Mind the knowledge gap…………..

Professor Robert Pickard, Emeritus Professor of Neurobiology at the University of Cardiff , takes a look at the nation’s understanding of red meat.

We recently conducted some research  with 2000 members of the public  to ascertain people’s views of red meat and to identify if people are aware of and understand its nutrient make-up. The results were quite surprising and revealed a few misconceptions. Misconceptions that could ultimately leave Britons at risk of health problems.

Perhaps one of the main things the report highlighted was the confusion about nutrients and which foods provide which nutrients. For example, nearly half of those asked thought that spinach was a better source of iron than red meat, which isn’t true. Red meat actually has three times as much iron as spinach and the iron in red meat comes in a far more readily absorbed form than that found in plants.

One in five also thought that green leafy vegetables provide vitamin D and one in ten thought  that citrus fruits provide vitamin D, when in fact they contain none. It was encouraging that one in 10 did identify that red meat is a useful source of vitamin D, but this again highlights a lack of overall awareness about where nutrients can be found.

Confirming people’s lack of understanding of red meat is the response that one in five admitted that they felt that they did not know enough about meat to buy at a butcher’s shop. Surprisingly,  less than half named pork as a type of red meat and one in five didn’t realise that lamb is also classed as a red meat.

However, it is heartening  to see that when it comes to our meat-eating habits, two out of three believe red meat is an important part of a healthy diet and almost half reported that they tuck into a red meat meal between one and four times a week.

Everyone wants a balanced, healthy diet and as the report showed, many people know that red meat has an important role to play in this. However, there are still some basic knowledge gaps that need to be addressed so that people have more opportunity to make the most of a healthy diet and enjoy their food.

If you want to learn more about red meat and its nutrients, take a look around our website to find out about its role in our diet

 

Vegetarianism

Professor Robert Pickard

Emeritus Professor of Neurobiology at the University of Cardiff

 

The ancestor of all the primates was a carnivorous tree shrew and human primates have progressively added plant material to their diet over a 7-million-year period. Currently, humans are classified as omnivores and one-third of their balanced diet is normally derived from foods of animal origin and two-thirds are normally derived from foods of plant origin. Humans thrive when they eat a little bit of everything and not too much of any one thing.

 The hallmarks of the omnivore can be seen in the dentition; the simple gut structure; the gut ecosystem; the adaptability and range of the digestive enzymes; and the requirement for essential nutrients that are usually provided by both animal and plant products. Unlike dedicated herbivores, we have no mechanism for the degradation of cellulose, the key molecule that differentiates plants from animals. Animal products, such as red meat with liver, provide humans with the full range of amino acids, fats, minerals and vitamins; all in forms so chemically suited to human digestion and absorption that there is usually little or no faecal waste. This is not surprising, since cows, sheep and pigs share 80% of their genes with humans.

 As we age beyond 60 years, our ability to make certain molecules diminishes, as does our absorption efficiency. Animal products, with their high nutrient densities, are particularly helpful at this time: a biological insurance. If we can’t make it, there’s a very good chance that a cow can. Plant products, such as broccoli with peas, nuts and yeast, provide humans with non-digestible fibre, most of the required amino acids, most of the required fats, most of the minerals and vitamins, notably vitamin C. In addition, plant foods provide carbohydrates, which are largely absorbed as sugars, and pharmacologically active phytonutrients, such as glucosinolates and salicylates.

 Sugars are vilified, unjustifiably, in the popular press because overconsumption is allowed to obscure their true nutritional significance. Sugars are the best source of energy for humans. Glucose is the major source of energy for the brain. DNA, required in most human cells, is constructed from a molecular variant of the sugar, ribose.

 Most vegetarians construct a healthy, balanced diet by supplementing plant foods with eggs, fish, dairy produce and a source of iron. Even extreme vegetarians, vegans, can still construct a healthy, balanced diet by supplementing plant foods with iron and vitamin B¹²  sources but this is more difficult and requires more awareness on the part of the eater. There is no biological justification for choosing to restrict one’s diet only to foods of plant origin but a vegetarian may have many other reasons for taking this course of action.

Why go meat-free when you can enjoy lean red meat in a healthy balanced diet?

Dr Carrie Ruxton, registered Dietitian and member of the Meat Advisory Panel

There’s an increasing number of so-called ‘awareness’ weeks and months encouraging us to turn to a vegetarian or vegan diet. Often these campaigns vilify meat, and more often than not incorrectly link red meat as a cause for health conditions.  Should we all be jumping on the bandwagon and turning vegetarian, or is it a better option to follow a healthy balanced diet made up of a number of food sources?

