Different methods of food preparation can affect that food’s vitamin content and bioavailability.
• Some micronutrients are most available, and best absorbed, when foods are eaten raw.
• Some micronutrients are most available, and best absorbed, when foods are cooked.
• Some micronutrients are most available, and best absorbed, when foods are eaten with other foods.
• Some micronutrients are most available, and best absorbed, when their structures are broken down first (e.g., by cutting or crushing).
We digest anthocyanins (the blue-red compounds in foods such as plums or eggplant skins) relatively quickly, often even starting in the stomach. Many types of anthocyanins, such as those in berries, are readily available when eaten raw.
Water-soluble vitamins can be lost in water during cooking and storage. This means the best methods to preserve vitamins include blanching, steaming,
sautéeing, roasting, and microwaving.
Boiling in water, and then discarding the water, will usually mean you lose nutrients. (However, if you keep the liquid for something like soup stock, you’ll retain many of those nutrients. And again, keep the big picture in mind (boiled and mashed potatoes are still far superior to fries.)
Some micronutrients, such as the lycopene in tomatoes or many carotenoids in yellow / orange / red plants, are often better absorbed when cooked.
Some micronutrients, such as the minerals in dark greens or bones, or soluble vitamins, become more (or less) available when cooked and / or eaten
with other foods.
• We need to eat fat to absorb fat-soluble vitamins. So put some olive oil, avocado, and / or nuts on your salad.
• We need vitamin C to best absorb iron from leafy greens, so add some fresh squeezed lemon to your kale.
• Some micronutrients (e.g. polyphenols) in grapefruit can enhance the absorption of some minerals (such as calcium, magnesium, phasphorus, copper, and zinc) yet inhibit the absorption of other substances (such as iron).
• Chopping or crushing garlic, then letting it sit for a few minutes before cooking with it, will release allicin, a powerful disease-fighting chemical.
You’ll notice here that, as al/ways, people don’t eat “nutrients”. They eat foods and meals.
Often, traditional or ancestral diets have figured out how to make the most of micronutrients.
The famed Mediterranean diet includes both crushed garlic and cooked tomatoes, not to mention the antimicrobial powers of the phytonutrients in fresh herbs.
South Asian cuisine does the same and throws in some anti-inflammatory turmeric and ginger plus painkilling hot peppers for good measure.
Arctic cultures such as Scandinavians and Inuit make sure to eat fish liver to give them enough vitamin D during the long, sunless winters. (The famous
icelandic sheep’s head dish, or svid, offers phosphorus and vitamin A to brave eaters who consume the eyes!