0:00:02 > 0:00:06MELLOW, SEDUCTIVE MUSIC
0:00:06 > 0:00:09Fine roast beef, cooked to perfection.
0:00:12 > 0:00:16Plump sausages, pan-fried and golden brown.
0:00:19 > 0:00:22Luscious lamb chops, grilled until pink and tender.
0:00:25 > 0:00:27This isn't just ordinary meat.
0:00:28 > 0:00:32Depending on what you've recently read or heard on the news,
0:00:32 > 0:00:37this is either a protein-rich and nutrient-packed dietary necessity...
0:00:37 > 0:00:39MUSIC: "Little Red Rooster"
0:00:39 > 0:00:43..or an artery-clogging, life-shortening food to avoid.
0:00:45 > 0:00:47I am genuinely confused
0:00:47 > 0:00:50and would dearly love to separate fact from fiction
0:00:50 > 0:00:54because for many of us, meat is a pleasurable part of our daily diet.
0:00:57 > 0:00:59Now as a family, we like meat.
0:00:59 > 0:01:03We eat it most days - chicken, lamb, beef,
0:01:03 > 0:01:05pork and of course, bacon and burgers.
0:01:07 > 0:01:08And we're not alone.
0:01:08 > 0:01:12Worldwide meat consumption has nearly doubled in the last 50 years.
0:01:12 > 0:01:15That's certainly how a burger should look.
0:01:15 > 0:01:17That's a very good burger.
0:01:17 > 0:01:21Could something that is so ingrained in our culture really be killing us?
0:01:22 > 0:01:26I'm going to track down the eminent scientists who study
0:01:26 > 0:01:28the impact of different types of meat.
0:01:29 > 0:01:32I want to find out what they've discovered
0:01:32 > 0:01:34but also what they themselves eat.
0:01:36 > 0:01:38Just what is the truth about meat?
0:01:55 > 0:01:59It's really early in the morning. It's cold, it's dark
0:01:59 > 0:02:03and I am off to see more meat than I have EVER seen in my life.
0:02:06 > 0:02:09In the last few years, meat has hit the front pages
0:02:09 > 0:02:11but for all the wrong reasons.
0:02:16 > 0:02:19Frankly, I'm sceptical about many of these headlines
0:02:19 > 0:02:21and want to find out what's behind them.
0:02:28 > 0:02:30Does meat really give you cancer?
0:02:30 > 0:02:34Whoa, right! Oh, that looks like an alien growth!
0:02:35 > 0:02:37Will eating it shorten your life?
0:02:37 > 0:02:40Those who consumed higher amounts of red meat had higher risks
0:02:40 > 0:02:44of total mortality, cardiovascular mortality and cancer mortality.
0:02:46 > 0:02:51Is it a killer, or are these claims greatly exaggerated?
0:02:53 > 0:02:57You're probably looking at about a difference of five years,
0:02:57 > 0:02:59four to five years in life expectancy.
0:03:03 > 0:03:06As well as investigating the latest science, I'm going to put
0:03:06 > 0:03:08myself on a high-meat diet
0:03:08 > 0:03:11to see what, if any, effects it has on my body.
0:03:22 > 0:03:25This is where a lot of the meat on our tables comes from,
0:03:25 > 0:03:28a huge meat wholesaler.
0:03:28 > 0:03:33Here they prepare up to 30 tonnes of beef, pork and lamb every day.
0:03:33 > 0:03:35It gets sent out to butchers
0:03:35 > 0:03:38and ends up on our dinner plates right across the nation.
0:03:40 > 0:03:44That's impressive, impressive speed at which you go. Blimey.
0:03:44 > 0:03:47Does being around all this meat put you off it at all?
0:03:47 > 0:03:49Definitely not, definitely not.
0:03:49 > 0:03:51I've got a very good appetite for meat.
0:03:51 > 0:03:53- How often?- What, do I eat meat?
0:03:53 > 0:03:57- Yeah.- I don't consider it a meal unless it's got meat in it, really.
0:03:58 > 0:04:01For people like Pete, in fact for most of us,
0:04:01 > 0:04:03eating meat is a normal thing to do.
0:04:06 > 0:04:09What's more, it has lots of good things in it.
0:04:10 > 0:04:13Meat provides some really important nutrients
0:04:13 > 0:04:16that are essential for health, so mainly protein.
0:04:16 > 0:04:17Meat is protein-rich
0:04:17 > 0:04:20and protein is very important in terms of repair of your body.
0:04:20 > 0:04:23And there's also some micro-nutrients such as...
0:04:23 > 0:04:27..iron which is good for helping us to have healthy red blood cells
0:04:27 > 0:04:30that help to transport oxygen around the body.
0:04:32 > 0:04:36Also B12, which is also involved in the working of our blood cells.
0:04:36 > 0:04:39B vitamins particularly sometimes can be very difficult to
0:04:39 > 0:04:41get from a plant-based diet.
0:04:42 > 0:04:48And zinc which is important for healthy hair, nails, and also
0:04:48 > 0:04:52has a role in wound healing and sort of helping us to repair ourselves.
0:04:54 > 0:04:56If you don't have meat in your diet, you can
0:04:56 > 0:04:59certainly still get all the nutrients that you need
0:04:59 > 0:05:03but you do have to think a little bit more about how you get those.
0:05:11 > 0:05:15As a species, we evolved eating meat, though probably not that much
0:05:15 > 0:05:19or that often. But how much is too much?
0:05:19 > 0:05:22Well, to find out you need to do big studies -
0:05:22 > 0:05:24lots of people followed for many years.
0:05:26 > 0:05:30It's those studies that I'm going to look closely at.
0:05:30 > 0:05:32Together, they involve almost a million people
0:05:32 > 0:05:36and for the most part, they're looking at particular types of meat.
0:05:42 > 0:05:44There is little evidence that chicken
0:05:44 > 0:05:48and other white meats pose a health risk so these are off the agenda.
0:05:56 > 0:05:58Really, the meats that are under fire
0:05:58 > 0:06:00are red meat and processed meat.
0:06:00 > 0:06:03Now red meat includes beef, lamb, pork,
0:06:03 > 0:06:07while processed meat could mean salami, bacon, sausages -
0:06:07 > 0:06:10so those are the meats that I'm going to focus on.
0:06:16 > 0:06:20Now I eat relatively modest amounts of meat but would it matter
0:06:20 > 0:06:21if I ate more?
0:06:23 > 0:06:26To find out, I'm going to go on a high-meat diet.
0:06:27 > 0:06:31I'm going to eat about twice the advised daily amount, something
0:06:31 > 0:06:36that around 25% of the adult male population in Britain already do.
0:06:41 > 0:06:43So let's see what I'll be eating more of.
0:06:44 > 0:06:48Red meat is stuff like steak, lamb or pork chops
0:06:48 > 0:06:51and ground red meat like beef mince,
0:06:51 > 0:06:54whereas processed meat has been preserved by salting, smoking
0:06:54 > 0:06:59or by adding preservatives - things like salami, sausages and ham.
0:07:04 > 0:07:09On average, Brits eat about 70 grams of red and processed meat every day.
0:07:09 > 0:07:14That doesn't include chicken or any other poultry, but about a quarter
0:07:14 > 0:07:19of British men eat around 130 grams so I'm going to adopt their diet.
0:07:25 > 0:07:27Now I think that on average
0:07:27 > 0:07:30I probably eat 65-70 grams of meat a day,
0:07:30 > 0:07:34but for the next month I'm going to be going up, nearly doubling it.
0:07:34 > 0:07:37So what does 130 grams of meat look like?
0:07:37 > 0:07:39Well, something like this.
0:07:39 > 0:07:42It could be a couple of bits of bacon in the morning
0:07:42 > 0:07:44for breakfast and a burger in the evening.
0:07:44 > 0:07:45That's 130 grams.
0:07:45 > 0:07:49Or you simply have a piece of steak about this size or maybe
0:07:49 > 0:07:52a pork chop this size - that's 130 grams.
0:07:52 > 0:07:56Or you might go for one sausage plus a couple of bits of ham for lunch.
0:08:00 > 0:08:02And if you're wondering how much that adds up to over
0:08:02 > 0:08:06the course of four weeks - well, it's about this much.
0:08:06 > 0:08:09And frankly that looks quite doable.
0:08:17 > 0:08:20To monitor how this seemingly moderate amount of meat
0:08:20 > 0:08:22affects my body, I've come to the Food
0:08:22 > 0:08:27and Nutritional Sciences Department at Reading University.
0:08:28 > 0:08:30- Hello there.- Michael.- Hello.
