Calcium absorption inhibited by fibre?

Q I was told that fibre prevents the absorption of calcium in our body. As such, when we take calcium-rich food that is fibrous, we are not able to benefit from it. For example, broccoli.

Kindly advise please.

ACalcium is an important mineral for strong bones and teeth and plays a role in blood clotting, regulating heartbeat and conducting nerve impulses. The daily recommendation of calcium ranges from 800 to 1000mg per day, depending on one's age and conditions such as pregnancy.

Calcium from dairy products such as milk, cheese and yogurt is more readily absorbed than those from plant sources.

Natural compounds such as oxalic and phytic acid in these foods can hamper the absorption of calcium. Oxalic acid is found in green leafy vegetables like spinach and broccoli and phytic acid is found in hulls of cereal grains and bran like wheat bran. They bind calcium from the diet and make it less absorbable in the body.

Research suggests that these compounds have greater impact on calcium absorption than fibre content. However, you should continue consuming green leafy vegetables in your diet - for vitamins, minerals, and fibre intake.

To meet your calcium recommendation, take foods rich in calcium such as milk, yogurt, tofu, beans as well as fortified foods like bread, soya bean milk, juices and cereals.

MS ASHU DATT IS A QUALIFIED MEMBER (DIETITIAN) OF THE SINGAPORE NUTRITION AND DIETETICS ASSOCIATION.

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Q Many people say that eating seafood such as crab and prawn raises cholesterol. But I have read many other reports that say taking seafood is good for the health, especially as it contains selenium which raises good cholesterol and protects the heart. I am really puzzled. Can you explain?

A Selenium is a mineral and is found mainly in seafood. It is an essential component in critical antioxidant enzymes the body uses to neutralise free radicals. As free radicals can lead to blood vessel blockage, selenium is thought to be beneficial for heart health.

Taking foods with moderate-to-high cholesterol does not directly increase body cholesterol levels.

In some seafood products, there is a high content of Pufa (Polyunsaturated Fatty Acids) which help lower triglyceride levels, another type of fat involved in heart disease.

Omega-3 fatty acids also contribute to the critical balance of lipoproteins, thus reducing the 'bad cholesterol': low-density lipoproteins (LDL) and very low density lipoproteins (VLDL).

In addition, omega-3 fatty acids help reduce the number and stickiness of blood platelets, thus helping to control the clotting of blood cells.

Recently, researchers also found non-cholesterol sterols in molluscs, such as clams, oysters, scallops and mussels. These sterols inhibit the absorption of cholesterol eaten at the same meal.

For a heart-friendly diet, however, you still need to ensure a dietary regime that is low in fat, saturated fat, and rich in fruit, vegetables and wholegrains.

You can also include fatty types of fishes like salmon and tuna twice a week.

MS MABEL YEONG IS A QUALIFIED MEMBER (DIETITIAN) OF THE SINGAPORE NUTRITION AND DIETETICS ASSOCIATION.