Low carb diet cholesterol response may depend on genes, study finds
Stanford-led research links genetic risk and saturated fat to LDL increases in some people eating low-carb diets.
By Tom Brennan · Health & Medicine Correspondent
3 min read
A low carb diet cholesterol response may depend partly on a person’s genes, according to new research being presented at NUTRITION 2026. The finding matters because low-carbohydrate eating plans can help some people with weight and blood sugar, yet their effects on LDL cholesterol have been uneven.
The American Society for Nutrition said the study found that saturated fat intake, which can rise when people cut carbohydrates, appeared to interact with genetic risk for higher LDL cholesterol. LDL cholesterol is commonly treated as an important marker of heart disease risk.
Alexa Barad, a postdoctoral scholar at Stanford University School of Medicine, said the results point to meaningful differences in how people respond to the same diet. Barad is scheduled to present the findings at the American Society for Nutrition’s annual meeting, held July 25-28 in National Harbor, Maryland.
Can a low-carb diet raise cholesterol because of genes?
The study suggests it can for some people. Participants on a healthy low-carb diet who had a stronger inherited tendency toward higher LDL cholesterol were more likely to see LDL rise, especially when they ate more saturated fat, according to the researchers.
The same pattern did not appear among participants assigned to a healthy low-fat diet. The researchers said that helps explain why one person may see LDL cholesterol increase on a low-carb diet while another person following a similar plan may not.
The analysis used data from DIETFITS, a randomized controlled trial that assigned more than 600 adults to either a healthy low-carb diet or a healthy low-fat diet for one year. The original trial found no clear weight-loss advantage for either diet.
For the new analysis, researchers focused on 431 DIETFITS participants who had genetic data available. They examined diet type, saturated fat intake, genotype and the change in LDL cholesterol from the start of the trial to six months.
Rather than looking at one gene variant at a time, the team combined thousands of variants across the genome into what is called a polygenic score. A polygenic score estimates a person’s overall inherited tendency for a trait, such as higher or lower LDL cholesterol.
Barad said clinicians may eventually be able to use such scores to identify people who are more likely to have an unfavorable cholesterol response to certain diet changes. The researchers said more studies are needed to confirm the findings and test whether they apply across diverse populations.
What should low-carb dieters take from the study?
The study does not say that all low-carb diets raise LDL cholesterol. It points instead to a more practical message: people who change their diet should monitor their own cholesterol response rather than assume they will match someone else’s results.
General dietary guidance cited by the researchers recommends keeping saturated fat below 10% of daily calories and choosing unsaturated fats more often. For people eating low-carb diets, Barad noted that nuts, seeds, olive oil and avocado may be better fat sources than butter, beef tallow, fatty meats and processed meats for reducing the risk of an adverse cholesterol response.
This story draws on original reporting from Medical Xpress.