requirement of vitamin D.

Pumpkin seeds

These small green seeds contain several minerals, notably magnesium, which is as important as calcium in maintaining bone density and reducing the risk of osteoporosis. They also contain vitamin E, which has antioxidant properties and supports the production of immune cells that fight infections. Vitamin E is stored in the liver and fat cells, and so on average, an adult male needs some 4mg from the diet daily, 3mg for a woman. A 30g serving of pumpkin seeds offers about 1mg as well as 20 per cent of your daily magnesium requirements.

Strawberries

Berries are rich in vitamin C, which is involved in fighting infection and making connective tissue. The body doesn’t store vitamin C, so it needs a regular supply of at least 80mg daily, which you can get from eating just eight large strawberries or one green pepper.

Brown rice

Unlike white rice, brown rice has only the outermost layer removed, which means that it has significantly higher levels of the vitamins B1, B3 and B6, which would otherwise be stripped away. The various B vitamins work together in the breakdown of carbohydrates, proteins and fats into energy. Brown rice is also rich in manganese, a mineral that helps to maintain bone density and aid effective wound healing. We only need 2mg of manganese daily and 100g of cooked brown rice provides more than half of this.

Seaweed

Iodine is perhaps best known for its role in the production of thyroid hormones, which help to regulate the body’s metabolic rate. Iodine is found in some vegetables, but levels can be inconsistent and dependent on the concentration of the mineral in the soil, whereas it is guaranteed in vegetation that grows in the sea. We only need trace amounts of 1.4mcg a day, which is easily found in 1g of dried seaweed.

Chia seeds are high in antioxidants

Chia seeds

The seeds can be black, brown or white, and although the nutritional value is more or less the same, the darker seeds have a slightly higher concentration of antioxidants. One serving of chia seeds — that’s about 15g or a level tablespoon — contains 75mg of calcium, 43mg of magnesium and 75mg of potassium. That may not seem like a huge amount but it’s a lot for a relatively small amount of food. Chia contains several antioxidant nutrients including quercetin, caffeic acid and chloregenic acid, giving these tiny seeds an impressively high ranking on the ORAC (oxygen radical absorbance capacity) scale, which ranks foods according to their antioxidant capacity. Chia comes in at 10,000 per 100g compared with blueberries at 9,000.

Brazil nuts

Just one Brazil nut supplies more than the 55mcg daily requirement of selenium, a mineral that is required for the creation of glutathione, a powerful antioxidant found in every cell in the body. Selenium supports the functioning of the immune system and helps with cell turnover.

Walnuts

Walnuts are unusual in that they are the only tree nuts that contain alpha-linolenic acid, or ALA, a plant-based type of omega-3 fat suitable for vegans and vegetarians who don’t eat oily fish. There is good evidence to suggest that eating walnuts may enhance cognitive function and play a role in protecting the brain from symptoms of depression and degenerative disease such as dementia. A typical portion would be 30g of walnuts a day (about ten nuts).

Plain popcorn is high in fibre

Popcorn

Not the type that’s covered in salt or sugar, but plain air-popped corn is a surprisingly good food, especially when compared with alternatives such as crisps. A 100g portion contains 15g of fibre, half of the recommended daily intake and only 387 calories. Popcorn also offers a little protein along with iron, magnesium, zinc and manganese. Like other wholegrains, popcorn contains B vitamins, making it an overall good choice for a snack.

Pak choi

Belonging to the same family as broccoli, kale and cauliflower, pak choi is a good source of indole-3-carbinol and sulforaphane, natural plant chemicals that may reduce the risk of some forms of cancer as they can inhibit the proliferation of mutant cells. Pak choi is also a good source of vitamin K, which is required for normal blood clotting, and 100g supplies more than half of daily requirements.

Shiitake mushrooms

The importance of vitamin D cannot be overstated, yet even now it is often lacking in the diet, so much so that the NHS suggests adults and children alike should consider taking a supplement of 10mcg daily. Vitamin D encourages calcium absorption and so is important for strong bones. It is only found in a handful of foods, most of which are animal-sourced, but shiitake mushrooms are a rare plant-based source. While 100mg shiitake mushrooms contain only 0.5mcg, the concentration of the vitamin increases if they are exposed to direct sunlight for 20 minutes before eating (this can be up to an eight-fold increase in strong sunlight).

