Nutrition and Eye Health

As some of you are aware, I work as a Clinic Assistant for a glaucoma clinic. So from Monday to Friday I'm looking at and talking about eyes. I thought it might be interesting to explore how nutrition can affect certain eye conditions. Sadly, I can't talk about glaucoma because it's predominantly a hereditary condition, but I would like talk about a condition known as Age- Related Macular Degeneration (AMD). The burning question is what is AMD? AMD is a condition  where the central part of the retina (macula) becomes damaged and central vision is gradually lost. As the name suggest this conditions tend to affect those who are aged 60 years and above. I know everyone reading this article is not in this age group but nutrition and lifestyle can play a significant role in the development of this condition later on in life. Throughout the course of this article, I intend to discuss how optimum and poor nutrition combined with lifestyle factors can both potentially influence the development of  AMD.

Risk factors
Similar to most cardiovascular and metabolic conditions, smoking is one of the greatest risk factors for AMD.   It has also been defined as one of the modifiable risks factors. How does smoking cause AMD?  As most of you know cigarette contains tobacco and when released into the bloodstream it stimulates the release of harmful substances known as Reactive Oxygen Species (ROS). An imbalance between the production of ROS and antioxidant defences, is known as oxidative stress. How does this effect the retina? The oxidative stress causes our DNA to become damaged and as a 'knock - on - effect' this causes the automatic death of the retinal cell. Consequently, the light can't be signalled to the brain and central vision is lost.

Inadequate Nutrition
What about poor nutrition does that play a role in the development of AMD? To date there is limited evidence to suggest that a diet high in cholesterol and saturated fat is linked to the development of AMD. However, studies have suggested that foods high in sugar causes the build-up of extra cellular yellow material known as drusen, which are clinical indicators of early AMD. Furthermore, a reduced intake of foods containing  anti-oxidants can increase the likelihood of AMD progression.

Maintaining Optimum Nutrition
So how does nutrition manage and/or prevent AMD? Various studies have shown that consuming foods that are rich in antioxidants and fish oils help reduce the build-up of ROS and 'Free radicals'. Let's start with discussing the different types of anti-oxidants and their mechanism of action. Vitamin C has been found to protect the body from ROS and free radicals, acquired through metabolic processes and  through toxins and cigarette smoke.  Vitamin E  provides protects the cells which line the retina and is responsible for neutralising free radicals.  Similar to Vitamin E, Zinc molecules play an essential role in maintaining  structure and functioning of the cells which line the retina. Studies have proven that a decreased amount of zinc makes these cells susceptible to oxidative damage, which is the primary cause of AMD. Unlike Vitamin E and Zinc, Lutein and Zexanthin have a more specific antioxidant role. They protect the macula (area of the retina that controls central vision), by 'absorbing blue light/and or quenching reactive oxygen species'.

Recommendations
I know a lot of you have been eagerly awaiting this section. As previously discussed, the management and prevention of AMD can be achieved by making both dietary and lifestyle modification. These should include:

-Reduce or avoid smoking
-Try to incorporate oily fish as part of your diet, the essential fatty acid DHA helps reduce the risk of oxidative stress in the retina. These includes foods such as trout, crab, haddock, mackerel, salmon, shrimp and sardines.
-Eat wide variety of fruit and vegetables, such as oranges, blackberries, cauliflower, Brussels sprouts, spinach, kale, sweet potatoes, apricots and squash. These foods are rich in many antioxidants such as vitamin C, E, and betacarotenes.
-Eat foods rich in zinc, these include Spinach, Seafood, Pumpkin and Squash Seeds.
-Take part in physical activity for at least 150 minutes a week, this will help maintain good circulation and prevent high pressures (ocular hypertension) in your eyes.

Nutrition and Women's Health

For most of us woman, we dread menstruation because of the aches and pains that accompanies it. Let’s focus on period pain for a moment. What causes it? There are a group of chemical messengers known as prostaglandins. These messengers restrict blood flow within the middle wall of the uterus and causes the muscles to contract; and this is why women often suffer within lower abdominal. Most of us are aware that taking pain relief such as paracetamol and ibuprofen can help reduce pain, but from my own personal experience and through various research articles, a nutritional approach can have a profound impact. In the next few paragraphs, I aim to explore both the negative and positive impacts nutrition on period pain and highlight some recommendations.