 Vegetarian diets are currently followed by 2 - 4% of the population, but if we take a moment to look at ourselves; we are omnivores – historically and physically. We are not designed to digest cellulose like naturally vegan animals, such as cows, rabbits and sheep.  

 In terms of health, choosing to follow a vegetarian, or vegan, diet is a lifestyle choice, it is not vital for health as some may suggest.  In fact, any choice that restricts eating habits, such as a meat-free diet, brings with it a risk of inadequate intake of nutrients.

 Studies have shown that vegetarian diets can be low in zinc, calcium, iron, manganese, selenium, and copper^[1]. Vegan and vegetarian diets can restrict vitamin D intake^[2],[3] and following these types of diets greatly reduce intakes of long-chain omega-3 fatty acids^[4]. Another key nutrient, vitamin B12 is a major issue in vegans as this nutrient is only present in foods of animal or microbiological origin^[5].

 While iron is present in some vegetables, beans and pulses, and fortified foods, it is of the non-haem variety which is poorly absorbed - only 10% of non-haem iron is absorbed compared with 30% of haem iron from red meat[6]. In addition, the presence of haem iron in foods increases the absorption of non-haem iron. Therefore, red meat is irreplaceable as a source of bioavailable iron in the diet.

With reference to red meat and health conditions, the evidence is inconsistent and research usually depends on observational studies which do not allow conclusions about ‘cause and effect’^[7]. In many cases, studies combine fatty meat pies and pastries with lean red meat, and most do not account for differences in fibre intakes. Indeed, other studies have not found associations between red meat and cancer^[8], and rates of bowel cancer are similar in meat eaters and vegetarians^[9].

 Including red meat in the diet offers an array of nutritional benefits and helps us, as omnivores, achieve our recommended intakes of vitamins and minerals. We should be aiming to eat up to 70g of cooked lean red meat per day and up to 500g per week^[10]which is beneficial for our overall health.

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[1] Freeland-Grave-J (1988) Mineral adequacy of vegetarian diets. The American Journal of Clinical Nutrition  48:859-62

[2] Calvo Ms, Whiting SJ, Barton CN (2005) Vitamin D intake: a global perspective of current status. Journal of Nutrition 135 310-6

[3] Laskowska-Kilta T, Chelchowska M, Ambroszkiewicz J, Gajewska J, Klemarczyk W (2011) The effect of vegetarian diet on selected essential nutrients in children 15:318-25

[4] Welch AA, Shakya-Shrestha S, Lentjes MA, Wareham NJ, Khaw KT (2010) Dietary intake and status of n-3 polyunsaturated fatty acids in a population of fish-eating and non-fish-eating meat-eaters, vegetarians, and vegans and the product-precursor ratio [corrected] of a-linolenic acid to long-chain n-3 polyunsaturated fatty acids: results from the EPIC-Norfolk cohort. The American Journal of Clinical Nutrition 92:1040-51

[5]Ambroszkiewicz J, Klemarczyk W, Chelchowska M, Gajewska J, Laskowska-Klita T (2006) Serum homocysteine, folate, vitamin B12 and total antioxidant status in vegetarian children.Advances in medical science 51:265-8

[6] SACN (2010). Iron and health. London: The Stationery Office. Available at: www.sacn.gov.uk/pdfs/sacn_iron_and_health_report_web.pdf

[7] Wyness L et al. (2011) Red meat in the diet: An update. Nutrition Bulletin 36: 34-77.

[8] Alexander DD et al. (2011) Meta-analysis of prospective studies of red meat consumption and colorectal cancer. European Journal of Cancer Prevention 20: 293-307.

[9] Key TJ et al. (2009) Cancer incidence in vegetarians: results from the European prospective investigation into cancer and nutrition (EPIC-Oxford). American Journal of Clinical Nutrition 89: 1620S–6S.

[10] SACN (2010). Iron and health. London: The Stationery Office. Available at: www.sacn.gov.uk/pdfs/sacn_iron_and_health_report_web.pdf

 

Why does fat get a bad name ?

Dr Carrie Ruxton, registered dietitian and member of the Meat Advisory Panel

Since the 1970s, dietary fats have been a major target of Government nutrition policy, with advice to lower fat intake making a regular appearance in dietary initiatives. Yet current science seems to indicate that not all fats are equal, suggesting that our rather negative view of dietary fats needs to be updated.

