Bridging Dietary Nutrient Gaps
By Ann Walker PhD RNut
Does your Diet Provide Enough Nutrients?
Good nutrition is the foundation of good health, but, unfortunately, many people do not reach their recommended target intakes for vitamins and minerals because of poor food choice or lack of exercise. Dietary surveys over the last few decades show that the average food intake in Britain is going down but average body weight is increasing. The main reason is lack of exercise. Overweight people try to lose weight by cutting down on food, but this also has the effect of reducing the intake of vitamins and minerals. Eating foods high in calories, but low in nutrients (sometimes called “empty calorie foods*), like sugar, white bread and fatty foods, will make the problem worse. Unfortunately, much nutritional advice is very negative: eat less fat or eat less sugar. While it is important to keep these “empty calorie foods” low in the diet, too little attention is given to positive dietary messages – i.e. what needs to be in the diet for the maintenance of good health.
Poor health has been shown in many studies to be linked to low intakes of essential nutrients. The cells of the immune system are particularly susceptible to nutrient insufficiency, as, with a short life and frequent replacement, nutrient requirements are high. Each cell of the body requires more than 40 essential nutrients to be continuously supplied to it via the bloodstream. Without an adequate supply of even one of these nutrients, cells get stressed and normal functioning becomes impaired.
If you experience symptoms of ill health such as fatigue, low mood or frequent infections, the first step towards putting things right is to consider your diet. There are 4 basic food groups that are important to consider, as low intakes of any of them will, over time, lead to nutrient insufficiency. If your answer is ‘no’ to any of the questions A to D below, then changing your diet should be your first priority in your journey towards full health.
A) Are you eating enough fruit and vegetables?
The recommended intake of five portions a day provides potassium, vitamins and phytochemicals in quantities that no other food group provides. The effect on the body is antioxidant and anti-inflammatory. Inflammation is the underlying cause of most disease conditions.
B) Are you eating wholegrain cereal products?
These are rich sources of magnesium, trace elements and B complex vitamins. Consumption of refined cereal products may jeopardise intakes of these vital nutrients and particularly magnesium. Three portions a day is a sensible target.
C) Are you balancing your essential fatty acids (EFAs)?
We require EFAs of two families: omega-6 and omega-3. Eating lots of polyunsaturated margarine and other products made from seed oils, such as sunflower oil (rich in omega-6 fats), and too little oily fish (rich in omega-3 fats), upsets the body’s balance of essential fatty acids and inflammation may result. Using olive oil instead of other oils and eating two portions of oily fish a week will go a long way towards reducing your inflammatory tendency.
D) Are you eating enough dairy products?
You need 3 portions of dairy products a day to reach your intake target for calcium. Dairy products of uniquely high in this important nutrient. People with dairy allergies or intolerance should look for milk or yoghurt from non-dairy sources that supply equivalent amounts of calcium to cow’s milk. If a non-daily product says on the pack that it has added calcium in it, then it has be equivalent to the cow’s milk product by law.
Bridging the Nutrient Gaps
Dietary supplements are always best used to augment a good diet, not to replace it. People who do not achieve the recommendations shown in A to D above are at risk of nutrient insufficiency and, if at all possible, should adapt their diet to improve their intake. However, there are always people who, for one reason or another, cannot comply with these recommendations: e.g. older people with dentition problems who cannot eat five portions of fruit and vegetables a day, or those with specific allergies. In such cases, a daily A-Z multivitamin and mineral supplement is likely to be a sensible choice. Those who might benefit also include people who are on slimming diets or cannot take exercise because of mobility problems. Others include people with diabetes and older people who may have higher nutrient requirements than the general population.
Several leading authorities in the USA have concluded that all adults would benefit taking a multi. Multi vitamins and mineral can help to ensure a good intake of trace elements. Wholegrains are particularly high in trace elements such as selenium and chromium, so if intake is low then intake of these is likely to become insufficient. Selenium is very important for the formation of key proteins in the body, including those that produce the active form of thyroxine – the thyroid hormone that is responsible for the rate of metabolism of the body. Chromium, on the other hand, is necessary for the body’s use of insulin and on account of this has been called the glucose tolerance factor. Fatigue can be a result of any nutrient deficiency, so a multi vitamin and mineral supplement would be good insurance against any unknown deficit.