 

Dietary unsaturated fatty acids and period pain

Let’s start with dietary unsaturated fatty acids. There are two forms, monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs).  Foods which contain PUFAs, particularly omega – 6 fatty acids, have been found to induce period pain. PUFAs such as linoleic acid have been found to increase the release of prostaglandins within the middle wall of the uterus and thus intensify the pain. Foods which are rich in linoleic acid or omega – 6 fatty acids include sunflower oil, vegetable oil and certain nuts. Therefore, it can be suggested that the consumption of these foods should be consumed in moderation. Are all foods rich in PUFAs bad for you? No! A lot of studies have confirmed that omega 3 – fatty acids have found to suppress pain and lower heart disease. Docosahexanoic acid (DHA) and eicosapentanoic acid (EPA) are the key products that suppress period. DHA and EPA and usually found in fish oils, nuts and seeds. 

Effects of a ‘Junk Free’ Diet

I mentioned previously that from personal experience I observed that nutrition has a profound impact on period pain. What was I referring to? During the summer, I went on a junk free diet for a month. This meant that I refrained from eating chocolates, crisps, biscuits and cakes. Pretty much anything high in processed sugar, sodium, trans- and saturated fats. Alongside my balanced meals, I ate a mixture of fruits such as apples, red and green grapes, oranges and bananas, and 1 piece of fruit for dessert. My lower abdominal pain and backaches was almost non-existent. The following month when the diet was over, the pain intensified. Why? I went back to eating sugary foods, especially whilst on holiday. It became clear to me that consumption of sugary foods not only cause a high amount of acne but also can intensify period pain. The probable reason for this is because a lot of sugary foods contain saturated fatty acids, which have been to cause many health problems such as Hypertension (high blood pressure).

Iron status and Menstruation

Another important nutrient that should be address is iron. Women lose a lot of iron during their period; which can make us feel fatigued. Therefore, it is very important that a rich source is maintained in their diet. So what foods contain iron? Foods such as shrimp, eggs, spinach, salmon, wheat, rye, barley, dried fruit and lean red meat contain iron. Eating these foods during and after our periods can help us to replenish the deficit. In addition, eating foods which are rich in vitamin C and zinc helps aids the absorption of iron.

Recommendations

Most recommendations for period pain can be centred on diet and lifestyle modifications. These should include:

• Avoiding sugary foods before and during your period;

• Try to incorporate oily fish eg salmon and nuts such as brazil, almond and cashew nuts and seeds. These contain a rich source of omega – 3 fatty acids.

• Eat more fruits and vegetables – e.g. oranges, strawberries, guavas, mangos, raw red and green peppers, broccoli, cauliflower and sweet potatoes. These foods contain a lot of anti-oxidants, which helps reduce the amount of inflammation which is associated with period pain.

• Try to take part in light/moderate exercise such as walking and jogging for 30 minutes, 3 times a week.

• Consume iron rich foods such as eggs, spinach, dried fruits and lean meats.

• Try going junk free for 3 months – currently doing this at the moment and have seen some good results!

Nutrition and Digestive Health

There has been a lot of interest and research into the bacteria which are found within different areas of the digestive tract. These have been defined as gut microbiota. These bacteria provide health benefits. For instance, protection against harmful bacteria, they enhance the body’s immune system and help to maintain adequate nutrients in the body. There are two types of food products which enable the gut microbiota to carry out these functions; these are known as prebiotics and probiotics. In the next few paragraphs, an explanation as to how the gut microbiota carries out these essential functions and how they are enhanced by prebiotics and probiotics.

Gut microbiota and Immunity

In order to ensure the immune system is regulated effectively, the small intestine is lined with many immune cells. These immune cells have been found to mature in the large intestine. When these cells have been placed in the lining of the small intestine, they have been found to initiate an inflammatory response. As well as protecting the small and large intestines from harmful bacteria, the gut microbiota plays an essential role in preventing excessive and harmful inflammatory reactions in the bloodstream. These problems can arise from the overgrowth and the underlying of existing microbiota.

Gut microbiota and its protective role

There are different factors that contribute to the protective function of gut microbiota. These include, the production of Antimicrobial Polypeptides (AMP), helping ‘the consumption of nutrients sources’, and ‘the physical presence of the gut microbiota’- which has been said to act as a ‘deterrent’ against foreign substances. Indeed, a lot of the activity of gut microbiota can be positively enhanced by the role of probiotics.

Probiotics

Probiotics can be defined as healthy bacteria that when ingested can promote a positive microbiota balance within the digestive tract.  Several authors have suggested that probiotics may improve both short and long term conditions, such as ‘lactose intolerance, diarrhoea, allergy, asthma and colorectal cancer’. As previously discussed, probiotics have been found to produce AMPs as well as strengthen the lining of the small intestine. There are two key groups of probiotics, these include Lactobacilli and Bifdobacteria. With respect to cancer, these Lactobacilli have been found ‘prevent tumour growth by 50%’ in colorectal cancers’. Moreover, Bifbobacteria has been found to reduce the histamine, which is a substance which stimulates many allergic symptoms, such as those seen in asthma sufferers.

