Consumption of certain foods like rapeseed/canola oil, avocados, and turmeric can lead to moderate to large reductions in LDL cholesterol levels.
The research was carried out by conducting a systematic evaluation of existing guidelines, systematic reviews, and Randomised Control Trials (RCTs); we have only referred to the latter for studies on coffee intake. This was done on databases such as PubMed, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials, alongside a search on the Trip database for guidelines. The time frame for the study was from its inception up until June 2019 and October 2019 respectively. Studies were included if they were at least 13 days in duration and were in English. Using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) method, 37 guidelines, 108 systematic reviews, and 20 RCTs were evaluated to analyze the strength of evidence in the context of food impacts on LDL cholesterol levels.
The results of the research reveal that foods high in unsaturated and low in saturated and trans fatty acids such as rapeseed or canola oil, those with added plant sterols/stanols, and those high in soluble fibre like oats, barley and psyllium cause moderate reductions in LDL cholesterol. A moderate to a large increase was observed with unfiltered coffee though. Soy protein, tomatoes, flaxseeds, and almonds cause small reductions. Meanwhile, foods like avocados and turmeric cause moderate to large reductions with a moderate level of evidence supporting this observation. Other foods like pulses, hazelnuts, walnuts, high-fiber/wholegrain foods, green tea result in small to moderate reductions, and sugar causes a small increase. Several foods identified were either neutral or had low or very low evidence regarding their effects on LDL cholesterol levels.