You might be interested in…Diet and Disease

Diet and Disease: Recent Literature
This week I would like to focus on some very interesting papers that have been published on the topic of diet and disease, but also, more importantly, disease prevention.

As the global population ages, it is critical to identify diets that, beyond preventing non-communicable diseases (NCDs), optimally promote healthy aging. The authors of this paper1 used longitudinal questionnaire data from the Nurses’ Health Study (1986–2016) and the Health Professionals Follow-Up Study (1986–2016). They examined the association of long-term adherence to eight dietary patterns and ultraprocessed food consumption with healthy aging, as assessed according to measures of cognitive, physical and mental health, as well as living to 70 years of age free of chronic diseases.

The results were as follows. After up to 30 years of follow-up, only 9,771 (9.3 per cent) of 105,015 participants (66 per cent women, mean age = 53 years) achieved healthy aging. For each dietary pattern, higher adherence was associated with greater odds of healthy aging and its domains.

The odds ratios for the highest quintile versus the lowest ranged from 1.45 for healthful plant-based diet to 1.86 for Alternative Healthy Eating Index.

When the age threshold for healthy aging was shifted to 75 years, the Alternative Healthy Eating Index diet showed the strongest association with healthy aging, with an odds ratio of 2.24.

Higher intakes of fruits, vegetables, whole grains, unsaturated fats, nuts, legumes and low-fat dairy products were linked to greater odds of healthy aging, whereas higher intakes of trans fats, sodium, sugary beverages and red or processed meats (or both) were inversely associated.

The authors conclude that dietary patterns rich in plant-based foods, with moderate inclusion of healthy animal-based foods, may enhance overall healthy aging, guiding future dietary guidelines.

This next paper also considers the impact of ultra-processed foods (UPF) compared with minimally-processed foods (MPF). UPF consumption is associated with increased non-communicable disease risk.

This trial2 aimed to assess its health impact within the context of national dietary guidelines. In a 2×2 crossover randomized controlled feeding trial, 55 adults in England (body mass index ≥25 to <40 kg/m2, habitual UPF intake ≥50 per cent kcal/day) were provided with two eight-week ad libitum diets following the UK Eatwell Guide: (1) MPF and (2) UPF, in a random order. Twenty-eight people were randomized to MPF then UPF, and 27 to UPF then MPF; 50 participants comprised the intention-to-treat sample.

The primary outcome was the within-participant difference in percent weight change (%WC) between diets, from baseline to Week 8. Participants were blinded to the primary outcome. MPF (%WC, −2.06) and UPF (%WC, −1.05) resulted in weight loss, with significantly greater %WC on MPF (%WC, −1.01). Mild gastrointestinal adverse events were common on both diets.

The authors suggest that their findings indicate greater weight loss on MPF than UPF diets and needing dietary guidance on food processing in addition to existing recommendations.

The next paper looks at the other end of the age spectrum. Nutrition during pregnancy and in early childhood can have a noticeable short-term and long-term impact on health of the mother/parent and the child, including complications related to pregnancy and development throughout childhood.

Promoting optimal nutrition during pregnancy and early childhood is important to address health inequalities among disadvantaged populations. This article3 summarises select recommendations from the new National Institute for Health and Care Excellence (NICE) guideline on maternal and child nutrition: nutrition and weight management in pregnancy, and nutrition in children up to five years. The authors summarise the recommendations into three basic practical points. These are:

• All healthcare practitioners have a role in improving uptake of vitamin supplements before and during pregnancy, during breastfeeding, and early childhood; supporting breastfeeding and/or safe and appropriate formula feeding; and timely and appropriate introduction of solids.
• Exclusive breastfeeding for six months and continued breastfeeding thereafter is recommended, and advice on infant feeding should be evidence based and non-commercial
• Optimal weight gain in pregnancy is uncertain and routine monitoring of weight in pregnancy is not recommended, unless there is a clinical indication such as gestational diabetes or hyperemesis gravidarum, and the focus should be on starting or maintaining healthy eating and physical activity.

This nested case−control study4> aimed to investigate the relationship between components of the Swedish food-based dietary guidelines (SDG) from 2015 and the risk of developing rheumatoid arthritis (RA). Data were obtained from the prospective Malmo Diet and Cancer Study (MDCS) conducted between1991−1996. Diet was assessed at baseline using a validated diet history method. Incident RA cases until 2016 were identified through register linkage, followed by a validation process through review of medical records.

For each case, 4 RA-free controls, matched for age, sex, and year of inclusion in the MDCS, were selected from the cohort. Adherence to the SDG was assessed using the SDG Score (SDGS) of five components. The findings were that higher intake of red/processed meat was associated with a higher risk of seropositive RA, whereas vegetables and fruit may reduce the risk of RA overall.

Intermittent fasting features periods of fasting or restricted energy intake alternating with periods of normal or ad-libitum energy consumption. While intermittent fasting is a popular weight loss strategy, the health effects of intermittent fasting compared with a usual caloric restriction or ad-libitum diet in humans remain unclear.

The aim of this systematic review and network meta-analysis5 of randomised clinical trials was to assess the effect of intermittent fasting diets, with continuous energy restriction or unrestricted (ad-libitum) diets on intermediate cardiometabolic outcomes from randomised clinical trials.

The authors found 99 randomised controlled trials that evaluated intermittent fasting diets, with continuous energy restriction, or ad-libitum diets on intermediate cardiometabolic outcomes. The findings were that all intermittent fasting strategies and continuous energy restriction diets showed a reduction in body weight when compared with an ad-libitum diet. Of three intermittent fasting diets (alternate day fasting, time restricted eating, and whole day fasting), alternate day fasting showed benefit in body weight reduction compared with continuous energy restriction.

References:

1. Tessier AJ et al. Optimal dietary patterns for healthy aging. Nature Medicine, Volume 31, May 2025 | 1644–1652. https://doi.org/10.1038/s41591-025-03570-5.
2. Dicken S et al. Ultraprocessed or minimally processed diets following healthy dietary guidelines on weight and cardiometabolic health: a randomized, crossover trial. Nature Medicine 2025 (Published Online Aug 2025). https://doi.org/10.1038/s41591-025-03842-0.
3. Deshpande S et al. Maternal and child nutrition: nutrition and weight management in pregnancy, and nutrition in children up to 5 years—summary of new NICE guidance. BMJ 2025;389:r954 http://doi.org/10.1136/bmj.r954.
4. Backlund R et al. Rheumatoid arthritis Quantified intakes of key diet components and the risk of developing rheumatoid arthritis: Results from a nested case—control study. Ann Rheum Dis 000(2025)1−10. https://doi.org/10.1016/j.ard.2025.06.2123.
5. Semnani-Azad Z et al Intermittent fasting strategies and their effects on body weight and other cardiometabolic risk factors: systematic review and network meta-analysis of randomised clinical trials. BMJ 2025;389:e082007 http://dx.doi.org/10.1136/bmj-2024‑082007.