0:08:30 > 0:08:32I'm going to have a health check before
0:08:32 > 0:08:37and after the diet to see if a bit of extra meat changes anything.
0:08:37 > 0:08:40What's happening at the moment is I'm about to have some blood
0:08:40 > 0:08:42taken so they can measure my cholesterol
0:08:42 > 0:08:46and they're also going to put me on the weighing machine over there
0:08:46 > 0:08:49so they can measure things like body fat, weight, things like that.
0:08:49 > 0:08:50Oh, yes, felt that one.
0:08:50 > 0:08:53And the idea is to get a baseline figure
0:08:53 > 0:08:57so that before I go on my enhanced meat diet, they've got some figures.
0:08:57 > 0:09:00I'll come back here in a few weeks' time, they'll do it all over
0:09:00 > 0:09:04again and we'll see if the meat has made that much of a difference.
0:09:06 > 0:09:10I'm just a sample size of one so the results will be very personal
0:09:10 > 0:09:12and not representative of everyone.
0:09:15 > 0:09:18Desirable ranges should be in the fat percentage
0:09:18 > 0:09:21between 11 and 22% and you are 15.3
0:09:21 > 0:09:24- so you're well within the desirable range.- I'm desirable.
0:09:29 > 0:09:33For a rather more scientific way to assess the impact of meat,
0:09:33 > 0:09:35I've come to Southern California.
0:09:37 > 0:09:40Here they've been conducting one of the longest studies ever
0:09:40 > 0:09:43into the effects of diet and lifestyle on health.
0:09:46 > 0:09:51I'm in Loma Linda which is in California near Los Angeles
0:09:51 > 0:09:53and I'm here to meet the Hucksey family
0:09:53 > 0:09:56who are part of an unusual group of people.
0:10:01 > 0:10:04They're unusual because their religious beliefs seem to
0:10:04 > 0:10:08contribute to their impressive longevity and general good health.
0:10:12 > 0:10:14Hello, good morning, hello. Very nice to meet you.
0:10:14 > 0:10:17- Welcome, please come in. - Thank you very much. Hiya, gang.
0:10:17 > 0:10:20- This is my family.- Hello.- Wife Danielle.- Hello.- Hello.
0:10:20 > 0:10:23The Huckseys are Seventh Day Adventists,
0:10:23 > 0:10:26a Protestant sect founded in the 1800s.
0:10:30 > 0:10:34Even though it's Saturday, we're off to church because
0:10:34 > 0:10:37that's when Seventh Day Adventists observe the Sabbath.
0:10:37 > 0:10:39CHURCH ORGAN PLAYS
0:10:47 > 0:10:52Now Seventh Day Adventists like the Huckseys live considerably
0:10:52 > 0:10:54longer than the average American.
0:10:55 > 0:11:01CONGREGATION: # Safe within his hand that guides us
0:11:01 > 0:11:02# Hidden in... #
0:11:02 > 0:11:05That's probably because they believe that leading a healthy,
0:11:05 > 0:11:08wholesome lifestyle is what God wants them to do.
0:11:12 > 0:11:17In the Bible, in 1st Corinthians 6, there is
0:11:17 > 0:11:21a verse that talks about our body is the temple of the Holy Spirit
0:11:21 > 0:11:25and that we should use our bodies for the glory of God,
0:11:25 > 0:11:29and that we are to take care of our bodies so that we can not only
0:11:29 > 0:11:34live longer but also be more helpful to other people while we ARE living.
0:11:34 > 0:11:38We're sitting down to a different kind of breakfast
0:11:38 > 0:11:41because their religion encourages vegetarianism.
0:11:41 > 0:11:43So can you tell me what I'm looking at here, then?
0:11:43 > 0:11:47So this is - it looks like scrambled eggs but it's not, is that right?
0:11:47 > 0:11:48Scrambled tofu.
0:11:48 > 0:11:52OK, scrambled tofu, and these, I'm guessing, are not pork sausages?
0:11:52 > 0:11:57- No, those are Saucettes, so another soy-based vegetarian.- OK.
0:11:57 > 0:12:00Heavenly Father, thank you for the chance to enjoy the Sabbath day
0:12:00 > 0:12:02and the food that you've prepared.
0:12:02 > 0:12:05Please bless our time together in Jesus' name, amen.
0:12:05 > 0:12:06Amen.
0:12:07 > 0:12:10The Huckseys are strict vegetarians
0:12:10 > 0:12:13but because their church only RECOMMENDS a veggie diet,
0:12:13 > 0:12:17many of the Adventist community eat some meat.
0:12:17 > 0:12:21Is it primarily religious, or ethical, or was it health?
0:12:21 > 0:12:26It was health and I wanted my kids to be healthier.
0:12:26 > 0:12:27I think often as parents,
0:12:27 > 0:12:31you do things for your kids that you wouldn't do normally
0:12:31 > 0:12:34and I wanted them to be healthier.
0:12:34 > 0:12:37And now that I have an eight-year-old,
0:12:37 > 0:12:40I think I want to live a long time for him and be healthy for him.
0:12:40 > 0:12:44You look at products that God has created, such as a grapefruit,
0:12:44 > 0:12:46whole grains, sweet potato.
0:12:46 > 0:12:48The closer you look at them,
0:12:48 > 0:12:51you realise how beautiful and nutritious they are.
0:12:51 > 0:12:54Not only is it showing that Adventists are living seven
0:12:54 > 0:13:00years longer, but the quality of those elderly years!
0:13:00 > 0:13:02How long do you expect to live till?
0:13:02 > 0:13:06My grandmother just passed away at 103.
0:13:06 > 0:13:08OK, right! That's impressive!
0:13:08 > 0:13:11CHURCH BAND PLAYS
0:13:11 > 0:13:16What makes Adventists of particular interest to scientists is that
0:13:16 > 0:13:20although half are vegetarian, around half eat meat
0:13:20 > 0:13:23so the two groups can be compared.
0:13:23 > 0:13:27And unlike the wider population, Adventist meat-eaters tend
0:13:27 > 0:13:32not to be heavy smokers or drinkers, factors which CAN influence
0:13:32 > 0:13:36any comparisons between vegetarians and more red-blooded Americans.
0:13:43 > 0:13:48Since the 1950s, scientists at Loma Linda University have been
0:13:48 > 0:13:51conducting numerous health studies on Adventists.
0:13:51 > 0:13:54The most recent have been trying to identify the health habits
0:13:54 > 0:13:56of the long-livers.
0:13:58 > 0:14:02I am here to meet Dr Gary Fraser who's been leading this
0:14:02 > 0:14:07research for three decades covering over 150,000 Adventists.
0:14:09 > 0:14:12These huge epidemiological studies track people's diets
0:14:12 > 0:14:15and lifestyles and look for associations between what
0:14:15 > 0:14:20they eat, their overall health and what eventually kills them.
0:14:22 > 0:14:26- Hello.- Hi.- Hi, Mike Mosley, hello. Nice to meet you.
0:14:26 > 0:14:28I'm joining the good doctor for lunch
0:14:28 > 0:14:32and as I'm on a high-meat diet, our choices couldn't be more different.
0:14:36 > 0:14:40OK, so differences in what we've got here, then.
0:14:40 > 0:14:46I've got pulled pork while Dr Fraser has a vegetarian salad with nuts.
0:14:46 > 0:14:49I have to confess, I had bacon for breakfast as well.
0:14:49 > 0:14:51- OK.- I had four rashers of bacon.
0:14:51 > 0:14:54Wow! All right. I hope you survive this experiment.
0:14:54 > 0:14:56Thank you!
0:14:57 > 0:14:59So kind of broadly, what have your studies revealed?
0:14:59 > 0:15:03That when you look at cardiovascular risk factors in a broad sense -
0:15:03 > 0:15:06diabetes, hypertension, being overweight,
0:15:06 > 0:15:09having increased blood lipid levels -
0:15:09 > 0:15:12that the vegetarians are doing better than the non-vegetarians.
0:15:12 > 0:15:16And indeed that has translated in most of the studies to
0:15:16 > 0:15:20the vegetarians having a lower risk of heart attack and cardiovascular
0:15:20 > 0:15:24disease, so that whole area, I think, is fairly well established.
0:15:24 > 0:15:28Dr Fraser found that men in the study who ate beef at least
0:15:28 > 0:15:32three times a week had double the risk of fatal heart disease
0:15:32 > 0:15:34compared to the vegetarians.
0:15:36 > 0:15:39And this apparently massive risk to health was in people eating
0:15:39 > 0:15:44under 60 grams a day, which is less than your average Brit
0:15:44 > 0:15:46and half what I'm currently eating.
