Step 1: Swap Saturated Fat for Unsaturated
Replacing 60% of saturated fat with other fats and avoiding 60% of dietary cholesterol may reduce total cholesterol 30.9 mg/dL (395 trials)
Altogether, 134 of the solid food experiments provided information on dietary intake of the major individual saturated fatty acids: laurate (C12:0), myristate (C14:0), palmitate (C16:0), and stearate (C18:0). Intake of the first three was positively related with blood cholesterol concentration, such that halving intake of each isocalorically would be expected to reduce blood total cholesterol by 0.32 mmol/l (12.4 mg/d). Isocaloric replacement of saturated fats by unsaturated fats produced about three times the reduction in blood cholesterol produced by replacement of total fat by complex carbohydrates. Avoiding 200 mg/day dietary cholesterol further decreased blood total cholesterol by 0.13 mmol/l (5 mg/dL) and low density lipoprotein cholesterol by 0.10 mmol/l (3.9 mg/dL). Conclusions: In typical British diets replacing 60% of saturated fats by other fats and avoiding 60% of dietary cholesterol would reduce blood total cholesterol by about 0.8 mmol/l (30.9 mg/dL) (that is, by 10-15%), with four fifths of this reduction being in low density lipoprotein cholesterol.
Replacing butter with any vegetable oil (even palm) may reduce LDL cholesterol up to 16.2 mg/dL; Safflower may be best (54 trials, n=2065)
Overall, 54 trials with 2,065 participants published were included in the network meta-analysis. Each 10% of dietary energy from butter replaced with an equivalent amount of safflower, sunflower, rapeseed, flaxseed, corn, olive, soybean, palm, and coconut oil, and beef fat was more effective in reducing LDL-C (−0.42 to −0.23 mmol/l (-16.24 to -8.9 mg/dL)). Safflower, sunflower, rapeseed, corn, and soybean oil had a more pronounced effect on LDL-C when compared with lard (−0.33 to −0.20 mmol/l). Moreover, sunflower oil was more effective in reducing LDL-C than olive and palm oil (−0.10 to −0.09 mmol/l). Safflower oil had the highest surface under the cumulative ranking curve value for decreases in LDL-C (82%), followed by rapeseed oil (76% for LDL-C), and sunflower oil (71% for LDL-C). The network meta-analysis showed that all vegetable oils were more effective in reducing LDL-C compared with butter.
Palm oil increases LDL by 9.3 mg/dL compared to vegetable oils low in saturated fat (30 trials, n=807)
Palm oil significantly increased LDL cholesterol by 0.24 mmol/L (9.3 mg/dL) compared with vegetable oils low in saturated fat. This effect was observed in randomized trials (0.31 mmol/L (12 mg/dL)) but not in nonrandomized trials. Conclusions: Palm oil consumption results in higher LDL cholesterol than do vegetable oils low in saturated fat. The effects of palm oil on blood lipids are as expected on the basis of its high saturated fat content, which supports the reduction in palm oil use by replacement with vegetable oils low in saturated and trans fat.
Low fat diets may reduce LDL by 7 mg/dL; moderate macronutrient diets by 5.2 mg/dL; both more effective than low carb (121 trials, n=21,942)
121 eligible trials with 21,942 patients were included and reported on 14 named diets and three control diets. Low carbohydrate diets had less effect than low fat diets and moderate macronutrient diets on reduction in LDL cholesterol (1.01 mg/dL, low certainty v 7.08 mg/dL, moderate certainty v 5.22 mg/dL, moderate certainty, respectively).
Using canola oil may reduce LDL cholesterol 6.4 mg/dL; may be superior to sunflower oil (27 trials, n=1359)
Twenty-seven trials, comprising 1359 participants, met the eligibility criteria. Results of this study showed that canola oil consumption significantly reduced total cholesterol (-7.24 mg/dl), and LDL (-6.4 mg/dl). Moreover, canola oil decreased LDL and total cholesterol compared to sunflower oil and saturated fat.
Extra virgin olive oil may reduce total cholesterol by 4.5 mg/dL compared to regular olive oil (26 trials)
Twenty-six studies were included. Compared to low polyphenol olive oil, high polyphenol olive oil (extra virgin) significantly improved measures of oxidized LDL and total cholesterol (mean difference 4.5 mg/dL).
