The term bioavailability refers to the proportion of nutrients that is absorbed and utilized by the body, which is consumed through diet. Bioavailability is the absorption of nutrients in our body. The nutrients’ bioavailability differs for each and every nutrient. The macro nutrients absorption is nearly about 90% whereas the micronutrients absorption may depend on several factors.
This bioavailability of the nutrients depends on many factors like our diet, nutrient concentration, nutritional status and health of the people. There are also other components that affect the availability of the nutrients as cooking, chemical form of the food and various interactions the chemical nature of the nutrient is going on.
Bioavailability of nutrients in raw foods
Raw foods are the foods that are fresh from the field. Raw foods possess high nutritional content when compared to the cooked form. This thought is been highlighted in recent times that is why the organic farming is at high trend. Picking a food from its field means we are cutting the nutritional source that is available to the food till that time. Hence, it should be used quickly or consumed as such as soon as possible. For example, the carrots straight way from the field is more delicious than the cooked one.
It is always best to consume the foods with high water soluble vitamins and minerals and which are heat sensitive too. Hence foods like broccoli, Brussels sprouts, spinach and peas are best when eaten raw. The vitamin which include Vitamin B1, Vitamin B5, folate and vitamin C are best available when consumed raw.
For example, raw spinach possesses about 3 times more vitamin C than the cooked one. We are to lose our B vitamins and a Vitamin C when exposed to cooking in hot water. So if you are on the process to cook the veggies possessing these, make sure you use less water and follow a cooking method that aids lower nutrient loss.
Here are the foods which are healthier when eaten raw.
- Onion and garlic – the component called allicin present in the garlic is made available when it is in raw stage. Chopping or crushing garlic releases the allinase, the enzyme that helps in the fighting of many diseases. The onion possesses the anti-platelet agent which is destroyed in cooking.
- Cabbage and Broccoli – the broccoli and cabbage are the food substance that contains anti cancer agents that aids in the prevention of cancer. The substances are lost while these foods are exposed to heating. However, the cruciferous agents should be treated or cooked well before consuming it to help thyroid patients.
- Bell peppers, turnip greens, Kale are some of the foods that are eaten raw to improve the bioavailability.
These above said, vegetables are eaten raw to get the best availability of the nutrients.
Cooking and the bioavailability
Bioavailability of the nutrients is somewhat destructed while cooking but to some extent cooking aids in the easy availability of nutrients. The cooking methods like steaming, blanching or sautéing helps in the preservation of nutrients since they use very little amount of water.
Generally vitamins like niacin, thiamine, and vitamin C are heat sensitive. They are tending to lose its quality when exposed to heat. On the other hand, the omega 3 fatty acids in the fish are easily made available when the fish is thoroughly cooked through the method of boiling. Thus it is always better to use simple cooking methods which use less water, to retain the water soluble vitamins.
Is all the nutrients in the food is lost?
No, the fat soluble vitamins are generally retained while cooking. The invisible fat that oozes out makes the food more palatable and more appetizing. The vitamins like A, D and K are more stable and better during cooking.
Certain elements like lycopene in tomatoes, beta carotene increases when the food is cooked. Lycopene is found to increase to about 23% while kept for boiling for 30 minutes. Cooking breaks the rigid walls of the plant foods. This breaking would helps in the easy absorption of nutrients when these foods are being consumed. Hence, spinach, carrots, sweet potatoes are made more nutrient bioavailable through cooking.
Cooking the eggs and meat denatures the protein present in, thus making it more digestible. The egg is found to have salmonella species, a micro organism. Eating a raw egg, may be sometimes prone you to be attacked by the salmonellois. Hence, always it is safe to consume egg only after cooking.
There are some phyto chemicals which prevents the bioavailability of the nutrients from the food. These chemicals are destructed during cooking making the nutrients like iron and other minerals more available to the body.
Cooking destructs the cyanides and other harmful substance in the food, to help in the easy absorption of the nutrients.
Apart from cooking there are also some other factors which decrease the quality of bioavailability of the nutrients. The anti nutrient substance like phytates, lectins which are naturally present in the food like rice, nuts and seeds, preserve the nutrients from making it available to the body. This nutrient binds the zinc, iron and calcium from being absorbed in the GI track. Luckily the cooking destructs these harmful compounds, but there are few methods to help us in our bioavailability. To make these nutrients more available, keep them soaked in water for a while, and then take them to cooking. The soaking or sprouting destructs the phytochemicals thus enhancing the bioavailability of the minerals in our GI track.
Hence our conclusion is that there are both merits and demerits in each in its own way. We have to be wise enough to use the methods in a right way. My suggestion is to use the combination of both raw and cooked foods for a meal. The effective pairing of the foods should be done to get nutrients in optimal way. For example, the iron rich food should be consumed along with the vitamin C rich food, so that the bioavailability of iron is made more easily.
Here are certain tips to increase the bioavailability of the nutrients.
- Always try to pick the easy and locally available foods, because the fresh products possess more nutrients than the long stored ones.
- Choose wise cooking methods like steaming, boiling and microwave cooking which use less water to retain the water soluble vitamins.
- Choose sprouting as best option to improve the bioavailability of nutrients.
- Keep your gut healthy to improve the availability of nutrients effectively in the body system.
- Always combine the cooked and raw foods for better availability of nutrients.
Thus, some foods are nutritious when eaten raw while some are more good in cooked form. So, always try to make use of combinations for good nutritious healthy body.