0:15:47 > 0:15:50So you have found that even eating what some people would regard
0:15:50 > 0:15:53- as quite a modest level of meat makes a difference.- Yes.
0:15:53 > 0:15:55I mean, how big a difference?
0:15:55 > 0:15:58You know, I don't think we have all of the answers on that to be
0:15:58 > 0:16:03very precise about it and of course your plate of food there has
0:16:03 > 0:16:06got some things on there that go beyond the meat that
0:16:06 > 0:16:10I wouldn't necessarily recommend. So let me put it this way.
0:16:10 > 0:16:14That plate as compared to this plate,
0:16:14 > 0:16:19where I have replaced the meat with nuts and with whole-grain bread
0:16:19 > 0:16:23and so forth, our evidence says that you're probably looking
0:16:23 > 0:16:27at a difference of five years, four to five years in life expectancy.
0:16:33 > 0:16:36The Adventist studies certainly suggest that vegetarians lead
0:16:36 > 0:16:38longer and healthier lives,
0:16:38 > 0:16:42and Dr Fraser makes a compelling case for avoiding meat.
0:16:42 > 0:16:47So is that the end of the story? Well, no.
0:16:53 > 0:16:58For starters, if meat is as bad for you as the Adventist study suggests,
0:16:58 > 0:17:00what's in it that is doing the harm?
0:17:08 > 0:17:11Let's take the five most popular meat products
0:17:11 > 0:17:14in the UK by volume purchased.
0:17:14 > 0:17:19They are whole chicken, bacon, pork sausages,
0:17:19 > 0:17:24pork sliced cooked meats - things like ham and salami -
0:17:24 > 0:17:25and beef mince.
0:17:27 > 0:17:31Since we are concentrating on red and processed meat, I want to
0:17:31 > 0:17:34compare bacon, pork sausages and beef mince
0:17:34 > 0:17:36with some vegetarian options,
0:17:36 > 0:17:40to find what's in the meat that could be damaging our health.
0:17:43 > 0:17:48Dr Orla Kennedy is a nutritionist and dietician at Reading University.
0:17:49 > 0:17:52She's chosen three popular vegetarian foods commonly eaten
0:17:52 > 0:17:56instead of meat to do a head-to-head comparison.
0:17:59 > 0:18:04We've got vegetarian sausages, we've got tofu, OK, made from
0:18:04 > 0:18:06soya bean curd and then we've got cheese,
0:18:06 > 0:18:09good old-fashioned Cheddar cheese.
0:18:09 > 0:18:11None of it looks terribly appetising, does it,
0:18:11 > 0:18:14- in a kind of cold state laid out? - No, no, not quite.
0:18:14 > 0:18:18Maybe the cheese looks the tastiest there right now, definitely.
0:18:18 > 0:18:21Well, the tofu - maybe not.
0:18:21 > 0:18:25Before I turn to the bad, I want to look at the good.
0:18:25 > 0:18:27Let's start off by looking at protein.
0:18:27 > 0:18:29What's the protein content of these different foods?
0:18:29 > 0:18:32Beef mince has the highest amount of protein
0:18:32 > 0:18:35and it's good high-quality protein.
0:18:35 > 0:18:40Not far behind that is the cheese, OK, quite high in protein as well.
0:18:41 > 0:18:47Cheese has just over 25 grams of protein per 100 grams,
0:18:47 > 0:18:50only slightly behind the beef mince.
0:18:51 > 0:18:53Vegetarian sausages and ordinary sausages,
0:18:53 > 0:18:55there's not much difference between them.
0:18:55 > 0:18:57Interesting that both the pork
0:18:57 > 0:19:01and veggie variety contain almost the same amount of protein.
0:19:02 > 0:19:06And the tofu is last. That's going off the pedestal.
0:19:06 > 0:19:10What's interesting in terms of the red meat is proteins are made
0:19:10 > 0:19:14up of amino acids and there are a number of amino acids
0:19:14 > 0:19:18which are essential which the body can't make but actually meats
0:19:18 > 0:19:23provide these, so meats are a complete set of proteins, whereas
0:19:23 > 0:19:28you won't get that in the vegetarian or the kind of tofu alternatives.
0:19:28 > 0:19:32What many people probably don't realise is that meat can be
0:19:32 > 0:19:35richer in micro-nutrients than vegetables, particularly
0:19:35 > 0:19:38when it comes to some of the less well-known vitamins.
0:19:38 > 0:19:40So what about vitamin B12?
0:19:40 > 0:19:44Now that's one of my favourite vitamins, not terribly well-known
0:19:44 > 0:19:47vitamin or talked about but associated with brain development.
0:19:47 > 0:19:51- I like my brain.- So king of the B12s is the beef again.
0:19:51 > 0:19:55Surprisingly, actually - cheese is quite high. It's very close.
0:19:55 > 0:20:00You get three micrograms of B12 in every 100 grams of beef mince.
0:20:00 > 0:20:03The cheese offers almost as much
0:20:03 > 0:20:07but the other veggie options tested have absolutely none.
0:20:09 > 0:20:12So far, the meat's doing well but how does it fare
0:20:12 > 0:20:16when it comes to the Lord Voldemort of the diet world?
0:20:16 > 0:20:18And finally, saturated fat.
0:20:18 > 0:20:20Saturated fat.
0:20:20 > 0:20:24It's actually the cheese that has the highest amount of saturated fat.
0:20:24 > 0:20:29That's over 20 grams of saturated fat per 100 grams of cheese.
0:20:29 > 0:20:31- That's surprising. - That is surprising.
0:20:31 > 0:20:35However, the recommendations in terms of portion sizes are -
0:20:35 > 0:20:39for cheese it's a lot less, so a typical portion is about 30 grams.
0:20:40 > 0:20:43People tend to eat less cheese than they do meat
0:20:43 > 0:20:46and the other vegetarian foods being tested have hardly any
0:20:46 > 0:20:50saturated fat, certainly compared to the fat.
0:20:50 > 0:20:52Beef mince, the bacon rashers
0:20:52 > 0:20:56and the pork sausages have almost the same level of fat.
0:20:56 > 0:20:58They're all much of a muchness.
0:20:58 > 0:21:02And that muchness is a considerable amount of saturated fat.
0:21:04 > 0:21:08They all contain around 16 times the amount found in the tofu.
0:21:13 > 0:21:18So while meat tends to deliver more nutrients and micro-nutrients,
0:21:18 > 0:21:22on the whole it also contains more saturated fat.
0:21:24 > 0:21:27And it's the high levels of saturated fat you find in red
0:21:27 > 0:21:31and processed meats that gives them their unhealthy reputation.
0:21:33 > 0:21:37The actual reasons why we see an increased risk of coronary
0:21:37 > 0:21:39heart disease with a higher intake
0:21:39 > 0:21:41of red meat and processed meat,
0:21:41 > 0:21:43we don't really know exactly
0:21:43 > 0:21:47but there are several suggestions as to why that could be.
0:21:47 > 0:21:50So firstly it could be the saturated fat content that we
0:21:50 > 0:21:53see in say fattier red meats and also processed meat.
0:21:53 > 0:21:58Saturated fats mainly come from animal sources so animal fats,
0:21:58 > 0:22:01things like lard, dairy fats, butter.
0:22:01 > 0:22:04These are all things that are high in saturated fats.
0:22:04 > 0:22:07They're the fats that you get around meat so around your chop,
0:22:07 > 0:22:11under the skin of chicken and also marbled through steak.
0:22:11 > 0:22:16Some red meats tend to have about 50% of the fat comes from
0:22:16 > 0:22:20saturated fat, and 50% from unsaturated fat.
0:22:24 > 0:22:27This is saturated animal fat.
0:22:27 > 0:22:29Now unlike vegetable oil,
0:22:29 > 0:22:32this is fat that is solid at room temperature.
0:22:32 > 0:22:36For decades, we've been told that eating saturated fat leads to
0:22:36 > 0:22:40elevated cholesterol, to heart disease and then eventually
0:22:40 > 0:22:44to death but it's perhaps not quite as simple as that.
0:22:49 > 0:22:53It was back in the 1950s when research in the USA started
0:22:53 > 0:22:57to show a link between saturated fat and heart disease.
0:22:57 > 0:23:00'The chemist heats a sample in an oven
0:23:00 > 0:23:02'and pours the fat into a flask.'
0:23:02 > 0:23:05At the time, red meat was considered to be a healthy
0:23:05 > 0:23:07and wholesome part of our diet.
0:23:07 > 0:23:10'Prepared meats are easy to serve and good to eat.
0:23:10 > 0:23:14'They are enjoyed by almost everyone, everywhere, every day.'
