Heart Disease

Home / Posts tagged "Heart Disease"
Whats the deal with free radicals and antioxidants?

Whats the deal with free radicals and antioxidants?

The world of nutrition has evolved hugely over the last few decades as interest in the topic has grown.  Basic dietary advice is no longer enough for many people as they seek out other ways to optimise their health, combat ageing, lose weight and maximise exercise performance.

The desire to learn more has helped drive this evolution but has also exposed us to information that may be lacking in reliable science.

One topic that has always been popular is that of free radicals and antioxidants.  These terms are frequently chucked around and often oversimplified as being either good or bad for us but is it really that simple?

A little too much knowledge can be dangerous

One of my old bosses many years ago once said to me that a little bit of knowledge can be a dangerous thing and this is something that always rings true when I listen to people talk about nutrition.

How has dietary advice evolved over the last couple of decades?

Not long after I started out as a nutritionist the Department of Health had just launched the five-a-day campaign (2003) to promote the health benefits of eating more fruits and vegetables in the diet.  This campaign was driven by the science which proved fruits and vegetables had a key role to play in the prevention of cardiovascular diseases, cancers and diabetes.

The conversation around diet and nutrition at this time was heavily focused on key public health messaging to help tackle obesity and heart disease.

In 2007 the Food Standards Agency launched the ‘Eatwell Plate’ to help people to understand how the five key food groups form the basis of a balanced diet. This has since been replaced with the updated ‘Eatwell Guide’ (1).

When did the conversation start to change?

After this is when the conversation began to change as more people took an interest in the topic of nutrition.

Reporting in the media began to focus more on research findings linking diet to disease (many of which were contradictory), food companies started to coin phrases such as ‘superfoods’ and many books and TV shows on the topic became hugely popular.

During this time the quality of advice given out was questioned by qualified health professionals and authors such as Ben Goldachre putting much of it down to bad science.  This also saw the demise of well-known ‘health experts’ who dominated our screens at this time.

Around this time was also when the food industry became more regulated as they had to provide evidence to support any health claims made on their products (2008).

In 2007 the UK regulator Ofcom introduced regulations banning the advertising of foods high in fat, salt and sugar on children’s TV channels.  Bans were also introduced on the advertising of these foods on non-children’s channels during, before and after programmes aimed at those aged between four and fifteen.

The UK was the first country to introduce statutory scheduling restrictions of food advertisements to children.

The birth of social media

Around the same time came the social media explosion with the birth of Twitter in 2006 and Instagram in 2010.

These social media platforms are now home to many health and wellness ambassadors who churn out advice and represent food and wellness brands in the media.  This has raised many issues as to the quality of nutrition and diet advice as people turn to unqualified influencers for information over experts (although there are now many trusted voices on these platforms).

The topic of free radicals and antioxidants

As our interest in the nitty gritty of nutrition has grown one of the topics that has continued to come up is that of free radicals and antioxidants.  The terms are chucked around willy nilly and while most people may be familiar with them, very few actually know what they are.

The problem of oversimplification

The science behind free radicals and antioxidants is actually quite complex.  One problem with delivering these concepts to people has been an oversimplification of the science which has led them to be classed as either being good or bad for you.

The idea that free radicals are bad and antioxidants are good is one that is used to sell myriad of products in the wellness market, but the science is not that straight forward.  Antioxidants are normally depicted as the superhero defending our body against ageing and chronic disease risk caused by free radical damage.

There is of course truth in this depiction but unfortunately biology is never that simple.

What are free radicals?

Free radicals are very reactive chemicals, which are created when an atom or molecule (chemical that has two or more atoms) either gains or loses an electron.  The most common type of free radicals produced in living tissue are called reactive oxygen species or ROS for short and these contain oxygen.

We produce free radicals naturally through chemical processes that occur in the body such as the breakdown of food and its transformation into energy used by cells.

We are perfectly equipped to deal with free radicals but they may become an issue when they build up in high concentrations.  This can put the body in a state of oxidative stress (when free radicals outweigh antioxidants), which has the potential to damage every major component of cells when it occurs over a prolonged period of time. The most significant damage is that caused to DNA, which is thought to play a role in the development of many health conditions including heart disease and cancer (2).

