1. According to this article
http://www.aging-no-more.com/advanced-glycation-end-products.html “The browning of food…is achieved by heating or cooking sugars with proteins
in the absence of water, and in this process AGEs are formed.”
“
water prevents sugars from binding to protein molecules. By eating fruits and vegetables raw or by cooking them in water or with steam prevents AGEs from forming.”
It seems that steaming or boiling creates an insignificant amount of AGES.
2. Neither dietary nor endogenous enzymes are capable of breaking down cellulose matter; intact cellulose rich foods pass completely undigested through the digestive system. In the case of cellulose rich vegetables, dietary enzymes are a moot point.
Juicing is an alternative; the cell walls are ruptured thoroughly in this case.
3. According to WHFoods:
“Cooking of vegetables and fruits for longer periods of time (10-20 minutes) can result in a loss of over one half the total vitamin C content.”
Vitamin C may be the most heat sensitive vitamin in vegetables and >50% loss is significant. However, a couple cups of raw broccoli have 370% of your daily need for vitamin C, if you lost half you would still have an ample 185%.
Some vegetable nutrients are said to be better absorbed when cooked, carotenes in particular. And of course vegetables are loaded with anti-nutrients that are deactivated by heating.
The nutrient tradeoff for raw vs. cooked veggies is in favor of cooked in my opinion. However, you can always have some of each to get the best of both worlds
.
4. The study cited above:
http://www.ncbi.nlm.nih.gov/pubmed/14690788 shows correlation not causation, perhaps people who ate more raw salads also exercised more, ate more nutritiously and avoided unhealthy habits such as smoking. If you take the study at face value it has some bizarre conclusions:
a. Wholegrain products are correlated with a reduced risk of cancer, yup aside from raw veggies, a big serving of cooked wholegrain products is the only other variable which keeps you healthy.
b. Fruit doesn’t correlate with reduced cancer risk. Similar to raw veggies, shouldn’t raw fruit be healthy? The research methods suggest that the fruit category was plain fruit and not a “fruity” substance like Apfelstrudel.
Based on the aforementioned information, I still think that a moderate approach regarding
vegetables is best, some raw and some cooked.