0:23:16 > 0:23:20But when the connection between fat and heart trouble was made,
0:23:20 > 0:23:23red and processed meat were firmly in the firing line.
0:23:25 > 0:23:29By 1955, fat had become such a big issue that
0:23:29 > 0:23:32when President Eisenhower suffered a heart attack, one of the first
0:23:32 > 0:23:37things his doctors did was put him on a low-fat diet.
0:23:37 > 0:23:39Red and processed meat went from something
0:23:39 > 0:23:43we enjoyed to something that could carry us off to an early grave.
0:23:44 > 0:23:48For years, studies continued to reinforce the apparent
0:23:48 > 0:23:51link between saturated fat and heart disease.
0:23:51 > 0:23:54It seemed we would never again eat meat without
0:23:54 > 0:23:56feeling our arteries groan.
0:24:03 > 0:24:08Saturated fat and, by association, fatty meat continued to be
0:24:08 > 0:24:13the big bad villain well into the 21st century but in the last
0:24:13 > 0:24:16couple of years new studies have thrown that association into
0:24:16 > 0:24:22question, suggesting saturated fat might not be quite so bad after all.
0:24:22 > 0:24:25One of the most influential people behind this research is
0:24:25 > 0:24:30a doctor who works in Berkeley, just across the bay from San Francisco.
0:24:30 > 0:24:33What he and others discovered has shaken confidence in some
0:24:33 > 0:24:36of the advice that has been mainstream for decades.
0:24:39 > 0:24:42Dr Ronald Krauss is a world expert on diet and health.
0:24:45 > 0:24:47Ever since he graduated from medical school,
0:24:47 > 0:24:51Dr Krauss has been researching the impact that cholesterol
0:24:51 > 0:24:53and diet have on heart disease.
0:24:55 > 0:24:59We're meeting for breakfast and, as I'm still on my special diet,
0:24:59 > 0:25:04I'm on the hunt for meat, not always as easy as it sounds.
0:25:04 > 0:25:07- I'm actually looking for bacon. Do you see the words bacon?- Bacon?
0:25:07 > 0:25:08This is a Jewish deli, so...
0:25:08 > 0:25:13Oh, right, I'm not going to - I'm not going to see bacon here!
0:25:13 > 0:25:15They might have it.
0:25:15 > 0:25:17It's a Jewish deli.
0:25:17 > 0:25:18But I wouldn't count on it.
0:25:22 > 0:25:27For years, Dr Krauss was an adviser to the American Heart Association
0:25:27 > 0:25:30and a firm believer that higher saturated fat
0:25:30 > 0:25:33meant a higher risk of heart disease.
0:25:35 > 0:25:38But when he tried lowering people's cholesterol levels
0:25:38 > 0:25:42by putting them on low-fat diets, he got a nasty surprise.
0:25:42 > 0:25:45We thought that everybody would get better on this diet,
0:25:45 > 0:25:48that their cholesterol profile would improve.
0:25:48 > 0:25:52What we found was that the average man, whom we were studying,
0:25:52 > 0:25:56with a normal profile to start with, actually got worse.
0:25:59 > 0:26:02Not surprisingly, this made Dr Krauss question
0:26:02 > 0:26:05whether saturated fat was quite as bad as everyone believed.
0:26:07 > 0:26:11So he re-analysed 21 separate studies
0:26:11 > 0:26:13that looked at saturated fat and heart disease.
0:26:15 > 0:26:18His new analysis found no obvious link.
0:26:20 > 0:26:24When I first read your paper, which was a while ago,
0:26:24 > 0:26:27it was a shock and a revelation at the same time,
0:26:27 > 0:26:31because, you know, I was also convinced saturated fat must be bad.
0:26:31 > 0:26:34Looking at all the studies, on the average, there was
0:26:34 > 0:26:39no net effect of saturated fat per se on heart disease risk,
0:26:39 > 0:26:43so heart-attack risk was slightly higher but not significant.
0:26:43 > 0:26:47Stroke risk was actually reduced and so overall
0:26:47 > 0:26:51if you took it across a fair range of disease, heart disease
0:26:51 > 0:26:56and stroke, there was absolutely zero effect on those conditions.
0:26:58 > 0:27:01Others have come to a similar conclusion.
0:27:01 > 0:27:04Now that doesn't mean saturated fat is a health tonic
0:27:04 > 0:27:09but it does suggest the fear of saturated fat has been overdone.
0:27:09 > 0:27:12But is there something else in red meat that could be
0:27:12 > 0:27:13clogging our arteries?
0:27:15 > 0:27:20So we know that there is an association between high
0:27:20 > 0:27:23intakes of processed meat, red meat and heart disease
0:27:23 > 0:27:25but we don't really know why.
0:27:25 > 0:27:27Of course the evidence with saturated fats has
0:27:27 > 0:27:30changed in recent times and so this kind of makes the whole arena
0:27:30 > 0:27:32much more interesting but a little confusing.
0:27:32 > 0:27:35And I think it's very important that we understand the mechanisms
0:27:35 > 0:27:38before we jump to conclusions about what we do about it.
0:27:38 > 0:27:41And so it will be very interesting to see what we learn
0:27:41 > 0:27:45next about the connection of red meats and cardiovascular diseases.
0:27:50 > 0:27:53Dr Krauss is currently involved in new, more controversial,
0:27:53 > 0:27:57research into meat coming out of the Cleveland Clinic.
0:27:58 > 0:28:01It suggests that, yes, there is an ingredient in red meat that
0:28:01 > 0:28:05could increase your risk of heart attacks but bizarrely,
0:28:05 > 0:28:09it's concentrated not in the fat but the lean part of the meat.
0:28:14 > 0:28:19It's a nutrient called L-carnitine which is abundant in red meat,
0:28:19 > 0:28:22like the steak Dr Krauss is cooking me for lunch.
0:28:24 > 0:28:28Carnitine was really the substance that led to concerns about meat.
0:28:28 > 0:28:32It does appear to have effects on the build-up of cholesterol
0:28:32 > 0:28:36in the cells that form plaque in the arteries.
0:28:38 > 0:28:41This research suggests that L-carnitine can react with
0:28:41 > 0:28:46bacteria in our gut to produce TMAO, a substance that can
0:28:46 > 0:28:50slow down removal of cholesterol from our arteries.
0:28:54 > 0:28:58It just happens that the bugs that live in our intestine seem
0:28:58 > 0:29:02to like to eat carnitine and they happen to produce this
0:29:02 > 0:29:06substance and they don't care what happens after that.
0:29:06 > 0:29:10So the TMAO, which are the kind of bacteria, have kicked off
0:29:10 > 0:29:13and are then going to be going into my arteries
0:29:13 > 0:29:16and they're going to be clinging onto the fat - that's right?
0:29:16 > 0:29:19That's kind of the hypothesis, that's the theory, is it?
0:29:19 > 0:29:20That's the hypothesis.
0:29:21 > 0:29:26It's still early days but research on animals has shown that
0:29:26 > 0:29:30feeding them carnitine does lead to clogged arteries.
0:29:30 > 0:29:35This is not something that has been proven to occur in our bodies
0:29:35 > 0:29:38but it's a potential mechanism for how this might work.
0:29:39 > 0:29:44Ironically, we now have evidence that saturated fat isn't so bad
0:29:44 > 0:29:47and that lean meat which we've been advised to eat instead
0:29:47 > 0:29:49could be doing damage.
0:29:49 > 0:29:52The L-carnitine hypothesis is very, very interesting -
0:29:52 > 0:29:54it certainly gives us another avenue to explore.
0:29:54 > 0:29:57But I think what's interesting is that it may not be
0:29:57 > 0:30:00the obvious offenders as we first thought they were,
0:30:00 > 0:30:02the saturated fat and the salt.
0:30:02 > 0:30:04They might be important for other reasons
0:30:04 > 0:30:05but it might be this other thing,
0:30:05 > 0:30:08when we're talking about meats, that is actually the problem.
0:30:19 > 0:30:24At the moment, the jury is still out about what it is in meat
0:30:24 > 0:30:27that can increase your risk of cardiac problems
0:30:27 > 0:30:30and also how big the risk really is.
0:30:37 > 0:30:39So where does that leave me?
0:30:39 > 0:30:42At this moment in time, pretty confused.
0:30:48 > 0:30:52As I tuck into yet another burger as part of my high-meat diet...
0:30:52 > 0:30:55That's how a burger should look, right there.
0:30:55 > 0:30:57It's clear that unearthing the truth about meat
0:30:57 > 0:30:59is far from straightforward.
0:30:59 > 0:31:00That's a very good burger.
