Author Archives for Catriona's Nutrition Blog

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.


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

Nutrition and Resilience

Catriona's Nutrition Blog

Food provides the energy and nutrients we need to be healthy. Healthy food is vital to our physical and mental performance. A diet rich in lean protein, whole grains, fruit, vegetables and low fat dairy products help lower the risk of diabetes and other diseases.

Studies have shown that there is a direct link between the food we eat and our overall mental health including our tendency towards depression.

People need to find out what food choices are right for them. The following options are available

Track your mood and food: This can be done by keeping a mood and food journal.

The Whole 30: This is an elimination diet which lasts for thirty days. You eliminate processed foods, refined sugar, dairy and gluten during this period and eat mainly whole foods.

Drink more water: The average healthy intake of water is between two and three litres per day. Dehydration…

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Nutrition and Resilience

Food provides the energy and nutrients we need to be healthy. Healthy food is vital to our physical and mental performance. A diet rich in lean protein, whole grains, fruit, vegetables and low fat dairy products help lower the risk of diabetes and other diseases.

Studies have shown that there is a direct link between the food we eat and our overall mental health including our tendency towards depression.

People need to find out what food choices are right for them. The following options are available

Track your mood and food: This can be done by keeping a mood and food journal.

The Whole 30: This is an elimination diet which lasts for thirty days. You eliminate processed foods, refined sugar, dairy and gluten during this period and eat mainly whole foods.

Drink more water: The average healthy intake of water is between two and three litres per day. Dehydration caused by a lack of water intake can cause unclear thinking, overheated body, constipation and kidney stones.

Eat less sugar: Processed or added sugars increase the risk of health issues such as Type 2 diabetes and heart disease. Reducing your sugar intake can make a huge difference on your physical and mental health.

Five foods that are good for the mind include:

Fatty fish: Since the brain is mainly composed of fat and our bodies are unable to make essential fatty acids, we need to depend on a diet rich in omega-3s to meet our daily needs. Foods high in omega 3 fatty acids include salmon, herring, sardines, seaweed, walnuts. These foods high in omega 3 fatty acids have been shown to decrease depression, attention deficit hyperactivity disorder and other mental disorders. Omega-3s also boost memory and learning by supporting the synapses in the brain.

Whole Grains: Complex carbohydrates release glucose slowly. This helps us to feel fuller for longer and provides a constant source of fuel for both the brain and body. Healthy sources of complex carbohydrates include oats, barley, beans, whole wheat products and soy.

Lean Protein: The amino acid tryptophan which is a building block of protein, influences mood by the production of the neurotransmitter serotonin. Serotonin is associated with depression. Lean protein food sources such as turkey, chicken, fish, eggs and beans help keep serotonin levels balanced.

Leafy Greens: Leafy greens such as spinach, mustard greens, broccoli are high in folic acid. Deficiencies in folate along with other B vitamins have been associated with higher rates of fatigue, depression and insomnia. Broccoli also contains selenium. Selenium plays an important role in our immune system functioning, reproduction and metabolism of thyroid hormone. Some studies have suggested that low levels of selenium contribute to anxiety, depression and fatigue.

Yoghurts with Active Cultures: Fermented foods including yoghurts with active cultures have been shown to decrease anxiety and stress hormones.

We can blame our busy lives, the affordability of processed foods for our diet and food choices. However we can increase our fruit and vegetable intake and limit our intake of processed foods that come from bags and boxes. Supermarkets such as Lidl sell good quality fruit and vegetables at low prices.

Nutrition is a key factor in resilience and good mental health. It must be remembered that it is one factor and not a substitute for other treatments i.e. talking to a doctor or counsellor.

My next blog topic is Science and Lies: The Impact of Lies on Nutrition Communication and Education.

Cheese – nutritional benefits versus weight gain

Cheese is a good source of both calcium and protein. However cheese can be high in sodium and saturated fats. Whether cheese is a healthy option depends on both the individual and the amount and type of cheese eaten.

There are many types of cheese. Cheese can range from mild to mature in flavour and low to high in fat composition. Cheeses that are low in both fat and sodium can be a healthy addition to most diets. Cheese can be made from cows, sheep, goats and other animals milk. Cheese is used on popular dishes such as pizzas, burgers, salads, sandwiches and Mexican dishes. Cheese can be eaten alone as a snack or appetiser. Cheese can be added to many dishes such as soups, pastas, sauces.

Nutritional content of cheese:

Cheese is a good source of calcium. Calcium is essential for healthy teeth and bones, blood clotting, wound healing and keeping normal blood pressure. Cheese can be high in sodium, calories and saturated fat. The breakdown of nutrients in cheese can vary a lot, depending on the type of cheese.

