It may be the season to pile on the sugar but is it a good idea during cold season? Some health care experts believe a big dose of sugar may suppress your immune system and make you more vulnerable to colds, flu and other infections.

A study done at Loma Linda University may make you think twice about gobbling up that extra piece of pie or cookie if you want a strong immune system. Researchers gave volunteers 100 grams of sugar (20 teaspoons or about the amount in a liter of soda pop). Blood, drawn from the study participants, was mixed with bacteria.

They discovered that infection-fighting white blood cells in those loaded up with sugar were suppressed. These suppressed cells consumed much less bacteria than the same type of cells in people who had just fasted or eaten an unsweetened starch.

Bottom line, limiting sugar, along with eating healthy foods, should be a first defense against getting colds or flu. Still not convinced? In another study, the amount of sugar in two sweetened beverages lowered participants’ immunity by 50 percent for up to five hours after drinking. A diet high in complex carbohydrates, fresh vegetables, nuts and seeds, had no negative effect on immunity.

How can you limit sugar when it’s swirling all around you during the holiday season? Make your own healthy treats to share at get-togethers, and put veggie and fruit platters out for snacking.

Here is a tasty treat recipe to get you started on lowering your sugar intake.

Raw Lemon Blueberry Bars, nut free

Here's what you need:

Bottom Layer
3/4 cup sunflower seeds, ground into a flour
1/4 cup fine unsweetened coconut flakes
2 T. coconut butter
dash of sea salt
zest of one lemon
1 T. unsweetened sunbutter

Middle Layer

Meat from one large avocado or two small
1/2 cup fresh or thawed frozen blueberries
Zest and juice of one lemon
1/4 cup softened coconut oil or coconut butter
Optional: Stevia, to taste

Top Layer
3 T. coconut oil plus 3 T. coconut butter, softened
Zest and juice of one lemon

Here's what you do:

For the bottom layer, grind the sunflower seeds into a course flour in a food processor or spice grinder. Continue adding the other ingredients to form a grainy dough. Press the dough into the bottom of a regular-sized loaf pan. I opted for a silicone loaf pan. Place the loaf pan in the fridge or freezer to harden up the bottom layer.

Without cleaning your food processor, add the middle layer ingredients and blend until smooth. Spread the lemon blueberry filling evenly over the bottom layer. Return the loaf pan to the fridge or freezer.

For the top layer, soften the coconut oil/coconut butter mixture in a microwave or over a pan of warm water for a raw version. Stir in the lemon zest and lemon juice. Continue stirring until the topping is thick and creamy. Use a spatula to spread the lemon topping over the filling. Return to the fridge or freezer for a few hours to harden. When ready to serve, cut into bars. Store leftovers in the fridge or freezer.