CARBOHYDRATE QUALITY AND HEALTHY AGEING

A recent study published in JAMA Network Open has found that the quality of carbohydrates we consume during midlife may be an important determinant of healthy aging.

Researchers analysed data from more than 47,500 women in the Nurses’ Health Study (NHS) to determine how midlife carbohydrate intake influenced health outcomes over a 30-year follow-up period.

They looked at several aspects of carbohydrate intake, including:

• total carbohydrates
• refined carbohydrates
• high-quality carbohydrates (the sum of carbohydrates from fruits, vegetables, whole grains, and legumes)
• carbohydrates from starchy vegetables
• dietary fibre intake, including fibre from fruits, vegetables, and cereals.
• glycemic index (GI) and glycemic load (GL)

The primary outcome was healthy aging which was defined as reaching at least 70 years of age and being free from 11 major chronic diseases (including type 2 diabetes, cancer and cardiovascular disease), having no impairments in cognitive or physical function and having good mental health.

After adjusting for multiple factors that could play a part in disease risk and healthy ageing, the researchers found that:

• Women who ate more high-quality carbohydrates had significantly higher odds of aging healthily. Every 10% increase in energy from these foods was linked to a 31% increase in the odds of healthy aging.
• Total carbohydrate intake was also positively associated with healthy aging (17% increase in odds).
• Women who had a higher intake of total dietary fibre, as well as fibre from fruits, vegetables, and grains, were more likely to age well.
• Refined carbohydrates were associated with a 13% lower odds of healthy aging.
• A higher dietary GI and a higher total carbohydrate-to-fibre ratio were associated with lower odds of healthy ageing in all domains.
• A higher dietary GL was associated with a higher odds of good mental health but not the other domains of healthy ageing.
• Replacing refined carbohydrates, animal protein, total fat or trans-fat with high quality carbs was associated with higher odds of healthy aging.

These findings are consistent with those of previous studies showing associations between dietary fibre and healthy aging and high-quality carbohydrate foods and chronic disease risk.

Overall, the findings of this study suggest that an eating plan for healthy ageing shouldn’t focus on eating fewer carbs but choosing the right ones. This means replacing refined carbs with foods like fruits, non-starchy vegetables, legumes and minimally processed wholegrains. These changes may also lead to an eating plan with a lower GI.