A bit of fat, with low carbs, could prolong life, research says
Representative image (Melissa d'Arabian via AP)
Research with more than 135,000 people across five continents has shown that a diet which includes a moderate intake of fat and fruits and vegetables, and avoidance of high carbohydrates, is associated with lower risk of death. This implied that the lowest risk of death was in those people who consume three to four servings (or a total of 375 to 500 grams) of fruits, vegetables and legumes a day, with little additional benefit from more.
The study has been recently published din the prestigious journal the Lancet and PGIMER was one of the participating institutes in the global study. The main institute involved in the study was Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences in Hamilton, Canada. The reports were presented on Tuesday at the Congress of the European Society of Cardiology in Barcelona, Spain.
As well, contrary to popular belief, consuming a higher amount of fat (about 35 per cent of energy) is associated with a lower risk of death compared to lower intakes. However, a diet high in carbohydrates (of more than 60 per cent of energy) is related to higher mortality, although not with the risk of cardiovascular disease.
The data are from the Prospective Urban Rural Epidemiology (PURE) study which followed more than 135,000 people from 18 low-income, middle-income and high income countries. The study asked people about their diet and followed them for an average of seven and half years.
The research on dietary fats found that they are not associated with major cardiovascular disease, but higher fat consumption was associated with lower mortality; this was seen for all major types of fats (saturated fats, polyunsaturated fats and mono unsaturated fats), with saturated fats being associated with lower stroke risk.
Total fat and individual types of fat were not associated with risk of heart attacks or death due to cardiovascular disease. The researchers point out that, while this may appear surprising to some, these new results are consistent with several observational studies and randomized controlled trials conducted in Western countries during the last two decades.
The large new study, when viewed in the context of most previous studies, questions the conventional beliefs about dietary fats and clinical outcomes, says Mahshid Dehghan, the lead author for the study and an investigator at PHRI.
"A decrease in fat intake automatically led to an increase in carbohydrate consumption and our findings may explain why certain populations such as South Asians, who do not consume much fat but consume a lot of carbohydrates, have higher mortality rates," she said.
The study also found current fruit, vegetable and legume intake globally is between three to four servings per day, but most dietary guidelines recommend a minimum of five daily servings. Given that fruits and vegetables are relatively expensive in most middle income and low-income countries, this level of consumption is unaffordable for most people in many regions of the world such as South Asia, China, Southeast Asia and Africa, where the levels of their consumption is much lower than in Western countries.
"Our study found the lowest risk of death in those who consumed three to four servings or the equivalent to 375 to 500 grams of fruits, vegetables and legumes per day, with little additional benefit for intake beyond that range," said Victoria Miller, a McMaster doctoral student and lead author of the paper. "Additionally, fruit intake was more strongly associated with benefit than vegetables.
Previous research has shown that eating fruits, vegetables and legumes decreases the risk of cardiovascular disease and deaths, but most studies were conducted mainly in North America and Europe with a few from other parts of the world.
"Raw vegetable intake was more strongly associated with a lower risk of death compared to cooked vegetable intake, but raw vegetables are rarely eaten in South Asia, Africa and Southeast Asia," Miller said. "Dietary guidelines do not differentiate between the benefits of raw versus cooked vegetables -- our results indicate that recommendations should emphasize raw vegetable intake over cooked."
What is PURE?
PURE study is prospective urban rural epidemiology study that included aged 35 to 70 years from 26 low-income, middle-income, and high-income countries on 5 continents. . The median follow up is 7.4 years and we are aiming for follow up people at least for 15 years. During 7.4 years of follow up more than 6000 CVD and 7000 mortality recorded.
What are the main findings?
Higher fruit, vegetable and legume intake is associated with a lower risk of cardiovascular, non-cardiovascular and total mortality. Our findings show the lowest risk of death in those who consume three to four servings (equivalent to 375-500 grams per day) of fruits, vegetables and legumes per day, with little additional benefit for intake beyond that range.
When examined separately, fruit intake is associated with lower risk of cardiovascular, non-cardiovascular and total mortality, while legume intake is inversely associated with non-cardiovascular and total mortality. For vegetables, raw vegetable intake is more strongly associated with lower risk of total mortality compared to cooked vegetable intake.