What is the nutrition gap?  

Nutrients extracted from the food that we eat are used initially for immediate needs, such as energy production and maintaining a variety of bodily processes. It is only if nutrients are ingested in excess of these immediate functional needs that there will be sufficient left for ‘housekeeping’ processes that support long-term health.

In this week’s blog, we discuss the many factors that may contribute to low intakes of micronutrients, regardless of food nutrient intake. At Cytoplan we refer to this as ‘The Nutrition Gap’, a phenomenon where even those eating a balanced healthy diet may be at risk of nutrient deficiencies due to a lack of vitamins and minerals contained in the food we eat today.

The evolution of the nutrition gap theory

In nutritional therapy we are often asked, can we obtain nutrients we need from diet alone?

Although a well-balanced healthy diet is essential for wellbeing it is often not adequate enough to provide optimal levels of all nutrients. Additionally, in many cases individuals are not consuming a healthy diet and therefore they have an increased requirement for micronutrients.

“Natural selection favours short term survival at the expense of long-term health.”

Professor Bruce Ames, 2006¹

Professor Bruce Ames, an American biochemist and Professor of Biochemistry and Molecular Biology Emeritus at the University of California proposed the theory that, through evolution, the body has developed a rationing response to shortages of micronutrients (vitamins and minerals).

When a particular micronutrient is in short supply, he proposes that its use will be prioritised for processes that are critical to short-term survival, at the expense of long-term health. He suggests that limiting these micronutrient deficiencies is key to preventing the onset of diseases of ageing, and we can do this by supplementing these vitamins and minerals.^1,2

In his 2006 paper, he concludes:¹

“I hypothesize that short-term survival was achieved by allocation of scarce micronutrients by triage. If this hypothesis is correct, micronutrient deficiencies that trigger the triage response would accelerate cancer, ageing and neural decay but would leave critical metabolic functions such as ATP production intact. A multivitamin-mineral supplement is one low-cost way to ensure intake of the Recommended Dietary Allowance of micronutrients throughout life.”

So, it is only if micronutrients are ingested in excess of immediate needs that there will be sufficient amounts left available as a reserve for future needs and long-term health protection. 

What is the nutrition gap & why does it occur?

The nutrition gap describes the difference between the levels of nutrients the average person, eating a reasonable Western diet, is obtaining from food and those nutrient levels identified by research as being needed for optimal health in the population. The nutritional status of our bodies is dependent on a number of factors, including:

• Our food choices
• The nutrient content of the food we eat
• The ability of our bodies to assimilate these nutrients
• Lifestyle factors, such as smoking, stress, alcohol intake, medications etc. which give rise to increased nutrient requirements
• Our level of activity
• Our genetics

Food choices

A significant factor in the nutrition gap is our food choices. Many people’s diets are high in refined, processed foods that offer low nutrient density and empty calories.

There is often an emphasis on how many calories we should be eating – but calories are not all created equal. For example, nuts and donuts are both high calorie and high fat foods. However, nuts contain fibre and also provide phytonutrients along with vitamins and minerals. Donuts on the other hand are high in sugar and refined carbohydrate, inflammatory fats and lacking in nutrition and micronutrients – they provide empty calories.

The 2019 published National Nutrition and Diet Survey³ concluded that “there was a downward trend in intakes of most vitamins and minerals over the 9-year period for many age/sex groups”. In particular, all age/sex groups showed a significant reduction in vitamin A and folate.  Furthermore, the survey showed vitamin D deficiency continues to be a problem, levels are lowest in January to March, with 19% of children aged 4 to 10 years, 37% aged 11 to 18 years and 29% of adults with 25-hydroxyvitamin D below the deficiency threshold.

The nutrient content of the food we eat

Early forms of agriculture were ‘sustainable’ as plants were grown in soil to which excess plant waste and waste from the animals (who had also consumed the plants) were returned. This process naturally re-mineralised and replenished the ground for the next crop.

Early ploughing techniques also helped to evenly distribute the plentiful and natural fertiliser ‘mycorrhiza’. The mycorrhiza is a ground fungus that ‘biotransforms’ inorganic minerals into an organic form that makes the minerals readily useable by plants, thus ensuring good mineral uptake.