Prebiotics

Alongside probiotics, prebiotics have also been found to exert health benefits when used solely or in unison with probiotics. Prebiotics are food ingredients which have been shown to increase the quantity and the action of gut microbiota. These are usually shorts chains of indigestible sugars, such as Fructose which is naturally found in food or could be added (fortified).Some examples to which include ‘chicory root, tomato, banana’, garlic, chive and leeks, raw asparagus and wheat bran. In a similar manner, prebiotics have been said to optimize the intestinal immune system and relieve constipation.

The effects of Nutrition

 It is important to note that the foods we eat don’t just benefit ourselves as individuals, but provide a source of energy and increase the quantity of pre-existing microbiota. For instance, several authors have reported that the production of short chain fatty acids, such as butyrate prevent the build – up of ‘toxic by – products’.  The gut microbiota has been found to facilitate the breakdown of complex sugars into simple sugars. Additionally, they have been found to prevent the build up of dietary fat in fat tissue. With this in mind, it could be suggested that the microbiota may play a role in body weight regulation.

Recommendations

It is evident from research that nutrition plays an important role in the activity, size and number of gut microbiota. Moreover, optimum nutrition may prevent certain digestive disorders and diseases such as lactose intolerance and colorectal cancers. Nutrition and lifestyle modifications have been listed below.

 

•     Limit your intake of red meats and other meats high in saturated fat.

•     Consume foods which contain both prebiotics and probiotics.
•   Probitic foods may include yoghurts produced by Danone:Activia and formulas containing Lactobacilli bacteria.

•       Try to eat dinner before 8pm.

•    Take part in regular exercise e.g. walking, jogging and running for 30 – 45 minutes.

 

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Nutrition and Cancer

As most of you know cancer is one the biggest killers in the UK and worldwide for that matter. Interestingly, there is a lot of evidence that shows that not just nutrition, but lifestyle and environmental factors play a significant role in its development and prevention.Before I start giving recommendations, I think it’s vital to define cancer. Cancer can be defined as a ‘malignant tumour’ or growth. It usually arises from the ‘uncontrollable, purposeless division of abnormal cells. These cells usually have abnormal features and contain damaged genes (the genetic information which controls the cell’s normal functions).

Let’s talk about environmental factors, things such as tobacco smoke, arsenic and nickel, can be defined carcinogenic (harmful substances which promote cancer). These carcinogens create as it were, an accelerated immune response. If the immune system cannot destroy or identify them, their prolonged activity (usually inflammation) can promote the development of cancer.

 Let’s get on to the bit you’re all waiting for, the nutrition factor. There is strong evidence that shows that a diet high in saturated fatty acid is associated with breast, colon, rectum and prostate cancers. This is mainly because saturated fatty acids promote the development of bad cholesterol known as Low density lipoprotein (LDL) - cholesterol; this promotes an imbalance of cholesterol in the body and can cause the development of harmful substances in the body when stored as fat in fat (adipose) tissue. In addition, some authors had found that consuming more than 40g of alcohol per day is directly associated with cancers of the ‘oral cavity, pharynx, oesophagus and larynx’.

On a more positive note, the following anti-oxidants Vitamins C, E and selenium have been found to reduce the uncontrolled rate of programmed cell death (apoptosis), which is often characterised in cancer development, as well as reducing the tumour size and growth, respectively. Foods rich in Vitamin A have been found to protect against chemicals, which can cause damage to cells (‘free radicals’). They too - have been found to protect against the ‘premalignant phase’ of tumour development. 

So what recommendation should be made?

The information below is modified from the World Cancer Research Fund/American Institute For Cancer Research Expert Paper (2007):

·      Individuals should strive to maintain a healthy BMI range 18 – 25 kg/m²   (NB this range may not consistent with those who have high muscle mass or pregnant).

·      Those who are relatively well enough should take part in exercise often – the British Heart Foundation recommends 30 – 45 minutes of light, moderate exercise.

·      Avoid energy dense foods – such as foods high in sugar and avoid sugary drinks

·      Eat as many foods of plant origin

·      Avoid processed and red meats

·      Limit alcoholic drinks – less than 40g a day

·      Limit consumption of salt – No more than 4g a day.

·      Make sure your nutritional requirements are sought through diet alone, don’t use nutritional supplements unless absolutely necessary.

·      Lactating mothers are recommended to breast feed their children until weaning as opposed to using formula milk.