Diets containing more saturated fats may lower stroke risks according to newly published prospective study.

So, in this study published in the Lancet, diets lower in carbohydrate and higher in fat, including saturated fat, were associated with a lower risk of cardiovascular disease, and diets higher in saturated fats in particular seemed to carry less risk of stroke.

Note that "high carbohydrate" in this study usually meant a diet containing mostly sugars and grains or flours. Fruits and vegetables were not considered to be high in carbohydrates compared to sugars and grains.

This study can be seen as yet another nail in the coffin of the old, now seeming quite incorrect "saturated fats bad, unsaturated fats good" dogma. When dietary components are broken down by animal type, beef and pork still seem to be less good for longevity than fish and poultry, though.

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ABSTRACT

Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study

Dr Mahshid Dehghan, PhD'Correspondence information about the author Dr Mahshid DehghanEmail the author Dr Mahshid Dehghan, Andrew Mente, PhD, Xiaohe Zhang, MSc, Sumathi Swaminathan, PhD, Prof Wei Li, PhD, Prof Viswanathan Mohan, MD, Romaina Iqbal, PhD, Prof Rajesh Kumar, MD, Edelweiss Wentzel-Viljoen, PhD, Prof Annika Rosengren, MD, Leela Itty Amma, MD, Prof Alvaro Avezum, MD, Jephat Chifamba, DPhil, Rafael Diaz, MD, Rasha Khatib, PhD, Prof Scott Lear, PhD, Prof Patricio Lopez-Jaramillo, MD, Xiaoyun Liu, PhD, Prof Rajeev Gupta, MD, Noushin Mohammadifard, PhD, Nan Gao, BSc, Aytekin Oguz, MD, Anis Safura Ramli, MD, Pamela Seron, PhD, Yi Sun, MSc, Prof Andrzej Szuba, MD, Lungiswa Tsolekile, MPH, Prof Andreas Wielgosz, MD, Rita Yusuf, PhD, Afzal Hussein Yusufali, MD, Prof Koon K Teo, MD, Sumathy Rangarajan, MSc, Gilles Dagenais, MD, Shrikant I Bangdiwala, PhD, Shofiqul Islam, MSc, Prof Sonia S Anand, Prof Salim Yusuf, DPhil on behalf of the show Prospective Urban Rural Epidemiology (PURE) study investigators

Published: 29 August 2017

DOI: http://dx.doi.org/10.1016/S0140-6736(17)32252-3 |

Background

The relationship between macronutrients and cardiovascular disease and mortality is controversial. Most available data are from European and North American populations where nutrition excess is more likely, so their applicability to other populations is unclear.

Methods

The Prospective Urban Rural Epidemiology (PURE) study is a large, epidemiological cohort study of individuals aged 35–70 years (enrolled between Jan 1, 2003, and March 31, 2013) in 18 countries with a median follow-up of 7·4 years (IQR 5·3–9·3). Dietary intake of 135 335 individuals was recorded using validated food frequency questionnaires. The primary outcomes were total mortality and major cardiovascular events (fatal cardiovascular disease, non-fatal myocardial infarction, stroke, and heart failure). Secondary outcomes were all myocardial infarctions, stroke, cardiovascular disease mortality, and non-cardiovascular disease mortality. Participants were categorised into quintiles of nutrient intake (carbohydrate, fats, and protein) based on percentage of energy provided by nutrients. We assessed the associations between consumption of carbohydrate, total fat, and each type of fat with cardiovascular disease and total mortality. We calculated hazard ratios (HRs) using a multivariable Cox frailty model with random intercepts to account for centre clustering.

Findings

During follow-up, we documented 5796 deaths and 4784 major cardiovascular disease events. Higher carbohydrate intake was associated with an increased risk of total mortality (highest [quintile 5] vs lowest quintile [quintile 1] category, HR 1·28 [95% CI 1·12–1·46], ptrend=0·0001) but not with the risk of cardiovascular disease or cardiovascular disease mortality. Intake of total fat and each type of fat was associated with lower risk of total mortality (quintile 5 vs quintile 1, total fat: HR 0·77 [95% CI 0·67–0·87], ptrend<0·0001; saturated fat, HR 0·86 [0·76–0·99], ptrend=0·0088; monounsaturated fat: HR 0·81 [0·71–0·92], ptrend<0·0001; and polyunsaturated fat: HR 0·80 [0·71–0·89], ptrend<0·0001). Higher saturated fat intake was associated with lower risk of stroke (quintile 5 vs quintile 1, HR 0·79 [95% CI 0·64–0·98], ptrend=0·0498). Total fat and saturated and unsaturated fats were not significantly associated with risk of myocardial infarction or cardiovascular disease mortality.

Interpretation

High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke. Global dietary guidelines should be reconsidered in light of these findings.