tonight on "nightline," danger's grain. olympic swimmer, tennis champ, tv stars. they have all sworn it off. it's gluten. and it's in a lot of what you eat. one doctor says addictive and makes you crave more food. tonight, inside the pros and cons of going gluten free. and cheney 2.0. his first interview since the heart transplant that saved his life. he opens up about chasing down death and what he really thinks of sarah palin. plus no boys allowed.

they are world class athlete bus they banned from the olympics because they are men. we get in the water with britta brittabri britain's only main sink know niced swim team. good evening. i'm cynthia mcfadden. it's all super market shelves, restaurant menus and now the gluden free diet is makes a splash at the olympic games. by choice or necessity, several champs are saying that cutting out of gluten in bread and pasta has helped their performance. does it make sense for you to try it too? here is terry moran, you are what you eat. >> about to win her first olympic gold medal and try to make it a world record as well.

yes! >> reporter: when dana vollmer won gold in the butterfly at the olympics, one american cheered. >> and congratulations to dana vollmer, by the way. she set a world record in butterfly and she happens to be gluten free. >> reporter: elisabeth hasselbeck of "the view," one of the most famous gluten free celebrities in america, and there is tennis star novak djokovic, going for bronze in beijing, he is gluten free. and another star, glunt free. elisabeth hasselbeck has celiac disease. which makes them ill tolerant to gluten. but dana feels better when she

avoids food contains gluten. it's a grain in rye, barley. and it's soups, sauces too. >> i think everybody should be off gluten. >> reporter: this doctor is a profit of going gluten free. >> most people, when they stop gluten, lose weight m they are energized. the aches and pains free up. they have more energy and they sleep better. it affects every system in the body. >> reporter: one of his biggest fans, tabitha coffee. the star of "tabitha takes over" on brav show. >> i am tabitha and i hate it when things give me a hard time. and i had to tell gluten to [ bleep ] off. >> reporter: elisabeth.

>> i feel like my name should be in here. >> reporter: we talked to her about shopping to avoid gluten, bread crumbs, pie crust, it's there. >> reporter: look around any grocery store and you see the business. it's a multibillion dollar market. >> those who are adopting it for fashion or trend they are going to light. >> do you think i would be better off reduce the gluten from my diet. >> i think if you gave yourself a challenge and you went gluten free, you would feel that your energy levels would soar. >> reporter: about 1 in 100 people are born with celiac diz.

should all of the us stop eaten gluten? >> yeah, the wheat of today is a food that probably no one should eat. now, that is talking as a clinician, there is no research to back this up yet. >> reporter: that's right. there is no conclusive scientific research proving any benefit from a glunt free diet. dr. peter green of columbia university is one of 9 world's expects in celiac disease. he spent a decade studying the body. there there benefits for a person who does not is a celiac disease to adopt a gluten free diet. >> reporter: not only that, but it might be bad for to you cut out gluten. many say that going gluten free can be dangerous. i see famous people telling me this is a helpful way to eat.

it sounds healthy. >> yeah -- well, a gluten free diet is not entirely healthy. often, it lacks fiber. and the manufacturers of wheat flour fortify wheat flour with vitamins and minitalls. >> reporter: so many scoff at the research of workers and doctors. >> why wouldn't i believe my patients telling me these things? i'm not surprised to hear athletes are doing better when they are an off gluten. >> reporter: the debate will continue. but for dana vollmer and others, it's settled. gluten free is golden. >> thanks to terry. next up, former vice president dick cheney tells us how his life was saved by surgery. and we hit the pool with the swim team barred from olympics for being guys. ♪

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controversial and powerful vice presidents in this country's history. dick cheney is a political lightning rod, loved by some, despiced by others. he has lived through the last two years in limbo, slowly wasting away as he waited nor a heart transplant. tonight, in a candid encounter, he tells it all to jonathan karl in a "nightline" interview. >> reporter: while we were walk requesting dick cheney in wyoming, we ran into a

12-year-old boy who was able to one up the vice president. >> how are you? >> he two heart transplants. >> i had just one. you are ahead of me. miracle stuff. >> reporter: the man talked to us about facing his own death two years ago as his heart, after six heart attacks, starte >> two years ago at this time, i was a respirator, heavily sedated. just had a pump installed on my heart. you know, it was the end. >> reporter: it was dick cheney like i had never seen him before. reflecting on his own mortality. personal. >> i was sefly sedated in the intensive care unit for weeks. i had pneumonia recovering from surgery. be by the time i looked in the mirror, what i saw was my dad shortly before he died. >> reporter: back then, he looked like a shadow of his own