The most likely cause of excess free radicals in the body are due to a combination of environmental, lifestyle and dietary factors which include pollution, stress, smoking, alcohol, sun exposure, infection and overconsumption of foods high in bad fats and sugar.

What are antioxidants?

Antioxidants are essential for the survival of all living things.  These chemicals are able to interact with free radicals and neutralising them without getting damaged or becoming a free radical themselves. Whilst the body relies on external source of antioxidants, which are gleaned from the diet, it’s also able to make some such as the cellular antioxidant glutathione.

Dietary antioxidants are found in fruits, vegetables and grains, which are all a rich source.  Examples of dietary antioxidants include lycopene and beta carotene found in red, orange and green vegetables as well as vitamins A, C, E and minerals such as selenium.  Plants also contain compounds such as polyphenols, which act as antioxidants and are found in foods such as berries and raw cacao.

Are free radicals always bad for us?

Most people equate free radicals to poor health but there is more to the story as they also play an important role in many normal cellular responses.

The immune system uses free radicals to help kill foreign invaders (phagocytes) in the body, which are just one of many ingredients in a cocktail of chemicals released in this defence mechanism, which is known as an oxidative burst.

Another interesting example of where free radicals may be beneficial is linked to exercise, particularly amongst athletes. Free radicals may play a key role in the benefits gained from exercise, which goes against much of the information provided on this topic.

One of the benefits of exercise is that it helps to improve insulin sensitivity, which is a good thing as the body becomes more attuned to maintaining blood sugar levels. Insulin resistance has the opposite effect resulting in higher insulin and blood sugar levels, which form part of the aetiology of diseases such as diabetes.

Research has shown that the oxidative stress (excess free radicals vs antioxidants) induced by exercise actually promotes insulin sensitivity and triggers an internal mechanism to protect the body against the potential damage from free radicals (3).  Interestingly, the same research has also shown that flooding the body with antioxidants (mostly in the form of supplements) may inhibit this health benefit from occurring.

These and similar findings have prompted experts in the field of sports nutrition to question the use of antioxidant supplements as part of their prescribed diet regime.

Are antioxidants always good?

The reputation of antioxidants has evolved over the decades into something of a panacea for good health.  Early research many decades ago identified their role in the ageing process and their association with health has stuck.

There is no doubt that antioxidants have a key role to play in the aetiology of disease and cell ageing, but this doesn’t mean that overdosing on them will help you to live longer, stop you getting sick or prevent wrinkles.

Antioxidant supplements

Supplements containing antioxidants have always been popular but the evidence to support their use in the reduction of disease risk is often lacking and often contradictory.

Supplements have their place and as the name suggests this is to supplement the diet to make up for any shortfalls that may exist when your diet may be compromised for whatever reason.  Public Health England currently recommend we supplement our diet with vitamin D during the winter months in the absence of sunlight and it has long been advised that women take folic acid during the early stages of pregnancy.

Supplements are also useful for young children, older adults and those following strict diets such as veganism.  In such cases there may be a greater risk of deficiency.

In some cases, supplements could do more harm than good and especially high doses of antioxidants.

One example is the link between beta carotene supplements and lung cancer as shown in the World Cancer Research Fund/American Institute for Cancer Research Third Expert Report Diet, Nutrition, Physical Activity and Cancer: a Global Perspective. This report found that there was strong evidence to show that taking high-dose beta carotene supplements increased the risk of lung cancer in both current and former smokers (4).

It’s all about balance  

Adopting a healthy diet which includes plenty of plant-based foods, especially brightly coloured fruits and vegetables, will ensure a good intake of antioxidants. Leading a healthy lifestyle which involves being active, maintaining a healthy body weight, not smoking and addressing stress and sleep issues can help to reduce excess free radicals.

I get that this may be easier said than done and behaviour change is a tricky thing that often challenges our ability maintain a healthy way of living.  However, focusing on the information and advice which is supported by science is always going to be a better long-term option than seeking out quick-fix fads.  A faddy approach to your health is  not only likely to be short-lived but may in fact be more detrimental to your health.