Step 2: Eat Less Meat
Vegetarian diets may reduce LDL cholesterol by 12.1 to 22.9 mg/dL (30 studies, 19 trials, n=10,143)
30 observational studies and 19 clinical trials met the inclusion criteria. The 30 observational studies included 10,143 participants. The trials included a total of 1,484 participants. Consumption of vegetarian diets was associated with lower mean concentrations of total cholesterol (-29.2 and -12.5 mg/dL), low-density lipoprotein cholesterol (-22.9 and -12.2 mg/dL), and high-density lipoprotein cholesterol (-3.6 and -3.4 mg/dL), compared with consumption of omnivorous diets in observational studies and clinical trials, respectively. Conclusions: Plant-based diets are associated with decreased total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol.
Vegan diet may reduce LDL cholesterol by 18.9 mg/dL (40 studies, n=12,619)
40 studies with 12,619 vegans and 179,630 omnivores were included. Compared to controls vegans had lower low density lipoprotein cholesterol (-0.49 mmol/L (18.9 mg/dL)). Results were consistent for studies with < and ≥ 50 vegans, and published before and after 2010.
Replacing red meat with plant protein, but not fish or refined carbohydrates, reduces LDL cholesterol 7.7 mg/dL (36 trials, n=1803)
Thirty-six studies totaling 1803 participants were included. When analyzed by specific comparison diets, relative to high-quality plant protein sources, red meat yielded lesser decreases in total cholesterol (weighted mean difference, 0.264 mmol/L (10.2 mg/dL)) and low-density lipoprotein (weighted mean difference, 0.198 mmol/L (7.7 mg/dL)). In comparison with fish, red meat yielded greater decreases in low-density lipoprotein (weighted mean difference, -0.173 mmol/L (6.7 mg/dL)) and high-density lipoprotein (weighted mean difference, -0.065 mmol/L (2.5 mg/dL)). Conclusions: Substituting red meat with high-quality plant protein sources, but not with fish or low-quality carbohydrates, leads to more favorable changes in blood lipids and lipoproteins.
Egg consumption associated with higher LDL by 5.55 mg/dL (28 studies)
The data were obtained from 28 studies. Results: Overall, egg consumption increased total cholesterol by 5.60 mg/dL and low density lipoprotein-cholesterol (LDL-C) by 5.55 mg/dL compared with the control group. Conclusion: Consumption of egg increases total cholesterol and LDL-C.
Step 3: Eat More Nuts
Best foods for reducing LDL may be nuts (9.3 to 13.1 mg/dL), beans and whole grains (4.6 to 11.6 mg/dL) (66 trials, N=3595)
A total of 66 randomized trials comparing 10 food groups and enrolling 3595 participants was identified. Nuts were ranked as the best food group at reducing LDL cholesterol (SUCRA: 93%), followed by legumes (85%) and whole grains (70%). However, these findings are limited by the low quality of the evidence. Nuts were more effective at reducing LDL cholesterol (−0.34 to −0.24 mmol/L (-13.1 to -9.3 mg/dL) compared with refined grains, eggs, fish, and red meat. Legumes and whole grains were more effective at reducing LDL cholesterol (−0.30 to −0.12 mmol/L (-11.6 to -4.6 mg/dL)) compared with refined grains, fish, and red meat. Conclusion: The present network meta-analysis provides evidence that increased intake of nuts, legumes, and whole grains is more effective at improving metabolic health than other food groups.
Pistachios may be best nut for lowering LDL cholesterol, followed by almonds (34 trials, n=1677)
This network meta-analysis of randomized clinical trials aimed to assess the comparative effects of walnuts, pistachios, hazelnuts, cashews, and almonds on typical lipid profiles. Thirty-four trials enrolling 1677 participants were included in this study. The pistachio-enriched diet was ranked best for LDL cholesterol and total cholesterol reductions. For total cholesterol reductions, the walnut-enriched diet was ranked as the second-best diet. Regarding LDL cholesterol reduction, the almond-enriched diet was ranked second best. The pistachio-enriched and walnut-enriched diets were more effective at lowering LDL cholesterol and total cholesterol compared with the control diet. Conclusions: The pistachio-enriched and walnut-enriched diet could be better alternatives for lowering LDL cholesterol and total cholesterol compared with other nut-enriched diets included in this study.
