Consuming more nuts seems to be linked to lower blood cholesterol levels, says a new study.
Recently, consumption of nuts has been the focus of intense research because of their potential to reduce coronary heart disease risk and to lower blood lipid (fat and cholesterol) levels based on their unique nutritional attributes.
Nuts are rich in plant proteins, fats (especially unsaturated fatty acids), dietary fibre, minerals, vitamins and other compounds, such as antioxidants and phytoesterols.
Joan Sabaté, Loma Linda University, California and colleagues pooled primary data from 25 nut consumption trials conducted in seven countries and involving 583 women and men with high cholesterol or normal cholesterol levels.
All the studies compared a control group to a group assigned to consume nuts; participants were not taking lipid-lowering medications.
Participants in the trials consumed an average of 67 grams of nuts daily. This was associated with an average 5.1 percent reduction in total cholesterol concentration, a 7.4 percent reduction in low-density lipoprotein (LDL-C, or bad cholesterol) and an 8.3 percent change in ratio of LDL cholesterol to high-density lipoprotein (HDL, or good cholesterol).
In addition, triglyceride levels declined by 10.2 percent among individuals with high triglyceride levels, although not among those with lower levels. Triglycerides are the chemical form in which most fat exists in food as well as in the body.
"The effects of nut consumption were dose related, and different types of nuts had similar effects on blood lipid levels," the authors write.
"The effects of nut consumption were significantly modified by LDL-C, body mass index and diet type: the lipid-lowering effects of nut consumption were greatest among subjects with high baseline LDL-C and with low body mass index and among those consuming Western diets."
"Increasing the consumption of nuts as part of an otherwise prudent diet can be expected to favourably affect blood lipid levels (at least in the short term) and have the potential to lower coronary heart disease risk," the study authors conclude, says a Loma Linda release.