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Dietary fibre – why is it good for you?

Dietary fibre has been consumed for centuries. It has been recognised as having health benefits. This is supported by over 100 years research into dietary fibre’s physical and chemical properties, physiology and metabolic effects.

Dietary fibre has many definitions. Dietary fibre includes plant based carbohydrates that are not digested in the small intestine and therefore reach the large intestine. Dietary fibre includes soluble fibre and insoluble fibre. Soluble forms of fibre include guar gum, pectin, ispaghula and psyllium. Insoluble forms of fibre include cellulose and wheat bran.

Adults in the UK are currently recommended to consume 30g of fibre per day using AOAC fibre method which includes starch and lignin as well as non starch polysaccharides. Unfortunately, a large proportion of adults in the UK lack fibre in their diet. This has been shown from the National Diet and Nutrition Survey (NDNS) results 2014-2016.

Foods that are rich in fibre include wholegrain bread, breakfast cereals, barley, oats, whole wheat pasta, pears, oranges, broccoli, carrots, nuts, seeds, peas, beans and lentils.

Fibre intake can be increased by using the following tips:

  •  Eat wholegrain cereals for breakfast i.e. Weetabix, bran flakes. Seeds and nuts can also be added to cereals to increase fibre intake.
  •  Eat wholemeal or wholegrain breads.
  •  Eat potatoes with skins to increase fibre intake.
  •  Add chickpeas, lentils and beans to salads and stews.
  •  Eat foods high in fibre for snacks i.e. oranges, oatcakes, carrot sticks, seeds, rye crackers.

Dietary fibre has many health benefits. These include increasing satiety by adding bulk to the diet. Fibre adds bulk to stools which reduces constipation. Fibre is fermented in the large intestine. A product produced in the fermentation process are short chain fatty acids (SCFA’s). SCFA’s promote colonic absorption and provide energy for the body. They may have an influence on satiety hormones in the large intestine. SCFA’s may decrease the risk of colorectal cancer. Fibre also has a function in the absorption of vitamin K. The US Food and Drug Administration agency have accepted health claims for foods which contain oat products (oats, oat bran and oat flour), psyllium and barley for their cholesterol lowering effects.

Dietary fibre in both soluble and insoluble forms is essential for gut health. Dietary fibre increases satiety and increases stool bulk, reducing constipation. Oats have been shown to have a cholesterol lowering effect. SCFA’s produced from the products of fermented fibre are beneficial to health by providing energy for the body and promoting colonic absorption. Dietary fibre is found in many foods. Fibre is indeed very beneficial for our health

 

References:

British Nutrition Foundation, 2018. Dietary fibre. [online] Available at:<https://www.nutrition.org.uk/healthyliving/basics/fibre.html > [Accessed 15 July 2019].

Dhingra, D., Michael, M., Rajput, H. & Patil, R.T. 2012. Dietary fibre in foods: a review, Journal of Food Science and Technology, vol. 49, no. 3, pp. 255-266.

Public Health England, 2018. National Diet and Nutrition Survey. Results from Years 7 and 8 (combined) of the Rolling Programme (2014/2015 to 2015/2016). London: Public Health England. Available at: <https://www.gov.uk/government/statistics/ndns-results-from-years-7-and-8-combined > [Accessed 12 August 2019].

Reynolds, A., Mann, J., Cummings, J., Winter, N., Mete, E. & Te Morenga, L. 2019, Carbohydrate quality and human health: a series of systematic reviews and meta-analyses, The Lancet, vol. 393, no. 10170, pp. 434-445.

 

 

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The Paleo diet

What is the Paleo diet?
It involves eating like our ancestors did. The Paleo diet involves eating naturally, eating grass-fed meats, wholefoods, fruit and vegetables. It was first promoted by Dr Walter L Voegtlin, a gastroenterologist. Dr Voegtlin’s book, The Stone Age diet, was published in 1975. There are many different Paleo approaches, their core principles are similar, but they vary in their restriction level. Other terms for the Paleo diet include hunter gatherer diet, caveman diet, Paleolithic diet.