Health benefits of cheese:

The protein, calcium, magnesium, zinc and vitamins A, D and K content in cheese contributes to healthy bone development in children and young adults and to the prevention of osteoporosis.

Cheese is a good source of calcium. Calcium has an important function in tooth formation. It has been concluded from at least one study that eating cheese can increase the pH level in dental plaque which protects against dental cavities.

Calcium can assist in reducing blood pressure. Low fat and low sodium cheeses are recommended. Examples include parmesan, ricotta cheese, cottage cheese, feta, goats cheese and low fat cream cheese.

It was concluded by researchers in 2014 that dairy products could be a good source of the antioxidant glutathione. Glutathione is vital for brain health and the prevention of age related neurodegeneration.

Protein is essential for the building and repair of cells. One ounce of cheddar cheese can provide 7g of protein. The amount of protein recommended for an individual depends on their size, age and activity level.

Negative aspects of cheese consumption:

One ounce of cheddar cheese can contain approximately 120 calories and 6g saturated fat. A high intake of saturated fat can raise the risk of obesity, diabetes and cardiovascular issues. Sodium can be especially high in processed cheeses and cheese flavoured products. There have been concerns raised about the presence of estrogen and other steroid hormones in dairy products. This could lead to a disruption of the endocrine system and could increase the risk of some types of cancer.

Individuals with lactose intolerance lack the enzyme required to break down and digest the sugar found in milk. The consumption of milk and dairy products can result in diarrhoea, bloating and flatulence.

Individuals with a milk allergy should avoid cheese. A sensitivity to casein (milk protein) can cause inflammation throughout the body. This can produce symptoms such as acne, sinus congestion, skin rashes and migraines.

Phosphorus can be present in high quantities in some cheeses. This may cause harm in individuals with a kidney disorder. If the kidneys are unable to remove excess phosphorus from the blood, this can be fatal.

Overall tips when choosing and consuming cheese:

Low fat and reduced fat cheeses are available. These can be good choices if a recipe calls for a large quantity of cheese.

It is important to remember that the sodium content of cheese varies. Processed cheeses generally contain high levels of sodium. Swiss cheese and Gruyere have lower levels of sodium.

To reduce calorie consumption, use strong flavoured cheeses i.e. Parmesan or blue cheese. You do not have to use as much, for example, in soups, salads, pastas, vegetable dishes.

My next blog topic – Nutrition and Resilience!





Functional Foods – What are functional foods and how do they benefit us?

Nutrition has moved on from the traditional concept of avoiding nutrient deficiencies to the concept of optimal nutrition. Nutrition research has moved to identifying components in foods which can optimise physical and mental well being and decrease the risk of disease. Functional foods are foods and drinks that are enriched with particular nutrients/substances that can positively influence health beyond their basic nutritional value.

Functional foods include foods generated around a particular functional ingredient i.e. stanols/sterols enriched low fat spread, foods fortified with a nutrient that would not usually be present i.e. folic acid fortified bread/breakfast cereals.

What is NOT a functional food: Functional foods and medicines are different from a legislative perspective. Claims about the ability to treat or prevent disease are not allowed on foods but are permitted on medicines.

Superfoods: there is no specific definition of a superfood and no method of testing whether a food is super or not. The term superfoods is sometimes used by journalists to describe a food that is rich in a particular nutrient or bioactive substance.

Examples of functional foods and their benefits :

Yoghurts/ yoghurt drinks: These contain probiotics. Probiotics are live microorganisms (mainly bacteria). Many probiotic bacterial strains are the result of fermentation.  Probiotics can also be added to foods to improve intestinal microbial balance i.e. lactobacillus and bifidobacteria. Prebiotics are a non digestible component that have beneficial effects by stimulating the growth of bacteria in the colon. Examples of prebiotics include oligofructose and inulin.  Foods containing both probiotics and prebiotics assist in optimal intestinal function and intestinal microbial balance.

Margarines: Many margarines are fortified with plant sterols and stability esters. These margarines assist with decreased LDL cholesterol and reduced risk of coronary heart disease.

Omega 3 fatty acids enriched eggs: The omega 3 fatty acids assist in the control of hypertension and lipids metabolism.

Functional foods may provide health benefits but should not be seen as an alternative to a balanced diet and healthy lifestyle. The research opportunities to explore the relationship between a food component and an improved state of health or reduction of disease, present a great challenge to scientific researchers both now and in the future. Communicating the health benefits to consumers is very important so that they have the knowledge to make informed choices about the foods they consume.