However, with modern farming techniques (that have been in use for decades) deep ploughing destroys the mycorrhiza and grown plants are harvested and shipped all over the world. In addition, the standard use of ‘NPK’ fertiliser (containing nitrogen, phosphorus and potassium) does not provide the soil with the sixty plus other nutrients that would normally be present.

Studies have shown that the levels of nutrients in our foods have changed. So even those who aim to eat a diet focused on wholefoods may not be achieving optimal intake of certain nutrients.

A government study between 1940 and 1991 determined the mineral content of a number of foods – 27 varieties of vegetable, 17 varieties of fruit, 10 cuts of meat and some milk and cheese products. The results “demonstrate that in every subgroup of foods investigated there has been a substantial loss in their mineral content”. For example, between 1978 and 1991 in vegetables there was an average loss of zinc of 59%.⁴

Pesticides and fungicides have resulted in the reduction of phytonutrients in plants – like flavonoids and carotenoids. These flavonoids and carotenoids not only protect the plant from disease, UV light and other damage, but have the same beneficial action in our bodies when we eat them. Plants that are sprayed have less requirement to produce high levels of phytonutrients.

Climate change is also affecting the nutrient content of our food, with rising CO2 levels altering plant chemistry. This poses a threat to the nutritional integrity of our food, compromising the levels of protein and concentrations of minerals.

Scientists estimated that increases in CO2 plus the effects of fertilisation, will decrease the availability of protein by 19.5%, zinc by 14.6% and iron by 13.6% by the year 2050.⁵

Already, a 2019 meta-analysis of vegetable responses reported declines in the concentrations of protein by 9.5%, magnesium by 9.2%, iron by 16% and zinc by 9.4%.⁶ This supports the idea put forward that a combination of rising CO2 and the use of yield enhancing methods will reduce the nutritional integrity of plants, which may have a significant impact on global nutrition and health.⁷

At first this might seem counterintuitive as carbon dioxide actually stimulates photosynthesis and growing and so might be considered to have a positive effect on food production. The precise biological mechanism by which climate change causes nutrient levels to fall is not well understood, however, research shows that increased carbon dioxide creates plants with higher carbohydrate concentrations and reduces the mineral and protein content.⁸

The ability of our bodies to digest, absorb and assimilate these nutrients

Ageing is associated with reduced gastric acid output and production of the digestive enzyme pepsin (secreted in the stomach and responsible for the digestion of protein).  Exposure to factors such as Helicobacter pylori infections, smoking, other conditions and medications can all affect acid production by the stomach. Unfortunately, some conditions are treated with proton pump inhibitors which then further reduce gastric acid output.

The consequences of compromised gastric function, in relation to nutritional status, may include:

• A reduced ability to absorb nutrients, particularly nutrients that require stomach acid in order for them to be cleaved from their carrier molecules. It has been established that B12, iron, magnesium, calcium and zinc absorption, in particular, are affected by low hydrochloric acid in the stomach⁹
• Reduced protein digestion and absorption (due to low hydrochloric acid and pepsin secretion). This may also mean that larger protein molecules are present in the small intestine, this can be a trigger for inflammation and leaky gut and is associated with food intolerances, atopic conditions and autoimmune diseases¹⁰

Lifestyle factors

Smoking, stress, medications and other lifestyle factors can increase requirements for micronutrients. For example, some prescription medications can have a significant impact on nutrient status by reducing absorption , increasing excretion or inhibiting the body’s own production of certain nutrients.

For example, according to US website www.mytavin.com, taking a combination of diclofenac (for pain), omeprazole (an antacid) and simvastatin (a statin) could lead to depletion of the following nutrients: folate, zinc, iron, B12, calcium, selenium, magnesium, omega-3, native bacteria and coenzyme Q10.

AGE UK (2019) estimated that nearly two million people over 65 years old are taking at least seven prescription medications, which doubles to four million for those taking at least five medications,¹¹ this has led to concerns over the impact of taking multiple medications long term.

Our level of activity

Our sedentary lifestyle means that we do not need to eat as much as we used to. Our physiology developed in the Paleolithic era 10,000 years ago and our physiology is relatively unchanged from that time. But our lifestyle is very different now. Our ancestors, hunter-gatherers, ate 4,000+ calories per day which was needed to fuel such active lifestyles. In contrast a more sedentary lifestyle means that on average people eat much less per day, but we still need the micronutrients from 4,000 calories. It is thought that most people even when eating enough calories for their activity needs, are not eating enough to get adequate amounts of vitamins and minerals, resulting in a well-fed but under-nourished situation.