self. tonight, he has transformed. thanks to an organ donor. >> do you know anything about the organ donor? >> i don't. i can't think of a better gift. >> reporter: don't think cheney has gone soft. when it comes to politics, he has is con reason toational as ever. even takes a shot of john mccain for choosing governor palin as a running mate. >> i like governor palan. i like her, i met. mu be e she had only been governor for two years. i don't think she passed the test. >> reporter: of being ready? >> of being ready to take over. and that was a mistake. >> reporter: and much harsher words for president obama. >> i think he is the weakst president. i disagree with him. i would be hard put to find any

democratic president that i have disagreed with more than barack obama? >> reporter: worse than jimmy carter? >> yes. >> reporter: he accused obama of blowing it in the middle east. >> i think obama has made big mistakes. i look at the middle east situation today, it seems to be growing chaotic. we have a conflict in syria where thousands of people have died. there are continuing problems in iraq. i look at what the obama administration has done. and it's head for the exist. with respect to afghanistan, we are in a similar situation now. it's tough, it's difficult. i know the public is tired of conflict. but if we turn our backs and walk away, we are just headed for trouble down the road. >> this administration is not in a position to do anything about it. because nobody trusts him. >> reporter: doesn't president obama deserve credit for the war

on terror? you have 24 high volume -- bid laden is dead. you can't say that he is soft on terror. >> i think he has made a number of mistakes. bid laden, fine, a lot of that intelligence came result of programs we had in the bush administration. >> reporter: do you think you will be going to the convention? >> no, i have a fishing trip planned that weekend. >> reporter: dick cheney may have faced mortality. but when it comes to the ligcy there is no change of heart. do you have any regrets? >> not really. >> reporter: really? >> no. >> reporter: you left office as one of the most unpopular vice presidents in our time. >> i never worried about polls. >> thanks to jon karl. just ahead they are men in a women's world. we need an all-male synchronized

swim team fighting for a chance to compete. [ female announcer ] over the last ten years, your mouth has giggled, snuggled, bubbled ...and yellowed. because if you're not whitening, you're yellowing. crest whitestrips remove over ten years of stains and whiten 25 times better than a leading whitening toothpaste. crest 3d white whitestrips.

earlier tonight, 17-year-old american victimer missy franklin took home olympic gold in the barack stroke. and teammate matt grevers brought home the gold. this makes the americans tied for first place with china in gold. not every team destined for

olympic glory has a chance. the next team can't compete because they are guys. we welcome in a report, a report of faster, higher, weirder. >> reporter: at this pool in the heart of london a group of medal winning athletes is training for one of the most demanding of olympic sports, synchronized swimming. no matter how hard hay train. no matter how good they are, they are not welcome in the olympic games. for one reason, they guys. >> well, it's what girls do. and we want to challenge and it say, no, boys do it as well. >> reporter: they brought home the gold in some of the biggest international competitions. but because men are still barred

from olympic synchronized swimming, they are on the signs of these olympic games. american kenyon smith was blocked from buy ving in '08. and bill may, who won awords with women, was kept away from athens in 2004. now, these brits say enough is enough. they have written a letter and they want the rules changed for real in 2016. so far, they say there is no response. how ironic this olympics seems to be all about equality and women having the opportunity and you guys are sitting here looking from the outside in. >> you people say, the few people who have try vd commented on how hard it is. >> reporter: butte ebutesther w made it look so easy.

and on "saturday night live," they made it a joke. >> it was not in the olympics yet. >> that's okay. because we could use the time. i'm not that strong of a swimmer. >> reporter: how do you get people to take men's synchronized swimming seriously? >> i have people to try it it. >> reporter: if i did synchronized swimming, would i have a stomach like that? >> maybe. >> reporter: never shying away from a challenge, i decided to take them up for their challenge. and i have do have two god medals and i like to think that i'm still in pretty good shape. first, the guys have to show me the proper way to start our routine. and it doesn't take long for me to realize this is a lot tougher than it works. >> one, two, three, four, five,

six, seven, eight. >> reporter: that is your coach a former yugoslav champion trying to whip them into shape. they lift me into the air and i pull off an effortless flip. or not. my first few are more like belly flops. then, my nose clip falls off. but despite the injury and after practice, i finally nail it. >> i managed to do one somersault, really, really good for beginners. >> reporter: and my final challenge, the flamingo, just like the old movies. i manage to impress with my

sleek moves but by now, i'm totally wiped out. all right, now we're talking. but some how, the guys are still kicking and they promise to keep pushing until men's synchronized swimming earn's its place on the medal stand. i played soccer growing up when women weren't playing that much. and they were laugh at us when we would go to brazil. how hard is it to keep training. >> we can encourage kids to get involved in it. and we will see guys doing it at the olympic level in a few year's time. >> reporter: first, my moment of truth. could this olympic athlete swim on their level? do you think i would make the team? >> yeah, definitely. you are good enough to -- i' reporter: for "nightline,"