0:31:00 > 0:31:04As well as health, meat is about our culture, who we are.
0:31:06 > 0:31:09We have to be clear that there are things above
0:31:09 > 0:31:14and beyond the health effects of foods that are very important to us.
0:31:17 > 0:31:21There is something about its place in our culture, in our society.
0:31:21 > 0:31:25It's a sign of affluence to be able to put meat on the table every day.
0:31:25 > 0:31:28Meat is also seen as quite a centrepiece to a meal.
0:31:28 > 0:31:32So if you think about Christmas or a Sunday roast,
0:31:32 > 0:31:36you usually have a big piece of meat in the middle of the table
0:31:36 > 0:31:39so a lot of families bond around that meal.
0:31:49 > 0:31:53So far, I've heard from two experts with radically different
0:31:53 > 0:31:54points of view.
0:31:54 > 0:31:57I still don't know how much meat is safe to eat.
0:31:57 > 0:32:01And amongst our favourites of beef, pork, mince, sausages,
0:32:01 > 0:32:05bacon and ham, are some clearly worse than others.
0:32:07 > 0:32:10Looking for more answers, I've come to Boston.
0:32:11 > 0:32:14At Harvard University's School of Public Health,
0:32:14 > 0:32:17they've recently completely the world's longest-ever study
0:32:17 > 0:32:20looking at the health effects of eating different foods.
0:32:24 > 0:32:27As part of it, the researchers also looked at red meat
0:32:27 > 0:32:31and processed meat separately, to assess their relative impact.
0:32:34 > 0:32:36The research is the life's work of the man
0:32:36 > 0:32:40some call the father of nutrition epidemiology,
0:32:40 > 0:32:42Dr Walter Willett.
0:32:44 > 0:32:47So, this is kind of healthy food, yes?
0:32:47 > 0:32:52Yes, this is I think a very good option of healthy alternatives
0:32:52 > 0:32:55and the food service here has been really great in terms
0:32:55 > 0:32:59of trying to offer what we see to be important for health outcomes.
0:32:59 > 0:33:01Enjoying the cartoon up there. Makes you look
0:33:01 > 0:33:04a little like Colonel Sanders of Kentucky Fried Chicken fame.
0:33:04 > 0:33:06No relationship.
0:33:06 > 0:33:10Dr Willett and his team have been following the diets of over
0:33:10 > 0:33:15100,000 people for over 30 years, another huge study.
0:33:15 > 0:33:19The results were clear, starting with those for unprocessed
0:33:19 > 0:33:24red meat, basically fresh meat like minced beef, steak and chops.
0:33:25 > 0:33:29We found in this population of about 120,000 men and women
0:33:29 > 0:33:33that those who consumed high amounts of red meat had higher risks
0:33:33 > 0:33:36of total mortality, cardiovascular mortality and cancer mortality.
0:33:36 > 0:33:39Right, so they died of heart attacks and they died of some cancers?
0:33:39 > 0:33:41Yes.
0:33:41 > 0:33:44They found eating red meat had a relatively modest impact.
0:33:44 > 0:33:4785 grams a day, the size of an average beef burger,
0:33:47 > 0:33:53was associated with a 13% increased risk of premature death.
0:33:53 > 0:33:55Eating processed meat was much worse.
0:33:55 > 0:34:01If you had steak, burgers, and then you have kind of bacon
0:34:01 > 0:34:04and hot dogs over here, which is the worst?
0:34:04 > 0:34:07Processed meat like bacon and boloney
0:34:07 > 0:34:12and sausage are ounce-for-ounce several times worse.
0:34:12 > 0:34:15In fact, the study suggested that eating about 35 grams
0:34:15 > 0:34:19of processed meat a day - a couple of rashers of bacon -
0:34:19 > 0:34:23was associated with a 20% increased risk of premature death.
0:34:23 > 0:34:28This was mainly because of an increased risk of heart disease
0:34:28 > 0:34:30and cancer.
0:34:30 > 0:34:34Bad news, considering three of the UK's top five favourites,
0:34:34 > 0:34:39bacon, pork sausages and ham, all fall into THAT category.
0:34:39 > 0:34:42How has your research affected how you eat?
0:34:42 > 0:34:45I grew up in the Midwest and red meat was part of our diet
0:34:45 > 0:34:48probably three times a day. And on most days,
0:34:48 > 0:34:51we often had it for breakfast in one form or another, sandwiches,
0:34:51 > 0:34:56hot dogs at school and usually hamburger, meat loaf,
0:34:56 > 0:34:58something like that at dinner time.
0:34:58 > 0:35:02But my diet has changed quite a bit in that way, as we've seen
0:35:02 > 0:35:07the data come in, that I have red meat maybe a few times a year.
0:35:07 > 0:35:08I'm not a strict vegetarian.
0:35:08 > 0:35:11- A few times a year? - A few times a year.
0:35:11 > 0:35:14Well, that was actually very disappointing, particularly
0:35:14 > 0:35:18as I'm on this high-meat diet, because I was hoping for just a
0:35:18 > 0:35:23few crumbs of comfort but Dr Willett had almost nothing good to say.
0:35:23 > 0:35:27Things are looking grim for lovers of burgers, beef and bacon.
0:35:35 > 0:35:38But just when I thought things were becoming clearer, I came across
0:35:38 > 0:35:43another study and its findings don't quite match up with Dr Willett's.
0:35:48 > 0:35:51The European Prospective Investigation into Cancer
0:35:51 > 0:35:54and Nutrition, or EPIC for short,
0:35:54 > 0:35:57followed even more people than the other studies I've looked into
0:35:57 > 0:36:00though for a shorter period, 12 years.
0:36:00 > 0:36:03When you compare it to the American studies,
0:36:03 > 0:36:06there's a striking difference in their findings.
0:36:06 > 0:36:08Now these are the results of the so-called EPIC study
0:36:08 > 0:36:10and it really was epic.
0:36:10 > 0:36:14The researchers followed half a million people in ten countries
0:36:14 > 0:36:16for more than 12 years,
0:36:16 > 0:36:19and their conclusions are very different to the Harvard study.
0:36:19 > 0:36:22They found that eating moderate amounts of red meat
0:36:22 > 0:36:24had no effect on mortality.
0:36:26 > 0:36:29In fact, they conclude that "a low -
0:36:29 > 0:36:33"but not zero - consumption of meat might be beneficial for health.
0:36:33 > 0:36:37"This is understandable as meat is an important source of protein,
0:36:37 > 0:36:40"iron, zinc, B vitamins, vitamin A
0:36:40 > 0:36:43"and essential fatty acids."
0:36:43 > 0:36:46In other words, eating small amounts of red meat seemed to be
0:36:46 > 0:36:49better for you than being a vegetarian.
0:36:49 > 0:36:53So, the Harvard study found a modest association between moderate
0:36:53 > 0:36:58red meat consumption and early death, the European study didn't.
0:36:58 > 0:37:02The red meat argument is slightly less clear at the moment.
0:37:03 > 0:37:06We wouldn't expect two studies to have identical results.
0:37:06 > 0:37:07However, in general,
0:37:07 > 0:37:10when studies have different results,
0:37:10 > 0:37:13it can be difficult to pinpoint the exact reason for the difference,
0:37:13 > 0:37:17so we're not as confident that there is a real
0:37:17 > 0:37:20association between red meat and early death.
0:37:20 > 0:37:25And the fact is that observational studies like these can never
0:37:25 > 0:37:30really prove that specific dietary habits cause a disease.
0:37:30 > 0:37:34These types of studies can find associations between dietary
0:37:34 > 0:37:38components, for example, red meat and disease,
0:37:38 > 0:37:41but we can't absolutely prove for certain that it is
0:37:41 > 0:37:44the dietary component that is causing the disease.
0:37:47 > 0:37:51In light of the varied results of these long-term studies, just
0:37:51 > 0:37:55how much red meat do the experts I've met think we should be eating?
0:37:59 > 0:38:02If one is able and comfortable
0:38:02 > 0:38:05to have no red meat at all...
0:38:05 > 0:38:07is a good thing.
0:38:07 > 0:38:11However, you know the population is not going to become vegetarian.
0:38:11 > 0:38:16Um, and so I think one starts with the concept of meatless days.
0:38:20 > 0:38:21It looks like having red meat
0:38:21 > 0:38:24quite infrequently,
0:38:24 > 0:38:26say once a month,
0:38:26 > 0:38:28is really an optimal diet.
0:38:28 > 0:38:32It's good to think of it as a special event, like, I don't know
0:38:32 > 0:38:36if you consider here, but in New England, lobster is a special event.
0:38:36 > 0:38:38It's not something that we have on an everyday basis.