43 grams of almonds per day may reduce LDL cholesterol by 5.8 mg/dL (15 trials, n=534)
Fifteen eligible trials analyzed a total of 534 subjects. The most appropriate stratum was selected with an almond dose closer to 42.5 g, with a control most closely matched for macronutrient composition, energy intake, and similar intervention duration. Almond intervention significantly decreased total cholesterol (summary net change: -10.69 mg/dL) and LDL cholesterol (summary net change: -5.83 mg/dL).
Walnuts may lower LDL cholesterol 5.5 mg/dL; stronger effects seen with worse diets (26 trials, n=1059)
Twenty-six clinical trials with a total of 1059 participants were included. The following weighted mean differences in reductions were obtained for walnut-enriched diets compared with control groups: -6.99 mg/dL (3.25% greater reduction) for total blood cholesterol and -5.51 mg/dL (3.73% greater reduction) for low-density lipoprotein (LDL) cholesterol. More pronounced reductions in blood lipids were observed when walnut interventions were compared with American and Western diets [weighted mean difference for total cholesterol = -12.30 and for LDL = -8.28].
Step 4: Eat More Whole Grains, Beans, and Fiber
Buckwheat may lower total cholesterol by 19.3 mg/dL (13 trials, 2 studies)
The aim of the present study was to comprehensively summarize studies in humans and animals, evaluating the impact of buckwheat consumption on CVD risk markers. Thirteen randomized, controlled human studies and two cross-sectional human studies were included. Using random-effects models, the weighted mean difference of post-intervention concentrations of total cholesterol was significantly decreased following buckwheat intervention compared with controls [differences in total cholesterol: 0.50 mmol/L (19.3 mg/dL)].
Non-soy legumes may lower LDL cholesterol by 8 mg/dL (10 trials; n=268)
Data from 10 trials representing 268 participants were examined using a random-effects model. Pooled mean net change in total cholesterol for those treated with a legume diet compared to control was -11.8 mg/dL; mean net change in low-density lipoprotein cholesterol was -8.0mg/dL.
Oatmeal may lower LDL cholesterol by 7 mg/dL (10 trials)
Ten trials met the inclusion criteria. Studies ranged in duration from 4 to 8 weeks. In eight of the included studies, the wholegrain component was oats. Seven of the eight studies reported lower total and low density lipoproteins (LDL) cholesterol with oatmeal foods than control foods. When the studies were combined in a meta-analysis lower total cholesterol (-0.20 mmol/L (7.7 mg/dL)) and LDL cholesterol (0.18 mmol/L (7 mg/dL)) were found with oatmeal foods. However, there is a lack of studies on other wholegrains or wholegrain diets.
3 grams of soluble fiber per day may reduce LDL cholesterol by 5 mg/dL (67 trials)
This meta-analysis of 67 controlled trials was performed to quantify the cholesterol-lowering effect of major dietary fibers. Results: Soluble fiber, 2-10 g/d, was associated with small but significant decreases in total cholesterol [-0.045 mmol L(-1).g soluble fiber], and LDL cholesterol [-0.057 mmol.L(-1).g(-1)]. The effects on plasma lipids of soluble fiber from oat, psyllium, or pectin were not significantly different. Lipid changes were independent of study design, treatment length, and background dietary fat content. Conclusions: Various soluble fibers reduce total and LDL cholesterol by similar amounts. The effect is small within the practical range of intake. For example, 3 g soluble fiber from oats (3 servings of oatmeal, 28 g each) can decrease total and LDL cholesterol by approximately 0.13 mmol/L (5 mg/dL). Increasing soluble fiber can make only a small contribution to dietary therapy to lower cholesterol.
Soy protein may reduce LDL cholesterol by 4.8 mg/dL (46 trials, n=2607)
Of the 46 trials identified by the FDA, 43 provided data for meta-analyses. Of these, 41 provided data for LDL cholesterol. Soy protein at a median dose of 25 g/d during a median follow-up of 6 wk decreased LDL cholesterol by 4.76 mg/dL compared with non-soy protein controls.
