Are we losing essential nutrients in foods through cooking?

By Casey O’Dell, Accredited Practising Dietitian (APD)

Raw eating is a growing nutrition trend. The raw eating movement claims a healthier diet when eating a food in its most natural form. So, does cooking a food destroy important nutrients and reduce the quality of our diet? Not really! There are some benefits for both eating raw foods and cooking foods, both of which are important to understand.

Raw Eating

The belief behind the raw food diet is that cooking food tends to destroy the naturally occurring enzymes and nutrients found in the foods which would otherwise enhance our health and promote weight loss. A raw food diet is mainly plant-based and includes fruits, vegetables, nuts, seeds, grains, juices and oils in their natural form.

While eating more fruit and vegetables is never a bad thing for your health, the science shows no significant difference to long term health or risk of disease by having them raw or cooked. In fact, cooking foods can help with digestion, allowing more of the nutrients to be absorbed by the body.

When you chose to eat exclusively raw, your nutrient diversity reduces as you are limited to those foods mentioned above. This can lead to a poor intake of nutrients such as protein, calcium, iron and zinc.

Cooking food

Heating foods can actually be better than raw in come cases as it can break down the cell wall to allow more nutrients to be released. Food is made up of a range of compounds, not just nutrients. These compounds can serve as prebiotics, antioxidants and anti-inflammatory benefits. Cooking losses of these compounds are considered small compared to the bioavailability benefits of cooking. One of the most important advantages of cooking food is that foods cooked at 75 degrees Celsius or higher will kill most of the harmful bacteria which can lead to food poisoning.

The 3 key considerations to getting the most out of your food when cooking are always water, temperature and time.

The higher the temperature and the longer the food is cooked for, the more potentially for nutrient losses. If you can steam or stir fry your vegetables rather than boil, they will cook quicker with less nutrient depletion.

What nutrients are at risk?

Most minerals are unaffected by cooking and the main vitamins that are impacted are vitamin C, folate and thiamine. Even so, depending on the cooking method, most will only drop to halve of their original value.

Maximising nutrient retention when cooking

• Don’t peel vegetables! Wash them well and eat the peel as well once cooked
• If you are boiling food, use as little water as possible
• Cook vegetables until they are firm rather than soft
• Cut larger pieces – whole food will have a smaller surface area and nutrient losses are minimised

The bottom line is – let’s eat more fruits and vegetables no matter how they are prepared. If cooking makes them tastier and more interesting, then you are more likely to eat them.