0:38:41 > 0:38:43We think that lean meat
0:38:43 > 0:38:47in particular is not a hazard to health
0:38:47 > 0:38:48if it's consumed in moderation.
0:38:53 > 0:38:57From the evidence so far, what I conclude is that eating
0:38:57 > 0:39:00a lot of red meat every day is not a great idea.
0:39:00 > 0:39:04But a modest amount a couple of days a week is unlikely to do you
0:39:04 > 0:39:06much harm.
0:39:06 > 0:39:09Now, before meat-eaters go off rejoicing, there is
0:39:09 > 0:39:12a sting in the tail, because both the EPIC study
0:39:12 > 0:39:15and the Harvard study found that eating moderate
0:39:15 > 0:39:20amounts of processed meat, that is, bacon, sausages, salami, did have a
0:39:20 > 0:39:24significant effect on your risk of getting heart disease and cancer.
0:39:34 > 0:39:38So, just how might processed meat cause cancer?
0:39:46 > 0:39:50Here at St Thomas's Hospital, they see hundreds of patients each year
0:39:50 > 0:39:54who are suspected of having colorectal and bowel cancer.
0:39:54 > 0:39:57It is the third most common cancer in the UK
0:39:57 > 0:40:01and the one that has the clearest links to a high-meat diet.
0:40:11 > 0:40:15Consultant gastroenterologist Dr Jeremy Sanderson uses
0:40:15 > 0:40:18a colonoscope to check for early signs of bowel cancer.
0:40:21 > 0:40:23It's a flexible tube with a camera attached
0:40:23 > 0:40:27inserted into the rectum and guided around the bowel,
0:40:27 > 0:40:30giving remarkable high-definition pictures inside the body.
0:40:31 > 0:40:34He's keen to show me how the equipment works.
0:40:34 > 0:40:36Much to his disappointment,
0:40:36 > 0:40:40I turn down the opportunity for a personal examination.
0:40:40 > 0:40:42This is a standard Olympus colonoscope.
0:40:42 > 0:40:46As you can see, it's about a metre and a half long but you'll be
0:40:46 > 0:40:50pleased to know we don't usually need to use all of that instrument.
0:40:50 > 0:40:51OK, how far do you go then normally?
0:40:51 > 0:40:54Normally, because the bowel is quite flexible, and in some people
0:40:54 > 0:40:58you can get almost all this telescope coiled up into the bowel
0:40:58 > 0:41:02if your bowel's very flexible, and that's the art of colonoscopy,
0:41:02 > 0:41:06is to be able to straighten it, concertina the bowel down.
0:41:06 > 0:41:08We sometimes say it ends up at the end of the treatment looking
0:41:08 > 0:41:10a bit like a question mark shape.
0:41:10 > 0:41:12What are you looking for?
0:41:12 > 0:41:15We're looking for the "polyps" they're called, they're little tiny
0:41:15 > 0:41:20mole-like growths on the lining of the bowel and steadily what
0:41:20 > 0:41:24happens over a period of five, ten years, those little growths turn,
0:41:24 > 0:41:28get bigger, and a bigger polyp, and finally can become a cancer.
0:41:29 > 0:41:32This is the view Dr Sanderson gets
0:41:32 > 0:41:35when he's searching for polyps in the large bowel.
0:41:35 > 0:41:37So, what am I looking at, at the moment?
0:41:37 > 0:41:41Well, essentially this...this is a normal colonoscopy so you're looking
0:41:41 > 0:41:44at the lining of the colon, you know, down the end
0:41:44 > 0:41:45of the instrument.
0:41:45 > 0:41:48It's a sort of very high resolution video camera.
0:41:48 > 0:41:51How far up, so to speak, are we?
0:41:51 > 0:41:53We're about 40cm up.
0:41:53 > 0:41:57As you can see, the nice normal smooth lining, you can
0:41:57 > 0:41:59make out blood vessels.
0:41:59 > 0:42:02In fact, when the bowel's altered or inflamed, one of the first things
0:42:02 > 0:42:06that goes is the ability to see the blood vessels in such detail.
0:42:06 > 0:42:08The architecture is very strange, isn't it?
0:42:08 > 0:42:12But things look very different when the patient has an abnormal bowel.
0:42:12 > 0:42:15Whoa, right, I had no idea.
0:42:15 > 0:42:17That... That is a polyp, is it?
0:42:17 > 0:42:19That is a polyp. So what you're seeing here,
0:42:19 > 0:42:21and in fact you can see it's on a stalk...
0:42:21 > 0:42:22- Can you see it here? - Oh, wow, there you go.
0:42:22 > 0:42:25- Here's another one.- Oh, that looks like an alien growth.
0:42:25 > 0:42:27Yes, it's grown to a size. And that started...
0:42:27 > 0:42:29It looks huge.
0:42:29 > 0:42:32Well, that's about... that's about 2cm.
0:42:32 > 0:42:34It started as a small, little polyp.
0:42:34 > 0:42:37It grew, it grew and it's pulled a bit of the lining with it.
0:42:37 > 0:42:39How old would this person be?
0:42:39 > 0:42:41This person is in their 50s.
0:42:41 > 0:42:44You'd come across that and you're going, "That's abnormal."
0:42:44 > 0:42:47If the polyps aren't removed, they can turn cancerous.
0:42:47 > 0:42:53Why might a diet rich in meat lead to polyps?
0:42:53 > 0:42:57Well...as doctors always say, it's complicated.
0:42:57 > 0:42:58There are various factors in meat,
0:42:58 > 0:43:02particularly in processed meats, chemical factors that have
0:43:02 > 0:43:09been shown to promote cancer or to promote increased growth of cells.
0:43:09 > 0:43:12In light of what I've heard from other experts,
0:43:12 > 0:43:16I'm curious to find out what Dr Sanderson himself eats.
0:43:16 > 0:43:17Do you eat red meat?
0:43:17 > 0:43:19I most certainly do eat red meat.
0:43:19 > 0:43:21I believe in being an omnivore.
0:43:21 > 0:43:24I don't think I'm an excessive meat eater.
0:43:24 > 0:43:25OK, define excessive.
0:43:25 > 0:43:27Well, I think I'll have... I'll have...
0:43:27 > 0:43:30maybe have...you know, two bits of red meat each week.
0:43:30 > 0:43:36If I was going to make one change to my diet, I think it's the...
0:43:36 > 0:43:40reducing those processed meats that is the one good opportunity
0:43:40 > 0:43:44and then you can keep your roast beef and your...and your steak.
0:43:44 > 0:43:47Dr Sanderson thinks the most effective way to prevent
0:43:47 > 0:43:52bowel cancer is to have a colonoscopy in your mid-50s,
0:43:52 > 0:43:53so any polyps can be removed.
0:43:53 > 0:43:57What we've done here is we have delivered this snare wire
0:43:57 > 0:44:00around the polyp and it's sitting on the stalk, and we've
0:44:00 > 0:44:04tightened it and now you'll see we're going to apply a current
0:44:04 > 0:44:08to this stalk, and then you'll see some smoke and burning generated.
0:44:08 > 0:44:10That's all on the end of the endoscope?
0:44:10 > 0:44:12Yes, so we're just tightening it and then...there it goes,
0:44:12 > 0:44:13and that's it, polyp gone.
0:44:13 > 0:44:16- It's gone, "pop". - We call that an ex-polyp.
0:44:22 > 0:44:26So, what is it that makes processed meat like ham and bacon
0:44:26 > 0:44:28potentially carcinogenic?
0:44:30 > 0:44:33What's in it that could promote the growth of cancerous polyps?
0:44:39 > 0:44:41I'm back at Reading University's
0:44:41 > 0:44:45Food and Nutritional Sciences Department to find out.
0:44:45 > 0:44:48And what better way than to actually make some?
0:44:53 > 0:44:57Dr Danny Commane is a specialist in gut health and colorectal cancer.
0:44:57 > 0:45:02He's gathered together everything we need to turn pork into bacon,
0:45:02 > 0:45:05the nation's, and my, favourite processed meat.
0:45:05 > 0:45:06Hi there.
0:45:06 > 0:45:08Hi, Michael, we're going to cure some bacon,
0:45:08 > 0:45:11- I'll give you the gloves. - I've never done this before.
0:45:11 > 0:45:15OK, so, we've got some sea salt and we need 12 teaspoons of it.
0:45:15 > 0:45:17- 12?! blimey!- OK.
0:45:17 > 0:45:18Yeah.
0:45:18 > 0:45:21It's only when you make it yourself you realise how much
0:45:21 > 0:45:22salt there is in it.