The antioxidant properties of fruit and vegetable is particularly important, and yet most people in Britain fail to achieve even half the recommended intake of five portions a day. Those achieving five-a-day normally get plenty of antioxidants and do not require supplementation. Cases where higher intakes, using supplemental vitamin C (may be helpful is when there is evidence of inflammation in the body (e.g. eczema, asthma, catarrh, headaches, hayfever or joint problems) or if the patient has a long history of poor diet. But antioxidants are more than just vitamin C. The term includes vitamin E, vitamin A, selenium and the phytochemicals (plant chemicals from fruit and vegetables) such as the pigments found in highly coloured plant foods. Together these provide an antioxidant network which is protective of health.
Balancing oils and fats
The two families of essential fatty acids are often provided in an unbalanced way by modern diet. In general, the diet of today is high in omega-6 fatty acids from seed oils such as sunflower oil and the spreads and products made from it. Substituting olive oil for cooking and salad dressings and using olive oils spreads will help to reduce the omega-6 intake and obviously eating oily fish will increase the omega-3 intake. This will help enormously to right any imbalance, but many people do not eat oily fish at all. An indication for need to re-balance your essential fatty acids is any evidence of inflammation. Omega-3 is one of the most anti-inflammatory elements that the diet can provide. The greater a person’s inflammation, the more likely it is that are higher dose of omega-3 will be helpful (up to 2 g per day of EPA plus DHA). These high doses cannot be reasonably obtained from diet, as two portions of oily fish per week only provides 0.5 g of omega-3 on a daily basis. If higher intakes are required then supplements of omega-3 will be needed. Vegetarian forms of active omega-3 are now available, but flax-seed oil which is often touted as a good source, is only a source of inactive and not active omega-3. In theory, the body can make the active forms of these fatty acids from the inactive forms, but in practice this conversion is slow or even non-existent. It is much better to use omega-3 from fish oil or the specialised vegetarian forms more recently derived from sea algae.
If you cannot eat 3 portions of dairy products a day, then it is likely that your intake of calcium is low. Non-dairy replacements for milk and yoghurt are often fortified with calcium and this will be to the level found in milk. Hence, soya and cereal milks, fortified with calcium are acceptable alternatives, but vegetables are not, as their contents of calcium are too low. If calcium is needed as a supplement, then use one also containing magnesium. High levels of calcium can deplete magnesium, so it is best to take a ‘bone formula’ containing the two minerals.
Vitamin D is required for the body’s absorption and utilisation of calcium. If there is an overt deficiency of vitamin D, then rickets – a bone deforming disease - can result. New areas of research are showing that vitamin D has previously unknown roles in supporting the immune system to deal with bacterial and viral invaders, for maintaining an anti-inflammatory environment in the body and reducing risk of certain cancers. Vitamin D can be provided in food, but even eating lots of oily fish – one of the main sources of the vitamin – we would not get enough to cover our basic requirements. We need sunlight on the skin for this, which is problematic for those who live in locations away from the equator. In winter, the problem is critical, as the sunlight is at such a low angle in the sky that all the UVB light, needed for the skin synthesis of vitamin D, is absorbed by the atmosphere.
For optimum health, studies indicate that blood vitamin D levels should be a minimum of 125 nmol/L, with optimal levels falling between 125-200 nmol/L. Based on the body's daily vitamin D usage, the Vitamin D Council (USA) recommends as much as 5,000 IU of supplemental vitamin D3 per day in the absence of sun exposure. Additionally, people with chronic health conditions such as autism, MS, cancer, heart disease, or obesity may need as much as double these amounts. In the UK, levels can be monitored regularly to make sure that you are maintaining the optimal levels, using the excellent service of Sandwell & West Birmingham Hospitals NHS Trust. They provide a kit (currently £28) which you can use easily at home, based on a finger-prick sample. Contact them on telephone number 0121 507 4278 – they will email the results to you within a week of obtaining your blood sample. For more information on vitamin D go to:- www.vitamindcouncil.org.