Does food lose nutrient value if I cook it?
I prefer to have my bananas heated in the oven, especially nowit’s cold in the mornings, and I put coconut yoghurt on them. Do I lose any nutrient value by heating them please? Could you elaborate on what fruit/veges not to cook if they cause nutrient loss? Thanks, Teresa.
Hi Teresa. Generally speaking cooking food tends to improve its digestibility and increase our ability to absorb nutrients.
However a number of nutrients are sensitive to heat and can be destroyed via cooking – which of course is also dependent on the method; whether this is baked, steamed, sauteed or grilled. However, several important nutrients are reduced by cooking, particularly:
Water-soluble vitamins such as B vitamins— thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), folic acid (B7), biotin (B8) and vitamin C.
There are specific nutrients that are actually enhanced by cooking, for example, studies suggest that the absorption of beta-carotene is 6.5 times greater in stir-fried carrots than in raw. In another study, blood lycopene levels increased by 80 per cent when people consumed tomatoes sauteed in olive oil as opposed to raw (typically cooking in a little bit of oil enhances nutrient absorption, specifically fatsoluble nutrients). I’ve been hearing a lot about B vitamins lately and their role in energy. Can you please give me a brief overviewof their role and if they do make a difference? Thanks, Calvin.
Hi Calvin. Food is essential to nourish our bodies, providing vital nutrients and minerals to drive the thousands of biochemical reactions in the body. It also supplies us with energy. Any food we eat is converted to energy, in the form of Adenosine Triphosphate (ATP).
There are many nutrients involved in the body’s ability to produce ATP. The most important group of nutrients for the conversion of food into ATP is B vitamins. Thiamine (B1), riboflavin (B2) and niacin (B3) are three B vitamins that are essential in the conversion of food to energy. Without sufficient vitamin B consumption energy conversion can be slow, leaving us feeling sluggish and tired.
All of the B vitamins are watersoluble, meaning that the body does not store them. The best place to get B vitamins is from our
Ask Dr Libby
Email your questions for Dr Libby to ask.drlibby@fairfaxmedia.co.nz. Please note, only a selection of questions can be answered. food, for when vitamins are obtained through food they are easily absorbed and utilised because you are also consuming co-nutrients that assist with the uptake and absorption.
Thiamine rich foods include beans and lentils, nuts, seeds and pork. If you eat pork, be sure to always choose free range. Leafy green vegetables, tomatoes, almonds and eggs are a good source of riboflavin.
Niacin is found in the highest concentrations in meat such as beef, pork, chicken and fish. Some can also be found in peanuts and beans.
Grains such as spelt, oats and rye will also boost your B vitamin intake, if your digestive system can tolerate them. Alternatively, quinoa is a gluten free source of B vitamins.