0:45:22 > 0:45:23Yeah, that's right.
0:45:23 > 0:45:26- Sugar, how much? - So, five teaspoons of sugar,
0:45:26 > 0:45:30and we've just got curing salt which contains our sodium nitrite.
0:45:30 > 0:45:34OK, it's not encouraging, it says, "toxic if not used correctly",
0:45:34 > 0:45:36and how much of this stuff? I'll be careful with this.
0:45:36 > 0:45:38- Just one teaspoon.- And then, presumably,
0:45:38 > 0:45:41- you just mix it up, do you? - That's right, yeah.- OK.
0:45:41 > 0:45:44And then we're going to massage it into our...into our meat,
0:45:44 > 0:45:47mix it well in, try and get into all the cracks and crannies in the meat.
0:45:49 > 0:45:53Once the cure is applied, the meat will need to be refrigerated
0:45:53 > 0:45:55to cure for about seven days.
0:45:58 > 0:46:00The first thing you notice is just how much salt is
0:46:00 > 0:46:02involved in the process.
0:46:02 > 0:46:07The salt is obviously not great for us. It's related to hypertension
0:46:07 > 0:46:10which is a leading cause of cardiovascular disease.
0:46:10 > 0:46:14But it's not just the salt that can cause problems, there's also
0:46:14 > 0:46:18the sodium nitrite I added which is often used in the curing process.
0:46:18 > 0:46:21So, what it is about the sodium nitrite, what does it do?
0:46:21 > 0:46:24The nitrite, it's very good for the meat, it kills
0:46:24 > 0:46:27the bacteria in the meat, it stops us getting botulism,
0:46:27 > 0:46:29however in the stomach environment
0:46:29 > 0:46:33it's believed that some of that nitrite reacts with amino acids -
0:46:33 > 0:46:37the building blocks of protein - to form what we call nitrosamines,
0:46:37 > 0:46:40and we believe that these are quite chemically reactive.
0:46:40 > 0:46:44And when they make their way down into the gastro-intestinal tract,
0:46:44 > 0:46:47they can start interacting with DNA in cells and tissues
0:46:47 > 0:46:51and that is what we believe initiates the cancer process.
0:46:51 > 0:46:57OK, and how strong is the evidence of a direct link between nitrites
0:46:57 > 0:46:58and cancer?
0:46:58 > 0:47:00It's a very complicated picture.
0:47:00 > 0:47:02Um, we believe that it may contribute
0:47:02 > 0:47:07but we want to understand why, and this is one potential mechanism.
0:47:07 > 0:47:11So nitrites are still only a suspect,
0:47:11 > 0:47:14we have yet to establish a direct link between them
0:47:14 > 0:47:16and colorectal cancer.
0:47:16 > 0:47:19And nitrites are not the only part
0:47:19 > 0:47:22of the curing process that researchers wonder about.
0:47:25 > 0:47:28There we go, we have liftoff!
0:47:29 > 0:47:33When meat is smoked, it's often done in massive cold stores,
0:47:33 > 0:47:36we're doing it on a much more intimate scale.
0:47:37 > 0:47:41One of the things that we do to flavour meat is we smoke it, and the
0:47:41 > 0:47:45same chemicals that we generate when we smoke cigarettes, things called
0:47:45 > 0:47:49polyaromatic hydrocarbons, are generated in the smoking process.
0:47:50 > 0:47:54These chemicals, known as PAHs, stick to the meat -
0:47:54 > 0:47:57and when we eat it, they can be absorbed by the body.
0:47:59 > 0:48:03They can react in a very similar way to the nitrosamines with DNA
0:48:03 > 0:48:06through our gastrointestinal tract
0:48:06 > 0:48:09and might be another potential mechanism whereby red
0:48:09 > 0:48:13and processed meats increase our risk of gastrointestinal cancers.
0:48:15 > 0:48:20Like nitrites, PAHs are still only potential suspects when it
0:48:20 > 0:48:25comes to finding a link between processed meat and cancer. Still,
0:48:25 > 0:48:29I'm starting to see why processed meat has such a bad reputation.
0:48:29 > 0:48:31But just how bad is bad?
0:48:34 > 0:48:37The Harvard and EPIC studies both suggest that eating
0:48:37 > 0:48:40a moderate amount of processed meat increases your annual
0:48:40 > 0:48:42risk of death by about 20%.
0:48:47 > 0:48:51But is this a statistic that's worth worrying about?
0:48:51 > 0:48:55How does the risk of eating processed meat compare with
0:48:55 > 0:48:58the risk of doing other everyday things?
0:49:04 > 0:49:07To untangle the numbers in the studies,
0:49:07 > 0:49:10I've recruited world renowned Cambridge statistician
0:49:10 > 0:49:12Professor David Spiegelhalter.
0:49:13 > 0:49:17By examining a broad range of stats about who we are
0:49:17 > 0:49:21and how we live, it's possible to determine how certain things
0:49:21 > 0:49:23might impact our life span.
0:49:23 > 0:49:26As a statistician, you kind of look at numbers,
0:49:26 > 0:49:29you look at studies and things like that, if you were to kind of nail
0:49:29 > 0:49:31down what we can really, really say
0:49:31 > 0:49:34about how long we live, what sort of things
0:49:34 > 0:49:37are we reasonably certain WILL cut years off your life?
0:49:37 > 0:49:42Well, the first thing of course is, sadly, being male.
0:49:42 > 0:49:48Every male has got the same risk of dying each year as a woman
0:49:48 > 0:49:49who's four years older than them.
0:49:49 > 0:49:52So, on average, men live four years less than women.
0:49:53 > 0:49:54Then there's smoking.
0:49:56 > 0:49:59We know, for example, that people who smoke 20-a-day have the same
0:49:59 > 0:50:00annual risk of death as someone
0:50:00 > 0:50:03who's about eight years older than themselves.
0:50:03 > 0:50:07So, on average, over the whole lifetime,
0:50:07 > 0:50:10if you smoke 20-a-day, it's about eight years off your life.
0:50:10 > 0:50:11What about alcohol?
0:50:11 > 0:50:15Well, I believe the evidence that says the first drink each day
0:50:15 > 0:50:17is actually medicine, it's going to do you good.
0:50:17 > 0:50:20But after that, of course, it's downhill all the way.
0:50:20 > 0:50:22And so if you have an extra couple of drinks a day
0:50:22 > 0:50:25and beyond that, maybe it's about a year off your life.
0:50:32 > 0:50:36So, what about the studies that suggest a 20% annual increased
0:50:36 > 0:50:39risk of death from eating processed meat?
0:50:41 > 0:50:45Well, let's take two 40-year-old men, who are similar in all ways
0:50:45 > 0:50:49and one of them has two rashers of bacon every day,
0:50:49 > 0:50:52say in a bacon sandwich. Now the bacon-eater
0:50:52 > 0:50:55would be expected to live two years less.
0:50:55 > 0:50:58So roughly you'd expect the 40-year-old
0:50:58 > 0:51:01who does eat the bacon, on average, to live till he's 78,
0:51:01 > 0:51:05whereas the one who doesn't, you'd expect him to live till 80.
0:51:05 > 0:51:08And losing 2 years over 40 years
0:51:08 > 0:51:13is pro-rata like losing one hour a day for that bacon sandwich.
0:51:13 > 0:51:16OK, that will certainly give me pause...pause for thought
0:51:16 > 0:51:18when I pick up my bacon sandwich.
0:51:18 > 0:51:20Eat it slowly.
0:51:20 > 0:51:24Eat it slowly and enjoy it as well. OK. Yeah. Wow.
0:51:27 > 0:51:31I'm actually quite shaken because if the studies are right
0:51:31 > 0:51:35and David is right, then that is an incredibly heavy price to pay.
0:51:35 > 0:51:40But statistics never convince people to change their mind, it is
0:51:40 > 0:51:44personal experience, so I'm really keen to discover what effect
0:51:44 > 0:51:47my heavy-meat diet has been having on my body.
0:51:47 > 0:51:53I've been eating about 130 grams of red and processed meat every day
0:51:53 > 0:51:57for four weeks, that's twice the level that's advised.
0:51:57 > 0:52:00Now, I'm only one person and I've only been on the diet for a short
0:52:00 > 0:52:04amount of time, so the results are going to be specific to me
0:52:04 > 0:52:07and I'm not reflective of the population as a whole,
0:52:07 > 0:52:11but that said, I'm obviously very interested to see
0:52:11 > 0:52:13if it's done anything to my body.
0:52:13 > 0:52:16I'm returning to Reading University, where I had a health check
0:52:16 > 0:52:17before I started my diet.