NRVs (Nutrient Reference Values) are not enough to bridge the nutrition gap

When the National Academy of Science drew up the Nutrient Reference Values (NRVs), formerly called RDAs, it never claimed that these represented nutrient intakes to achieve optimum health.

They were never intended as any more than a ‘safety net’ with the specific purpose of preventing diseases of overt deficiency. However, many people still mistakenly believe NRVs are levels of intake that will give rise to optimum health.

The Committee on Food and Nutrition of the National Research Council was established in 1940 to advise on nutrition problems in connection with national defence. One of its first concerns was to work out NRVs for the various dietary essentials for people of different ages. The first NRVs were set in 1941 to prevent scurvy (vitamin C deficiency), pellagra (niacin deficiency) and beriberi (vitamin B1 deficiency) and, indeed, these new NRVs were very effective. For example, obtaining 30mg of vitamin C per day will prevent scurvy – but we now know that we need a much higher amount of vitamin C for optimal health, tissue repair and antioxidant activity.

Summary

In conclusion, the nutritional value of the foods that we eat today has considerably declined, with factors such as nutrient availability and farming practices influencing the quality of the food itself, alongside lifestyle factors, physical activity, personal food choices, genetics and the health of the individual and their ability to digest, absorb and assimilate these nutrients.

The need to recognise and support this gap between the nutrients the body requires and the nutrients that are available in food is of upmost importance for both practitioners and their clients.

References

1. Ames, B. (2006) ‘Low micronutrient intake may accelerate the degenerative diseases of aging through allocation of scarce micronutrients by triage’. PNAS, 103, 47, 17589-94
2. Ames, B. (2018) ‘Prolonging healthy aging: longevity vitamins and proteins. PNAS, 115, 45, 10836-44
3. National Nutrition and Diet Survey (2019) Years 1 to 9 of the Rolling Programme (2008/2009 – 2016/2017): Time trend and income analyses. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/772434/NDNS_UK_Y1-9_report.pdf
4. Thomas, D. (2003) ‘A Study on the mineral depletion of the foods available to us as a nation over the period 1940 to 1991’. Nutrition and Health, 17, pp. 85-115 0260-1060
5. Beach RH, Sulser TB, Crimmins A, et al. Combining the effects of increased atmospheric carbon dioxide on protein, iron, and zinc availability and projected climate change on global diets: a modelling study [published correction appears in Lancet Planet Health. 2020 Sep;4(9):e385. doi: 10.1016/S2542-5196(20)30207-2]. Lancet Planet Health. 2019;3(7):e307-e317. doi:10.1016/S2542-5196(19)30094-4
6. Gazell, K.A. (2019) ‘Climate change and food quality. How a changing climate impacts the nutritional value of food.’ Natural Medicine Journal, Vol. 11, Issue 8.
7. Ziska LH. Rising Carbon Dioxide and Global Nutrition: Evidence and Action Needed. Plants (Basel). 2022;11(7):1000. Published 2022 Apr 6. doi:10.3390/plants11071000
8. Dong J., Gruda N., Lam S.K., Li X., Duan Z. Effects of elevated CO2 on nutritional quality of vegetables: A review. Front. Plant Sci. 2018;9:924–928. doi: 10.3389/fpls.2018.00924.
9. Guilliams TG, Drake LE. Meal-Time Supplementation with Betaine HCl for Functional Hypochlorhydria: What is the Evidence?. Integr Med (Encinitas). 2020;19(1):32-36.
10. Textbook of functional medicine. 2008. Institute for Functional Medicine.
11. Age UK (2019). Age UK Calls for a More Considered Approach to Prescribing Medicines for Our Older Population. [online] www.ageuk.org.uk. Available at: https://www.ageuk.org.uk/latest-press/articles/2019/august/age-uk-calls-for-a-more-considered-approach-to-prescribing-medicines-for-older-people/.

All of our blogs are written by our team of expert Nutritional Therapists. If you have questions regarding the topics that have been raised, or any other health matters, please do contact them using the details below:

nutrition@cytoplan.co.uk
01684 310099

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Last updated on 2nd August 2024 by cytoffice