Why follow the Paleo diet?                                                                                                  Advocates state that it promotes a natural way of eating with low sugar and salt levels and no processed or refined foods. A lot of followers of the Paleo diet believe that our digestive systems have changed very little since pre-agricultural or Paleolithic times. Many foods that we eat today could not be eaten raw in Paleolithic times. Therefore, Paleo followers believe that the following foods can create strain on the gastrointestinal tract: legumes, refined sugar, processed foods, potatoes, cereal grains, dairy, salt, refined vegetable oils and root vegetables.

It must be remembered that diets in pre-agricultural times varied in different locations due to seasonality, climate etc. People in pre-agricultural times were also a lot more active, than they are in modern times. Energy expenditure levels would have been higher in Paleolithic times.

Criticisms of the Paleo diet
The Paleo diet ignores the benefits of eating beans/legumes which have a low glycaemic index which is useful for individuals with blood sugar problems. It also ignores the benefits of consuming starchy vegetables, a source of nutrient dense energy and wholegrains which add bulk to the diet and assist with bowel movements. The omission of dairy limits calcium intake in the diet. Those at risk of osteoporosis should speak to a dietitian before going on the Paleo diet. The Paleo diet could be difficult to maintain on a long-term basis due to omission of food groups i.e. dairy.

What is the evidence on the Paleo diet?                                                                                 Studies have found the Paleo diet to be associated with an increase in satiety. This is independent of the number of calories or composition of nutrients. Improvements in waist circumference, body weight, blood pressure and lipid profiles have been found. However, these studies were of a short duration and had a small number of participants involved.  Also, a study by Melburg found increased weight loss on the Paleo diet at six months compared to a healthy control diet, but there was no difference in weight loss between the two diets at two years.

Studies have found palatability and compliance issues with the Paleo diet. The cost of the Paleo diet was indicated to be 10% more expensive than a diet of similar nutritional value after modelling the cost of the Paleo diet. This would make it unsuitable for those on a low income.

More research is needed on the Paleo diet. Larger studies of a longer duration are required before conclusions can be made about the effectiveness of the Paleo diet.

 

References:
Fisher, R., 2019. What is the Paleo diet? [online] Available at: Accessed [12th August 2019].

Manheimer, E.W., van Zuuren, E.J., Fedorowicz, Z. & Pijl, H. 2015, Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis, The American Journal of Clinical Nutrition, vol. 102, no. 4, pp. 922-932.

Mellberg, C., Sandberg, S., Ryberg, M., Eriksson, M., Brage, S., Larsson, C., Olsson, T., Lindahl, B., Medicinska fakulteten, Umeå universitet, Medicin, Institutionen för folkhälsa och klinisk medicin, Samhällsvetenskapliga fakulteten, Statistik, Handelshögskolan vid Umeå universitet, Institutionen för kostvetenskap & Yrkes- och miljömedicin 2014. Long-term effects of a Palaeolithic-type diet in obese postmenopausal women: a 2-year randomized trial, European journal of clinical nutrition, vol. 68, no. 3, pp. 350-357.

Pitt, C.E., 2016. Cutting through the Paleo hype: The evidence for the Palaeolithic diet. Australian family physician, 45(1/2), p.35.

The Importance and Relevance of Personalised Nutrition

Personalised nutrition is relevant to many areas – nutrition, genetics, health care and public health. The consumer has a major impact on the importance and future of personalised nutrition. At present personalised nutrition is very unregulated. Personalised nutrition needs to be based on scientific evidence. This evidence needs to be communicated clearly to the consumer so that the consumer can make an informed choice.

The aim of personalised nutrition is to maintain and or improve health of individuals by using genetic, clinical and dietary information to provide healthy eating advice and implement the necessary dietary changes. Personalised nutrition is not new. It has been used in the treatment of rare genetic disorders i.e. phenylketonuria and also more common disorders i.e. lactose intolerance. Personalised nutrition is based on the concept that individual nutrition advice will be more effective than generic advice. Personalised nutrition can be based on 1) evidence of different responses to foods and nutrients due to genotypic/phenotypic characteristics. 2) examination of current preferences, behaviour and delivering interventions which enable each individual to make the required changes to their eating patterns. An individual’s genotype is the set of genes that they have. Their phenotype are their observable characteristics which are influenced by their phenotype and their environment i.e. height, weight, plasma cholesterol, blood pressure, behaviour.