0:52:20 > 0:52:24Nutritional biochemist Dr Gunter Kuhnle studies the impact
0:52:24 > 0:52:26meat has on the gut.
0:52:30 > 0:52:35A simple way of finding out how my gut responded to a high-meat diet
0:52:35 > 0:52:38is by providing the lucky man with a sample of my faeces.
0:52:42 > 0:52:47Dr Kuhnle's team are looking for levels of N-nitroso compounds,
0:52:47 > 0:52:51compounds that can be formed when we digest red and processed meat
0:52:51 > 0:52:53and are suspects when it comes to bowel cancer.
0:52:53 > 0:52:57What about the effects of my stool samples?
0:52:57 > 0:52:59We analysed your stool samples and we were quite surprised
0:52:59 > 0:53:03- because we didn't find any change in faecal nitroso compounds.- OK.
0:53:03 > 0:53:06So, what we would normally have expected that with this increase
0:53:06 > 0:53:07in meat, we would have seen
0:53:07 > 0:53:10an increase in faecal nitroso compounds,
0:53:10 > 0:53:14and these are the compounds we suspect that are linked...
0:53:14 > 0:53:16are the link between meat and cancer risk
0:53:16 > 0:53:17and we didn't find anything there.
0:53:17 > 0:53:20OK, so something, any explanation again?
0:53:20 > 0:53:24Well, after we looked at your diet, a possible explanation is that
0:53:24 > 0:53:27you consume quite a lot of fruit and vegetables -
0:53:27 > 0:53:28well beyond the five a day -
0:53:28 > 0:53:32and fibre is known to reduce the formation of these compounds.
0:53:32 > 0:53:35Right, so, the fibre, although I was eating a lot more processed meat,
0:53:35 > 0:53:37I was also eating quite a lot of fibre
0:53:37 > 0:53:40and that kind of, to some degree, protected me against the changes.
0:53:40 > 0:53:42Well, that's quite encouraging I suppose.
0:53:42 > 0:53:45Dr Kuhnle has also checked my pre
0:53:45 > 0:53:50and post-diet blood samples to look at the levels of cholesterol.
0:53:50 > 0:53:53Well, your cholesterol went up from 6.2 to 6.8,
0:53:53 > 0:53:55so that's quite a bit of an increase.
0:53:55 > 0:53:57Right that is a lot, isn't it?
0:53:57 > 0:53:58It is.
0:53:58 > 0:54:02Not only that, but it was the levels of LDL - the bad cholesterol -
0:54:02 > 0:54:04that really went up.
0:54:06 > 0:54:10Perhaps I'll get better news when I have my body fat checked.
0:54:12 > 0:54:18OK, Michael, the news is that your body fat has gone up by three kilos.
0:54:18 > 0:54:20- Three kilos?- Three kilos.- Blimey.
0:54:20 > 0:54:24And most of this is in the trunk area, which is not good
0:54:24 > 0:54:28because this fat is close to the internal organs which means
0:54:28 > 0:54:30you can become insulin resistant and diabetic.
0:54:30 > 0:54:31Indeed, visceral fat
0:54:31 > 0:54:33- and sadly I know all about it. - Not good news, yes.
0:54:33 > 0:54:35- Three kilos!- Putting it simply.
0:54:35 > 0:54:38- That's absolutely phenomenal. - Yes, yes absolutely.
0:54:38 > 0:54:39Right.
0:54:40 > 0:54:42Yet more bad news.
0:54:42 > 0:54:46There's one last chance for some good news with my blood pressure.
0:54:46 > 0:54:50OK, so, Michael, the reading has gone up this time,
0:54:50 > 0:54:54when you first came to see us it was 118 over 69.
0:54:54 > 0:54:56Right, so that was kind of in the good range, wasn't it?
0:54:56 > 0:55:01It was in the...yeah, the really good range on the lower side,
0:55:01 > 0:55:04now it's 141 over 81.
0:55:04 > 0:55:08- Blimey.- Which means you have now gone into the high blood pressure
0:55:08 > 0:55:11range but at the bottom of the high blood pressure range, OK?
0:55:11 > 0:55:14- Blimey, that is high, isn't it? - Yes, it is.
0:55:14 > 0:55:16Could you say that number again? It's 141 over...
0:55:16 > 0:55:18141 over 81.
0:55:18 > 0:55:22- 81?- Yes.- God, that has shot up, hasn't it?- Absolutely.
0:55:22 > 0:55:24That is actually quite upsetting.
0:55:24 > 0:55:26Yes. That's right, yes...
0:55:26 > 0:55:29when you think that it's probably due to diet.
0:55:29 > 0:55:31I think it's entirely due to the fact
0:55:31 > 0:55:33I've been on this high-meat diet.
0:55:33 > 0:55:34Yes.
0:55:34 > 0:55:37- I don't think that's done me any good at all.- No.
0:55:37 > 0:55:39Well, that was a nasty shock, particularly
0:55:39 > 0:55:43the effect on my blood pressure and on my cholesterol. So I'm going
0:55:43 > 0:55:46to go home now and I'm going to return to my normal diet
0:55:46 > 0:55:48and I've got to try and get rid of
0:55:48 > 0:55:51these extra three kilos of abdominal fat.
0:55:57 > 0:56:01Tonight, my family and I are having friends around for dinner.
0:56:03 > 0:56:05I want to put what I've discovered
0:56:05 > 0:56:08and digested about meat onto the table.
0:56:13 > 0:56:15OK.
0:56:15 > 0:56:18When I started making this programme, I didn't think that
0:56:18 > 0:56:22eating more red and processed meat would have much impact.
0:56:23 > 0:56:28So, it was, I must admit, a nasty shock the effect that all that bacon
0:56:28 > 0:56:31and processed meat I was eating had on my body.
0:56:31 > 0:56:33I sort of expected it might have a very small effect
0:56:33 > 0:56:36but I was actually quite genuinely shocked by how big the effect.
0:56:36 > 0:56:39We should probably cut back, particularly discourage
0:56:39 > 0:56:41- the kids from eating quite as much as they do.- Yeah.
0:56:41 > 0:56:43Yes, no, I think that's probably right.
0:56:43 > 0:56:45There was a point where we were buying...
0:56:45 > 0:56:47I don't know how many packs a week...
0:56:47 > 0:56:50- Bacon, yes.- ..and they were having it...- And they were... No, quite.
0:56:50 > 0:56:52..before every meal and after every meal as they could.
0:56:52 > 0:56:54No, quite, there we go.
0:56:54 > 0:56:56The pigs can live happy.
0:56:56 > 0:56:57THEY LAUGH
0:56:59 > 0:57:01We all need to make our own decisions.
0:57:01 > 0:57:04Me? I'm going to cut right back on the processed stuff -
0:57:04 > 0:57:06which will make my wife happy.
0:57:06 > 0:57:11But I think this kind of red meat, unprocessed and fairly lean
0:57:11 > 0:57:14is fine on occasion - which will make me happy.
0:57:14 > 0:57:16- Lovely. Thank you.- Very helpful.
0:57:16 > 0:57:18Lovely, it's very kind of you.
0:57:18 > 0:57:21If you are cutting back on meat, perhaps going largely
0:57:21 > 0:57:26vegetarian or vegan, make sure what you're eating has enough protein,
0:57:26 > 0:57:30iron, zinc and B12, all the things that red meat has in spades.
0:57:30 > 0:57:33And don't replace meat with food
0:57:33 > 0:57:36high in sugar or refined carbohydrates.
0:57:37 > 0:57:40At the moment, the British Heart Foundation recommends that
0:57:40 > 0:57:44meat can be included as part of a healthy, balanced diet.
0:57:44 > 0:57:47I think the problems come when it's not a balanced diet
0:57:47 > 0:57:52and there's too much emphasis on eating meat and processed meat.
0:57:54 > 0:57:58I think what we can be clear for you is that the healthiest diet
0:57:58 > 0:58:01is a predominantly plant-based diet supplemented with meat.
0:58:02 > 0:58:07Roughly per week, how many grams of red meat would you say
0:58:07 > 0:58:09the average person should eat?
0:58:09 > 0:58:12I think that the evidence suggests that eating up to, say,
0:58:12 > 0:58:16100 grams which is about 4oz every so often is not
0:58:16 > 0:58:19going to do you any harm. I think it's much better to kind of vary it.
0:58:19 > 0:58:22So I think, you know, a bit of fish here, chicken, a bit of meat there.
0:58:22 > 0:58:24I think personally I would... I think
0:58:24 > 0:58:28I'd prefer to eat more vegetables, vegetables, vegetables.
0:58:33 > 0:58:37MUSIC: "Little Red Rooster"