Fats can be grouped into two different ‘families’ called saturated and unsaturated fats. Within these, there are several categories of fatty acids, as shown below:

• Saturated fats: mainly from animal foods, such as dairy products, chocolate and meat products (pies and pasties), but also from some plant foods, such as coconut
• Omega-3 polyunsaturated fats: mainly from oily fish, eggs, red meat, nuts, seeds and marine oil supplements
• Omega-6 polyunsaturated fats: mainly from vegetable oils, such as sunflower oil and rapeseed oil, poultry, eggs, avocado and nuts
• Omega-9 polyunsaturated fats: mainly from olive oil, rapeseed oil and nut oils.

Traditionally, saturated fats were viewed as ‘bad’ while unsaturated fats were viewed as ‘good’. This was informed by people -based studies which suggested associations between high intakes of saturated fat and an increased risk of heart disease. However, this opinion has been challenged in recent years due to evidence that certain saturated fatty acids, such as myristic and palmitic acids, have a negative impact on blood cholesterol levels while others, such as stearic acid present in red meat, does not appear to affect cholesterol1 . This suggests that saturated fats behave differently in the body.

There is also debate from some nutrition commentators on whether saturated fat should be targeted at all in dietary recommendations due to the weak association between saturated fat consumption and mortality from cardiovascular disease. However, this view has not been accepted by Government experts and more evidence is needed.

In the meantime, it is wise to continue choosing lower fat, nutrient-rich foods which provide a variety of types of fatty acids in the diet. Lean red meat is a good choice as it is now lower in fat and calories thanks to changes in farming practices over the past few decades. In fact many people don’t realise that red meat, on average, contains more unsaturated than saturated fats. It also contains a range of fatty acids, including those from the beneficial omega-3 and omega-6 groups.

[1] Hunter JE, Zhang J, Kris-Etherton PM. Cardiovascular disease risk of dietary stearic acid compared with trans, other saturated, and unsaturated fatty acids: a systematic review. Am J Clin Nutr. 2010;91:46–63.

Medical writing; the limitations on reporting on medical trials and research

Dr Gill Jenkins BM, DRCOG, DFFP, BA

As a media medic I’m aware of the power of science and how it is reported. Front page stories often carry new information on what is supposedly good, or bad, for us. But by the nature of the limited space in most media for the full report, much of this information is incomplete, or not taken in context and can be confusing. Often unproven associations are made by people who don’t understand the science or the detail of the study. For people with health or body concerns, some stories could unnecessarily increase anxiety.

Looking briefly at a health story we can go through what has been said, or not said, by the science. For example,  I use the study ‘Increased Iron Levels and Decreased Tissue Integrity in Hippocampus of Alzheimer’s Disease Detected in vivo with Magnetic Resonance Imaging’, from the Journal of Alzheimer’s Disease, 2013.

This used radiographic imaging to measure iron levels in people with and without Alzheimer’s in a section of the brain called the Hippocampus, which supports memory function and can be damaged in the early stages of Alzheimer’s. It showed that people with Alzheimer’s had a higher presence of iron in the Hippocampus. A couple of resulting headlines ran ‘Alzheimer’s’ link to red meat’ and ‘Too much red meat may raise Alzheimer’s risk, scientists warn’.

From the headlines you might think there must be a link between red meat and Alzheimer’s but in the study the diet of participants was not considered and so the source of this iron was not identified, nor why people with Alzheimer’s have more iron in their Hippocampus. The study was not designed to do that, but was designed to simply find out how much iron is present. The study doesn’t explore what role red meat plays in Alzheimer’s. Some of the participants with Alzheimer’s may be vegetarian or have a diet low in red meat - Broccoli, lentils, sardines and pumpkin seeds are also rich sources of iron that could be a cause for the increased iron presence.

The connection to red meat by the media is poorly thought out guess work, with questionable logic. We do not know whether the patients smoked, drank excessively or exercised, for example, or whether there were other factors such as genetic reasons for the high iron deposits. When studies suggest behaviours could create the element of risk in developing an illness it accepts that it can make no significant claim. This makes the information a very small piece of a very big puzzle. I believe that incremental innovation is essential but we need to resist the temptation to reach a dubious conclusion on the information before the science proves that there is definitely a conclusion to reach.   

The Mediterranean diet, super-foods, or a just a play on words?

Dr Emma Derbyshire

Recently there appears to have been a lot of articles reporting that the key to good health appears to be to follow a Mediterranean diet. It’s also reported that the Mediterranean diet means eating less red meat. But is this a correct understanding of the diet? There are 18 countries on the Mediterranean coastline with differing diets, so I think a Mediterranean diet has become a phrase more than a diet. Here’s why.   

