Background on nutrition
- Good nutrition is an adequate well-balanced diet underpinned by regular physical activity. It is the cornerstone to good health. Poor nutrition can lead to reduced immunity, increased susceptibility to disease, impaired physical and mental development and reduced productivity.
- Nutrients is an umbrella term that encompasses: fat, carbohydrates, proteins, minerals, vitamins and water. This can be divided into 2 broad categories of macronutrients (fats, carbohydrates, proteins) that are required in large amounts from diet and micronutrients (minerals, vitamins, trace elements and amino acids) that are required in smaller quantities.
- Micronutrients have an important role in human development, regulation of metabolism and a wide range of biological processes e.g. antioxidant properties. A lack of micronutrients can lead to growth deficiency in children and increased risk of a variety of adult diseases. Deficiencies include rickets (lack of vitamin D), scurvy (lack of vitamin C) and osteoporosis (lack of vitamin C).
- Types of micronutrients:
- Vitamins – water soluble/lipid soluble – water soluble need to be taken regularly whereas lipid can accumulate in the body.
- Macrominerals (e.g. calcium, magnesium, phosphorus, sodium, potassium) needed in larger amounts.
- Microminerals (e.g. copper) needed in smaller amounts.
- Oxidation can cause production of harmful molecules (free radicals), which can cause cell and tissue damage. Antioxidants are compounds that inhibit oxidation and include:
- Vitamin C (oranges, peppers, broccoli)
- Vitamin E (plant oils, nuts, seeds)
- Beta-carotene (red/orange pigmented food)
- Lycopene (red coloured fruit and vegetables)
- Lutein (green leafy vegetables)
- Selenium (tuna, chicken, beef)
- Zinc (seafood, cheese)
- NHS guidelines provide a rough range on what levels of micronutrients we need but individual requirements are influenced by a number of factors including: age, gender, growth phase, pregnancy and lactation, geographical location, methods of food preparation, pollution, cultural practices and food accessibility.
- Micronutrient deficiency is caused by dietary intake and excess processed food consumption, drug therapy (e.g. antibiotics, NSAIDs, antihypertensives), malabsorption, systemic disease (e.g. renal disease, diabetes), increased utilisation (e.g. during pregnancy) and lifestyle (e.g. chronic alcohol use, nicotine use).
What’s the link with periodontitis?
- The pathogenesis of periodontitis includes the interaction between the host and biofilm as well as risk factors. The host response is responsible for 80% of the damage (Grossi et al). The disease process involves activation of epithelial cells which in turn causes activation of factors that release proinflammatory cytokines. These orchestrate an inflammatory response including recruitment of neutrophils. Neutrophils can kill bacteria through – netosis (DNA net traps), phagocytosis (silent killing/engulfing) or degranulation. Degranulation causes tissue damage – when the bacteria and neutrophil come together, molecules are kicked out to kill off the bacteria – this causes an increase in oxidative stress and thereafter periodontal tissue damage.Tissue damage only occurs with excess release of free radicals and enzymes from neutrophils (and /or there is low levels of antioxidants).
- Oxidative stress is actually a key component of many other diseases including atherosclerosis, rheumatoid arthritis, diabetes, chronic kidney disease and COPD. The oxidative stress from periodontitis also spills over into the circulation so the effects are not just local.
- Antioxidants can protect cells/tissues from oxidative stress. These can be synthesised in cells but also ingested in the in diet. This is the key link between diet and periodontal disease.
- Health is a balancing act – antioxidants vs oxidative stress. It’s a double whammy with periodontitis as you have low levels of antioxidants and too much oxidative stress.
- Atoms have electrons and inflammation can knock out an electron. An unpaired electron a very reactive free radical which drives oxidative stress. It’s unpaired so wants to interact and can cause DNA damage and mitochondrial damage. Antioxidants can donate an electron to stabilise the molecule, so it then becomes non-harmful.
- In periodontal disease, micronutrients may act on neutrophils, reactive oxygen species, proteolytic enzymes, NETS and other protein complexes involved in the pathogenic process. They help regulate the inflammatory response. Those that may impact on periodontal disease include: vitamin C, vitamin E and zinc.