My next blog topic is – cheese – nutritional benefits versus weight gain.






Genetically Modified Foods

Genetically Modified Foods is a topic close to my heart. I completed my Masters thesis on consumers attitudes towards GM foods – The effect of social class and area on the attitudes of Irish consumers towards Genetically Modified Foods. It was concluded that the majority of consumers stated that their concerns about GM foods would stop them from buying GM foods for both Dublin and Limerick. This was also the case for all of Dublin and all of Limerick. Social class did have an effect on Irish consumers mean level of knowledge about GM foods, their concerns about chemical sprays and on their moral views regarding GM foods. Area of residence did not have an effect on Irish consumers attitudes towards GM foods.

Genetically Modified Foods are foods where the DNA has been altered in a way that does not occur naturally. The technology can be called ‘modern biotechnology’, ‘recombinant DNA technology’, ‘genetic engineering’ or ‘genetic technology’. This results in allowing desirable traits i.e. herbicide resistance, pest protection and improved nutritional qualities. GM foods include foods that have an added or deleted gene sequence, animal products produced from animals that were fed GM feed and products produced by GM organisms.

How safety assessment of GM food is conducted: this focuses on 1. direct health effects 2. allergenicity 3. specific components thought to have toxic/ nutritional properties 4. stability of inserted gene 5.  nutritional effects associated with genetic modification 6. unintended effects which could result from insertion of gene.

The benefits of GM foods: These include increased yield, increased resistance to disease, less likely to be damaged by insects, improved nutritional value, increased shelf life, increased climatic survival, increased crop yields, decreased farm costs and increased farm profits.

Criticism of GM foods: These include environmental hazards – unintended harm to other organisms, decreased effectiveness of pesticides. Human health risks – allergenicity, the introduction of genes may create more allergies, unknown effects on human health. Economic concerns – a costly and lengthy process.

Public concern of GM foods: Many consumers accept more readily biotechnology as benefiting their health i.e. medicines with improved treatment potential/increased safety. European consumers confidence in food safety decreased with BSE and other public food safety scares. Consumers questioned the validity of risk assessments – focusing particularly on the long term effects of GM foods.

Future of GM foods: GM advocates are confident that the next generation of GM foods will be even more promising. The current techniques used to introduce genes into plant cells result in random insertion into genome. New techniques have been devised which allow precise insertion of genes into locations in the genome. This avoids the potential unknown effects of disrupting plants normal genome with random integrations. The political pressure from GM critics will remain a powerful source.

My next blog topic will be about functional foods and their benefits 🍇🍅


Nutrition, Genes and Health!

Hi again. Here is my blog post on nutrition, genes and health!

In the past nutrition research focused on impairment of health and nutrient deficiencies. Nutrigenomics has created the opportunity to deepen the understanding of how nutrients deepen gene expression, protein biosynthesis and metabolism. Nutrigenomics is the study of the genome influence on nutrition. It applies genomics technologies in food technology and nutritional sciences. Nutrigenetics is how an individual is genetically programmed to respond in a certain way to a nutrient. It deals with our genetic variation and how this manages our response to certain nutrition.

Nutrition science needs to understand the mechanism of nutrient dependent interactions at genetic molecular protein production and metabolic profile levels. The main aim of nutrigenetics is to clarify the impact of the variability of genes on the interactions between nutrients and diseases. Nutrigenomics studies the genome broad impact on nutrition.

Examples of nutrigenomics: phenylketonuria patients need to avoid phenylalanine rich food. Deficiency of aldehyde dehydrogenase enzyme which metabolizes ethanol.  This results in annoying manifestation of individuals after consuming alcohol – this is seen in many Asian populations.

Examples of nutrigenetics:

MTHFR is involved in the metabolism of folic acid and maintaining normal blood level of homocysteine. A particular MTHFR gene SNP is linked with elevated homocysteine levels in the blood especially if there is a deficiency of folic acid in the diet. This is associated with cardiovascular diseases and raised predisposition of colon cancers (especially if there is a inadequate amount of folic acid in the diet when compared to recommended daily requirement.

Ethics and social issues:

For nutrigenomic developments it is important how the message is communicated and by whom. Consumers fear the consequences of characterisation of genome and identification of mutations of highly penetrant genes i.e. those responsible for forms of cancer. The consequence of this could impact an individual’s ability to gain employment, insurance or finance. The benefit in relation to the prevention of disease – knowledge of a person’s genetic profile could be used to create specific risk reducing actions involving diet which could reduce risk of disease and improve quality of life.

I will discuss genetic modified foods next week, an interesting and controversial topic!