This week’s article gives an overview of the latest permitted claims authorised by the European Commission and two claims that are currently pending authorisation, including; Calcium and Vitamin D contribute to a reduction in the risk of Bone Mineral Density (BMD) and thus a reduction in the risk of bone fracture; vitamin D contributes to a reduction in the risk of falling (further information for this claim on a recent Cytoplan blog – please follow the link); Zinc contributes to normal growth and finally, Selenium contributes to the protection of DNA, proteins and lipids from oxidative damage.
In this article we will look into the scientific mechanisms behind the claims as well as looking at the scientific opinions of the European Food Safety Authority (EFSA) on the authorisations.
Vitamin D/Calcium “may reduce the risk of osteoporotic fractures by reducing bone loss” (AUTHORISED)
Target Population: Women 50 years and over
The increasing number of fractures in the elderly is a growing problem “with an estimated lifetime risk for 50 year old Caucasians of at least 40% for women and 13% for men” as reported in an article titled ‘Reducing fracture risk with calcium and vitamin D.’
The course of action needed to reduce the numbers of fractures in the elderly revolves around attempting to prevent the onset of Osteoporosis and the overall loss of bone mineral density (BMD).
Doctors and scientists globally acknowledge that vitamin D and Calcium are essential for the maintenance of bone mass and strength, with the former being essential for the absorption of calcium. Let us evaluate the science behind this claim that “vitamin D and calcium may reduce the risk in loss of Bone Mineral Density (BMD).”
Science behind the claim
Osteoporosis is a skeletal condition that is characterised by loss of Bone Mineral Density (BMD). The main symptom of Osteoporosis is an increase in and general occurrence of bone fractures. The most common bones associated with osteoporotic fractures are in the wrist, hip, or spine but it can potentially affect any bone in the body. The vitamin D council reported that if you have Osteoporosis your chance of breaking a bone increases to “1 in 2 for women and 1 in 4 for men.” The higher prevalence of osteoporotic bone fractures in women explains why EFSA directed this claim at women over the age of 50.
Throughout life our bodies are constantly replenishing bone; making new bone and disposing of old bone. At the age of 30, our bones gradually become less dense as we begin to lose more bone than our bodies are able to produce, increasing the loss of BMD and with it increasing the likelihood of Osteoporosis setting in.
The role of vitamin D and Calcium
Although human bones contain many different minerals, calcium is by far the most important for maintaining bone density. A research study cited by EFSA in their ‘Scientific Opinion’ article highlights this claim:
“A meta-analysis of 15 calcium supplementation trials (400-2000 mg calcium/day) in 1806 post-menopausal women reported a 1.6-2 % difference in bone loss over a 2y period for BMD at all sites except lumbar spine (Shea et al., 2002)”
Although this research demonstrates the importance of calcium for bone health, in order to ensure the efficient absorption of calcium it is essential to have a good intake of vitamin D.
If your body is lacking in vitamin D then it is unable to form a sufficient amount of Calcitriol (active form of vitamin D) which leads to an inefficient amount of calcium being absorbed from the diet. In itself this is detrimental to bone health, but it doesn’t end there; if, as we said, there is not enough vitamin D to absorb the calcium then the body ‘calls’ upon its supply of calcium in the skeleton. This process weakens existing bone in the body and prevents the formation of new bone which leads to the loss of bone mineral density and eventually the onset of Osteoporosis.
The above claim was further strengthened when the vitamin D council reported that researchers “have discovered that people with osteoporosis tend to have lower levels of vitamin D in their blood than people who do not have osteoporosis.”
The key point to be emphasized with regards to this claim is that although both vitamin D and calcium are absolutely essential for bone health, their function is only utilised properly if they work in conjunction with each other, meaning a sufficient intake of both is necessary. Calcium is crucial for the density of bones and keeping them strong throughout life, however without sufficient vitamin D the calcium cannot be absorbed and therefore cannot function efficiently.
Vitamin D “reduces the risk of falling” (AUTHORISED)
Target Population: Men and Women 60 years of age and older
You can read more about this latest claim for vitamin D in our recent blog ‘Vitamin D “reduces the risk of falling” – The Mechanisms Unfolded’
Zinc “contributes to normal growth”
Target Population: Children up to 3 years of age (PENDING AUTHORISATION)
The World Health Organization (WHO) has reported that over a quarter of children under 5 years of age are suffering from stunted growth, with many of them also being zinc deficient. It is now understood that this may be no coincidence and with the European Commission being in the process of authorising this latest claim, the assumption is only fuelled.
An article from the ‘WHO’ website titled: ‘Zinc supplementation and growth in children’ states that despite various studies with inconsistent results, an analysis from a particular study found that “a dose of 10 mg zinc per day for 24 weeks led to a net a gain of 0.37 (±0.25) cm in height of children who received zinc supplements compared to those who did not.” This study further proves the idea that “zinc may contribute to normal growth” in children up to three years of age, so let us look at the science behind the claim.
Science behind the claim
Zinc is a mineral that cannot be naturally synthesized by the body and so without a good intake from dietary sources deficiencies can regularly occur and are extremely common on a global level. Recent statistics cited in the article ‘Zinc Supplementation for Mortality, Morbidity and Growth Failure’ state that “the global prevalence of zinc deficiency is approximately 17% (Wessells 2012a), and rates of deficiency approach 73% in some regions”. The latter statistic is especially the case for developing countries where children are growing up in poverty without access to foods that contain sufficient zinc, as they are often found in foods that are more expensive such as red meats, legumes and nuts.