Europe vs. UK, who eats more red meat?

I don’t deny that the scientific literature on the diet has come to define the Mediterranean diet from Spain, Italy and Greece as high in olive oil, legumes, fruits and vegetables, fish and with a moderate consumption of meat and dairy products[1]. However, statistics also show that Mediterranean countries consume more red meat than the UK[2]. Greece, Spain and Italy are all famous for the meats they produce and eat as a staple. This meat intake is quite different to what is currently communicated as the Mediterranean diet.

Mediterranean diet – the real definition

I think there are problems with the current definition of the Mediterranean diet. Firstly, whilst studies into the Mediterranean diet have considered the dietary pattern generally, there are no substantial studies or meta-analysis research that has looked to define the quantities and regularity of food actually consumed. This is particularly the case with red meat intakes.

Secondly, confusion comes from the scientific definition. Scientists define the Mediterranean diet as a diet with low fatty acid levels.  Grains and vegetable oils, amongst others, provide oleic acid and alpha linoleic acid whilst fish provides a higher amount of omega-3’ acids to omega-6 acids. These acid intakes mean that there is more unsaturated than saturated fat in the diet and this is seen as the highest health benefit to the diet. However, whilst the fatty acid content of a diet is being profiled, again scientists are not actually looking at how much red meat is being eaten.

The fairest way to see a Mediterranean diet is to view it as a nutrient rich diet, this actually means a red meat rich diet as well. To suggest reducing the amount of red meat eaten is an incorrect definition of a Mediterranean diet.

 

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[1] "Get your Meds: the Mediterranean Diet and Health", Ellen Gooch, Epikouria Magazine, Fall 2005

[2] Food and Agriculture Organisation of United Nations, FAOSTAT, Food Balance sheet 2009.

 

Red meat – friend or foe?

by Dr Carrie Ruxton

 

The Meat Advisory Panel recently conducted some research with healthcare professionals to find out their views about red meat in the diet, and to determine what advice should be given to patients about including red meat in their diets. Here's a snapshot of the survey findings.

 

Four out of five healthcare professionals expressed a favourable view about the contribution red meat makes to a balanced diet and, when asked about meat intake levels, 46% didn’t think people were eating too much and most thought the right approach was to persuade people to switch from processed meats to leaner, fresh cuts of red meat.

Given the number of ‘scaremongering’ media reports when it comes to red meat, it was encouraging to see that 94% of respondents would not change their diet or patient advice on the basis of media coverage of red meat. Of these, two in five said that they would pay no attention while over half said they would check out the evidence before taking a decision.

A large majority (70%) also told us that they were sceptical about claims that red meat causes conditions such as heart disease and diabetes. This opinion corresponds with the Meat Advisory Panel’s view, given that most of the studies reporting associations between red meat intake and disease risk or mortality, arise from the US where meat consumption is far higher than in the UK.

The studies also do not correct adequately for other factors that can influence disease risk, such as high intakes of fat and alcohol, low physical activity levels, or low intakes of fruit, vegetables and fibre. Overall, there is no credible evidence that red meat causes heart disease and, indeed, lean red meat is a source of selenium and vitamin D which have been associated with reduced risk of chronic conditions such as heart disease, cancer and type 2 diabetes.

Navigating through confusion

One area of concern was the general agreement from healthcare professionals that patients are confused about the differences between lean red meat and processed meat. This is a key point with regard to media articles about meat as many studies actually involve high intakes of processed meat, which tend to be higher in salt and fat, rather than healthier lean red meats. Often this is not made clear in the resulting press stories which adds to patients’ confusion about whether lean red meat is a healthy choice (it is!).

When looking at the role lean red meat has to play in the diet, healthcare professionals recognised that the ‘reduce meat’ message wasn’t appropriate for everyone. When asked who should be advised to eat more red meat, they suggested vulnerable groups at risk from low nutrient intakes, such as those at risk of iron deficient (66%), children and teenagers (28%), pregnant women (22%) and elderly people (22%).  Less than 35% would not advise an increase for any groups and over 23% would not advise any groups to eat less meat.

Public Health advice

Healthcare professionals have an important role in helping patients navigate conflicting information about red meat in the diet and, given the results from our research, it appears that healthcare professionals consider lean red meat to be very much a friend in a balanced diet.

Let us know what you think about the role lean red meat has to play in the nation’s health. Do you think it is an important part of a patient’s diet?

If you are a healthcare professional, what do you think of the findings? Do you provide diet advice to patients? Do you advise them about their red meat intake? Email Jonathon.Falcone@nexuspr.com with your thoughts.