Personalised nutrition involves the use of both nutrigenomics and nutrigenetics. Nutrigenomics refers to applying principles of genomics in nutrition research. It enables the formation of associations between specific nutrients and genetic factors i.e. how foods/food ingredients influence expression of genes. Diets that are unbalanced can change nutrient-gene interactions, increasing the risk of chronic diseases. Nutrient imbalances are considered as factors in cancer, diabetes, cardiovascular disease, aging, immune disorders, stroke, neurological disorders. Genetic makeup variations are considered as factors in digestive diseases, gastrointestinal cancers, osteoporosis, inflammatory conditions.

Nutrigenetics examines the effect of individual differences at the genetic level that influence the individual’s response to diet. The individual differences can be at the single nucleotide polymorphism (SNP) level rather than at gene level. SNPs change individuals dietary metabolic responses. SNPs can have an effect on the production of risks for the onset of disease. A good example is the relationship between folate and MTHFR. Folate is required for the efficient functioning of MTHFR. MTHFR has a role in supplying 5-MTHF. This is necessary for the remethylation of homocysteine for methionine production. The 677C→T polymorphism in MTHFR results in a significant decreased activity. Individuals with TT unstable copies who also have low folic acid intake, will have increased plasma homocysteine. This increases their risk of cardiovascular disease. When these individuals increase their folic acid intake, they can restore their normal levels of methionine (through metabolization of homocysteine).

Consumers do have concerns about personalised nutrition. Consumers have questioned the evidence that nutrigenomics (and nutrigenetics) can make a difference to an individual’s health. Consumers are especially concerned about what happens to the genetic information that is given to a company to examine and test. Consumers need to know who has access to this information. They also need to know if insurers or employers could access this information. Consumers have concerns about the security of personal data in public databases. Consumers have also expressed concern regarding the regulation of nutrigenomics (and nutrigenetics).

It must be stressed that the majority of the evidence supporting personalised nutrition has only involved observational studies. There is a need for more randomised controlled trials where clinical endpoints can be measured. At present, there is a limited ability to implement current research. There is a need for a framework and clear guidelines for the assessment of diet-gene interactions. There is also a need for more educational resources for personalised nutrition. Evidence based personalised nutrition research should be used for the provision of dietary advice to decrease disease risk and promote long-term health. Ultimately, it is consumers who will decide the relevance and importance of personalised nutrition, for the future.

References:

Garg, R., Sharma, N. & Jain, S. 2014, “Nutrigenomics and nutrigenetics: Concepts and applications in nutrition research and practice”, Acta Medica International, vol. 1, no. 2, pp. 124.

Grimaldi, K.A., van Ommen, B., Ordovas, J.M., Parnell, L.D., Mathers, J.C., Bendik, I., Brennan, L., Celis-Morales, C., Cirillo, E., Daniel, H., de Kok, B., El-Sohemy, A., Fairweather-Tait, S.J., Fallaize, R., Fenech, M., Ferguson, L.R., Gibney, E.R., Gibney, M., Gjelstad, I.M.F., Kaput, J., Karlsen, A.S., Kolossa, S., Lovegrove, J., Macready, A.L., Marsaux, C.F.M., Alfredo Martinez, J., Milagro, F., Navas-Carretero, S., Roche, H.M., Saris, W.H.M., Traczyk, I., van Kranen, H., Verschuren, L., Virgili, F., Weber, P. & Bouwman, J. 2017, “Proposed guidelines to evaluate scientific validity and evidence for genotype-based dietary advice”, Genes & nutrition, vol. 12, no. 1, pp. 35.

Institute of Medicine, 2007. Nutrigenomics and Beyond: Informing the Future: Workshop Summary. Washington, DC, The National Academies Press.

Ordovas, J.M., Ferguson, L.R., Tai, E.S. & Mathers, J.C. 2018, “Personalised nutrition and health”, BMJ (Clinical research ed.), vol. 361, pp. bmj.k2173.