- Vitamin C is an important antioxidant in collagen synthesis. It is also important in glutathione recycling (key intracellular antioxidant). Severe deficiency is rare but hypo vitaminosis can be found in 10% of the population, 30% of smokers and 60% hospitalised patients. Vitamin C levels are lower in smokers with periodontal disease compared to both non-smokers and non-smokers with periodontal disease (Aziz et al 2013). Studies indicate that patients with a depletion of deficiency had increased attachment loss (Schectman et al 1991; Amalioya et al 2007). A large-scale epidemiological study has shown that: low serum levels of vitamin C and total antioxidant concentration were associated with periodontitis; this association was stronger in severe disease and increased serum antioxidant concentrations are associated with a reduced relative risk of periodontitis (Chapple et al 2007). Adults with higher levels of vitamin C intake showed increased serum levels in non-smokers but not in smokers with chronic periodontitis (Dodington et al 2015). Supplementation reduced levels of bleeding but not periodontal tissue loss (Leggott 1986, 1991). Supplementation alongside periodontal treatment did not improve periodontal outcomes in non-smokers with periodontal disease (Abou Sulaiman et al 2010).
- Vitamin E is found in high levels in vegetable oils, cereal grains and nuts. It is an important antioxidant with a wide range of biological actions resulting in lower levels of radical damage and reduced inflammation. The NHANES study (4708 subjects) showed no association between vitamin E and periodontitis (Chapple 2017). However, a study from same cohort looking at vitamin E status did show an association between vitamin E and severity of periodontitis. An investigation of 1258 men in Ireland showed no association between vitamin E and periodontal health (Linden et al 2009).
- Zinc is important in a variety of biological functions including growth, healing and repair. It has a key role in enzyme activity. Patients with reduced serum zinc showed increased alveolar bone resorption (Frithiof et al 1980). A case control study investigating diabetic and non-diabetic periodontitis patients showed significantly lower zinc levels in both groups of periodontitis patients when compared to healthy controls (Thomas et al 2010). Non-surgical periodontal therapy was shown to increase serum zinc in type 2 diabetic patients with periodontal disease (Sundaram et al 2017).
- Prebiotics are compounds that have the ability to promote the growth or activity of beneficial micronutrients. The have shown efficacy in gastro-intestinal diseases such a irritable bowel disease. A recent study (Slomka et al 2017) has showed the ability of certain prebiotics to enhance the beneficial bacteria resident in the biofilm to >95%.
- A study (Milward et al 2012) showed that the micronutrient lipoic acid exerts an anti-inflammatory effect on oral epithelial cells exposed to periodontal bacteria and thus may provide a novel adjunctive treatment to periodontal disease. This study was an initial proof of concept and clinical studies are required to determine any clinical efficacy.
- Considerations when reading the evidence:
- Serum levels of a particular nutrient may not the best biomarker of a subject’s nutrient level.
- Often dietary supplementation is patient-reported so this may mean issues with compliance – looking at biomarkers to support claimed compliance is more useful.
- If using natural food supplements, it is difficult to standardise supplement intake and there may be confounding of ingredients.
- Baseline nutritional status is important.
- Consider if supplements are absorbed and how they get to the cells.
- We need more highly powdered intervention studies to determine benefits.
- Consider if outcomes are clinically
So how do I use this on clinic?
- Take the opportunity of taking a diet history, get an idea of the dietary balance and amount of refined sugar and fats vs fresh fruit and vegetables.
- Ask about smoking and indicate the effect on nutrient levels.
- Talk about the risk of type 2 diabetes and how diet could impact, and link with periodontal disease.
- Explain the potential dietary impact both in systemic and oral disease.
- Encourage a well-balanced diet with regular fresh fruit and vegetables. This is preferred over supplements.
- Diet is important in oral and systemic disease.
- Periodontal disease has been associated with reduced levels of key micronutrients.
- Some intervention studies using supplements appear to show small clinical benefit.
- Antioxidant micronutrients have the potential to impact on periodontal disease pathogenesis.
- Diet modification is preferred to the use of supplements.
- More studies are required to better understand the impact of diet on periodontal disease, but dental professionals can play a key role in delivering the healthy diet message.
The summary was created from a talk by Dr Milward at the BSP conference Oct 2018. For more information on events organised by the BSP, please see:http://www.bsperio.org.uk/events/