References  

  1. https://www.gov.uk/government/publications/the-eatwell-guide
  2. https://www.sciencedirect.com/science/article/pii/S2231253611110048
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2680430/
  4. https://www.wcrf.org/dietandcancer
Join Cancer Research UK in giving up sugar for February

Join Cancer Research UK in giving up sugar for February

Addicted to sugar? Learn more about how you can ditch the sweet stuff!

Sugar is the villain in the world of nutrition and most significantly those added to foods, which are referred to as being ‘free’.  We all eat too much of it and it’s supposedly more addictive than class A drugs.  So, what’s the deal with sugar and how can we start to cut it out of our diet?

This month we’ve been challenged by Cancer Research UK to ditch the white stuff in the name of charity but why is it so bad for our health, how much are we eating and how can we reduce it?

What are free sugars?

Free sugars are considered to be the ‘bad guys’ and have been defined by Public Health England as all added sugars in any form which include (1):

  • All sugars naturally present in fruit and vegetable juices, purées and pastes
  • All sugars in drinks
  • All sweeteners including table sugar, honey, barley malt, maple syrup, coconut nectar, palm sugar, agave nectar, date sugar and brown rice syrup

Other sugars found naturally in foods such as whole fruits, cereals and dairy foods (not flavoured milks) are not as damaging to health.  Blood glucose levels are less affected by the sugars in these foods as their fibre, fat and protein content slows down its release into the bloodstream.  Foods containing these sugars are also much more nutritious and contain many other nutrients which are beneficial to health.

How much free sugar should we be eating?

Sugar is high on the health agenda with both the World Health Organisation (WHO) and the Scientific Advisory Committee on Nutrition (SACN) urging us to reduce free sugars to just 5% of our daily calorie intake.  Guidance from Public Health England is to limit free sugar intake to no more than 30g (6 tsp) per day.

How much free sugar are we eating in the UK?

Findings from the UK National Diet and Nutrition Survey (2018) have shown that most of us consume too much free sugar (2).  The greatest contributors come from the sweeteners we add to food and drinks, soft drinks and then the usual suspects of confectionary and other sweet treats.

Sugar and heart disease

The relationship between sugar and heart disease has been widely researched and a recent study published in JAMA Internal Medicine found that a high-sugar diet was associated with a greater risk of dying from the condition.  Researchers not only found a strong association between sugar intake and heart disease but that the higher your intake of sugar the greater your risk of disease (3).

It’s not fully clear how sugar and heart disease are related but several indirect pathways have been implicated. The liver converts excess sugar into fat and when overloaded this may increase the likelihood of fatty liver disease, which contributes to diabetes risk (a key factor in the aetiology of heart disease).  Other risk factors for heart disease such as high blood pressure and inflammation have also been associated with diets high in sugar (3)

Sugar and cancer?

Sugar is often talked about with respect to cancer but according to Cancer Research UK, there’s no direct link between the two.  Saying that, the two may be indirectly associated with one another, which has more to do with the impact of obesity.  An unhealthy diet, which may include an excess of sugar in the diet has the potential to cause weight gain and evidence from research has shown that being overweight or obese can increase the risk of many different types of cancer including breast, bowel, oesophageal and pancreatic (4).

Beyond smoking, obesity is one of the greatest preventable risk factors in the development of cancer.  It’s been predicted that by 2035 almost three quarters of the UK population will be overweight or obese, which may cause a further 670,000 new cases of cancer over the next 20 years.

Exactly how being overweight or obese causes cells to become cancerous is not yet fully understood but is thought to be triggered by chemical signals released from excess body fat. We need some fat for the body to function properly, but excess may be harmful as it releases hormones and growth-promoting signals in the body, which encourage inflammation and influence how often our cells divide. These changes in cell division are thought to be one of the most likely reasons why carrying excess fat increases the risk of cancer (5).

How to start cutting free sugars out of your diet

Food surveys have shown we all eat too much of the white stuff and yet most of us find it impossible to cut it out of our diet.  Ditching free sugars for good is probably an unrealistic goal for the majority of people, but this current campaign led by Cancer Research UK offers an opportunity to kick-start new eating habits and explore ways to reduce them from your diet.

Top tips to tackling sugar in your diet

Try and make simple changes to your diet that involve cutting down on the amount of free sugars you consume.  The tips below can help you to reduce the amount of free sugars in your diet and beat the cravings that act as a key barrier to change.