Quinoa can boost energy

Quinoa

A 100g serving of quinoa contains 4.4g of protein but unlike most other grains it is termed a “complete” protein, which means it is comparable to the proteins found in animal products. This makes it useful for anyone following a plant-based diet. In addition, 100g of cooked quinoa contains 23 per cent of our daily requirement of magnesium, which we need for energy production, and about 10 per cent of our daily requirement of iron.

Tomatoes

Carotenoids are nutrients that give fruits and vegetables their red, orange or yellow colour and have antioxidant properties. There are more than 600 types, including lycopene, found in watermelon, guava and red peppers, but especially rich in tomato. The body absorbs more from cooked than raw tomato and so adding tomato sauce, paste or puree to food daily ensures a supply of easily absorbed lycopene. Carotenoids require a little fat for their absorption so are best eaten alongside any food containing fat, or with a little oil drizzled onto the vegetables. While daily requirements of carotenoids have not been established, some studies suggest 22mg daily, found in two tablespoons of tomato puree.

Kefir

Gut bacteria influence many aspects of health, ranging from the immune system to mood, and play a role in the breakdown of foods and the manufacture of nutrients in the body. Fermented foods such as kefir are a great way to get a daily dose of good bacteria. Made from milk, kefir has a slightly tart flavour and is an excellent source of several strains of Lactobacillus and Bifidobacterium. It can be made from any animal milk, although goat’s milk is commonly found in shop-bought versions. If milk isn’t for you, try any fermented foods such as sauerkraut or kimchi.

Radishes can help reduce blood pressure

Radishes

Nitrates are found in higher concentration in radishes than any other vegetable. On contact with saliva these naturally occurring plant chemicals are converted into nitrites, a compound containing nitric oxide that helps expand blood vessels, thus allowing blood to flow more easily, easing blood pressure. Radishes also contain glucosinolates — the plant compound responsible for their sharp, peppery flavour — that break down in the stomach to form indole-3-carbinol, which may offer a small degree of protection against breast and prostate cancer. We tend to eat radishes raw, sliced into a salad, but in France they are often enjoyed on toast with a little butter and salt.

Wholemeal bread

A slice of wholemeal bread — even plain old supermarket sliced — has some 2g of fibre as well as a variety of B vitamins, a little protein, magnesium and iron. Bread also has the advantage of being nutritionally very good value for money.

Lentils

Like all beans and pulses, lentils are a good source of fibre and 100g of cooked lentils contains 8g. Lentils also offer calcium, iron and manganese and are surprisingly rich in plant-based protein, with 9g per 100g cooked lentils. They are rich in folate, a B vitamin that, along with vitamin B6, helps to metabolise the amino acid homocysteine, which, if it builds up too much, is linked to cardiovascular disease.

Tea

A lot of emphasis has been placed on the health benefits of green tea in recent years, and with good reason, as it contains various types of catechins, flavanols that may halt the progression of a protein found in cancerous cells.

Catechins are also found in white and oolong tea, but regular black tea is a source of different flavanols, namely quercetin and kaempferol, which exhibit mild anti-inflammatory properties. Advice varies on how much to drink a day, but since the average cup of tea contains 20mg of caffeine and the maximum safe daily intake is 300mg, fewer than ten cups a day is sensible.

Pineapple

Pineapple is a rare dietary source of bromelain, a phytonutrient that can help to reduce excess levels of mucus in the nose and throat, which can lead to congestion and breathing problems. Bromelain has anti-inflammatory effects and may help recovery time from injuries and aches.

Pineapple is also a rich source of manganese, which is used in the metabolism of glucose and fat into energy. One thick slice of pineapple contains 40 per cent of our daily requirement.

References

Ian MarberFriday September 02 2022, 12.00pm, The Times