Deciphering the Riddles in Nutrition and Cardiovascular Disease

Are We Nuts Over Coconuts? Studying the Effects of Coconut Oil on Low-Density Lipoprotein and Cardiovascular Diseases: A Systematic Review

Coconut oil has been gaining popularity recently, especially with health enthusiasts claiming it to be the best fat for consumption. What is the ideal cooking fat? The answer that we are all looking for is just not solely based on one health consequence but several. Our study focuses on the cardiovascular aspects of using coconut oil by its influence on low-density lipoprotein (LDL). Cardiovascular diseases (CVDs) are the major cause of death and mortality worldwide. Hence, they are the focus of this study. For centuries, coconut oil has been used by several populations worldwide who consume it as part of their staple diets. However, they have also been consuming the flesh/meat of coconuts and decreased processed foods. One such population is the pacific islanders, who had increased LDL and decreased high-density lipoprotein (HDL) when they moved out of their natural habitat and accepted a more westernized diet. Even though coconut oil has a stronghold on the LDL aspect of the lipid parameters, which is our study's focus, it also increases HDL, whose effects on cardiovascular health are still controversial although it is called "good cholesterol."

Cardiologists now utilize the ratio of total to HDL cholesterol to assess CVD risk more reliably. There have not been many human studies to support coconut oil's LDL and CVD advantages, considering all these variables. A thorough search of five databases, including PubMed, PubMed Central, Google Scholar, Cochrane Library, and ScienceDirect, was done. The last search was done on October 8th, 2021. Studies were selected based on the following criteria: last five years, English language, human studies, randomized controlled trials (RCTs), systematic reviews and meta-analysis, narrative reviews, and cross-sectional studies were included using medical subject headings (MeSH) search and keyword search. Eight hundred and ninety-nine articles were found, and eight papers were picked after quality appraisal. These included one narrative review, three RCTs, one cross-sectional study, and three systematic reviews and meta-analyses. The results showed that coconut oil did not behave differently than other saturated fats to reduce LDL. One study showed that coconut oil did not increase LDL compared to additional saturated fat like butter or lard. Coconut oil also has antioxidant properties that may prevent oxidative stress that affects cardiovascular health. However, studies in this sector are limited.

Ruminant fat intake improves gut microbiota, serum inflammatory parameter and fatty acid profile in tissues of Wistar rats

This study tested the hypothesis that naturally and industrially produced trans-fatty acids can exert distinct effects on metabolic parameters and on gut microbiota of rats. Wistar rats were randomized into three groups according to the diet: CONT-control, with 5% soybean oil and normal amount of fat; HVF-20% of hydrogenated vegetable fat (industrial); and RUM-20% of ruminant fat (natural). After 53 days of treatment, serum biochemical markers, fatty acid composition of liver, heart and adipose tissue, histology and hepatic oxidative parameters, as well as gut microbiota composition were evaluated. HVF diet intake reduced triglycerides (≈ 39.39%) and VLDL levels (≈ 39.49%). Trans-fatty acids levels in all tissue were higher in HVF group. However, RUM diet intake elevated amounts of anti-inflammatory cytokine IL-10 (≈ 14.7%) compared to CONT, but not to HVF. Furthermore, RUM intake led to higher concentrations of stearic acid and conjugated linoleic acid in all tissue; this particular diet was associated with a hepatoprotective effect. The microbial gut communities were significantly different among the groups. Our results show that ruminant fat reversed the hepatic steatosis normally caused by high fat diets, which may be related to the remodelling of the gut microbiota and its anti-inflammatory potential.