Step 5: Exercise
Combination of aerobic and resistance exercise may lower LDL more than aerobic exercise alone (-10.2 mg/dL) (12 trials, n=555)
12 trials with 555 youths were included in the meta-analysis. Compared with aerobic exercise alone, combination of aerobic and resistance exercise resulted in greater reductions in low-density lipoprotein cholesterol (mean difference=-10.20 mg/dL). Differences were larger for longer term programmes (>24 weeks).
Yoga may lower LDL cholesterol (42 studies)
Forty two studies were included in the meta-analysis. Interventions that included yoga asanas were associated with reduced cholesterol and low density lipoprotein, compared to active control.
Diet may be superior to aerobic exercise in lowering LDL cholesterol
Seven-hundred and eighty-eight men and women from 6 studies were included. Non-overlapping 95% confidence intervals were observed for diet and diet+aerobic exercise with respect to lowering total cholesterol, LDL cholesterol and triglycerides while reductions in aerobic exercise were limited to triglycerides. No significant changes in HDL cholesterol were observed. When compared to exercise, reductions in total cholesterol and LDL cholesterol were greater for diet and diet+aerobic exercise. Conclusions: Diet, especially diet+aerobic exercise, are superior to exercise for improving selected lipids and lipoproteins in adults.
What Doesn’t Lower Cholesterol: Low Carb Diets and Fish
Low carb diets may not affect LDL cholesterol (17 trials, n=1141)
A total of 23 reports, corresponding to 17 clinical investigations, were identified as meeting the pre-specified criteria. Meta-analysis carried out on data obtained in 1,141 obese patients, showed low-density lipoprotein cholesterol and creatinine did not change significantly.
Ketogenic diets may increase LDL cholesterol by 5 mg/dL (13 trials, n=1257)
The role of very-low-carbohydrate ketogenic diets (VLCKD) in the long-term management of obesity is not well established. The present meta-analysis aimed to investigate whether individuals assigned to a VLCKD (i.e. a diet with no more than 50 g carbohydrates/d) achieve better long-term cardiovascular risk factor management when compared with individuals assigned to a conventional low-fat diet (LFD; i.e. a restricted-energy diet with less than 30% of energy from fat). A total of thirteen studies met the inclusion/exclusion criteria. In the overall analysis, five outcomes revealed significant results. Individuals assigned to a VLCKD showed increased HDL-C (weighted mean difference 0·09 mmol/l) and LDL-C (weighted mean difference 0·12 mmol/l (4.64 mg/dL)).
Eating fish does not affect total or LDL cholesterol levels (4 trials, n=1378)
4 trials, including a total of 1378 individuals, fulfilled the inclusion criteria for this study. Consuming oily fish was associated with significant increase in HDL-cholesterol was observed (0.06 mmol/L). No significant effect could be observed on other vascular risk factors such as total cholesterol and LDL cholesterol.
Fish oil supplements may increase LDL cholesterol by 2.3 mg/dL (47 trials)
The final analysis comprised of 47 studies in otherwise untreated subjects showed that taking fish oils (weighted average daily intake of 3.25 g of EPA and/or DHA) produced no change in total cholesterol and very slight increases in HDL (0.01 mmol/L) and LDL cholesterol (0.06 mmol/L (2.3 mg/dL)).
Reducing sodium may increase cholesterol by 6 mg/dL (185 trials, n=12,210)
A total of 185 studies were included. The average sodium intake was reduced from 201 mmol/day (corresponding to high usual level) to 66 mmol/day (corresponding to the recommended level). In plasma or serum, there was a significant increase in cholesterol. All effects were stable in 125 study populations with a sodium intake below 250 mmol/day and a sodium reduction intervention of at least one week. Authors’ conclusions: Sodium reduction from an average high usual sodium intake level (201 mmol/day) to an average level of 66 mmol/day, which is below the recommended upper level of 100 mmol/day (5.8 g salt), resulted in a decrease in SBP/DBP of 1/0 mmHg in white participants with normotension and a decrease in SBP/DBP of 5.5/2.9 mmHg in white participants with hypertension. The effects on hormones and lipids were similar in people with normotension and hypertension. Cholesterol increased 5.59 mg/dL (2.9%).