Letter: Dietary advice to seniors wrong way around
To the editor:
Re: My comments on outdated views on fats and cholesterol expressed by columnist Bobbi Kittle (Deciphering Between Healthy and Unhealthy Fats, Capital News, Feb. 18).
The information in the Fitness for Seniors column was based on outdated views that have never been proven to be true. The column states that "high-fat diet is associated with obesity, cardiovascular disease, diabetes and some types of cancer." Studies done 40 years ago did show an association, but these were observational studies that could not show cause and effect. So although they showed high fat diets were correlated with cardiovascular disease in some studies, they did not show that high fat diets caused obesity and heart disease. Since the 1970s many randomized control trials have been done comparing low fat diets to low carb/high fat diets. These types of studies have more power to show cause and effect compared to observational studies. In virtually every one of these trials the high fat diets resulted in not only more weight loss, but larger reductions in cardiovascular risk factors. (1)(2)
The column states that saturated fats are "bad fats" because they increase your risk of disease and elevate cholesterol. This is another hypothesis that was popular in the 1980s but has since been refuted by the scientific literature. A Meta analysis published in the American Journal of Clinical Nutrition in 2010 found that "there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD." (3)
High cholesterol has been thought to cause heart disease but a study of over 200,000 people admitted to hospital with coronary artery disease showed that over half of those admitted had normal or low cholesterol. (4)
Other studies have shown low cholesterol is associated with an increased risk of death from some cancers and suicide. (5) The column recommends low fat or no fat dairy. Many people think full fat dairy contributes to obesity but this is has not been shown to be true. A study published in 2013 concluded: "The observational evidence does not support the hypothesis that dairy fat or high-fat dairy foods contribute to obesity or cardio metabolic risk, and suggests that high-fat dairy consumption within typical dietary patterns is inversely associated with obesity risk." (6)
Other outdated advice was given to substitute polyunsaturated vegetable oils for saturated fats like butter. The Sydney Diet Heart Study was conducted in the 1970s. In the study the experimental group reduced their saturated fat intake and instead ate more polyunsaturated vegetable oil (omega-6 linoleic acid). The results showed "that the omega-6 linoleic acid group had a higher risk of death from all causes, as well as from cardiovascular disease and coronary heart disease, compared with the control group." (7)
Polyunsaturated fats oxidize very easily and omega 6 vegetable oils are pro-inflammatory and over consumption of these unstable fats contribute to many disease states. (8) The advice to avoid foods that contain cholesterol is especially troubling when it is an column for seniors. For most people eating cholesterol has no effect on cholesterol levels since your body makes most of the cholesterol in your body. (9)
Most people think of cholesterol as bad but it is a vital molecule in the body. Practically every cell in our bodies can make cholesterol because every cell in our bodies need cholesterol. Studies have shown that seniors with the highest cholesterol live the longest. (10) (11)
Telling seniors to reduce saturated fat in the diet for the last 40 years has led to an increase in carbohydrate consumption. A study published in 2012 showed that "Older people who load up their plates with carbohydrates have nearly four times the risk of developing mild cognitive impairment." It also showed that those with the highest consumption of fat in their diet were 42 per cent less likely to get cognitive impairment. (12)
High fat diets can reduce blood glucose levels. High blood glucose has been linked to Alzheimer disease. Some researchers are now calling Alzheimers type 3 diabetes. (13)
Even if we are not convinced by the science we can resort to common sense. There are a lot of seniors in the Okanagan from the Prairies. Ask a farmer how they fatten livestock. My grandparents would take the cream off the milk to make butter which they ate. They fed the skim milk that was left to their pigs because it was great for fattening them up for market. Ask any beef farmer how to fatten cows and they will tell you to feed them grains.
"Grain fed" beef is famous for being well marbled with fat. So farmers feed skim milk and grains to their livestock to make them fat.
What do nutritionist and dieticians tell us to eat to lose weight? Skim milk and whole grains—doesn't make much sense does it?
Kelowna (1) http://jama.jamanetwork.com/article.aspx?articleid=205916 (2) http://authoritynutrition.com/23-studies-on-low-carb-and-low-fat-diets/ (3) http://ajcn.nutrition.org/content/early/2010/01/13/ajcn.2009.27725.abstract (4) http://www.ncbi.nlm.nih.gov/pubmed/19081406 (5) http://archinte.jamanetwork.com/article.aspx?articleid=616450 (6) http://link.springer.com/article/10.1007%2Fs00394-012-0418-1 (7) http://group.bmj.com/group/media/latest-news/study-raises-questions-about-dietary-fats-and-heart-disease-guidance (8) http://www.ncbi.nlm.nih.gov/pubmed/19022225 (9) http://www.ncbi.nlm.nih.gov/pubmed/19022225 (10) https://circ.ahajournals.org/content/95/2/342.full (11) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3303886/ (12) http://www.usatoday.com/story/news/nation/2012/10/17/carb-diet-alzheimers/1637481/ (13) http://www.nejm.org/doi/full/10.1056/NEJMoa1215740?query=featured_home&