Abstract

Background: The World Health Organization has developed global benchmarks for sodium levels in foods across different food categories and subcategories including the subcategory description of bread. Nigeria is yet to establish sodium benchmarks across food categories. There is clear evidence that excessive consumption of sodium adversely affects blood pressure, which alone accounts for an estimated 10.8 million deaths in 2019. Also, High sodium intakes are responsible for 3 million of the estimated 11 million deaths globally associated with poor diet. WHO recommends a population-based daily intake of less than 2 g of sodium per adult to reduce blood pressure and the risk of cardiovascular disease, stroke and coronary heart disease. Studies have shown that bread contributes significantly to total dietary sodium intake. Concerns have been raised about the potential impact of the consumption of bread on the risk of high blood pressure in Nigeria and adopting the WHO global sodium benchmark for bread on dietary sodium intake in Nigeria.
The Lagos State Commissioner for Health, Akin Abayomi, revealed that 30 per cent of Lagos State's resident suffer from hypertension, a staggering 8.67 million people. Hypertension is a leading cause of heart disease, which is a leading cause of death.
Aim: To assess the potential impact of adopting the WHO global sodium benchmark on dietary sodium intake and risk from bread in Lagos, Nigeria.
Methods: The level of sodium in bread in Lagos, Nigeria was estimated from on-pack nutrition labels of bread sold in the open markets and supermarkets in some local government areas in Lagos, Nigeria and daily bread consumption data from the GEMS/Food Cluster Diets. These calculations were done to estimate dietary sodium intake and risk from bread using the methods stipulated in the Codex Food Safety Risk Analysis Manual and FAO Dietary Risk – Pesticide Registration Toolkit. Comparison of the estimated dietary intake was made with the Nutrient Reference Value – Noncommunicable Disease for Sodium from Codex Guidelines on Nutrition Labelling. Also, a comparison of the estimated sodium content in bread was made with the WHO global sodium benchmark.
Results: The estimated dietary sodium intake was 1.99 g per day and contributes 100% of the WHO recommended maximum dietary sodium intake per day. The estimated dietary sodium intake if the WHO benchmark was adopted was 1.1 g per day and contributes 55% of the recommended WHO maximum dietary sodium intake per day. The estimated dietary risks of excess sodium intake from bread in the absence and presence of the WHO global sodium benchmark are 199% and 110% respectively. The estimated relative risk is 0.55 and relative risk reduction is 45%.
Conclusion: This study suggests that a significant proportion of sodium in the diet comes from bread. Consumption of bread poses a significant risk of excess sodium intake and hypertension.. The adoption of the WHO global sodium benchmark may contribute to reducing dietary sodium intake and risk from bread significantly.

Keywords:Dietary Intake; Risk Assessments; Bread; WHO Global Sodium Benchmark

Introduction

The World Health Organization (WHO) has developed global benchmarks for sodium levels in foods across different food categories and subcategories including the subcategory description of bread [1]. Nigeria is yet to establish sodium benchmarks across food categories. High dietary sodium intake (intake of more than 2,000 mg sodium per day), which increases blood pressure and the risk of cardiovascular diseases, is responsible for 3 million of the estimated yearly 11 million deaths globally associated with poor diet. Cardiovascular diseases are the leading cause of noncommunicable diseases globally, responsible for 32% of all deaths [2-5]. Hypertension poses a major public health concern in Nigeria, with a prevalence among adults of approximately 31%. In 2019, 19.1 million adults aged 30-79 years were with hypertension in Nigeria and the average sodium consumption among Nigerian adults has been estimated to be 2.8 g per day, exceeding the WHO’s daily recommendation of not more than 2 g per day [6-8]. This significant deviation underscores the potential for elevated health risks related to hypertension and cardiovascular diseases within the population. An effective way of reducing dietary sodium intake (thus, lowering blood pressure and reducing noncommunicable diseases) is by lowering sodium content in foods that contribute significantly to increased total dietary sodium intake [9-11]. Study has showed that bread is classified as excessive in sodium and contributes more than 10% of the recommended daily dietary sodium intake, and as such likely to contribute significantly to total dietary sodium intake in Nigeria. This may largely be due to lack of reformulation targets for sodium levels for bread in Nigeria. Studies have shown that the WHO global sodium benchmarks are useful in setting national sodium targets, which is a key step towards reducing population sodium intake. One of the four key policies that are the targets of National Sodium Reduction Programme in Nigeria is mandatory limits of sodium in pre-packaged foods. Concerns have been raised about the potential impact of the consumption of bread on the risk of high blood pressure in Nigeria and adopting the WHO global sodium benchmark for bread on dietary sodium intake in Nigeria. The importance of addressing these concerns is stressed in the recently published national policy on food safety and quality and its implementation plan [12].

This study assessed the potential impact on risk of excessive dietary sodium intake in Lagos, Nigeria of consumption of bread and adopting the WHO global sodium benchmark.

Methods

Sodium content of bread in Nigeria

Market data on sodium content of bread in Lagos [13], Nigeria was estimated from on-pack nutrition labels of bread sold in open markets and supermarkets in some local government areas of Lagos, Nigeria (Table 1).

Consumption of bread in Nigeria

Data on bread consumption was estimated from the GEMS/ Food Cluster Diets (Table 2).

Estimation of Dietary Sodium Intake (EDI)

Using the information on sodium content and consumption level, dietary sodium intake was estimated as stated below.

