More people are buying this health food, which lowers bad cholesterol, is high in antioxidants and fibre and is a source of omega-3 fatty acids.
Andrea Ong reports
Walnuts are round, single-seeded stone fruits enclosed in a green, leathery, fleshy husk (left). The removal of the husk reveals a wrinkly hard shell (right). This encloses the kernel which is usually sold as shelled walnuts. — PHOTOS: REUTERS, ST FILE
Singaporeans are discovering the goodness of walnuts.
Local suppliers are reporting a surge in demand for this gnarled kernel, as its health benefits become more well-known.
Walnuts, which contain protein, unsaturated fat, omega-3 fatty acids, plenty of fibre and antioxidants, can be good for heart health when eaten as part of a healthy diet.
Prime Minister Lee Hsien Loong may be a believer too. When The Straits Times photographed him in his Istana office recently, a can of shelled walnuts was sitting on his table, within easy reach.
Four suppliers contacted by Mind Your Body said sales of walnuts have increased.
Over the last six months, the sales of walnuts have tripled at Tai Sun Food Industries over the same period last year, said its marketing manager, Ms Esther Loo.
The company sells baked walnuts from the United States under its Nature’s Wonders brand.
Ms Loo noted: "Customers are becoming increasingly aware and discerning. They even come to us requesting specifically for US walnuts because they heard that these walnuts have better taste and quality."
Tong Garden is looking into introducing plain baked walnuts to its product range next year. This is in response to the healthy demand for the honey roasted walnuts mixed with cashews it now sells, said a spokesman.
Sales of this mix have risen by about 20 per cent over the last two years.
The companies attributed the spike to a growing market for healthy food products and more research on the health benefits of walnuts.
Seng Hua Hng Foodstuff, which manufactures the Camel Nuts brand, said sales of its baked and raw walnuts have gone up by 39 per cent this year, after articles on the cancer-fighting properties of walnuts were published last year.
But overall, walnuts still account for less than 1 per cent of its total sales. Cashews, pistachios and almonds are among its bestsellers.
For organic food wholesaler and retailer Nature’s Glory, however, walnuts are one of the top sellers among its nut and seed products – and the demand for them is growing.
The spike in demand is probably due to recent research on omega-3 fatty acids in walnuts, said its research and development manager, Mr Christopher Lim.
Dietitians and nutritionists said walnuts are chock-full of nutrients.
A study by the University of Scranton in Pennsylvania in the US last year showed that a handful of walnuts contains twice as much antioxidants as that in a handful of other nuts such as almonds and pecans.
Antioxidants help to protect cells from damage by harmful substances which could cause cancer or heart disease.
Walnuts are also one of the few plant sources of omega-3 fatty acids, said Singapore Nutrition and Dietetics Association spokesman Kalpana Bhaskaran.
This nutrient, more commonly found in fatty fish such as salmon and tuna, reduces inflammation and helps fight chronic heart disease, said Ms Bhaskaran, who is also the section head of nutrition research at Temasek Polytechnic.
Other plant sources of omega-3 include flax and chia seeds.
Omega-3 is also known as "brain food" as it is thought to boost memory and brain health, added Ms Sheeba Majmudar, a nutritionist at Verita Advanced Wellness, which offers fitness and nutrition advice to its clients.
"Funnily enough, it looks like a brain too!" she quipped.
Eating about 40g of walnuts – or about 12 of them – a day could lower total and bad cholesterol levels without affecting that of good cholesterol, noted Ms Bhaskaran, citing a recent analysis of 13 studies conducted on the topic.
"Good" cholesterol, or high-density lipoprotein cholesterol, prevents "bad" or low-density lipoprotein cholesterol from being deposited on artery walls. This helps to reduce the risk of heart disease.
Polyunsaturated fat, which walnuts are high in, improve the effects of good cholesterol. Saturated fat and trans fat, on the other hand, raise bad cholesterol levels.
Walnuts have very low amounts of saturated fat and have no trans fat, thought to be the unhealthiest form of fat, said Ms Bhaskaran.
Taken as part of a low-fat, plant-based diet, walnuts can help prevent arteries from hardening, she added.
Nuts in general are high in unsaturated fat, which helps reduce the risk of heart disease, the Health Promotion Board (HPB) said.
Nuts are also good sources of protein and dietary fibre, it noted.
But it cautioned against eating too many nuts, as they are high in calories. People should also eat a variety of nuts to reap the most benefits.
The HPB recommends eating a small handful, or about 40g, of all kinds of nuts a few times a week, while Ms Bhaskaran said eating about 30g of nuts five times a week should result in good health benefits.
Nuts are also best eaten raw and unsalted. Processes such as baking, heating and roasting destroy its beneficial properties, said Ms Majmudar.
Financial analyst Elise Tan, 26, said walnuts are her favourite snack.
She has been snacking regularly on roasted walnuts since she read about their health benefits about three years ago. She said she likes them because they are tasty and contain many nutrients.
Other healthy options
One brazil nut is packed with enough selenium – a mineral that is a potent antioxidant – for a day.
Antioxidants help protect cells from damage by harmful substances which could cause cancer or heart disease.
Brazil nuts are also high in the minerals magnesium and zinc. Magnesium helps maintain bone structure and muscle and nerve function, while zinc boosts the immune system and helps wounds to heal.
They are high in vitamin E, an antioxidant which boosts the immune system.
They are also high in protein and fibre. Protein is essential to bone and muscle health and tissue repair, while fibre maintains bowel health by preventing constipation.
Almonds have more bone-building calcium than other nuts, making it an important source of the mineral for those who cannot consume dairy products.
They are rich in magnesium and copper, which help the brain and the body’s red blood cells to function.
Raw cashews have a low glycaemic index (GI), which means the carbohydrates they contain are broken down more slowly by the body. This results in a slower rise in blood glucose levels.
Food with a low GI index is sometimes used for weight management and is thought to be good for those with diabetes.
They are high in vitamin B6, which the body needs to transport oxygen in the blood and maintain the nervous system.
Pistachios are also good for the eyes. They contain the antioxidants lutein and zeaxanthin, which have been shown to lower the risk of age-related macular degeneration, an eye disease that commonly causes blindness in the elderly.