 

Tips on reducing salt intake in your diet

The amount of sodium (in the form of salt) consumed in Europe is greater than levels recommended by WHO. Excess sodium intake increases blood pressure and increases risk of stroke and CHD. The WHO guideline for sodium intake is less than 2g per day which is equivalent to 5g of salt. Approximately 99% of the world’s adult population have a mean salt intake above recommended levels. Processed foods where sodium is added during food processing is a major source of sodium for the Western diet. Other sodium sources include salt added during food preparation and cooking and salt added while eating.

Tips for reducing salt intake

Shop for lower salt foods

Compare nutrition labels on food packaging

Choose the breakfast cereal/pizza that is lower in salt

Eat less of cured meats and fish as these can be high in salt

Buy tinned pulses and vegetables that have no added salt

Watch out for salt content in ready made pasta sauces – cheesy sauces, sauces that contain bacon, ham or olives can be higher in salt than tomato based sauces

If eating crackers or crisps; choose the ones lower in salt

Watch intake of pickles, mustard, mayonnaise and soy sauce; these can be high in salt

Cook with less salt

Salt alternatives – use black pepper as seasoning – try on pizza, soup, fish, scrambled egg and pasta

Use fresh herbs and spices in vegetables, meat and pasta dishes

Use lime, garlic, ginger in stir fries

Make sauces using garlic and ripe tomatoes

Salt tips when eating out

Pizza – choose toppings with chicken and vegetables instead of bacon, pepperoni

Pasta – choose dishes with a tomato sauce with chicken/vegetables instead of sausage, cheese or bacon

Burgers – opt for salad toppings and avoid bacon, cheese and barbecue sauce

Foods to limit – these are usually high in salt

Pot noodles/instant noodles

Sandwiches filled with processed meat/cheese

Whole milk/cream; majority of cheeses – cheddar, parmesan, processed and cream cheese

Butter, lard, suet, palm and coconut oil

Processed meats i.e. ham, bacon, pate, corned beef, sausages, gammon, burgers

Sausage rolls, meat pies

Smoked fish, tinned tuna in brine

Cakes, cheesecake, ice-cream, majority of cream based desserts, fudge, chocolate, toffee

Crisps, salted popcorn, olives, cheese flavoured biscuits, cheese dips, sour cream dips

Rock sea and table salt, stock cubes, marmite

Barbecue sauce, ketchup, horseradish, mayonnaise, salad cream, mustard

Low salt options

Shredded wheat, muesli with no added salt, porridge oats, rice, pasta, potatoes, couscous

Skimmed milk, low fat/fat free yoghurt

Olive oil, rapeseed oil, sunflower oil

Fresh lean meat, oily and white fish, tinned fish in water

Fresh, dried and frozen fruit, vegetables and pulses

Tinned vegetables and fruit with no added salt

Rice pudding, fruit salad, dried fruit, sugar free jelly

Plain breadsticks, rice cakes, unsalted popcorn, no added salt crisps, salsa dips

Vinegar, lemon juice, herbs and spices, tomato puree, apple sauce, cranberry sauce

CANCER – Attitudes Now Can help prevent it Eat Healthily Regular Activity

Being overweight or obese is an increasing cause of cancer in the UK. Cancer Research UK found more than a third of all cancer cases were avoidable. Cancer Research UK also found that excess weight as a cause of cancer; has increased from 5.5% in 2011 to 6.3% (present  figure). Other preventable causes of cancer include drinking alcohol and eating too little fibre. This article focuses mainly on how to reduce obesity by eating a healthy diet which can assist in decreasing your cancer risk.

Obesity is now linked to up to twelve different forms of cancer – liver, prostate (advanced), ovary, mouth and throat, stomach, bowel, breast (post-menopause), kidney, gallbladder, pancreas, oesophagus and womb. The World Cancer Research Fund has stated that consuming a healthy diet, being active and maintaining a healthy weight are – after not smoking – the most important ways that you can decrease your cancer risk.

