Does diet affect the biggest killers of men and women differently?

A new study on diet and leading causes of death finds that those on a low carbohydrate, low fat and high protein diet had a lower risk of early death, but a lower risk of cardiovascular disease only in men.

For dementia the findings were less clear, but women who ate moderate amounts of sugar and high levels of fibre were at lower risk of developing the disease.

Lead author Briar McKenzie from The George Institute for Global health said there was an established link between diet and cardiovascular disease (CVD), the relationship between diet and dementia was less well known.

“There is no cure for dementia and not  many treatment options, so it’s important to focus on prevention and identify things people can do to reduce their risk of developing the disease,” she said.

In Australia, as in the UK, the leading cause of death for men is heart disease, and for women it is dementia.

For this study, George Institute researchers used the UK Biobank, a large-scale biomedical database that recruited over half a million Britons aged 40-69 years between 2006 and 2010. They were asked to complete an online dietary assessment asking what food and drink they had consumed the previous 24 hours.

They estimated participants’ total energy, fat (total, saturated, polyunsaturated), carbohydrate (total, sugar, fibre), and protein intake as well as assessing what percentage of the population were not meeting UK dietary recommendations.

Over 120,000, or twenty percent of the UK Biobank population completed two or more of the 24-hr diet recall assessments, just over half (57 percent) were women. Around two thirds were classified as overweight or obese. In terms of diet quality, they found:

  • 38 percent of the population were consuming more energy than recommended;
  • one third (33 percent) were eating more fat than recommended;
  • almost two thirds (63 percent) exceeded sugar intake recommendations, and
  • nearly all (98%) were failing to meet fibre recommendations.

The researchers then looked at overall rates of death as well as deaths from, or cases of cardiovascular disease and dementia.

“Only carbohydrate and protein intake were associated with overall death rates – those getting the highest proportion of their energy intake from carbohydrates had a higher risk of death, and a higher percentage energy intake from protein was associated with a lower risk,” Briar said.

In terms of deaths from CVD and dementia, moderate total energy intake was linked to a decreased risk. Higher sugar intake was associated with an increased risk of CVD whereas moderate protein intake was associated with a decreased risk.

Men with diets characterised by low carbohydrate, low fat, and high protein intake had a lower risk of CVD.

“Our study suggests the biggest benefit from diet related policy and interventions would be gained by considering combinations of carbohydrate, fat and protein intakes,” added Briar.

“As we also saw sex differences in how diet is linked to disease, we think that that associations between diet and disease by sex should continue to be investigated.”