As mentioned in the above article (‘Zinc Supplementation for mortality, morbidity and growth failure’), “Zinc is in every cell of the human body and is required for normal functioning. It plays critical catalytic, structural, and regulatory roles. Zinc enables hundreds of enzymes to function, facilitates protein synthesis and folding, and regulates processes such as gene expression and apoptosis.”
Zinc is an essential mineral for the efficiency of cell proliferation and division in various ways; as mentioned above it is pivotal for enabling the function of hundreds of enzymes in the body and this includes enzymatic systems that are crucial to cell proliferation which, in turn, happens to be an essential cellular process for somatic growth from a young age.
Zinc “also influences hormonal regulation of cell division. Specifically, the pituitary growth hormone (GH)–insulin-like growth factor-I (IGF-I) axis is responsive to zinc status. Both increased and decreased circulating concentrations of GH have been observed in zinc deficiency” as reported in the article ‘The Role of Zinc in Growth and Cell Proliferation.’
The growth hormone naturally occurs in the pituitary gland (located in the brain) and stimulates the growth of muscle and bone. Zinc is regarded as an important micronutrient when it comes to the efficiency and function of the body’s growth hormone and its secretion from the pituitary gland. If this process is not functioning efficiently then growth from a young age may be well stunted.
Several studies have been conducted that attempt to find a link between zinc deficiency and a lack of growth hormones being secreted from the pituitary gland. In the article previously mentioned (‘The Role of Zinc in Growth and Cell Proliferation’) – research has highlighted that when a deficiency in zinc is present, the efficiency and overall function of the growth hormone being secreted from the pituitary gland is far less efficient: “Zinc deficiency caused failure of GH secretion from the pituitary (Root et al. 1979).”
This provides an overview of the science behind how zinc may promote growth in children, however, it is important to note that although zinc clearly has a significant effect on growth, a good all-round diet that includes a sufficient intake of zinc is key.
Selenium “acts as an antioxidant to protect cells and tissues from oxidative damage” (PENDING AUTHORISATION)
Target Population: Children up to 3 years of age
Selenium is a trace mineral that is naturally present in many foods and is also commonly available as a form of supplementation. It plays a critical role in processes such as thyroid hormone metabolism, reproduction and protection from oxidative damage and infections. It is considered to be a pivotal micronutrient for the prevention of serious diseases such as cancer and heart disease. Let us look at the science behind this latest claim stating that selenium “acts as an antioxidant to protect cells and tissues from oxidative damage.”
Science behind the claim
The following is taken from the EFSA website, explaining how Selenium is “an indirect component of the antioxidant network” and thus helps to prevent damage to DNA, proteins and lipids: “Reactive oxygen species (ROS), including several kinds of radicals, are generated in biochemical processes (e.g. respiratory chain) and as a consequence of exposure to exogenous factors (e.g. radiation, pollutants). These reactive intermediates damage biologically relevant molecules such as DNA, proteins and lipids if they are not intercepted by the antioxidant network, which includes free radical scavengers such as antioxidant nutrients.”
Selenium and the Immune System
Selenium is known to be important for optimal immune response due to its antioxidant potential and activity, however the technicality behind this is extremely complex.
The immune system grows stronger and matures as it is exposed to ‘challenges’. As referenced in the research titled Selenium in the Immune System’ “Both the T and B lymphocytes form the major effector cells of the acquired system that mature with exposure to immune challenges. Selenium-deficient lymphocytes are less able to proliferate.”
This means that if there is not enough Selenium contained in the lymphocytes then the ability for them to multiply is far less efficient thus hindering the ability to prevent against oxidative damage.
Selenium and Glutathione Peroxidase
In their ‘Scientific Opinion’ article regarding this claim, EFSA referred to research stating that “The antioxidant defence system comprises low molecular weight antioxidants and antioxidant enzymes, such as glutathione peroxidases, which catalyse the reduction of hydrogen peroxide or organic hydroperoxides.”
Selenium is regarded as being integral to the above process as the essential mineral is known to regulate the activity and function of Glutathione Peridoxases. This is highlighted by EFSA: “These enzymes and other selenoenzymes, such as the thioredoxin reductases, which are also involved in antioxidant defence, are selenium dependent and can respond to selenium supplementation”.
This provides further confirmation that selenium does in fact have antioxidant properties and can enhance the activity and function of the bodily defence system.
It is important to note with regards to the above claims that the last two authorisations have not yet been authorised as such, they can be used as the applications were made in time for the transition period, which means that they can be used while awaiting formal ‘authorisation’. This could be a long time coming as this is dependent on other Regulations.
The first two claims are newly-authorised so may not be in use much as yet. In this case the authorisation process was particularly long following the EFSA opinions.
If you have any questions regarding this article, any of the health topics raised, or any other health matters please do contact me (Amanda) by phone or email at any time.
Amanda Williams, Cytoplan Ltd
email@example.com, 01684 310099
Last updated on 8th April 2015 by cytoffice