It’s not what we eat, but what we absorb. That’s why experiments showing that the sulforaphane from broccoli and broccoli sprouts can make it into breast tissue it critical for explaining how crucifers may help with breast cancer protection.
Too much nutrient absorption can sometimes be a problem though. Meeting iron needs through plant-based foods (non-heme iron) may help reduce excess iron risk (see also here). Avoiding too much iron absorption from supplements is especially important for non-anemic, pregnant women.
The allium vegetables, which include garlic and onions, may help us absorb minerals. Eating flax could also help nourish our good bacteria that in turn can aid with phytonutrient absorption. Dressings or toppings with healthy fats from nuts or seeds can help maximize phytonutrient absorption when we eat a salad.
Nutrient absorption may differ among foods. For example, calcium from broccoli and kale may be absorbed almost twice as well as calcium from milk.
Most people cannot absorb more than 1.5 micrograms of Vitamin B12 before the body can take more four to six hours later. The body absorbs B12 in such a way that the most cost-effective way to take B12 may be through one 2500 microgram sublingual, chewable, or liquid supplement of cyanocobalamin once a week. It may be better for your health to take the B12 from a supplement or fortified food instead of an animal source.
Phytosterols, which may help reduce cholesterol, are better absorbed through seeds and nuts than supplements or phytosterol-fortified spreads and beverages. Phytosterol intake does not reduce food vitamin absorption.
Anyone predisposed to oxalate absorption may want to avoid beets, which have high oxalate levels, as a plant-based nitrate source. Two spices with potential benefits are turmeric and cinnamon, but because of the soluble oxalate that can be absorbed, turmeric intake should be no more than one teaspoon per day. Since the oxalate in cinnamon is not as easily absorbed, most people can probably take up to a few teaspoons a day.
Macronutrient absorption of certain foods may also influence satiety. A study showed the fat absorption from walnuts to be filling enough to possibly help with daily overall calorie reduction. Research suggests that adding nuts and nut butters to one’s diet doesn’t lead to significant weight gain.
To maximize Vitamin D absorption, researchers have suggested that Vitamin D supplements are best taken with the largest meal of the day.
If you drink calcium-fortified soymilk, shaking the container before you drink the soymilk helps you optimize calcium absorption. Some phytonutrients are better absorbed if the plant foods are cooked rather than raw, and vice-versa. So, to best benefit your health, consider eating both raw and cooked plant foods (see also here).
Topic summary contributed by Randy.