Understand sugar on the label

Many of the foods typically high in free sugars are obvious to spot, but a significant amount of those we consume are hidden in salad dressings, condiments, breakfast cereals, soups, cook-in-sauces and ready meals.

The front of pack labelling highlights the amount of sugar in a food product so opt for green or amber traffic lights. This labelling can be misleading as it represents all the sugars so also refer to the ingredient list.  To identify free sugars, look for anything that ends in ‘ose’ (sucrose, glucose, fructose) as well as any healthier sounding alternatives, such as raw sugar, barley malt, maple syrup, coconut nectar, palm sugar, agave nectar, date sugar and brown rice syrup.  These are all classed as free sugars.

Switch to sweet snacks lower in free-sugars

To reduce the amount of free sugar you add to food you can opt for dried fruits or homemade compotes.  If you’re looking for something sweet to snack on, then try fresh or dried fruits alone or topped onto plain yoghurt.  You can also control the amount of sugar you add to homemade fruit breads, which can be topped with nut butters.

Include plenty of protein in your diet

Protein helps to keep you feeling full and can lessen the desire to snack between meals.  Structure your meals by teaming proteins with healthy fats (olive oil, avocado, nuts and seeds), fibre (wholegrains) and plenty of vegetables.  If you need to snack between meals then something protein-based such as boiled eggs, pulse-based dips (hummus) or lean meat proteins are a great option.

Get a little spicy!

Sweet spices such as ground ginger, allspice, nutmeg and cinnamon can make a great substitute for sugar.  These spices can be added to hot beverages and smoothies or sprinkled over porridge and yoghurt in place of sweeteners such as sugar or honey.

Ditch sugary drinks

Soft drinks are one of the biggest contributors to sugar in the diet and even so-called health drinks can be loaded with sugar in one of its many forms.  Try flavouring sparkling water with fruits, vegetables and herbs such as lemons, limes, strawberries, mint, cucumber, rosemary, fresh ginger and basil. Herbal teas are also lovely when brewed, chilled and sweetened with a little honey.

Keep occupied

Research shows that the desire for something sweet after you have eaten is more likely to stem from habits formed during childhood as opposed to anything more biological (6). Evenings are the downfall of most people when it comes to snacking, so the first step is to keep sweet treats out of the house.  The next step is to find ways to occupy your time such as going out for a walk, doing something around the house or having a nice bath with a good book rather than flopping in front of the TV with a family pack of minstrels.  There’s some truth in the saying, “Idle hands make for the devil’s work”.

Gum

Research findings are mixed but have shown that chewing gum may help overcome sweet cravings in some people (7). Make sure you opt for sugar-free varieties!

Learn to chill

We’re more likely to seek out sweet treats and comfort foods when under stress.  Try to adopt other ways to manage your stress rather than relying on food. Magnesium helps to relax the body and can be found in foods such as nuts, seeds and even a little high-cocoa dark chocolate, which is also rich in the compounds phenylethylamine that acts as mild mood booster.

Try chromium

This mineral has been shown to help manage blood glucose (sugar) as part of something called the glucose tolerance factor (GTF).  This factor increases the effectiveness of insulin, which is a hormone that helps to control blood sugar levels by transporting glucose into cells.  Chromium also helps the body to process the carbohydrates, fats and proteins in the foods we eat.  Whilst not conclusive, research has suggested that chromium supplements may help with cravings (8) and anecdotally, some people find these a useful way to reduce sugar cravings by taking with meals.

References

  1. https://www.ncbi.nlm.nih.gov/pubmed/29587886
  2. https://www.gov.uk/government/statistics/ndns-results-from-years-7-and-8-combined
  3. https://www.ncbi.nlm.nih.gov/pubmed/24493081
  4. https://scienceblog.cancerresearchuk.org/2017/05/15/sugar-and-cancer-what-you-need-to-know/
  5. https://www.cancer.gov/about-cancer/causes-prevention/risk/obesity/obesity-fact-sheet
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2531152/
  7. https://www.ncbi.nlm.nih.gov/pubmed/17118491
  8. https://www.ncbi.nlm.nih.gov/pubmed/16184071