Results from a 19-year study show that those consuming diets rich in vegetable proteins have reduced levels of type 2 diabetes (T2D) compared to those consuming similar protein quantities from meat.
This is the first long term research indicating the benefits of replacing meat based protein sources with plants, and to find that meat protein itself is not a diabetes risk factor - other compounds within meats aid the spread of diabetes.
Those consuming the highest quantities of plant-based protein had a 35% lower risk of T2D onset than those consuming the lowest quantities.
Using mathematical modelling, researchers estimated that by replacing just 5 grams of meat based protein per day with vegetable substitutes, the overall risk could decrease by 18%.
Researchers also determined that the overall consumption of protein has no direct link with T2D, and that other substances within meat and fish – particularly processed white meat and unprocessed red meat – are attributable to T2D risks.
Higher consumption of plants – particularly grains and potatoes, and eggs - contributed to lower levels of the disease by omitting other compounds found in meats from the diet.
Whilst there exists a wealth of research linking high meat consumption - particularly red meats - with diabetes and cardiovascular diseases, there is less understanding of how different sources of proteins vary in associated risks. As stated in the report, "The roles of different dietary proteins in the aetiology of (T2D) remain unclear".
In 2011 a study in the American Journal of Clinical Nutrition showed a 100 gram daily serving of red meat could increase risk of T2D by 19%, the chances were found to more than double when meat was processed.
The Kuopio Ischaemic Heart Disease Study (KIHD), an ongoing research project at the University of Eastern Finland, began examining participants in 1984. All participants were male, aged between 42 and 60 at the time of the projects launch, and none had been diagnosed with T2D.
19 years later, 432 of the original 2332 participants were suffering from the disease. Researchers used dietary records, questionnaires, blood glucose measurements and oral glucose measurements to determine diabetes risk.
The findings showed that replacing 1% of total energy intake from animal protein with plant protein was associated with 18% decreased risk for T2D, this association remained after results were adjusted for the varying body mass index (BMI) of participants.
Another finding was that replacing 1% of energy from carbohydrates with energy from protein was associated with a 5% increased risk of T2D - but this association collapsed after adjusting the results for varying fibre intake.
The results were published in the British Journal of Nutrition.
Source: British Journal of Nutrition
Published 2017; DOI: https://doi.org/10.1017/S0007114517000745
Title: 'Intake of different dietary proteins and risk of type 2 diabetes in men: the Kuopio Ischaemic Heart Disease Risk Factor Study'
Authors: Heli E. K. Virtanen et al.