Cancer Research UK recommends that in order to keep a healthy weight, eat mainly –

Vegetables, fruits, wholegrains, protein foods such as pulses, fish and fresh chicken

Cancer Research UK recommends cutting down on the following –

Red and processed meats, high calorie foods and sugary drinks

Increase fruit and vegetables in diet

Fruit and vegetables are an excellent fibre source and low in calories. This can help you maintain a healthy weight. Cancer Research UK has stated that the increased consumption of fruit and vegetables can decrease the risk of throat, mouth and lung cancers.

Tips to increase your fruit and vegetable daily intake:

Make a habit of adding fruit to your cereal, porridge or yoghurt

Stock your freezer with frozen vegetables which can be stir-fried or steamed

Top a baked potato with beans, tuna and sweetcorn or broccoli and low fat cheese

Use fruit as a dessert i.e. fresh fruit salad, banana with low fat frozen yoghurt etc.

Have vegetable omelettes i.e. add mushrooms, tomatoes, peppers, onions to an omelette

Pre cut vegetables can be used for snacks, in lunches or as side dishes i.e. green, yellow, red peppers, carrot/celery sticks, sliced cucumber

Aim to eat five portions of fruit and vegetables per day. Eat one to two portions of fruit and/or vegetables with each meal. Make fruit or vegetables first choice as a snack.

Portion of fruit/vegetable examples:

One portion is 80g or any of the following:

Fruit:

One banana, orange, apple, pear or a similar sized fruit

Half a grapefruit/avocado

Two plums/satsumas or similar sized fruit

Two handfuls of blueberries or raspberries

A handful of grapes

Vegetables:

Three heaped tablespoons of vegetables including raw, frozen, cooked or tinned vegetables

One cereal bowl of watercress, lettuce or spinach

Tips on increasing wholegrain foods in diet:

Choose brown, wholegrain bread instead of white bread

Use brown rice instead of white rice

Use whole wheat pasta instead of white pasta

Eat wholegrain breakfast cereals such as Weetabix, porridge, bran flakes etc.

Add barley to stews and soups

Tips on eating less processed and red meats:

Try to have vegetarian only meals one or two days per week

Decrease portion sizes of red and processed meats and increase vegetable portion size

Swap red meats and processed meats for fresh fish and chicken

Use lentils, beans and chickpeas instead of meat when cooking; these pulses are a good source of fibre and protein

Tips on decreasing daily salt intake:

Eat more fresh fruit and vegetables; drain and rinse canned vegetables

Check food labels before buying and purchase less salty options

Use spices, herbs, garlic and citrus juices in place of salt for adding flavour to your food

Limit your intake of salt to less than six grams per day (2.4g sodium)

Tips to reduce high calorie foods and drinks:

Eating more wholegrain foods, vegetables and pulses during meals helps fill you up more on fewer calories

Decrease or avoid sugary drinks; drink water instead

Decrease fast foods and takeaway meals; cook more at home

Prepare fruit and vegetables for snacks and avoid high calorie snacks – chocolate, crisps, biscuits etc.

The Eat Well Guide shows the balance of foods that should be eaten on a daily basis to maintain a healthy weight.

Eatwell_Guide

Obesity and being overweight is a huge health risk at present. The UK government needs to build on their successes in smoking prevention to decrease the numbers of obesity and overweight related cancers. Healthy eating guidelines, healthy eating promotion and nutrition education are vital tools in the prevention and reduction of obesity. The food industry also has a role to play in tackling obesity i.e. reducing over sized food portions and adapting recipes to decrease sugar, salt and nutrient dense foods. This can make it easier for people to make healthier choices and assist with preventing and reducing obesity.

References:

Eat Right. 20 Ways to Enjoy More Fruit and Vegetables. Academy of Nutrition and Dietetics; 2014.

Fruit and vegetables – how to get five-a-day. Food Fact Sheet. The Association of UK Dietitians; 2017.

The Eatwell Guide. British Nutrition Foundation; 2016.

Therrien Alex. Rise in cancers ’caused by weight’ . BBC News Website http://www.bbc.co.uk/news/health; 2018.

Boseley Sarah. Obesity now linked to 12 different cancers. Guardian Website https://www.theguardian.com/society/2018/may/23; 2018.

Cancer Research UK. How to enjoy a healthy diet. Cancer Research UK Website http://www.cancerresearchuk.org/about-cancer/causes-of-cancer/diet-and-cancer; 2016.

