STORY: My husband when we first started Paleo had an autoimmune celiac-like response to gluten. He also had GI responses to soy, nightshades, and even more normal foods like veggies because his gut was damaged and needed to heal. If you follow GAPS - I don't believe in the enemas or everything but most of Dr. Natasha's explanation is good. You have to heal the gut and immune system or you could potentially respond to anything!
Now after nearly after 1 year of Paleo he can consume all nightshades, raw dairy, and CROSS_contaminated gluten! His gut healed! We did a LOT of probiotics - dairy and fermented veggies, refrigerated probiotic pills, etc.
My mother used to cheat occasionally with gluten. This is in spite of the fact her mother DIED from autoimmune ulcerative colitis. My mother used to have eczema and cold triggered hives (urticaria) that disappeared with Paleo.
Then I last heard from Mom, "Oh, I can't digest wheat anymore - I tried a piece of bread and I got bad stomach upset." I told her, "You NEVER could digest it." Your body was too inflamed in the past for you to notice it.
Take the analogy of boiling a frog SLOWLY. The frog (you) may not notice the water slowly heating (that is slow inflammation that people are trying to adapt to from constant gluten and gut irritants). But when you cool down the inflammation to near 0, and suddenly you get inflamed from gluten that would make things very hot!
Let's say the most people on SAD are inflamed level from level 7-10 (with 10 being highest). On Paleo let's say you're inflamed 0-5. Well you're going to notice inflammation a lot more easily when you go from 1 to 7 when you eat wheat after Paleo then when you are chronically inflamed and go from inflammation 7 to inflammation level 9!
As for Asians and grains ...
Dr. Peter Attia and Mark Sisson have written well:
http://eatingacademy.com/nutrition/how-do-some-cultures-stay-lean-while-still-consuming-high-amounts-of-carbohydrates
http://www.marksdailyapple.com/the-asian-paradox-how-can-asians-eat-so-much-rice-and-not-gain-weight/
If rice is so benign for Asians why do we have Asians going rice- free and having great results!
http://www.marksdailyapple.com/a-primal-comeback/
I've seen rice bellies in parts of India and other Asian countries just as well as wheat bellies. They have hypertension and have diabetes, and/or pre-diabetes.
http://www.cbsnews.com/8301-504763_162-57398765-10391704/eating-white-rice-daily-ups-diabetes-risk-study-shows/
There are some healthy Indians .. BUT...
India has skyrocketing diabetes/metabolic, autoimmune diseases, cancer, etc.. Most of it is under-diagnosed just like gluten intolerance and celiac. Doctors will just blame IBS type syndrome on bad food, water, and/or parasites which is confusing because some symptoms are similar! If 90% celiacs aren't diagnosed in America what do you think that number is in India - 99.9%??!
http://www.thehindu.com/news/national/article24750.ece
Almost half Indians (50%) have poor lipid profiles - triglycerides, HDL, LDL. Maharashtra, Gujarat, and Tamil Nadu have the worst (note 2 out of the 3, other then Tamil Nadu are heavy wheat eaters). 22 year medical student had heart attack.
Indian cardiologist says he's had 30-40% increase in heart patients aged below 40 in just the last few years! http://indianherald.com.au/featured/smoking-hastens-cardiac-problems/1680/
India has 1 billion people+ but look how few athletes they have produced per capita compared to other Asian (primarily omnivorous countries like China & Japan). The Indian Army is composed from 10-15% Sikh religion (Sikh officers are 20%) - a reform Protestant version of Hinduism but Sikh's are omnivorous and can eat any meat - including beef. Yet Sikhs are less than 2% of the entire Indian population! What percentage vegetarian or vegan warriors or people in defense are you going to find worldwide??!! http://en.wikipedia.org/wiki/Sikh
In Gujarat, most are vegetarian Hindu and they have among the poorest nutrition and fitness. The average height of many Gujarati woman approaches under 5 feet and tend to be emaciated looking or overweight/obese- suggesting nutrition deficiencies from grains blocking minerals like magnesium, zinc, iron, calcium, etc. FYI I've known groups of strict lifelong vegetarians carrying the burden of modern disease - cancer, autoimmune, heart disease etc - almost everything on the symptoms of gluten intolerance below.
In some cultures food is so important they would rather die then change their diet - or they will change when they are in such excruciating pain that when offered the knowledge that contradicts their belief system they may change aspects (may not all) of their diet.
A great number of Bollywood actors/actresses and nearly all (perhaps all) of the beauty pageant (Miss Universe, Miss World) winners are omnivore (often Muslim/Christian) and are either from the Punjab area or Bengal, with some South Indians. Although you can look good on the outside and still be inflamed on the inside. Some people have delayed effects of a poor diet - in the 20's and 30's but then it catches up!
In some Indian villages they use sugar as a filler so you cannot taste the food - all you taste is sugar so 1 bowl of "tomato soup," tastes like sugar soup. They deep fry in vegetable oils and often there 3 meals consist of deep-fried wheat. They don't eat enough non-starchy vegetables - they tend to be very grain-based.
Those that have raw dairy (or low temperature pasteurized dairy), and eat less or no wheat, and eat eggs are better off. Vegetarians could gain some benefit from Lacto-Ovo-Paleo but the sicker they are the more they have to benefit from including eating grass-fed ruminants and wild caught fish in their diet and eliminating gut irritants.
The obesity of cities like Baroda (Vadodara) India approaches Texas and there are heart centers/clinics on every block like Starbucks. (Everything is big in Texas - the SUVs, houses, and the people ...) LOL!
The highest rates of celiac are found in the areas with the greatest wheat consumption - Gujarat and Punjab - and they are not healing because so many foods including spices can be cross-contaminated.
http://www.ncbi.nlm.nih.gov/pubmed/11569725
Am J Gastroenterol. 2001 Sep;96(9):2804-5. Increasing incidence of celiac disease in India. Sood A, Midha V, Sood N, Kaushal V, Puri H.
Gujarati and Punjabi Indians who settled in England get 3 times more celiac then Europeans!
http://www.medscape.com/viewarticle/588631_3
http://en.wikipedia.org/wiki/Autoimmune_disease
http://www.aarda.org/autoimmune_statistics.php Total Autoimmune disease has outpaced CANCER and HEART DISEASE in the numbers in the US.
All the below conditions/symptoms related to gluten intolerance are skyrocketing in India. Some of these conditions change over time in the same individual!
Some of 300 symptoms associated with gluten intolerance and/or made worse by gluten- Sound familiar?
Weight loss/gain
Nutritional deficiencies due to malabsorbtion e.g. low iron/anemia, Vitamin D, magnesium, zinc etc..
GI, IBS, bloating, pain, gas, constipation, diarrhea, GERD, acid reflex, fatty stool, nausea,vomiting, flatulence, celiac, Crohn's, Ulcerative Colitis, Lactose Intolerance
Joint pain, Osteoporosis/Osteopenia, Cramps, tingling and numbness
Depression, Headaches, Migraine, Fatigue, Schizophrenia, Mood Swings, Irritability, Brain fog, seizures, ataxia (clumsiness), MS
Infertility, irregular menstrual cycle and miscarriage, Slow infant and child growth
Eczema, Allergies, Hives (Urticaria), Psoriasis, Acne, Rosacea
Type 1 diabetes, Lupus, Alopecia (hair loss, balding)
Down, Turner, and Williams Syndrome
Decline in dental health, dental enamel irregularities
Thyroid disease (both hypo and hyper)