Calculation:

(Sodium content in g per 100 g of bread x consumption of bread in g per day) / 100.

Acceptable daily intake (ADI)

(WHO global sodium benchmark for bread in g per 100 g x acceptable serving size [14], not more than 300 g, per day) / 100.

Nutrient Reference Value – Noncommunicable Disease for Sodium

The value was obtained from the Codex Guidelines on Nutrition Labelling (Table 3): nutrient intake levels not to exceed and nutrient intake levels to achieve.

Global Sodium Benchmark

The value of the global sodium benchmark was obtained from the WHO Global Sodium Benchmarks for Different Food Categories (Table 4).

Risk characterization

The risk was characterized by comparing the estimated dietary sodium intake with the nutrient reference value – noncommunicable disease for sodium.

Chronic dietary risk

Chronic dietary risk is expressed as a percentage of the acceptable daily intake. If the calculated %ADI is less than 100, the risk is generally considered to be acceptable.

Relative risk

Dietary intake when there is benchmark / Dietary intake when there is no benchmark.

Relative risk reduction

(Dietary intake when there is no benchmark – Dietary intake when there is benchmark / Dietary intake when there is no benchmark) x 100.

Results and Discussion

The sodium content of bread is shown in Table 1. The sodium content ranged from 0.132 g to 0.9 g in 100 g bread according to their nutrition facts panels. The mean content was 0.598 g per 100 g which exceeds the WHO global sodium benchmark of 0.330 g per 100 g for bread [15]. More than 90% of the on-pack sodium content values are higher than the WHO global sodium benchmark that applies to bread.

The acceptable daily intake of sodium from bread is not more than 0.99 g per day. The estimated daily intake of sodium from bread is 1.99 g per day, which is more than double the acceptable daily intake.

The calculated %ADI is 99 whereas, the calculated %EDI is 199. Hence, the dietary risk of excess sodium intake from the consumption of bread in Lagos, Nigeria is high. This suggests that bread could be a highest contributor for sodium in the Nigeria diet and a high risk of bread consumers exceeding the recommended intake level which poses sodium-related health hazards and high risk of diet-related noncommunicable diseases such as, high blood pressure. Thus, there is an urgent need to set national sodium benchmark for bread to promote reformulation and lower sodium concentrations in this food subcategory, and also to establish guidelines on the consumption of bread.

If the WHO global sodium benchmark is adopted in Nigeria, the EDI will be 1.1 g per day and the %EDI will be 110, which is not less than 100. Adaptation of the WHO global sodium benchmark to a value that is less than 0.330 g per 100 g is strongly recommended.

The relative risk with regards to dietary sodium intake from bread is 0.55. This indicates that the risk of excess dietary sodium intake in the presence of WHO global sodium benchmark is lower than the risk without a sodium benchmark for bread. The relative risk with regards to dietary sodium content in bread is 0.55. This could mean that the risk of high sodium content of bread in the presence of WHO global sodium benchmark is lower than the risk without a sodium benchmark for bread.

The relative risk reduction with regards to dietary sodium intake from bread is 45%. The adoption of WHO global sodium benchmark could reduce the risk of excess dietary sodium intake from bread consumed in Lagos, Nigeria by 45% [16]. This implies that adopting the WHO global benchmark would have positive impact on the dietary sodium intake from bread in Lagos, Nigeria and its associated NCD risk. The estimated 45% reduction if the WHO global sodium target is adopted would contribute significantly to national efforts to reduce population sodium intake and achieve the WHO global target of a 30% reduction in mean population sodium intake by 2030.

The relative risk reduction with regards to dietary sodium content in bread is 45%. This suggests that the adoption of WHO global sodium benchmark could reduce the risk of high sodium content in bread by 45%. The contributions of bread consumption in Lagos [17], Nigeria to the WHO recommended daily sodium intake in the absence and presence of a WHO global sodium benchmark is estimated to be 100% and 55% respectively. This suggests possible interrelationships among sodium levels in bread, high dietary sodium intake and the high prevalence of hypertension in Lagos, Nigeria. It also demonstrates a positive impact of adopting the WHO global sodium benchmark and provides information needed for the setting of priorities for the sodium risk management of bread.

This study assessed the potential contribution of bread to the consumption of excess sodium and provided scientific insight on the likelihood that the consumer in Lagos, Nigeria is exposed to high levels of sodium in bread. It also provides policymakers with information about the impact of WHO recommended risk management option. It concludes that there is high risk of excessive sodium intake through the consumption of bread, which has been shown to contribute significantly to dietary sodium intake. Consumption of bread makes it more likely for the diet to exceed the recommended not more than 2 g/day sodium intake [18]. As a result, consumers may not be adequately protected if sodium benchmark is not set for bread in Nigeria. Hence, there is urgent need to set and implement policies that support sodium benchmark for bread to mitigate nutritional risks to public health and help achieve recommended dietary sodium intake levels.

Not implementing a national sodium benchmark for bread puts over 30 million Nigerians at risk of excess dietary sodium intake, hypertension and hypertension-related deaths, affecting all socioeconomic groups.

Limitations and Assumptions

1. A more accurate dietary intake estimate would have been made if available national bread consumption data were used.
2. It is assumed that the on-pack sodium content data reflects correct analytical data.
3. The acceptable consumption per day was estimated to arrive at a %ADI of less than 100.

Acknowledgement

Prof. Dan Ramdath for paper review.

References

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