 

 

Criticisms of Nutrition Science/Science and Lies – The Spread of True and False News Online

Nutrition Science is criticised for relying too much on observational studies and on small short term interventions. Nutrition Science is also criticised for its conclusions continually changing. The reliability of nutrition evidence is criticised in comparison to other disciplines. Evidence based nutrition is best served by using all the evidence across multiple types of studies.

Current controversies in nutrition include the relevance of saturated fat and its diverse food sources including dairy foods, value of very low carbohydrate diets; the effects of vitamin D or fish oil supplements. Other nutrition controversies include health effects of potatoes and fat sources i.e. plant oils, relevance of counting calories versus diet quality for long term control of weight. The time gap between the generation of new knowledge and the implementation of it creates the appearance of additional controversy and an increase in confusion amongst the public. It must be remembered that uncertainty exists in all scientific areas for example cardiology i.e. the usefulness of glucose control and anti-diabetic drugs for decreasing heart attacks and death.

Government and non-profit organisational support for nutrition research is limited. The food industry has a key role in the funding of nutrition research. However, there is a potential for bias. There is a growing range of premium chocolate products – promoted using words such as natural, organic, cacao rich etc. The message (though not stated on the packaging) that new improved chocolate, especially dark chocolate, is good for your health.

Chocolate manufacturers have put a lot of money into funding nutrition science which has been interpreted and selectively reported to show their products in a positive light (during the past twenty years). Consuming flavanols in cocoa is linked with decreased blood pressure. More recent research has used much higher levels of flavanols than are available in products sold commercially. The blood pressure study involved participants receiving an average of 670mg of flavanols. To get that much, a person would have to consume twelve standard 100g bars of dark chocolate or fifty bars of milk chocolate daily.

Research has continually shown that when food companies pay for the studies, they are more likely to get helpful results. US researchers who studied two hundred and six studies about juice, soft drinks and milk, found that those who received industry money were six times more likely to receive neutral or favourable findings compared to those who did not. However it must be stressed that the food industry’s expertise and innovation can help address difficulties in food production and distribution. All parts of the food system will need to be part of the solution whether by voluntary action or legislation.

Most people have an opinion on food and nutrition. The opinion is not always based on science. The loudest most extreme voices can drown out the well informed. New social technologies i.e. Twitter, which assist in the rapid sharing of information can also assist in the spread of misinformation. Vosoughi, Roy and Aral, 2018, found that falsehood diffused significantly farther, deeper, faster and more broadly than the truth in all categories studied. The categories of information studied included politics, urban legends, business, terrorism, science, entertainment and natural disasters. Falsehood was found to reach far more people than the truth. It was also found that many more individuals retweeted falsehood than the truth. From analysis of all news categories studied, it was shown that news about politics, urban legends and science spread to the most people. It was found that falsehoods were seventy percent more likely to be retweeted than the truth. This was even the case when account age, activity level, number of followers/followees of the original tweeter and whether the original tweeter was a verified user – were taken into consideration.

It was found that false rumours inspired greater surprise and greater disgust. It was also found that false news is more novel and that novel information was more likely to be retweeted. False news can drive the misallocation of resources and the misalignment of business investments. The increased likelihood of people to retweet false news than true news is what drives the spread of false news (in spite of network and individual factors that favour the truth). The first step in containing false news is understanding how it is spread.

Nutrition science has been criticised as unreliable. However it must be stressed that nutrition science has made contributions to human health. Understanding of nutrition has progressed from isolated nutrient deficiencies to the importance of food and dietary patterns in chronic disease. Improvements in research methods have generated enough scientific evidence for the formulation of key public health guidelines. Vested interests need to be managed to avoid bias in research findings and public messaging of dietary advice. All stakeholders (including the food industry) must come together to solve nutrition health.

References:

Fleming N. The Dark Truth about Chocolate. The Observer 2018

Mozaffarian D, Forouhi N. Dietary guidelines and health—is nutrition science up

to the task? BMJ 2018 360:k822 doi: 10.1136/bmj.k822

Vosoughi et al. The spread of true and false news online. Science 2018; 359:1146-51