Nutritional risk factors for SARS-CoV-2 infection: prospective study from the NutriNet-Santé cohort

Background

Many hypotheses were raised regarding a role of nutrition in COVID-19 (susceptibility to infection, disease severity) based on the importance of macronutrients, vitamins or minerals for a proper functioning of the immune system. Our objective was to study the associations between dietary intakes and the seroprevalence SARS-CoV-2 infection in a large population-based sample.

Methods

Our analyses included 7766 adults from the French NutriNet-Santé cohort who provided at least 6 valid 24h dietary records in the two years preceding the start of the COVID-19 pandemic in France (February 2020). An ELISA assay was used to detect anti-SARS-CoV-2 antibodies: 311 participants were positive and 7455, negative. Associations between dietary intakes and the seroprevalence of anti-SARS-CoV-2 antibodies were investigated using multi-adjusted logistic regressions.

Results

A lower seroprevalence of SARS-CoV-2 infection was associated to higher intakes of vitamin B9 (HR = 0.84 (0.72-0.98)), vitamin C (HR = 0.85 (0.75-0.97)), vitamin K (HR = 0.86 (0.74-0.99)), dietary fibres (HR = 0.84 (0.72-0.97)), and fruit and vegetables (HR = 0.84 (0.74-0.97)). Higher intakes of calcium (HR = 1.17 (1.01-1.35)) and dairy products (HR = 1.19 (1.06-1.33)) associated to a higher seroprevalence of SARS-CoV-2 infection. No association was observed with other food groups or nutrients or with the overall diet.

Conclusions

Based on exhaustive seroprevalence data in a large population-based sample, our results suggested that higher intakes of vitamin C, folates, vitamin K, dietary fibres and fruit and vegetables were associated with a lower susceptibility to SARS-CoV-2 infection.

Key messages

Higher intakes of vitamin C, folates, vitamin K, dietary fibres and fruit and vegetables were associated to a lower susceptibility to SARS-CoV-2 infection, assessed with exhaustive seroprevalence data. Beyond its established role in the prevention of non-communicable diseases, nutrition could also contribute to prevent some infectious diseases such as COVID-19.

Body weight, body composition and risk of SARS-CoV-2 infection in a large population-based sample

Background

Obesity has been identified as an important risk factor for COVID-19 severity. Besides, several reports also suggested that obesity (or a higher BMI) may also be associated with a higher susceptibility to SARS-CoV-2 infection although this remains unclear. Going beyond BMI, our objective was to study several anthropometric characteristics in relation to the seroprevalence of SARS-CoV-2 infection in a large population-based sample.

Methods

21,376 participants from the French NutriNet-Santé cohort study were included in the main analyses. An ELISA assay was used to detect anti-SARS-CoV-2 antibodies: 1027 participants were positive and 20,349, negative. Associations between a wide range of anthropometric characteristics (body mass index but also waist and hip circumference and body composition) and the seroprevalence of anti-SARS-CoV-2 antibodies were investigated using multi-adjusted logistic regressions.

Results

A positive yet unclear association was observed between BMI and SARS-CoV-2 seroprevalence in women (positive linear trend (P = 0.07) that was significant using restricted cubic splines (P = 0.04), but no association with standard categories of BMI). No association was observed in men. Waist circumference (P = 0.04) and waist-to-hip ratio (P = 0.01) associated with a higher seroprevalence in women while opposite trends were observed in men (P = 0.08 and 0.03 respectively). Body, trunk and visceral fat (all P < 0.05), but not lean or muscle mass, associated with higher seroprevalence, especially in women.

Conclusions

Our results highlight a higher susceptibility to SARS-CoV-2 infection in women with higher body fat, suggesting that central adiposity may be an important factor to consider for risk stratification in the population.

Key messages

A higher seroprevalence of SARS-CoV-2 infection was observed in women with a higher body fat, but not in men. Central adiposity may be a risk factor for SARS-CoV-2 infection and not only for COVID-19 severity.

Adherence to the new WCRF cancer prevention recommendations associates with a decreased cancer risk

Background

Cancer remains one of the leading causes of death worldwide. In 2018, following its summary report, the World Cancer Research Fund (WCRF) issued its recommendations for cancer prevention based on the nutritional risk factors with a sufficient level of evidence. Our objective was to study whether adherence to these new recommendations leads to a reduced risk of cancer.

Methods

This study included 80,604 participants from the NutriNet-Santé population-based cohort study (2009-2019). Adherence to the 2018 WCRF recommendations was assessed using the operationalized score on a 7-point scale, proposed by Shams-White et al (Nutrients 2019), including: weight, physical activity, fruit and vegetables, dietary fibers, ultra-processed foods, red and processed meat, sugary drinks and alcohol. Usual dietary intakes were assessed using repeated 24h-dietary records and physical activity level using the IPAQ questionnaire. Multi-adjusted Cox proportional hazard models were used for the analyses.

Results

A total of 2,438 incident cancer cases were diagnosed during follow-up (median: 7.4 years). The median WCRF 2018 adherence score was 3.75 (IQR: 3.25-4.50). An increase of 1-point increment in the score was associated with a decreased risk of cancer overall (HR = 0.90; 95%CI 0.86-0.90; P<.0001), and of obesity-related cancers (n = 1549 cases, HR = 0.89; 0.84-0.94; P<.0001), aerodigestive cancers (n = 390, HR = 0.83; 0.74-0.93; P = 0.001), breast cancer (n = 749, HR = 0.92; 0.85-1.00; P = 0.04) and a non-significant trends for prostate (n = 332, HR = 0.89; 0.79-1.01; P = 0.07) and colorectal (n = 218, HR = 0.88; 0.76-1.03; P = 0.1) cancers.

Conclusions

Our results suggest that a higher adherence to the WCRF 2018 recommendations for cancer prevention is associated to a decreased risk of cancer. Given the consistency between overall food-based dietary guidelines and the WCRF cancer recommendations, our result support their general promotion to the general public and transposition as public health actions.

Key messages

Following the recommendations for cancer prevention issued by the WCRF in 2018 can contribute to decrease the burden of cancer. The WCRF cancer recommendations are consistent with overall food-based dietary guidelines and should be promoted to the general public and transposed as public health actions.